1 /*
   2  * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "asm/macroAssembler.hpp"
  27 #include "asm/macroAssembler.inline.hpp"
  28 #include "ci/ciReplay.hpp"
  29 #include "classfile/systemDictionary.hpp"
  30 #include "code/exceptionHandlerTable.hpp"
  31 #include "code/nmethod.hpp"
  32 #include "compiler/compileLog.hpp"
  33 #include "compiler/disassembler.hpp"
  34 #include "compiler/oopMap.hpp"
  35 #include "jfr/jfrEvents.hpp"
  36 #include "opto/addnode.hpp"
  37 #include "opto/block.hpp"
  38 #include "opto/c2compiler.hpp"
  39 #include "opto/callGenerator.hpp"
  40 #include "opto/callnode.hpp"
  41 #include "opto/cfgnode.hpp"
  42 #include "opto/chaitin.hpp"
  43 #include "opto/compile.hpp"
  44 #include "opto/connode.hpp"
  45 #include "opto/divnode.hpp"
  46 #include "opto/escape.hpp"
  47 #include "opto/idealGraphPrinter.hpp"
  48 #include "opto/loopnode.hpp"
  49 #include "opto/machnode.hpp"
  50 #include "opto/macro.hpp"
  51 #include "opto/matcher.hpp"
  52 #include "opto/mathexactnode.hpp"
  53 #include "opto/memnode.hpp"
  54 #include "opto/mulnode.hpp"
  55 #include "opto/node.hpp"
  56 #include "opto/opcodes.hpp"
  57 #include "opto/output.hpp"
  58 #include "opto/parse.hpp"
  59 #include "opto/phaseX.hpp"
  60 #include "opto/rootnode.hpp"
  61 #include "opto/runtime.hpp"
  62 #include "opto/stringopts.hpp"
  63 #include "opto/type.hpp"
  64 #include "opto/vectornode.hpp"
  65 #include "runtime/arguments.hpp"
  66 #include "runtime/signature.hpp"
  67 #include "runtime/stubRoutines.hpp"
  68 #include "runtime/timer.hpp"
  69 #include "utilities/copy.hpp"
  70 #if defined AD_MD_HPP
  71 # include AD_MD_HPP
  72 #elif defined TARGET_ARCH_MODEL_x86_32
  73 # include "adfiles/ad_x86_32.hpp"
  74 #elif defined TARGET_ARCH_MODEL_x86_64
  75 # include "adfiles/ad_x86_64.hpp"
  76 #elif defined TARGET_ARCH_MODEL_aarch64
  77 # include "adfiles/ad_aarch64.hpp"
  78 #elif defined TARGET_ARCH_MODEL_sparc
  79 # include "adfiles/ad_sparc.hpp"
  80 #elif defined TARGET_ARCH_MODEL_zero
  81 # include "adfiles/ad_zero.hpp"
  82 #elif defined TARGET_ARCH_MODEL_ppc_64
  83 # include "adfiles/ad_ppc_64.hpp"
  84 #endif
  85 
  86 // -------------------- Compile::mach_constant_base_node -----------------------
  87 // Constant table base node singleton.
  88 MachConstantBaseNode* Compile::mach_constant_base_node() {
  89   if (_mach_constant_base_node == NULL) {
  90     _mach_constant_base_node = new (C) MachConstantBaseNode();
  91     _mach_constant_base_node->add_req(C->root());
  92   }
  93   return _mach_constant_base_node;
  94 }
  95 
  96 
  97 /// Support for intrinsics.
  98 
  99 // Return the index at which m must be inserted (or already exists).
 100 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
 101 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual) {
 102 #ifdef ASSERT
 103   for (int i = 1; i < _intrinsics->length(); i++) {
 104     CallGenerator* cg1 = _intrinsics->at(i-1);
 105     CallGenerator* cg2 = _intrinsics->at(i);
 106     assert(cg1->method() != cg2->method()
 107            ? cg1->method()     < cg2->method()
 108            : cg1->is_virtual() < cg2->is_virtual(),
 109            "compiler intrinsics list must stay sorted");
 110   }
 111 #endif
 112   // Binary search sorted list, in decreasing intervals [lo, hi].
 113   int lo = 0, hi = _intrinsics->length()-1;
 114   while (lo <= hi) {
 115     int mid = (uint)(hi + lo) / 2;
 116     ciMethod* mid_m = _intrinsics->at(mid)->method();
 117     if (m < mid_m) {
 118       hi = mid-1;
 119     } else if (m > mid_m) {
 120       lo = mid+1;
 121     } else {
 122       // look at minor sort key
 123       bool mid_virt = _intrinsics->at(mid)->is_virtual();
 124       if (is_virtual < mid_virt) {
 125         hi = mid-1;
 126       } else if (is_virtual > mid_virt) {
 127         lo = mid+1;
 128       } else {
 129         return mid;  // exact match
 130       }
 131     }
 132   }
 133   return lo;  // inexact match
 134 }
 135 
 136 void Compile::register_intrinsic(CallGenerator* cg) {
 137   if (_intrinsics == NULL) {
 138     _intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
 139   }
 140   // This code is stolen from ciObjectFactory::insert.
 141   // Really, GrowableArray should have methods for
 142   // insert_at, remove_at, and binary_search.
 143   int len = _intrinsics->length();
 144   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual());
 145   if (index == len) {
 146     _intrinsics->append(cg);
 147   } else {
 148 #ifdef ASSERT
 149     CallGenerator* oldcg = _intrinsics->at(index);
 150     assert(oldcg->method() != cg->method() || oldcg->is_virtual() != cg->is_virtual(), "don't register twice");
 151 #endif
 152     _intrinsics->append(_intrinsics->at(len-1));
 153     int pos;
 154     for (pos = len-2; pos >= index; pos--) {
 155       _intrinsics->at_put(pos+1,_intrinsics->at(pos));
 156     }
 157     _intrinsics->at_put(index, cg);
 158   }
 159   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 160 }
 161 
 162 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
 163   assert(m->is_loaded(), "don't try this on unloaded methods");
 164   if (_intrinsics != NULL) {
 165     int index = intrinsic_insertion_index(m, is_virtual);
 166     if (index < _intrinsics->length()
 167         && _intrinsics->at(index)->method() == m
 168         && _intrinsics->at(index)->is_virtual() == is_virtual) {
 169       return _intrinsics->at(index);
 170     }
 171   }
 172   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 173   if (m->intrinsic_id() != vmIntrinsics::_none &&
 174       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 175     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 176     if (cg != NULL) {
 177       // Save it for next time:
 178       register_intrinsic(cg);
 179       return cg;
 180     } else {
 181       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 182     }
 183   }
 184   return NULL;
 185 }
 186 
 187 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
 188 // in library_call.cpp.
 189 
 190 
 191 #ifndef PRODUCT
 192 // statistics gathering...
 193 
 194 juint  Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
 195 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
 196 
 197 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 198   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 199   int oflags = _intrinsic_hist_flags[id];
 200   assert(flags != 0, "what happened?");
 201   if (is_virtual) {
 202     flags |= _intrinsic_virtual;
 203   }
 204   bool changed = (flags != oflags);
 205   if ((flags & _intrinsic_worked) != 0) {
 206     juint count = (_intrinsic_hist_count[id] += 1);
 207     if (count == 1) {
 208       changed = true;           // first time
 209     }
 210     // increment the overall count also:
 211     _intrinsic_hist_count[vmIntrinsics::_none] += 1;
 212   }
 213   if (changed) {
 214     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 215       // Something changed about the intrinsic's virtuality.
 216       if ((flags & _intrinsic_virtual) != 0) {
 217         // This is the first use of this intrinsic as a virtual call.
 218         if (oflags != 0) {
 219           // We already saw it as a non-virtual, so note both cases.
 220           flags |= _intrinsic_both;
 221         }
 222       } else if ((oflags & _intrinsic_both) == 0) {
 223         // This is the first use of this intrinsic as a non-virtual
 224         flags |= _intrinsic_both;
 225       }
 226     }
 227     _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
 228   }
 229   // update the overall flags also:
 230   _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
 231   return changed;
 232 }
 233 
 234 static char* format_flags(int flags, char* buf) {
 235   buf[0] = 0;
 236   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 237   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 238   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 239   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 240   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 241   if (buf[0] == 0)  strcat(buf, ",");
 242   assert(buf[0] == ',', "must be");
 243   return &buf[1];
 244 }
 245 
 246 void Compile::print_intrinsic_statistics() {
 247   char flagsbuf[100];
 248   ttyLocker ttyl;
 249   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
 250   tty->print_cr("Compiler intrinsic usage:");
 251   juint total = _intrinsic_hist_count[vmIntrinsics::_none];
 252   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 253   #define PRINT_STAT_LINE(name, c, f) \
 254     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 255   for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
 256     vmIntrinsics::ID id = (vmIntrinsics::ID) index;
 257     int   flags = _intrinsic_hist_flags[id];
 258     juint count = _intrinsic_hist_count[id];
 259     if ((flags | count) != 0) {
 260       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 261     }
 262   }
 263   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
 264   if (xtty != NULL)  xtty->tail("statistics");
 265 }
 266 
 267 void Compile::print_statistics() {
 268   { ttyLocker ttyl;
 269     if (xtty != NULL)  xtty->head("statistics type='opto'");
 270     Parse::print_statistics();
 271     PhaseCCP::print_statistics();
 272     PhaseRegAlloc::print_statistics();
 273     Scheduling::print_statistics();
 274     PhasePeephole::print_statistics();
 275     PhaseIdealLoop::print_statistics();
 276     if (xtty != NULL)  xtty->tail("statistics");
 277   }
 278   if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
 279     // put this under its own <statistics> element.
 280     print_intrinsic_statistics();
 281   }
 282 }
 283 #endif //PRODUCT
 284 
 285 // Support for bundling info
 286 Bundle* Compile::node_bundling(const Node *n) {
 287   assert(valid_bundle_info(n), "oob");
 288   return &_node_bundling_base[n->_idx];
 289 }
 290 
 291 bool Compile::valid_bundle_info(const Node *n) {
 292   return (_node_bundling_limit > n->_idx);
 293 }
 294 
 295 
 296 void Compile::gvn_replace_by(Node* n, Node* nn) {
 297   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 298     Node* use = n->last_out(i);
 299     bool is_in_table = initial_gvn()->hash_delete(use);
 300     uint uses_found = 0;
 301     for (uint j = 0; j < use->len(); j++) {
 302       if (use->in(j) == n) {
 303         if (j < use->req())
 304           use->set_req(j, nn);
 305         else
 306           use->set_prec(j, nn);
 307         uses_found++;
 308       }
 309     }
 310     if (is_in_table) {
 311       // reinsert into table
 312       initial_gvn()->hash_find_insert(use);
 313     }
 314     record_for_igvn(use);
 315     i -= uses_found;    // we deleted 1 or more copies of this edge
 316   }
 317 }
 318 
 319 
 320 static inline bool not_a_node(const Node* n) {
 321   if (n == NULL)                   return true;
 322   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
 323   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
 324   return false;
 325 }
 326 
 327 // Identify all nodes that are reachable from below, useful.
 328 // Use breadth-first pass that records state in a Unique_Node_List,
 329 // recursive traversal is slower.
 330 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 331   int estimated_worklist_size = live_nodes();
 332   useful.map( estimated_worklist_size, NULL );  // preallocate space
 333 
 334   // Initialize worklist
 335   if (root() != NULL)     { useful.push(root()); }
 336   // If 'top' is cached, declare it useful to preserve cached node
 337   if( cached_top_node() ) { useful.push(cached_top_node()); }
 338 
 339   // Push all useful nodes onto the list, breadthfirst
 340   for( uint next = 0; next < useful.size(); ++next ) {
 341     assert( next < unique(), "Unique useful nodes < total nodes");
 342     Node *n  = useful.at(next);
 343     uint max = n->len();
 344     for( uint i = 0; i < max; ++i ) {
 345       Node *m = n->in(i);
 346       if (not_a_node(m))  continue;
 347       useful.push(m);
 348     }
 349   }
 350 }
 351 
 352 // Update dead_node_list with any missing dead nodes using useful
 353 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 354 void Compile::update_dead_node_list(Unique_Node_List &useful) {
 355   uint max_idx = unique();
 356   VectorSet& useful_node_set = useful.member_set();
 357 
 358   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
 359     // If node with index node_idx is not in useful set,
 360     // mark it as dead in dead node list.
 361     if (! useful_node_set.test(node_idx) ) {
 362       record_dead_node(node_idx);
 363     }
 364   }
 365 }
 366 
 367 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
 368   int shift = 0;
 369   for (int i = 0; i < inlines->length(); i++) {
 370     CallGenerator* cg = inlines->at(i);
 371     CallNode* call = cg->call_node();
 372     if (shift > 0) {
 373       inlines->at_put(i-shift, cg);
 374     }
 375     if (!useful.member(call)) {
 376       shift++;
 377     }
 378   }
 379   inlines->trunc_to(inlines->length()-shift);
 380 }
 381 
 382 // Disconnect all useless nodes by disconnecting those at the boundary.
 383 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
 384   uint next = 0;
 385   while (next < useful.size()) {
 386     Node *n = useful.at(next++);
 387     if (n->is_SafePoint()) {
 388       // We're done with a parsing phase. Replaced nodes are not valid
 389       // beyond that point.
 390       n->as_SafePoint()->delete_replaced_nodes();
 391     }
 392     // Use raw traversal of out edges since this code removes out edges
 393     int max = n->outcnt();
 394     for (int j = 0; j < max; ++j) {
 395       Node* child = n->raw_out(j);
 396       if (! useful.member(child)) {
 397         assert(!child->is_top() || child != top(),
 398                "If top is cached in Compile object it is in useful list");
 399         // Only need to remove this out-edge to the useless node
 400         n->raw_del_out(j);
 401         --j;
 402         --max;
 403       }
 404     }
 405     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 406       record_for_igvn(n->unique_out());
 407     }
 408   }
 409   // Remove useless macro and predicate opaq nodes
 410   for (int i = C->macro_count()-1; i >= 0; i--) {
 411     Node* n = C->macro_node(i);
 412     if (!useful.member(n)) {
 413       remove_macro_node(n);
 414     }
 415   }
 416   // Remove useless CastII nodes with range check dependency
 417   for (int i = range_check_cast_count() - 1; i >= 0; i--) {
 418     Node* cast = range_check_cast_node(i);
 419     if (!useful.member(cast)) {
 420       remove_range_check_cast(cast);
 421     }
 422   }
 423   // Remove useless expensive node
 424   for (int i = C->expensive_count()-1; i >= 0; i--) {
 425     Node* n = C->expensive_node(i);
 426     if (!useful.member(n)) {
 427       remove_expensive_node(n);
 428     }
 429   }
 430   // clean up the late inline lists
 431   remove_useless_late_inlines(&_string_late_inlines, useful);
 432   remove_useless_late_inlines(&_boxing_late_inlines, useful);
 433   remove_useless_late_inlines(&_late_inlines, useful);
 434   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
 435 }
 436 
 437 //------------------------------frame_size_in_words-----------------------------
 438 // frame_slots in units of words
 439 int Compile::frame_size_in_words() const {
 440   // shift is 0 in LP32 and 1 in LP64
 441   const int shift = (LogBytesPerWord - LogBytesPerInt);
 442   int words = _frame_slots >> shift;
 443   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
 444   return words;
 445 }
 446 
 447 // To bang the stack of this compiled method we use the stack size
 448 // that the interpreter would need in case of a deoptimization. This
 449 // removes the need to bang the stack in the deoptimization blob which
 450 // in turn simplifies stack overflow handling.
 451 int Compile::bang_size_in_bytes() const {
 452   return MAX2(_interpreter_frame_size, frame_size_in_bytes());
 453 }
 454 
 455 // ============================================================================
 456 //------------------------------CompileWrapper---------------------------------
 457 class CompileWrapper : public StackObj {
 458   Compile *const _compile;
 459  public:
 460   CompileWrapper(Compile* compile);
 461 
 462   ~CompileWrapper();
 463 };
 464 
 465 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 466   // the Compile* pointer is stored in the current ciEnv:
 467   ciEnv* env = compile->env();
 468   assert(env == ciEnv::current(), "must already be a ciEnv active");
 469   assert(env->compiler_data() == NULL, "compile already active?");
 470   env->set_compiler_data(compile);
 471   assert(compile == Compile::current(), "sanity");
 472 
 473   compile->set_type_dict(NULL);
 474   compile->set_type_hwm(NULL);
 475   compile->set_type_last_size(0);
 476   compile->set_last_tf(NULL, NULL);
 477   compile->set_indexSet_arena(NULL);
 478   compile->set_indexSet_free_block_list(NULL);
 479   compile->init_type_arena();
 480   Type::Initialize(compile);
 481   _compile->set_scratch_buffer_blob(NULL);
 482   _compile->begin_method();
 483 }
 484 CompileWrapper::~CompileWrapper() {
 485   _compile->end_method();
 486   if (_compile->scratch_buffer_blob() != NULL)
 487     BufferBlob::free(_compile->scratch_buffer_blob());
 488   _compile->env()->set_compiler_data(NULL);
 489 }
 490 
 491 
 492 //----------------------------print_compile_messages---------------------------
 493 void Compile::print_compile_messages() {
 494 #ifndef PRODUCT
 495   // Check if recompiling
 496   if (_subsume_loads == false && PrintOpto) {
 497     // Recompiling without allowing machine instructions to subsume loads
 498     tty->print_cr("*********************************************************");
 499     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 500     tty->print_cr("*********************************************************");
 501   }
 502   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
 503     // Recompiling without escape analysis
 504     tty->print_cr("*********************************************************");
 505     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 506     tty->print_cr("*********************************************************");
 507   }
 508   if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
 509     // Recompiling without boxing elimination
 510     tty->print_cr("*********************************************************");
 511     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
 512     tty->print_cr("*********************************************************");
 513   }
 514   if (env()->break_at_compile()) {
 515     // Open the debugger when compiling this method.
 516     tty->print("### Breaking when compiling: ");
 517     method()->print_short_name();
 518     tty->cr();
 519     BREAKPOINT;
 520   }
 521 
 522   if( PrintOpto ) {
 523     if (is_osr_compilation()) {
 524       tty->print("[OSR]%3d", _compile_id);
 525     } else {
 526       tty->print("%3d", _compile_id);
 527     }
 528   }
 529 #endif
 530 }
 531 
 532 
 533 //-----------------------init_scratch_buffer_blob------------------------------
 534 // Construct a temporary BufferBlob and cache it for this compile.
 535 void Compile::init_scratch_buffer_blob(int const_size) {
 536   // If there is already a scratch buffer blob allocated and the
 537   // constant section is big enough, use it.  Otherwise free the
 538   // current and allocate a new one.
 539   BufferBlob* blob = scratch_buffer_blob();
 540   if ((blob != NULL) && (const_size <= _scratch_const_size)) {
 541     // Use the current blob.
 542   } else {
 543     if (blob != NULL) {
 544       BufferBlob::free(blob);
 545     }
 546 
 547     ResourceMark rm;
 548     _scratch_const_size = const_size;
 549     int size = (MAX_inst_size + MAX_stubs_size + _scratch_const_size);
 550     blob = BufferBlob::create("Compile::scratch_buffer", size);
 551     // Record the buffer blob for next time.
 552     set_scratch_buffer_blob(blob);
 553     // Have we run out of code space?
 554     if (scratch_buffer_blob() == NULL) {
 555       // Let CompilerBroker disable further compilations.
 556       record_failure("Not enough space for scratch buffer in CodeCache");
 557       return;
 558     }
 559   }
 560 
 561   // Initialize the relocation buffers
 562   relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
 563   set_scratch_locs_memory(locs_buf);
 564 }
 565 
 566 
 567 //-----------------------scratch_emit_size-------------------------------------
 568 // Helper function that computes size by emitting code
 569 uint Compile::scratch_emit_size(const Node* n) {
 570   // Start scratch_emit_size section.
 571   set_in_scratch_emit_size(true);
 572 
 573   // Emit into a trash buffer and count bytes emitted.
 574   // This is a pretty expensive way to compute a size,
 575   // but it works well enough if seldom used.
 576   // All common fixed-size instructions are given a size
 577   // method by the AD file.
 578   // Note that the scratch buffer blob and locs memory are
 579   // allocated at the beginning of the compile task, and
 580   // may be shared by several calls to scratch_emit_size.
 581   // The allocation of the scratch buffer blob is particularly
 582   // expensive, since it has to grab the code cache lock.
 583   BufferBlob* blob = this->scratch_buffer_blob();
 584   assert(blob != NULL, "Initialize BufferBlob at start");
 585   assert(blob->size() > MAX_inst_size, "sanity");
 586   relocInfo* locs_buf = scratch_locs_memory();
 587   address blob_begin = blob->content_begin();
 588   address blob_end   = (address)locs_buf;
 589   assert(blob->content_contains(blob_end), "sanity");
 590   CodeBuffer buf(blob_begin, blob_end - blob_begin);
 591   buf.initialize_consts_size(_scratch_const_size);
 592   buf.initialize_stubs_size(MAX_stubs_size);
 593   assert(locs_buf != NULL, "sanity");
 594   int lsize = MAX_locs_size / 3;
 595   buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
 596   buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
 597   buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
 598 
 599   // Do the emission.
 600 
 601   Label fakeL; // Fake label for branch instructions.
 602   Label*   saveL = NULL;
 603   uint save_bnum = 0;
 604   bool is_branch = n->is_MachBranch();
 605   if (is_branch) {
 606     MacroAssembler masm(&buf);
 607     masm.bind(fakeL);
 608     n->as_MachBranch()->save_label(&saveL, &save_bnum);
 609     n->as_MachBranch()->label_set(&fakeL, 0);
 610   }
 611   n->emit(buf, this->regalloc());
 612 
 613   // Emitting into the scratch buffer should not fail
 614   assert (!failing(), err_msg_res("Must not have pending failure. Reason is: %s", failure_reason()));
 615 
 616   if (is_branch) // Restore label.
 617     n->as_MachBranch()->label_set(saveL, save_bnum);
 618 
 619   // End scratch_emit_size section.
 620   set_in_scratch_emit_size(false);
 621 
 622   return buf.insts_size();
 623 }
 624 
 625 
 626 // ============================================================================
 627 //------------------------------Compile standard-------------------------------
 628 debug_only( int Compile::_debug_idx = 100000; )
 629 
 630 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 631 // the continuation bci for on stack replacement.
 632 
 633 
 634 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
 635                   bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing )
 636                 : Phase(Compiler),
 637                   _env(ci_env),
 638                   _log(ci_env->log()),
 639                   _compile_id(ci_env->compile_id()),
 640                   _save_argument_registers(false),
 641                   _stub_name(NULL),
 642                   _stub_function(NULL),
 643                   _stub_entry_point(NULL),
 644                   _method(target),
 645                   _entry_bci(osr_bci),
 646                   _initial_gvn(NULL),
 647                   _for_igvn(NULL),
 648                   _warm_calls(NULL),
 649                   _subsume_loads(subsume_loads),
 650                   _do_escape_analysis(do_escape_analysis),
 651                   _eliminate_boxing(eliminate_boxing),
 652                   _failure_reason(NULL),
 653                   _code_buffer("Compile::Fill_buffer"),
 654                   _orig_pc_slot(0),
 655                   _orig_pc_slot_offset_in_bytes(0),
 656                   _has_method_handle_invokes(false),
 657                   _mach_constant_base_node(NULL),
 658                   _node_bundling_limit(0),
 659                   _node_bundling_base(NULL),
 660                   _java_calls(0),
 661                   _inner_loops(0),
 662                   _scratch_const_size(-1),
 663                   _in_scratch_emit_size(false),
 664                   _dead_node_list(comp_arena()),
 665                   _dead_node_count(0),
 666 #ifndef PRODUCT
 667                   _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
 668                   _in_dump_cnt(0),
 669                   _printer(IdealGraphPrinter::printer()),
 670 #endif
 671                   _congraph(NULL),
 672                   _comp_arena(mtCompiler),
 673                   _node_arena(mtCompiler),
 674                   _old_arena(mtCompiler),
 675                   _Compile_types(mtCompiler),
 676                   _replay_inline_data(NULL),
 677                   _late_inlines(comp_arena(), 2, 0, NULL),
 678                   _string_late_inlines(comp_arena(), 2, 0, NULL),
 679                   _boxing_late_inlines(comp_arena(), 2, 0, NULL),
 680                   _late_inlines_pos(0),
 681                   _number_of_mh_late_inlines(0),
 682                   _inlining_progress(false),
 683                   _inlining_incrementally(false),
 684                   _print_inlining_list(NULL),
 685                   _print_inlining_idx(0),
 686                   _interpreter_frame_size(0),
 687                   _max_node_limit(MaxNodeLimit) {
 688   C = this;
 689 
 690   CompileWrapper cw(this);
 691 #ifndef PRODUCT
 692   if (TimeCompiler2) {
 693     tty->print(" ");
 694     target->holder()->name()->print();
 695     tty->print(".");
 696     target->print_short_name();
 697     tty->print("  ");
 698   }
 699   TraceTime t1("Total compilation time", &_t_totalCompilation, TimeCompiler, TimeCompiler2);
 700   TraceTime t2(NULL, &_t_methodCompilation, TimeCompiler, false);
 701   bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
 702   if (!print_opto_assembly) {
 703     bool print_assembly = (PrintAssembly || _method->should_print_assembly());
 704     if (print_assembly && !Disassembler::can_decode()) {
 705       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
 706       print_opto_assembly = true;
 707     }
 708   }
 709   set_print_assembly(print_opto_assembly);
 710   set_parsed_irreducible_loop(false);
 711 
 712   if (method()->has_option("ReplayInline")) {
 713     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 714   }
 715 #endif
 716   set_print_inlining(PrintInlining || method()->has_option("PrintInlining") NOT_PRODUCT( || PrintOptoInlining));
 717   set_print_intrinsics(PrintIntrinsics || method()->has_option("PrintIntrinsics"));
 718   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 719 
 720   if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
 721     // Make sure the method being compiled gets its own MDO,
 722     // so we can at least track the decompile_count().
 723     // Need MDO to record RTM code generation state.
 724     method()->ensure_method_data();
 725   }
 726 
 727   Init(::AliasLevel);
 728 
 729 
 730   print_compile_messages();
 731 
 732   _ilt = InlineTree::build_inline_tree_root();
 733 
 734   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 735   assert(num_alias_types() >= AliasIdxRaw, "");
 736 
 737 #define MINIMUM_NODE_HASH  1023
 738   // Node list that Iterative GVN will start with
 739   Unique_Node_List for_igvn(comp_arena());
 740   set_for_igvn(&for_igvn);
 741 
 742   // GVN that will be run immediately on new nodes
 743   uint estimated_size = method()->code_size()*4+64;
 744   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 745   PhaseGVN gvn(node_arena(), estimated_size);
 746   set_initial_gvn(&gvn);
 747 
 748   if (print_inlining() || print_intrinsics()) {
 749     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
 750   }
 751   { // Scope for timing the parser
 752     TracePhase t3("parse", &_t_parser, true);
 753 
 754     // Put top into the hash table ASAP.
 755     initial_gvn()->transform_no_reclaim(top());
 756 
 757     // Set up tf(), start(), and find a CallGenerator.
 758     CallGenerator* cg = NULL;
 759     if (is_osr_compilation()) {
 760       const TypeTuple *domain = StartOSRNode::osr_domain();
 761       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 762       init_tf(TypeFunc::make(domain, range));
 763       StartNode* s = new (this) StartOSRNode(root(), domain);
 764       initial_gvn()->set_type_bottom(s);
 765       init_start(s);
 766       cg = CallGenerator::for_osr(method(), entry_bci());
 767     } else {
 768       // Normal case.
 769       init_tf(TypeFunc::make(method()));
 770       StartNode* s = new (this) StartNode(root(), tf()->domain());
 771       initial_gvn()->set_type_bottom(s);
 772       init_start(s);
 773       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
 774         // With java.lang.ref.reference.get() we must go through the
 775         // intrinsic when G1 is enabled - even when get() is the root
 776         // method of the compile - so that, if necessary, the value in
 777         // the referent field of the reference object gets recorded by
 778         // the pre-barrier code.
 779         // Specifically, if G1 is enabled, the value in the referent
 780         // field is recorded by the G1 SATB pre barrier. This will
 781         // result in the referent being marked live and the reference
 782         // object removed from the list of discovered references during
 783         // reference processing.
 784         cg = find_intrinsic(method(), false);
 785       }
 786       if (cg == NULL) {
 787         float past_uses = method()->interpreter_invocation_count();
 788         float expected_uses = past_uses;
 789         cg = CallGenerator::for_inline(method(), expected_uses);
 790       }
 791     }
 792     if (failing())  return;
 793     if (cg == NULL) {
 794       record_method_not_compilable_all_tiers("cannot parse method");
 795       return;
 796     }
 797     JVMState* jvms = build_start_state(start(), tf());
 798     if ((jvms = cg->generate(jvms)) == NULL) {
 799       if (!failure_reason_is(C2Compiler::retry_class_loading_during_parsing())) {
 800         record_method_not_compilable("method parse failed");
 801       }
 802       return;
 803     }
 804     GraphKit kit(jvms);
 805 
 806     if (!kit.stopped()) {
 807       // Accept return values, and transfer control we know not where.
 808       // This is done by a special, unique ReturnNode bound to root.
 809       return_values(kit.jvms());
 810     }
 811 
 812     if (kit.has_exceptions()) {
 813       // Any exceptions that escape from this call must be rethrown
 814       // to whatever caller is dynamically above us on the stack.
 815       // This is done by a special, unique RethrowNode bound to root.
 816       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 817     }
 818 
 819     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 820 
 821     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 822       inline_string_calls(true);
 823     }
 824 
 825     if (failing())  return;
 826 
 827     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
 828 
 829     // Remove clutter produced by parsing.
 830     if (!failing()) {
 831       ResourceMark rm;
 832       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 833     }
 834   }
 835 
 836   // Note:  Large methods are capped off in do_one_bytecode().
 837   if (failing())  return;
 838 
 839   // After parsing, node notes are no longer automagic.
 840   // They must be propagated by register_new_node_with_optimizer(),
 841   // clone(), or the like.
 842   set_default_node_notes(NULL);
 843 
 844   for (;;) {
 845     int successes = Inline_Warm();
 846     if (failing())  return;
 847     if (successes == 0)  break;
 848   }
 849 
 850   // Drain the list.
 851   Finish_Warm();
 852 #ifndef PRODUCT
 853   if (_printer) {
 854     _printer->print_inlining(this);
 855   }
 856 #endif
 857 
 858   if (failing())  return;
 859   NOT_PRODUCT( verify_graph_edges(); )
 860 
 861   // Now optimize
 862   Optimize();
 863   if (failing())  return;
 864   NOT_PRODUCT( verify_graph_edges(); )
 865 
 866 #ifndef PRODUCT
 867   if (PrintIdeal) {
 868     ttyLocker ttyl;  // keep the following output all in one block
 869     // This output goes directly to the tty, not the compiler log.
 870     // To enable tools to match it up with the compilation activity,
 871     // be sure to tag this tty output with the compile ID.
 872     if (xtty != NULL) {
 873       xtty->head("ideal compile_id='%d'%s", compile_id(),
 874                  is_osr_compilation()    ? " compile_kind='osr'" :
 875                  "");
 876     }
 877     root()->dump(9999);
 878     if (xtty != NULL) {
 879       xtty->tail("ideal");
 880     }
 881   }
 882 #endif
 883 
 884   NOT_PRODUCT( verify_barriers(); )
 885 
 886   // Dump compilation data to replay it.
 887   if (method()->has_option("DumpReplay")) {
 888     env()->dump_replay_data(_compile_id);
 889   }
 890   if (method()->has_option("DumpInline") && (ilt() != NULL)) {
 891     env()->dump_inline_data(_compile_id);
 892   }
 893 
 894   // Now that we know the size of all the monitors we can add a fixed slot
 895   // for the original deopt pc.
 896 
 897   _orig_pc_slot =  fixed_slots();
 898   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
 899   set_fixed_slots(next_slot);
 900 
 901   // Compute when to use implicit null checks. Used by matching trap based
 902   // nodes and NullCheck optimization.
 903   set_allowed_deopt_reasons();
 904 
 905   // Now generate code
 906   Code_Gen();
 907   if (failing())  return;
 908 
 909   // Check if we want to skip execution of all compiled code.
 910   {
 911 #ifndef PRODUCT
 912     if (OptoNoExecute) {
 913       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
 914       return;
 915     }
 916     TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
 917 #endif
 918 
 919     if (is_osr_compilation()) {
 920       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
 921       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
 922     } else {
 923       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
 924       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
 925     }
 926 
 927     env()->register_method(_method, _entry_bci,
 928                            &_code_offsets,
 929                            _orig_pc_slot_offset_in_bytes,
 930                            code_buffer(),
 931                            frame_size_in_words(), _oop_map_set,
 932                            &_handler_table, &_inc_table,
 933                            compiler,
 934                            env()->comp_level(),
 935                            has_unsafe_access(),
 936                            SharedRuntime::is_wide_vector(max_vector_size()),
 937                            rtm_state()
 938                            );
 939 
 940     if (log() != NULL) // Print code cache state into compiler log
 941       log()->code_cache_state();
 942   }
 943 }
 944 
 945 //------------------------------Compile----------------------------------------
 946 // Compile a runtime stub
 947 Compile::Compile( ciEnv* ci_env,
 948                   TypeFunc_generator generator,
 949                   address stub_function,
 950                   const char *stub_name,
 951                   int is_fancy_jump,
 952                   bool pass_tls,
 953                   bool save_arg_registers,
 954                   bool return_pc )
 955   : Phase(Compiler),
 956     _env(ci_env),
 957     _log(ci_env->log()),
 958     _compile_id(0),
 959     _save_argument_registers(save_arg_registers),
 960     _method(NULL),
 961     _stub_name(stub_name),
 962     _stub_function(stub_function),
 963     _stub_entry_point(NULL),
 964     _entry_bci(InvocationEntryBci),
 965     _initial_gvn(NULL),
 966     _for_igvn(NULL),
 967     _warm_calls(NULL),
 968     _orig_pc_slot(0),
 969     _orig_pc_slot_offset_in_bytes(0),
 970     _subsume_loads(true),
 971     _do_escape_analysis(false),
 972     _eliminate_boxing(false),
 973     _failure_reason(NULL),
 974     _code_buffer("Compile::Fill_buffer"),
 975     _has_method_handle_invokes(false),
 976     _mach_constant_base_node(NULL),
 977     _node_bundling_limit(0),
 978     _node_bundling_base(NULL),
 979     _java_calls(0),
 980     _inner_loops(0),
 981 #ifndef PRODUCT
 982     _trace_opto_output(TraceOptoOutput),
 983     _in_dump_cnt(0),
 984     _printer(NULL),
 985 #endif
 986     _comp_arena(mtCompiler),
 987     _node_arena(mtCompiler),
 988     _old_arena(mtCompiler),
 989     _Compile_types(mtCompiler),
 990     _dead_node_list(comp_arena()),
 991     _dead_node_count(0),
 992     _congraph(NULL),
 993     _replay_inline_data(NULL),
 994     _number_of_mh_late_inlines(0),
 995     _inlining_progress(false),
 996     _inlining_incrementally(false),
 997     _print_inlining_list(NULL),
 998     _print_inlining_idx(0),
 999     _allowed_reasons(0),
1000     _interpreter_frame_size(0),
1001     _max_node_limit(MaxNodeLimit) {
1002   C = this;
1003 
1004 #ifndef PRODUCT
1005   TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
1006   TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
1007   set_print_assembly(PrintFrameConverterAssembly);
1008   set_parsed_irreducible_loop(false);
1009 #endif
1010   set_has_irreducible_loop(false); // no loops
1011 
1012   CompileWrapper cw(this);
1013   Init(/*AliasLevel=*/ 0);
1014   init_tf((*generator)());
1015 
1016   {
1017     // The following is a dummy for the sake of GraphKit::gen_stub
1018     Unique_Node_List for_igvn(comp_arena());
1019     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
1020     PhaseGVN gvn(Thread::current()->resource_area(),255);
1021     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
1022     gvn.transform_no_reclaim(top());
1023 
1024     GraphKit kit;
1025     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1026   }
1027 
1028   NOT_PRODUCT( verify_graph_edges(); )
1029   Code_Gen();
1030   if (failing())  return;
1031 
1032 
1033   // Entry point will be accessed using compile->stub_entry_point();
1034   if (code_buffer() == NULL) {
1035     Matcher::soft_match_failure();
1036   } else {
1037     if (PrintAssembly && (WizardMode || Verbose))
1038       tty->print_cr("### Stub::%s", stub_name);
1039 
1040     if (!failing()) {
1041       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
1042 
1043       // Make the NMethod
1044       // For now we mark the frame as never safe for profile stackwalking
1045       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
1046                                                       code_buffer(),
1047                                                       CodeOffsets::frame_never_safe,
1048                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
1049                                                       frame_size_in_words(),
1050                                                       _oop_map_set,
1051                                                       save_arg_registers);
1052       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
1053 
1054       _stub_entry_point = rs->entry_point();
1055     }
1056   }
1057 }
1058 
1059 //------------------------------Init-------------------------------------------
1060 // Prepare for a single compilation
1061 void Compile::Init(int aliaslevel) {
1062   _unique  = 0;
1063   _regalloc = NULL;
1064 
1065   _tf      = NULL;  // filled in later
1066   _top     = NULL;  // cached later
1067   _matcher = NULL;  // filled in later
1068   _cfg     = NULL;  // filled in later
1069 
1070   set_24_bit_selection_and_mode(Use24BitFP, false);
1071 
1072   _node_note_array = NULL;
1073   _default_node_notes = NULL;
1074 
1075   _immutable_memory = NULL; // filled in at first inquiry
1076 
1077   // Globally visible Nodes
1078   // First set TOP to NULL to give safe behavior during creation of RootNode
1079   set_cached_top_node(NULL);
1080   set_root(new (this) RootNode());
1081   // Now that you have a Root to point to, create the real TOP
1082   set_cached_top_node( new (this) ConNode(Type::TOP) );
1083   set_recent_alloc(NULL, NULL);
1084 
1085   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1086   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1087   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1088   env()->set_dependencies(new Dependencies(env()));
1089 
1090   _fixed_slots = 0;
1091   set_has_split_ifs(false);
1092   set_has_loops(has_method() && method()->has_loops()); // first approximation
1093   set_has_stringbuilder(false);
1094   set_has_boxed_value(false);
1095   _trap_can_recompile = false;  // no traps emitted yet
1096   _major_progress = true; // start out assuming good things will happen
1097   set_has_unsafe_access(false);
1098   set_max_vector_size(0);
1099   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1100   set_decompile_count(0);
1101 
1102   set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
1103   set_num_loop_opts(LoopOptsCount);
1104   set_do_inlining(Inline);
1105   set_max_inline_size(MaxInlineSize);
1106   set_freq_inline_size(FreqInlineSize);
1107   set_do_scheduling(OptoScheduling);
1108   set_do_count_invocations(false);
1109   set_do_method_data_update(false);
1110   set_rtm_state(NoRTM); // No RTM lock eliding by default
1111   method_has_option_value("MaxNodeLimit", _max_node_limit);
1112 #if INCLUDE_RTM_OPT
1113   if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
1114     int rtm_state = method()->method_data()->rtm_state();
1115     if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
1116       // Don't generate RTM lock eliding code.
1117       set_rtm_state(NoRTM);
1118     } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
1119       // Generate RTM lock eliding code without abort ratio calculation code.
1120       set_rtm_state(UseRTM);
1121     } else if (UseRTMDeopt) {
1122       // Generate RTM lock eliding code and include abort ratio calculation
1123       // code if UseRTMDeopt is on.
1124       set_rtm_state(ProfileRTM);
1125     }
1126   }
1127 #endif
1128   if (debug_info()->recording_non_safepoints()) {
1129     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1130                         (comp_arena(), 8, 0, NULL));
1131     set_default_node_notes(Node_Notes::make(this));
1132   }
1133 
1134   // // -- Initialize types before each compile --
1135   // // Update cached type information
1136   // if( _method && _method->constants() )
1137   //   Type::update_loaded_types(_method, _method->constants());
1138 
1139   // Init alias_type map.
1140   if (!_do_escape_analysis && aliaslevel == 3)
1141     aliaslevel = 2;  // No unique types without escape analysis
1142   _AliasLevel = aliaslevel;
1143   const int grow_ats = 16;
1144   _max_alias_types = grow_ats;
1145   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1146   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1147   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1148   {
1149     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1150   }
1151   // Initialize the first few types.
1152   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1153   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1154   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1155   _num_alias_types = AliasIdxRaw+1;
1156   // Zero out the alias type cache.
1157   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1158   // A NULL adr_type hits in the cache right away.  Preload the right answer.
1159   probe_alias_cache(NULL)->_index = AliasIdxTop;
1160 
1161   _intrinsics = NULL;
1162   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1163   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1164   _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1165   _range_check_casts = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1166   register_library_intrinsics();
1167 #ifdef ASSERT
1168   _type_verify_symmetry = true;
1169 #endif
1170 }
1171 
1172 //---------------------------init_start----------------------------------------
1173 // Install the StartNode on this compile object.
1174 void Compile::init_start(StartNode* s) {
1175   if (failing())
1176     return; // already failing
1177   assert(s == start(), "");
1178 }
1179 
1180 StartNode* Compile::start() const {
1181   assert(!failing(), "");
1182   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1183     Node* start = root()->fast_out(i);
1184     if( start->is_Start() )
1185       return start->as_Start();
1186   }
1187   fatal("Did not find Start node!");
1188   return NULL;
1189 }
1190 
1191 //-------------------------------immutable_memory-------------------------------------
1192 // Access immutable memory
1193 Node* Compile::immutable_memory() {
1194   if (_immutable_memory != NULL) {
1195     return _immutable_memory;
1196   }
1197   StartNode* s = start();
1198   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1199     Node *p = s->fast_out(i);
1200     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1201       _immutable_memory = p;
1202       return _immutable_memory;
1203     }
1204   }
1205   ShouldNotReachHere();
1206   return NULL;
1207 }
1208 
1209 //----------------------set_cached_top_node------------------------------------
1210 // Install the cached top node, and make sure Node::is_top works correctly.
1211 void Compile::set_cached_top_node(Node* tn) {
1212   if (tn != NULL)  verify_top(tn);
1213   Node* old_top = _top;
1214   _top = tn;
1215   // Calling Node::setup_is_top allows the nodes the chance to adjust
1216   // their _out arrays.
1217   if (_top != NULL)     _top->setup_is_top();
1218   if (old_top != NULL)  old_top->setup_is_top();
1219   assert(_top == NULL || top()->is_top(), "");
1220 }
1221 
1222 #ifdef ASSERT
1223 uint Compile::count_live_nodes_by_graph_walk() {
1224   Unique_Node_List useful(comp_arena());
1225   // Get useful node list by walking the graph.
1226   identify_useful_nodes(useful);
1227   return useful.size();
1228 }
1229 
1230 void Compile::print_missing_nodes() {
1231 
1232   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1233   if ((_log == NULL) && (! PrintIdealNodeCount)) {
1234     return;
1235   }
1236 
1237   // This is an expensive function. It is executed only when the user
1238   // specifies VerifyIdealNodeCount option or otherwise knows the
1239   // additional work that needs to be done to identify reachable nodes
1240   // by walking the flow graph and find the missing ones using
1241   // _dead_node_list.
1242 
1243   Unique_Node_List useful(comp_arena());
1244   // Get useful node list by walking the graph.
1245   identify_useful_nodes(useful);
1246 
1247   uint l_nodes = C->live_nodes();
1248   uint l_nodes_by_walk = useful.size();
1249 
1250   if (l_nodes != l_nodes_by_walk) {
1251     if (_log != NULL) {
1252       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1253       _log->stamp();
1254       _log->end_head();
1255     }
1256     VectorSet& useful_member_set = useful.member_set();
1257     int last_idx = l_nodes_by_walk;
1258     for (int i = 0; i < last_idx; i++) {
1259       if (useful_member_set.test(i)) {
1260         if (_dead_node_list.test(i)) {
1261           if (_log != NULL) {
1262             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1263           }
1264           if (PrintIdealNodeCount) {
1265             // Print the log message to tty
1266               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1267               useful.at(i)->dump();
1268           }
1269         }
1270       }
1271       else if (! _dead_node_list.test(i)) {
1272         if (_log != NULL) {
1273           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1274         }
1275         if (PrintIdealNodeCount) {
1276           // Print the log message to tty
1277           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1278         }
1279       }
1280     }
1281     if (_log != NULL) {
1282       _log->tail("mismatched_nodes");
1283     }
1284   }
1285 }
1286 #endif
1287 
1288 #ifndef PRODUCT
1289 void Compile::verify_top(Node* tn) const {
1290   if (tn != NULL) {
1291     assert(tn->is_Con(), "top node must be a constant");
1292     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1293     assert(tn->in(0) != NULL, "must have live top node");
1294   }
1295 }
1296 #endif
1297 
1298 
1299 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1300 
1301 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1302   guarantee(arr != NULL, "");
1303   int num_blocks = arr->length();
1304   if (grow_by < num_blocks)  grow_by = num_blocks;
1305   int num_notes = grow_by * _node_notes_block_size;
1306   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1307   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1308   while (num_notes > 0) {
1309     arr->append(notes);
1310     notes     += _node_notes_block_size;
1311     num_notes -= _node_notes_block_size;
1312   }
1313   assert(num_notes == 0, "exact multiple, please");
1314 }
1315 
1316 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1317   if (source == NULL || dest == NULL)  return false;
1318 
1319   if (dest->is_Con())
1320     return false;               // Do not push debug info onto constants.
1321 
1322 #ifdef ASSERT
1323   // Leave a bread crumb trail pointing to the original node:
1324   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1325     dest->set_debug_orig(source);
1326   }
1327 #endif
1328 
1329   if (node_note_array() == NULL)
1330     return false;               // Not collecting any notes now.
1331 
1332   // This is a copy onto a pre-existing node, which may already have notes.
1333   // If both nodes have notes, do not overwrite any pre-existing notes.
1334   Node_Notes* source_notes = node_notes_at(source->_idx);
1335   if (source_notes == NULL || source_notes->is_clear())  return false;
1336   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1337   if (dest_notes == NULL || dest_notes->is_clear()) {
1338     return set_node_notes_at(dest->_idx, source_notes);
1339   }
1340 
1341   Node_Notes merged_notes = (*source_notes);
1342   // The order of operations here ensures that dest notes will win...
1343   merged_notes.update_from(dest_notes);
1344   return set_node_notes_at(dest->_idx, &merged_notes);
1345 }
1346 
1347 
1348 //--------------------------allow_range_check_smearing-------------------------
1349 // Gating condition for coalescing similar range checks.
1350 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1351 // single covering check that is at least as strong as any of them.
1352 // If the optimization succeeds, the simplified (strengthened) range check
1353 // will always succeed.  If it fails, we will deopt, and then give up
1354 // on the optimization.
1355 bool Compile::allow_range_check_smearing() const {
1356   // If this method has already thrown a range-check,
1357   // assume it was because we already tried range smearing
1358   // and it failed.
1359   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1360   return !already_trapped;
1361 }
1362 
1363 
1364 //------------------------------flatten_alias_type-----------------------------
1365 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1366   int offset = tj->offset();
1367   TypePtr::PTR ptr = tj->ptr();
1368 
1369   // Known instance (scalarizable allocation) alias only with itself.
1370   bool is_known_inst = tj->isa_oopptr() != NULL &&
1371                        tj->is_oopptr()->is_known_instance();
1372 
1373   // Process weird unsafe references.
1374   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1375     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1376     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1377     tj = TypeOopPtr::BOTTOM;
1378     ptr = tj->ptr();
1379     offset = tj->offset();
1380   }
1381 
1382   // Array pointers need some flattening
1383   const TypeAryPtr *ta = tj->isa_aryptr();
1384   if (ta && ta->is_stable()) {
1385     // Erase stability property for alias analysis.
1386     tj = ta = ta->cast_to_stable(false);
1387   }
1388   if( ta && is_known_inst ) {
1389     if ( offset != Type::OffsetBot &&
1390          offset > arrayOopDesc::length_offset_in_bytes() ) {
1391       offset = Type::OffsetBot; // Flatten constant access into array body only
1392       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
1393     }
1394   } else if( ta && _AliasLevel >= 2 ) {
1395     // For arrays indexed by constant indices, we flatten the alias
1396     // space to include all of the array body.  Only the header, klass
1397     // and array length can be accessed un-aliased.
1398     if( offset != Type::OffsetBot ) {
1399       if( ta->const_oop() ) { // MethodData* or Method*
1400         offset = Type::OffsetBot;   // Flatten constant access into array body
1401         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1402       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1403         // range is OK as-is.
1404         tj = ta = TypeAryPtr::RANGE;
1405       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1406         tj = TypeInstPtr::KLASS; // all klass loads look alike
1407         ta = TypeAryPtr::RANGE; // generic ignored junk
1408         ptr = TypePtr::BotPTR;
1409       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1410         tj = TypeInstPtr::MARK;
1411         ta = TypeAryPtr::RANGE; // generic ignored junk
1412         ptr = TypePtr::BotPTR;
1413       } else {                  // Random constant offset into array body
1414         offset = Type::OffsetBot;   // Flatten constant access into array body
1415         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
1416       }
1417     }
1418     // Arrays of fixed size alias with arrays of unknown size.
1419     if (ta->size() != TypeInt::POS) {
1420       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1421       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
1422     }
1423     // Arrays of known objects become arrays of unknown objects.
1424     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1425       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1426       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1427     }
1428     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1429       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1430       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1431     }
1432     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1433     // cannot be distinguished by bytecode alone.
1434     if (ta->elem() == TypeInt::BOOL) {
1435       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1436       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1437       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1438     }
1439     // During the 2nd round of IterGVN, NotNull castings are removed.
1440     // Make sure the Bottom and NotNull variants alias the same.
1441     // Also, make sure exact and non-exact variants alias the same.
1442     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
1443       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1444     }
1445   }
1446 
1447   // Oop pointers need some flattening
1448   const TypeInstPtr *to = tj->isa_instptr();
1449   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1450     ciInstanceKlass *k = to->klass()->as_instance_klass();
1451     if( ptr == TypePtr::Constant ) {
1452       if (to->klass() != ciEnv::current()->Class_klass() ||
1453           offset < k->size_helper() * wordSize) {
1454         // No constant oop pointers (such as Strings); they alias with
1455         // unknown strings.
1456         assert(!is_known_inst, "not scalarizable allocation");
1457         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1458       }
1459     } else if( is_known_inst ) {
1460       tj = to; // Keep NotNull and klass_is_exact for instance type
1461     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1462       // During the 2nd round of IterGVN, NotNull castings are removed.
1463       // Make sure the Bottom and NotNull variants alias the same.
1464       // Also, make sure exact and non-exact variants alias the same.
1465       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1466     }
1467     if (to->speculative() != NULL) {
1468       tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
1469     }
1470     // Canonicalize the holder of this field
1471     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1472       // First handle header references such as a LoadKlassNode, even if the
1473       // object's klass is unloaded at compile time (4965979).
1474       if (!is_known_inst) { // Do it only for non-instance types
1475         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
1476       }
1477     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1478       // Static fields are in the space above the normal instance
1479       // fields in the java.lang.Class instance.
1480       if (to->klass() != ciEnv::current()->Class_klass()) {
1481         to = NULL;
1482         tj = TypeOopPtr::BOTTOM;
1483         offset = tj->offset();
1484       }
1485     } else {
1486       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1487       if (!k->equals(canonical_holder) || tj->offset() != offset) {
1488         if( is_known_inst ) {
1489           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
1490         } else {
1491           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
1492         }
1493       }
1494     }
1495   }
1496 
1497   // Klass pointers to object array klasses need some flattening
1498   const TypeKlassPtr *tk = tj->isa_klassptr();
1499   if( tk ) {
1500     // If we are referencing a field within a Klass, we need
1501     // to assume the worst case of an Object.  Both exact and
1502     // inexact types must flatten to the same alias class so
1503     // use NotNull as the PTR.
1504     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1505 
1506       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1507                                    TypeKlassPtr::OBJECT->klass(),
1508                                    offset);
1509     }
1510 
1511     ciKlass* klass = tk->klass();
1512     if( klass->is_obj_array_klass() ) {
1513       ciKlass* k = TypeAryPtr::OOPS->klass();
1514       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
1515         k = TypeInstPtr::BOTTOM->klass();
1516       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1517     }
1518 
1519     // Check for precise loads from the primary supertype array and force them
1520     // to the supertype cache alias index.  Check for generic array loads from
1521     // the primary supertype array and also force them to the supertype cache
1522     // alias index.  Since the same load can reach both, we need to merge
1523     // these 2 disparate memories into the same alias class.  Since the
1524     // primary supertype array is read-only, there's no chance of confusion
1525     // where we bypass an array load and an array store.
1526     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1527     if (offset == Type::OffsetBot ||
1528         (offset >= primary_supers_offset &&
1529          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1530         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1531       offset = in_bytes(Klass::secondary_super_cache_offset());
1532       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1533     }
1534   }
1535 
1536   // Flatten all Raw pointers together.
1537   if (tj->base() == Type::RawPtr)
1538     tj = TypeRawPtr::BOTTOM;
1539 
1540   if (tj->base() == Type::AnyPtr)
1541     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1542 
1543   // Flatten all to bottom for now
1544   switch( _AliasLevel ) {
1545   case 0:
1546     tj = TypePtr::BOTTOM;
1547     break;
1548   case 1:                       // Flatten to: oop, static, field or array
1549     switch (tj->base()) {
1550     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
1551     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
1552     case Type::AryPtr:   // do not distinguish arrays at all
1553     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
1554     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1555     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
1556     default: ShouldNotReachHere();
1557     }
1558     break;
1559   case 2:                       // No collapsing at level 2; keep all splits
1560   case 3:                       // No collapsing at level 3; keep all splits
1561     break;
1562   default:
1563     Unimplemented();
1564   }
1565 
1566   offset = tj->offset();
1567   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1568 
1569   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1570           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1571           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1572           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1573           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1574           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1575           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
1576           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1577   assert( tj->ptr() != TypePtr::TopPTR &&
1578           tj->ptr() != TypePtr::AnyNull &&
1579           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1580 //    assert( tj->ptr() != TypePtr::Constant ||
1581 //            tj->base() == Type::RawPtr ||
1582 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1583 
1584   return tj;
1585 }
1586 
1587 void Compile::AliasType::Init(int i, const TypePtr* at) {
1588   _index = i;
1589   _adr_type = at;
1590   _field = NULL;
1591   _element = NULL;
1592   _is_rewritable = true; // default
1593   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1594   if (atoop != NULL && atoop->is_known_instance()) {
1595     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1596     _general_index = Compile::current()->get_alias_index(gt);
1597   } else {
1598     _general_index = 0;
1599   }
1600 }
1601 
1602 BasicType Compile::AliasType::basic_type() const {
1603   if (element() != NULL) {
1604     const Type* element = adr_type()->is_aryptr()->elem();
1605     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1606   } if (field() != NULL) {
1607     return field()->layout_type();
1608   } else {
1609     return T_ILLEGAL; // unknown
1610   }
1611 }
1612 
1613 //---------------------------------print_on------------------------------------
1614 #ifndef PRODUCT
1615 void Compile::AliasType::print_on(outputStream* st) {
1616   if (index() < 10)
1617         st->print("@ <%d> ", index());
1618   else  st->print("@ <%d>",  index());
1619   st->print(is_rewritable() ? "   " : " RO");
1620   int offset = adr_type()->offset();
1621   if (offset == Type::OffsetBot)
1622         st->print(" +any");
1623   else  st->print(" +%-3d", offset);
1624   st->print(" in ");
1625   adr_type()->dump_on(st);
1626   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1627   if (field() != NULL && tjp) {
1628     if (tjp->klass()  != field()->holder() ||
1629         tjp->offset() != field()->offset_in_bytes()) {
1630       st->print(" != ");
1631       field()->print();
1632       st->print(" ***");
1633     }
1634   }
1635 }
1636 
1637 void print_alias_types() {
1638   Compile* C = Compile::current();
1639   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1640   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1641     C->alias_type(idx)->print_on(tty);
1642     tty->cr();
1643   }
1644 }
1645 #endif
1646 
1647 
1648 //----------------------------probe_alias_cache--------------------------------
1649 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1650   intptr_t key = (intptr_t) adr_type;
1651   key ^= key >> logAliasCacheSize;
1652   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1653 }
1654 
1655 
1656 //-----------------------------grow_alias_types--------------------------------
1657 void Compile::grow_alias_types() {
1658   const int old_ats  = _max_alias_types; // how many before?
1659   const int new_ats  = old_ats;          // how many more?
1660   const int grow_ats = old_ats+new_ats;  // how many now?
1661   _max_alias_types = grow_ats;
1662   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1663   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1664   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1665   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1666 }
1667 
1668 
1669 //--------------------------------find_alias_type------------------------------
1670 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1671   if (_AliasLevel == 0)
1672     return alias_type(AliasIdxBot);
1673 
1674   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1675   if (ace->_adr_type == adr_type) {
1676     return alias_type(ace->_index);
1677   }
1678 
1679   // Handle special cases.
1680   if (adr_type == NULL)             return alias_type(AliasIdxTop);
1681   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1682 
1683   // Do it the slow way.
1684   const TypePtr* flat = flatten_alias_type(adr_type);
1685 
1686 #ifdef ASSERT
1687   {
1688     ResourceMark rm;
1689     assert(flat == flatten_alias_type(flat),
1690            err_msg("not idempotent: adr_type = %s; flat = %s => %s", Type::str(adr_type),
1691                    Type::str(flat), Type::str(flatten_alias_type(flat))));
1692     assert(flat != TypePtr::BOTTOM,
1693            err_msg("cannot alias-analyze an untyped ptr: adr_type = %s", Type::str(adr_type)));
1694     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1695       const TypeOopPtr* foop = flat->is_oopptr();
1696       // Scalarizable allocations have exact klass always.
1697       bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1698       const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1699       assert(foop == flatten_alias_type(xoop),
1700              err_msg("exactness must not affect alias type: foop = %s; xoop = %s",
1701                      Type::str(foop), Type::str(xoop)));
1702     }
1703   }
1704 #endif
1705 
1706   int idx = AliasIdxTop;
1707   for (int i = 0; i < num_alias_types(); i++) {
1708     if (alias_type(i)->adr_type() == flat) {
1709       idx = i;
1710       break;
1711     }
1712   }
1713 
1714   if (idx == AliasIdxTop) {
1715     if (no_create)  return NULL;
1716     // Grow the array if necessary.
1717     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1718     // Add a new alias type.
1719     idx = _num_alias_types++;
1720     _alias_types[idx]->Init(idx, flat);
1721     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1722     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1723     if (flat->isa_instptr()) {
1724       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1725           && flat->is_instptr()->klass() == env()->Class_klass())
1726         alias_type(idx)->set_rewritable(false);
1727     }
1728     if (flat->isa_aryptr()) {
1729 #ifdef ASSERT
1730       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1731       // (T_BYTE has the weakest alignment and size restrictions...)
1732       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1733 #endif
1734       if (flat->offset() == TypePtr::OffsetBot) {
1735         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1736       }
1737     }
1738     if (flat->isa_klassptr()) {
1739       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1740         alias_type(idx)->set_rewritable(false);
1741       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1742         alias_type(idx)->set_rewritable(false);
1743       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1744         alias_type(idx)->set_rewritable(false);
1745       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1746         alias_type(idx)->set_rewritable(false);
1747     }
1748     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1749     // but the base pointer type is not distinctive enough to identify
1750     // references into JavaThread.)
1751 
1752     // Check for final fields.
1753     const TypeInstPtr* tinst = flat->isa_instptr();
1754     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1755       ciField* field;
1756       if (tinst->const_oop() != NULL &&
1757           tinst->klass() == ciEnv::current()->Class_klass() &&
1758           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1759         // static field
1760         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1761         field = k->get_field_by_offset(tinst->offset(), true);
1762       } else {
1763         ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1764         field = k->get_field_by_offset(tinst->offset(), false);
1765       }
1766       assert(field == NULL ||
1767              original_field == NULL ||
1768              (field->holder() == original_field->holder() &&
1769               field->offset() == original_field->offset() &&
1770               field->is_static() == original_field->is_static()), "wrong field?");
1771       // Set field() and is_rewritable() attributes.
1772       if (field != NULL)  alias_type(idx)->set_field(field);
1773     }
1774   }
1775 
1776   // Fill the cache for next time.
1777   ace->_adr_type = adr_type;
1778   ace->_index    = idx;
1779   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1780 
1781   // Might as well try to fill the cache for the flattened version, too.
1782   AliasCacheEntry* face = probe_alias_cache(flat);
1783   if (face->_adr_type == NULL) {
1784     face->_adr_type = flat;
1785     face->_index    = idx;
1786     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1787   }
1788 
1789   return alias_type(idx);
1790 }
1791 
1792 
1793 Compile::AliasType* Compile::alias_type(ciField* field) {
1794   const TypeOopPtr* t;
1795   if (field->is_static())
1796     t = TypeInstPtr::make(field->holder()->java_mirror());
1797   else
1798     t = TypeOopPtr::make_from_klass_raw(field->holder());
1799   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1800   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1801   return atp;
1802 }
1803 
1804 
1805 //------------------------------have_alias_type--------------------------------
1806 bool Compile::have_alias_type(const TypePtr* adr_type) {
1807   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1808   if (ace->_adr_type == adr_type) {
1809     return true;
1810   }
1811 
1812   // Handle special cases.
1813   if (adr_type == NULL)             return true;
1814   if (adr_type == TypePtr::BOTTOM)  return true;
1815 
1816   return find_alias_type(adr_type, true, NULL) != NULL;
1817 }
1818 
1819 //-----------------------------must_alias--------------------------------------
1820 // True if all values of the given address type are in the given alias category.
1821 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1822   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1823   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
1824   if (alias_idx == AliasIdxTop)         return false; // the empty category
1825   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1826 
1827   // the only remaining possible overlap is identity
1828   int adr_idx = get_alias_index(adr_type);
1829   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1830   assert(adr_idx == alias_idx ||
1831          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1832           && adr_type                       != TypeOopPtr::BOTTOM),
1833          "should not be testing for overlap with an unsafe pointer");
1834   return adr_idx == alias_idx;
1835 }
1836 
1837 //------------------------------can_alias--------------------------------------
1838 // True if any values of the given address type are in the given alias category.
1839 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1840   if (alias_idx == AliasIdxTop)         return false; // the empty category
1841   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
1842   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1843   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
1844 
1845   // the only remaining possible overlap is identity
1846   int adr_idx = get_alias_index(adr_type);
1847   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1848   return adr_idx == alias_idx;
1849 }
1850 
1851 
1852 
1853 //---------------------------pop_warm_call-------------------------------------
1854 WarmCallInfo* Compile::pop_warm_call() {
1855   WarmCallInfo* wci = _warm_calls;
1856   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
1857   return wci;
1858 }
1859 
1860 //----------------------------Inline_Warm--------------------------------------
1861 int Compile::Inline_Warm() {
1862   // If there is room, try to inline some more warm call sites.
1863   // %%% Do a graph index compaction pass when we think we're out of space?
1864   if (!InlineWarmCalls)  return 0;
1865 
1866   int calls_made_hot = 0;
1867   int room_to_grow   = NodeCountInliningCutoff - unique();
1868   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1869   int amount_grown   = 0;
1870   WarmCallInfo* call;
1871   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1872     int est_size = (int)call->size();
1873     if (est_size > (room_to_grow - amount_grown)) {
1874       // This one won't fit anyway.  Get rid of it.
1875       call->make_cold();
1876       continue;
1877     }
1878     call->make_hot();
1879     calls_made_hot++;
1880     amount_grown   += est_size;
1881     amount_to_grow -= est_size;
1882   }
1883 
1884   if (calls_made_hot > 0)  set_major_progress();
1885   return calls_made_hot;
1886 }
1887 
1888 
1889 //----------------------------Finish_Warm--------------------------------------
1890 void Compile::Finish_Warm() {
1891   if (!InlineWarmCalls)  return;
1892   if (failing())  return;
1893   if (warm_calls() == NULL)  return;
1894 
1895   // Clean up loose ends, if we are out of space for inlining.
1896   WarmCallInfo* call;
1897   while ((call = pop_warm_call()) != NULL) {
1898     call->make_cold();
1899   }
1900 }
1901 
1902 //---------------------cleanup_loop_predicates-----------------------
1903 // Remove the opaque nodes that protect the predicates so that all unused
1904 // checks and uncommon_traps will be eliminated from the ideal graph
1905 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
1906   if (predicate_count()==0) return;
1907   for (int i = predicate_count(); i > 0; i--) {
1908     Node * n = predicate_opaque1_node(i-1);
1909     assert(n->Opcode() == Op_Opaque1, "must be");
1910     igvn.replace_node(n, n->in(1));
1911   }
1912   assert(predicate_count()==0, "should be clean!");
1913 }
1914 
1915 void Compile::add_range_check_cast(Node* n) {
1916   assert(n->isa_CastII()->has_range_check(), "CastII should have range check dependency");
1917   assert(!_range_check_casts->contains(n), "duplicate entry in range check casts");
1918   _range_check_casts->append(n);
1919 }
1920 
1921 // Remove all range check dependent CastIINodes.
1922 void Compile::remove_range_check_casts(PhaseIterGVN &igvn) {
1923   for (int i = range_check_cast_count(); i > 0; i--) {
1924     Node* cast = range_check_cast_node(i-1);
1925     assert(cast->isa_CastII()->has_range_check(), "CastII should have range check dependency");
1926     igvn.replace_node(cast, cast->in(1));
1927   }
1928   assert(range_check_cast_count() == 0, "should be empty");
1929 }
1930 
1931 // StringOpts and late inlining of string methods
1932 void Compile::inline_string_calls(bool parse_time) {
1933   {
1934     // remove useless nodes to make the usage analysis simpler
1935     ResourceMark rm;
1936     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
1937   }
1938 
1939   {
1940     ResourceMark rm;
1941     print_method(PHASE_BEFORE_STRINGOPTS, 3);
1942     PhaseStringOpts pso(initial_gvn(), for_igvn());
1943     print_method(PHASE_AFTER_STRINGOPTS, 3);
1944   }
1945 
1946   // now inline anything that we skipped the first time around
1947   if (!parse_time) {
1948     _late_inlines_pos = _late_inlines.length();
1949   }
1950 
1951   while (_string_late_inlines.length() > 0) {
1952     CallGenerator* cg = _string_late_inlines.pop();
1953     cg->do_late_inline();
1954     if (failing())  return;
1955   }
1956   _string_late_inlines.trunc_to(0);
1957 }
1958 
1959 // Late inlining of boxing methods
1960 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
1961   if (_boxing_late_inlines.length() > 0) {
1962     assert(has_boxed_value(), "inconsistent");
1963 
1964     PhaseGVN* gvn = initial_gvn();
1965     set_inlining_incrementally(true);
1966 
1967     assert( igvn._worklist.size() == 0, "should be done with igvn" );
1968     for_igvn()->clear();
1969     gvn->replace_with(&igvn);
1970 
1971     _late_inlines_pos = _late_inlines.length();
1972 
1973     while (_boxing_late_inlines.length() > 0) {
1974       CallGenerator* cg = _boxing_late_inlines.pop();
1975       cg->do_late_inline();
1976       if (failing())  return;
1977     }
1978     _boxing_late_inlines.trunc_to(0);
1979 
1980     {
1981       ResourceMark rm;
1982       PhaseRemoveUseless pru(gvn, for_igvn());
1983     }
1984 
1985     igvn = PhaseIterGVN(gvn);
1986     igvn.optimize();
1987 
1988     set_inlining_progress(false);
1989     set_inlining_incrementally(false);
1990   }
1991 }
1992 
1993 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
1994   assert(IncrementalInline, "incremental inlining should be on");
1995   PhaseGVN* gvn = initial_gvn();
1996 
1997   set_inlining_progress(false);
1998   for_igvn()->clear();
1999   gvn->replace_with(&igvn);
2000 
2001   int i = 0;
2002 
2003   for (; i <_late_inlines.length() && !inlining_progress(); i++) {
2004     CallGenerator* cg = _late_inlines.at(i);
2005     _late_inlines_pos = i+1;
2006     cg->do_late_inline();
2007     if (failing())  return;
2008   }
2009   int j = 0;
2010   for (; i < _late_inlines.length(); i++, j++) {
2011     _late_inlines.at_put(j, _late_inlines.at(i));
2012   }
2013   _late_inlines.trunc_to(j);
2014 
2015   {
2016     ResourceMark rm;
2017     PhaseRemoveUseless pru(gvn, for_igvn());
2018   }
2019 
2020   igvn = PhaseIterGVN(gvn);
2021 }
2022 
2023 // Perform incremental inlining until bound on number of live nodes is reached
2024 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2025   PhaseGVN* gvn = initial_gvn();
2026 
2027   set_inlining_incrementally(true);
2028   set_inlining_progress(true);
2029   uint low_live_nodes = 0;
2030 
2031   while(inlining_progress() && _late_inlines.length() > 0) {
2032 
2033     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2034       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2035         // PhaseIdealLoop is expensive so we only try it once we are
2036         // out of live nodes and we only try it again if the previous
2037         // helped got the number of nodes down significantly
2038         PhaseIdealLoop ideal_loop( igvn, false, true );
2039         if (failing())  return;
2040         low_live_nodes = live_nodes();
2041         _major_progress = true;
2042       }
2043 
2044       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2045         break;
2046       }
2047     }
2048 
2049     inline_incrementally_one(igvn);
2050 
2051     if (failing())  return;
2052 
2053     igvn.optimize();
2054 
2055     if (failing())  return;
2056   }
2057 
2058   assert( igvn._worklist.size() == 0, "should be done with igvn" );
2059 
2060   if (_string_late_inlines.length() > 0) {
2061     assert(has_stringbuilder(), "inconsistent");
2062     for_igvn()->clear();
2063     initial_gvn()->replace_with(&igvn);
2064 
2065     inline_string_calls(false);
2066 
2067     if (failing())  return;
2068 
2069     {
2070       ResourceMark rm;
2071       PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2072     }
2073 
2074     igvn = PhaseIterGVN(gvn);
2075 
2076     igvn.optimize();
2077   }
2078 
2079   set_inlining_incrementally(false);
2080 }
2081 
2082 
2083 // Remove edges from "root" to each SafePoint at a backward branch.
2084 // They were inserted during parsing (see add_safepoint()) to make
2085 // infinite loops without calls or exceptions visible to root, i.e.,
2086 // useful.
2087 void Compile::remove_root_to_sfpts_edges(PhaseIterGVN& igvn) {
2088   Node *r = root();
2089   if (r != NULL) {
2090     for (uint i = r->req(); i < r->len(); ++i) {
2091       Node *n = r->in(i);
2092       if (n != NULL && n->is_SafePoint()) {
2093         r->rm_prec(i);
2094         if (n->outcnt() == 0) {
2095           igvn.remove_dead_node(n);
2096         }
2097         --i;
2098       }
2099     }
2100   }
2101 }
2102 
2103 //------------------------------Optimize---------------------------------------
2104 // Given a graph, optimize it.
2105 void Compile::Optimize() {
2106   TracePhase t1("optimizer", &_t_optimizer, true);
2107 
2108 #ifndef PRODUCT
2109   if (env()->break_at_compile()) {
2110     BREAKPOINT;
2111   }
2112 
2113 #endif
2114 
2115   ResourceMark rm;
2116   int          loop_opts_cnt;
2117 
2118   NOT_PRODUCT( verify_graph_edges(); )
2119 
2120   print_method(PHASE_AFTER_PARSING);
2121 
2122  {
2123   // Iterative Global Value Numbering, including ideal transforms
2124   // Initialize IterGVN with types and values from parse-time GVN
2125   PhaseIterGVN igvn(initial_gvn());
2126   {
2127     NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
2128     igvn.optimize();
2129   }
2130 
2131   print_method(PHASE_ITER_GVN1, 2);
2132 
2133   if (failing())  return;
2134 
2135   {
2136     NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
2137     inline_incrementally(igvn);
2138   }
2139 
2140   print_method(PHASE_INCREMENTAL_INLINE, 2);
2141 
2142   if (failing())  return;
2143 
2144   if (eliminate_boxing()) {
2145     NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
2146     // Inline valueOf() methods now.
2147     inline_boxing_calls(igvn);
2148 
2149     if (AlwaysIncrementalInline) {
2150       inline_incrementally(igvn);
2151     }
2152 
2153     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2154 
2155     if (failing())  return;
2156   }
2157 
2158   // Now that all inlining is over, cut edge from root to loop
2159   // safepoints
2160   remove_root_to_sfpts_edges(igvn);
2161 
2162   // Remove the speculative part of types and clean up the graph from
2163   // the extra CastPP nodes whose only purpose is to carry them. Do
2164   // that early so that optimizations are not disrupted by the extra
2165   // CastPP nodes.
2166   remove_speculative_types(igvn);
2167 
2168   // No more new expensive nodes will be added to the list from here
2169   // so keep only the actual candidates for optimizations.
2170   cleanup_expensive_nodes(igvn);
2171 
2172   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2173     NOT_PRODUCT(Compile::TracePhase t2("", &_t_renumberLive, TimeCompiler);)
2174     initial_gvn()->replace_with(&igvn);
2175     for_igvn()->clear();
2176     Unique_Node_List new_worklist(C->comp_arena());
2177     {
2178       ResourceMark rm;
2179       PhaseRenumberLive prl = PhaseRenumberLive(initial_gvn(), for_igvn(), &new_worklist);
2180     }
2181     set_for_igvn(&new_worklist);
2182     igvn = PhaseIterGVN(initial_gvn());
2183     igvn.optimize();
2184   }
2185 
2186   // Perform escape analysis
2187   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2188     if (has_loops()) {
2189       // Cleanup graph (remove dead nodes).
2190       TracePhase t2("idealLoop", &_t_idealLoop, true);
2191       PhaseIdealLoop ideal_loop( igvn, false, true );
2192       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2193       if (failing())  return;
2194     }
2195     ConnectionGraph::do_analysis(this, &igvn);
2196 
2197     if (failing())  return;
2198 
2199     // Optimize out fields loads from scalar replaceable allocations.
2200     igvn.optimize();
2201     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2202 
2203     if (failing())  return;
2204 
2205     if (congraph() != NULL && macro_count() > 0) {
2206       NOT_PRODUCT( TracePhase t2("macroEliminate", &_t_macroEliminate, TimeCompiler); )
2207       PhaseMacroExpand mexp(igvn);
2208       mexp.eliminate_macro_nodes();
2209       igvn.set_delay_transform(false);
2210 
2211       igvn.optimize();
2212       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2213 
2214       if (failing())  return;
2215     }
2216   }
2217 
2218   // Loop transforms on the ideal graph.  Range Check Elimination,
2219   // peeling, unrolling, etc.
2220 
2221   // Set loop opts counter
2222   loop_opts_cnt = num_loop_opts();
2223   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2224     {
2225       TracePhase t2("idealLoop", &_t_idealLoop, true);
2226       PhaseIdealLoop ideal_loop( igvn, true );
2227       loop_opts_cnt--;
2228       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2229       if (failing())  return;
2230     }
2231     // Loop opts pass if partial peeling occurred in previous pass
2232     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
2233       TracePhase t3("idealLoop", &_t_idealLoop, true);
2234       PhaseIdealLoop ideal_loop( igvn, false );
2235       loop_opts_cnt--;
2236       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2237       if (failing())  return;
2238     }
2239     // Loop opts pass for loop-unrolling before CCP
2240     if(major_progress() && (loop_opts_cnt > 0)) {
2241       TracePhase t4("idealLoop", &_t_idealLoop, true);
2242       PhaseIdealLoop ideal_loop( igvn, false );
2243       loop_opts_cnt--;
2244       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2245     }
2246     if (!failing()) {
2247       // Verify that last round of loop opts produced a valid graph
2248       NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
2249       PhaseIdealLoop::verify(igvn);
2250     }
2251   }
2252   if (failing())  return;
2253 
2254   // Conditional Constant Propagation;
2255   PhaseCCP ccp( &igvn );
2256   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2257   {
2258     TracePhase t2("ccp", &_t_ccp, true);
2259     ccp.do_transform();
2260   }
2261   print_method(PHASE_CPP1, 2);
2262 
2263   assert( true, "Break here to ccp.dump_old2new_map()");
2264 
2265   // Iterative Global Value Numbering, including ideal transforms
2266   {
2267     NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
2268     igvn = ccp;
2269     igvn.optimize();
2270   }
2271 
2272   print_method(PHASE_ITER_GVN2, 2);
2273 
2274   if (failing())  return;
2275 
2276   // Loop transforms on the ideal graph.  Range Check Elimination,
2277   // peeling, unrolling, etc.
2278   if(loop_opts_cnt > 0) {
2279     debug_only( int cnt = 0; );
2280     while(major_progress() && (loop_opts_cnt > 0)) {
2281       TracePhase t2("idealLoop", &_t_idealLoop, true);
2282       assert( cnt++ < 40, "infinite cycle in loop optimization" );
2283       PhaseIdealLoop ideal_loop( igvn, true);
2284       loop_opts_cnt--;
2285       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2286       if (failing())  return;
2287     }
2288   }
2289 
2290   {
2291     // Verify that all previous optimizations produced a valid graph
2292     // at least to this point, even if no loop optimizations were done.
2293     NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
2294     PhaseIdealLoop::verify(igvn);
2295   }
2296 
2297   if (range_check_cast_count() > 0) {
2298     // No more loop optimizations. Remove all range check dependent CastIINodes.
2299     C->remove_range_check_casts(igvn);
2300     igvn.optimize();
2301   }
2302 
2303   {
2304     NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
2305     PhaseMacroExpand  mex(igvn);
2306     if (mex.expand_macro_nodes()) {
2307       assert(failing(), "must bail out w/ explicit message");
2308       return;
2309     }
2310   }
2311 
2312  } // (End scope of igvn; run destructor if necessary for asserts.)
2313 
2314   dump_inlining();
2315   // A method with only infinite loops has no edges entering loops from root
2316   {
2317     NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
2318     if (final_graph_reshaping()) {
2319       assert(failing(), "must bail out w/ explicit message");
2320       return;
2321     }
2322   }
2323 
2324   print_method(PHASE_OPTIMIZE_FINISHED, 2);
2325 }
2326 
2327 
2328 //------------------------------Code_Gen---------------------------------------
2329 // Given a graph, generate code for it
2330 void Compile::Code_Gen() {
2331   if (failing()) {
2332     return;
2333   }
2334 
2335   // Perform instruction selection.  You might think we could reclaim Matcher
2336   // memory PDQ, but actually the Matcher is used in generating spill code.
2337   // Internals of the Matcher (including some VectorSets) must remain live
2338   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2339   // set a bit in reclaimed memory.
2340 
2341   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2342   // nodes.  Mapping is only valid at the root of each matched subtree.
2343   NOT_PRODUCT( verify_graph_edges(); )
2344 
2345   Matcher matcher;
2346   _matcher = &matcher;
2347   {
2348     TracePhase t2("matcher", &_t_matcher, true);
2349     matcher.match();
2350   }
2351   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2352   // nodes.  Mapping is only valid at the root of each matched subtree.
2353   NOT_PRODUCT( verify_graph_edges(); )
2354 
2355   // If you have too many nodes, or if matching has failed, bail out
2356   check_node_count(0, "out of nodes matching instructions");
2357   if (failing()) {
2358     return;
2359   }
2360 
2361   // Build a proper-looking CFG
2362   PhaseCFG cfg(node_arena(), root(), matcher);
2363   _cfg = &cfg;
2364   {
2365     NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
2366     bool success = cfg.do_global_code_motion();
2367     if (!success) {
2368       return;
2369     }
2370 
2371     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2372     NOT_PRODUCT( verify_graph_edges(); )
2373     debug_only( cfg.verify(); )
2374   }
2375 
2376   PhaseChaitin regalloc(unique(), cfg, matcher);
2377   _regalloc = &regalloc;
2378   {
2379     TracePhase t2("regalloc", &_t_registerAllocation, true);
2380     // Perform register allocation.  After Chaitin, use-def chains are
2381     // no longer accurate (at spill code) and so must be ignored.
2382     // Node->LRG->reg mappings are still accurate.
2383     _regalloc->Register_Allocate();
2384 
2385     // Bail out if the allocator builds too many nodes
2386     if (failing()) {
2387       return;
2388     }
2389   }
2390 
2391   // Prior to register allocation we kept empty basic blocks in case the
2392   // the allocator needed a place to spill.  After register allocation we
2393   // are not adding any new instructions.  If any basic block is empty, we
2394   // can now safely remove it.
2395   {
2396     NOT_PRODUCT( TracePhase t2("blockOrdering", &_t_blockOrdering, TimeCompiler); )
2397     cfg.remove_empty_blocks();
2398     if (do_freq_based_layout()) {
2399       PhaseBlockLayout layout(cfg);
2400     } else {
2401       cfg.set_loop_alignment();
2402     }
2403     cfg.fixup_flow();
2404   }
2405 
2406   // Apply peephole optimizations
2407   if( OptoPeephole ) {
2408     NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
2409     PhasePeephole peep( _regalloc, cfg);
2410     peep.do_transform();
2411   }
2412 
2413   // Do late expand if CPU requires this.
2414   if (Matcher::require_postalloc_expand) {
2415     NOT_PRODUCT(TracePhase t2c("postalloc_expand", &_t_postalloc_expand, true));
2416     cfg.postalloc_expand(_regalloc);
2417   }
2418 
2419   // Convert Nodes to instruction bits in a buffer
2420   {
2421     // %%%% workspace merge brought two timers together for one job
2422     TracePhase t2a("output", &_t_output, true);
2423     NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
2424     Output();
2425   }
2426 
2427   print_method(PHASE_FINAL_CODE);
2428 
2429   // He's dead, Jim.
2430   _cfg     = (PhaseCFG*)((intptr_t)0xdeadbeef);
2431   _regalloc = (PhaseChaitin*)((intptr_t)0xdeadbeef);
2432 }
2433 
2434 
2435 //------------------------------dump_asm---------------------------------------
2436 // Dump formatted assembly
2437 #ifndef PRODUCT
2438 void Compile::dump_asm(int *pcs, uint pc_limit) {
2439   bool cut_short = false;
2440   tty->print_cr("#");
2441   tty->print("#  ");  _tf->dump();  tty->cr();
2442   tty->print_cr("#");
2443 
2444   // For all blocks
2445   int pc = 0x0;                 // Program counter
2446   char starts_bundle = ' ';
2447   _regalloc->dump_frame();
2448 
2449   Node *n = NULL;
2450   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
2451     if (VMThread::should_terminate()) {
2452       cut_short = true;
2453       break;
2454     }
2455     Block* block = _cfg->get_block(i);
2456     if (block->is_connector() && !Verbose) {
2457       continue;
2458     }
2459     n = block->head();
2460     if (pcs && n->_idx < pc_limit) {
2461       tty->print("%3.3x   ", pcs[n->_idx]);
2462     } else {
2463       tty->print("      ");
2464     }
2465     block->dump_head(_cfg);
2466     if (block->is_connector()) {
2467       tty->print_cr("        # Empty connector block");
2468     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
2469       tty->print_cr("        # Block is sole successor of call");
2470     }
2471 
2472     // For all instructions
2473     Node *delay = NULL;
2474     for (uint j = 0; j < block->number_of_nodes(); j++) {
2475       if (VMThread::should_terminate()) {
2476         cut_short = true;
2477         break;
2478       }
2479       n = block->get_node(j);
2480       if (valid_bundle_info(n)) {
2481         Bundle* bundle = node_bundling(n);
2482         if (bundle->used_in_unconditional_delay()) {
2483           delay = n;
2484           continue;
2485         }
2486         if (bundle->starts_bundle()) {
2487           starts_bundle = '+';
2488         }
2489       }
2490 
2491       if (WizardMode) {
2492         n->dump();
2493       }
2494 
2495       if( !n->is_Region() &&    // Dont print in the Assembly
2496           !n->is_Phi() &&       // a few noisely useless nodes
2497           !n->is_Proj() &&
2498           !n->is_MachTemp() &&
2499           !n->is_SafePointScalarObject() &&
2500           !n->is_Catch() &&     // Would be nice to print exception table targets
2501           !n->is_MergeMem() &&  // Not very interesting
2502           !n->is_top() &&       // Debug info table constants
2503           !(n->is_Con() && !n->is_Mach())// Debug info table constants
2504           ) {
2505         if (pcs && n->_idx < pc_limit)
2506           tty->print("%3.3x", pcs[n->_idx]);
2507         else
2508           tty->print("   ");
2509         tty->print(" %c ", starts_bundle);
2510         starts_bundle = ' ';
2511         tty->print("\t");
2512         n->format(_regalloc, tty);
2513         tty->cr();
2514       }
2515 
2516       // If we have an instruction with a delay slot, and have seen a delay,
2517       // then back up and print it
2518       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
2519         assert(delay != NULL, "no unconditional delay instruction");
2520         if (WizardMode) delay->dump();
2521 
2522         if (node_bundling(delay)->starts_bundle())
2523           starts_bundle = '+';
2524         if (pcs && n->_idx < pc_limit)
2525           tty->print("%3.3x", pcs[n->_idx]);
2526         else
2527           tty->print("   ");
2528         tty->print(" %c ", starts_bundle);
2529         starts_bundle = ' ';
2530         tty->print("\t");
2531         delay->format(_regalloc, tty);
2532         tty->cr();
2533         delay = NULL;
2534       }
2535 
2536       // Dump the exception table as well
2537       if( n->is_Catch() && (Verbose || WizardMode) ) {
2538         // Print the exception table for this offset
2539         _handler_table.print_subtable_for(pc);
2540       }
2541     }
2542 
2543     if (pcs && n->_idx < pc_limit)
2544       tty->print_cr("%3.3x", pcs[n->_idx]);
2545     else
2546       tty->cr();
2547 
2548     assert(cut_short || delay == NULL, "no unconditional delay branch");
2549 
2550   } // End of per-block dump
2551   tty->cr();
2552 
2553   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
2554 }
2555 #endif
2556 
2557 //------------------------------Final_Reshape_Counts---------------------------
2558 // This class defines counters to help identify when a method
2559 // may/must be executed using hardware with only 24-bit precision.
2560 struct Final_Reshape_Counts : public StackObj {
2561   int  _call_count;             // count non-inlined 'common' calls
2562   int  _float_count;            // count float ops requiring 24-bit precision
2563   int  _double_count;           // count double ops requiring more precision
2564   int  _java_call_count;        // count non-inlined 'java' calls
2565   int  _inner_loop_count;       // count loops which need alignment
2566   VectorSet _visited;           // Visitation flags
2567   Node_List _tests;             // Set of IfNodes & PCTableNodes
2568 
2569   Final_Reshape_Counts() :
2570     _call_count(0), _float_count(0), _double_count(0),
2571     _java_call_count(0), _inner_loop_count(0),
2572     _visited( Thread::current()->resource_area() ) { }
2573 
2574   void inc_call_count  () { _call_count  ++; }
2575   void inc_float_count () { _float_count ++; }
2576   void inc_double_count() { _double_count++; }
2577   void inc_java_call_count() { _java_call_count++; }
2578   void inc_inner_loop_count() { _inner_loop_count++; }
2579 
2580   int  get_call_count  () const { return _call_count  ; }
2581   int  get_float_count () const { return _float_count ; }
2582   int  get_double_count() const { return _double_count; }
2583   int  get_java_call_count() const { return _java_call_count; }
2584   int  get_inner_loop_count() const { return _inner_loop_count; }
2585 };
2586 
2587 #ifdef ASSERT
2588 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
2589   ciInstanceKlass *k = tp->klass()->as_instance_klass();
2590   // Make sure the offset goes inside the instance layout.
2591   return k->contains_field_offset(tp->offset());
2592   // Note that OffsetBot and OffsetTop are very negative.
2593 }
2594 #endif
2595 
2596 // Eliminate trivially redundant StoreCMs and accumulate their
2597 // precedence edges.
2598 void Compile::eliminate_redundant_card_marks(Node* n) {
2599   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
2600   if (n->in(MemNode::Address)->outcnt() > 1) {
2601     // There are multiple users of the same address so it might be
2602     // possible to eliminate some of the StoreCMs
2603     Node* mem = n->in(MemNode::Memory);
2604     Node* adr = n->in(MemNode::Address);
2605     Node* val = n->in(MemNode::ValueIn);
2606     Node* prev = n;
2607     bool done = false;
2608     // Walk the chain of StoreCMs eliminating ones that match.  As
2609     // long as it's a chain of single users then the optimization is
2610     // safe.  Eliminating partially redundant StoreCMs would require
2611     // cloning copies down the other paths.
2612     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
2613       if (adr == mem->in(MemNode::Address) &&
2614           val == mem->in(MemNode::ValueIn)) {
2615         // redundant StoreCM
2616         if (mem->req() > MemNode::OopStore) {
2617           // Hasn't been processed by this code yet.
2618           n->add_prec(mem->in(MemNode::OopStore));
2619         } else {
2620           // Already converted to precedence edge
2621           for (uint i = mem->req(); i < mem->len(); i++) {
2622             // Accumulate any precedence edges
2623             if (mem->in(i) != NULL) {
2624               n->add_prec(mem->in(i));
2625             }
2626           }
2627           // Everything above this point has been processed.
2628           done = true;
2629         }
2630         // Eliminate the previous StoreCM
2631         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
2632         assert(mem->outcnt() == 0, "should be dead");
2633         mem->disconnect_inputs(NULL, this);
2634       } else {
2635         prev = mem;
2636       }
2637       mem = prev->in(MemNode::Memory);
2638     }
2639   }
2640 }
2641 
2642 //------------------------------final_graph_reshaping_impl----------------------
2643 // Implement items 1-5 from final_graph_reshaping below.
2644 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
2645 
2646   if ( n->outcnt() == 0 ) return; // dead node
2647   uint nop = n->Opcode();
2648 
2649   // Check for 2-input instruction with "last use" on right input.
2650   // Swap to left input.  Implements item (2).
2651   if( n->req() == 3 &&          // two-input instruction
2652       n->in(1)->outcnt() > 1 && // left use is NOT a last use
2653       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
2654       n->in(2)->outcnt() == 1 &&// right use IS a last use
2655       !n->in(2)->is_Con() ) {   // right use is not a constant
2656     // Check for commutative opcode
2657     switch( nop ) {
2658     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
2659     case Op_MaxI:  case Op_MinI:
2660     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
2661     case Op_AndL:  case Op_XorL:  case Op_OrL:
2662     case Op_AndI:  case Op_XorI:  case Op_OrI: {
2663       // Move "last use" input to left by swapping inputs
2664       n->swap_edges(1, 2);
2665       break;
2666     }
2667     default:
2668       break;
2669     }
2670   }
2671 
2672 #ifdef ASSERT
2673   if( n->is_Mem() ) {
2674     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
2675     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
2676             // oop will be recorded in oop map if load crosses safepoint
2677             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
2678                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
2679             "raw memory operations should have control edge");
2680   }
2681   if (n->is_MemBar()) {
2682     MemBarNode* mb = n->as_MemBar();
2683     if (mb->trailing_store() || mb->trailing_load_store()) {
2684       assert(mb->leading_membar()->trailing_membar() == mb, "bad membar pair");
2685       Node* mem = mb->in(MemBarNode::Precedent);
2686       assert((mb->trailing_store() && mem->is_Store() && mem->as_Store()->is_release()) ||
2687              (mb->trailing_load_store() && mem->is_LoadStore()), "missing mem op");
2688     } else if (mb->leading()) {
2689       assert(mb->trailing_membar()->leading_membar() == mb, "bad membar pair");
2690     }
2691   }
2692 #endif
2693   // Count FPU ops and common calls, implements item (3)
2694   switch( nop ) {
2695   // Count all float operations that may use FPU
2696   case Op_AddF:
2697   case Op_SubF:
2698   case Op_MulF:
2699   case Op_DivF:
2700   case Op_NegF:
2701   case Op_ModF:
2702   case Op_ConvI2F:
2703   case Op_ConF:
2704   case Op_CmpF:
2705   case Op_CmpF3:
2706   // case Op_ConvL2F: // longs are split into 32-bit halves
2707     frc.inc_float_count();
2708     break;
2709 
2710   case Op_ConvF2D:
2711   case Op_ConvD2F:
2712     frc.inc_float_count();
2713     frc.inc_double_count();
2714     break;
2715 
2716   // Count all double operations that may use FPU
2717   case Op_AddD:
2718   case Op_SubD:
2719   case Op_MulD:
2720   case Op_DivD:
2721   case Op_NegD:
2722   case Op_ModD:
2723   case Op_ConvI2D:
2724   case Op_ConvD2I:
2725   // case Op_ConvL2D: // handled by leaf call
2726   // case Op_ConvD2L: // handled by leaf call
2727   case Op_ConD:
2728   case Op_CmpD:
2729   case Op_CmpD3:
2730     frc.inc_double_count();
2731     break;
2732   case Op_Opaque1:              // Remove Opaque Nodes before matching
2733   case Op_Opaque2:              // Remove Opaque Nodes before matching
2734   case Op_Opaque3:
2735     n->subsume_by(n->in(1), this);
2736     break;
2737   case Op_CallStaticJava:
2738   case Op_CallJava:
2739   case Op_CallDynamicJava:
2740     frc.inc_java_call_count(); // Count java call site;
2741   case Op_CallRuntime:
2742   case Op_CallLeaf:
2743   case Op_CallLeafNoFP: {
2744     assert( n->is_Call(), "" );
2745     CallNode *call = n->as_Call();
2746     // Count call sites where the FP mode bit would have to be flipped.
2747     // Do not count uncommon runtime calls:
2748     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
2749     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
2750     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
2751       frc.inc_call_count();   // Count the call site
2752     } else {                  // See if uncommon argument is shared
2753       Node *n = call->in(TypeFunc::Parms);
2754       int nop = n->Opcode();
2755       // Clone shared simple arguments to uncommon calls, item (1).
2756       if( n->outcnt() > 1 &&
2757           !n->is_Proj() &&
2758           nop != Op_CreateEx &&
2759           nop != Op_CheckCastPP &&
2760           nop != Op_DecodeN &&
2761           nop != Op_DecodeNKlass &&
2762           !n->is_Mem() ) {
2763         Node *x = n->clone();
2764         call->set_req( TypeFunc::Parms, x );
2765       }
2766     }
2767     break;
2768   }
2769 
2770   case Op_StoreD:
2771   case Op_LoadD:
2772   case Op_LoadD_unaligned:
2773     frc.inc_double_count();
2774     goto handle_mem;
2775   case Op_StoreF:
2776   case Op_LoadF:
2777     frc.inc_float_count();
2778     goto handle_mem;
2779 
2780   case Op_StoreCM:
2781     {
2782       // Convert OopStore dependence into precedence edge
2783       Node* prec = n->in(MemNode::OopStore);
2784       n->del_req(MemNode::OopStore);
2785       n->add_prec(prec);
2786       eliminate_redundant_card_marks(n);
2787     }
2788 
2789     // fall through
2790 
2791   case Op_StoreB:
2792   case Op_StoreC:
2793   case Op_StorePConditional:
2794   case Op_StoreI:
2795   case Op_StoreL:
2796   case Op_StoreIConditional:
2797   case Op_StoreLConditional:
2798   case Op_CompareAndSwapI:
2799   case Op_CompareAndSwapL:
2800   case Op_CompareAndSwapP:
2801   case Op_CompareAndSwapN:
2802   case Op_GetAndAddI:
2803   case Op_GetAndAddL:
2804   case Op_GetAndSetI:
2805   case Op_GetAndSetL:
2806   case Op_GetAndSetP:
2807   case Op_GetAndSetN:
2808   case Op_StoreP:
2809   case Op_StoreN:
2810   case Op_StoreNKlass:
2811   case Op_LoadB:
2812   case Op_LoadUB:
2813   case Op_LoadUS:
2814   case Op_LoadI:
2815   case Op_LoadKlass:
2816   case Op_LoadNKlass:
2817   case Op_LoadL:
2818   case Op_LoadL_unaligned:
2819   case Op_LoadPLocked:
2820   case Op_LoadP:
2821   case Op_LoadN:
2822   case Op_LoadRange:
2823   case Op_LoadS: {
2824   handle_mem:
2825 #ifdef ASSERT
2826     if( VerifyOptoOopOffsets ) {
2827       assert( n->is_Mem(), "" );
2828       MemNode *mem  = (MemNode*)n;
2829       // Check to see if address types have grounded out somehow.
2830       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
2831       assert( !tp || oop_offset_is_sane(tp), "" );
2832     }
2833 #endif
2834     break;
2835   }
2836 
2837   case Op_AddP: {               // Assert sane base pointers
2838     Node *addp = n->in(AddPNode::Address);
2839     assert( !addp->is_AddP() ||
2840             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
2841             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
2842             "Base pointers must match" );
2843 #ifdef _LP64
2844     if ((UseCompressedOops || UseCompressedClassPointers) &&
2845         addp->Opcode() == Op_ConP &&
2846         addp == n->in(AddPNode::Base) &&
2847         n->in(AddPNode::Offset)->is_Con()) {
2848       // Use addressing with narrow klass to load with offset on x86.
2849       // On sparc loading 32-bits constant and decoding it have less
2850       // instructions (4) then load 64-bits constant (7).
2851       // Do this transformation here since IGVN will convert ConN back to ConP.
2852       const Type* t = addp->bottom_type();
2853       if (t->isa_oopptr() || t->isa_klassptr()) {
2854         Node* nn = NULL;
2855 
2856         int op = t->isa_oopptr() ? Op_ConN : Op_ConNKlass;
2857 
2858         // Look for existing ConN node of the same exact type.
2859         Node* r  = root();
2860         uint cnt = r->outcnt();
2861         for (uint i = 0; i < cnt; i++) {
2862           Node* m = r->raw_out(i);
2863           if (m!= NULL && m->Opcode() == op &&
2864               m->bottom_type()->make_ptr() == t) {
2865             nn = m;
2866             break;
2867           }
2868         }
2869         if (nn != NULL) {
2870           // Decode a narrow oop to match address
2871           // [R12 + narrow_oop_reg<<3 + offset]
2872           if (t->isa_oopptr()) {
2873             nn = new (this) DecodeNNode(nn, t);
2874           } else {
2875             nn = new (this) DecodeNKlassNode(nn, t);
2876           }
2877           n->set_req(AddPNode::Base, nn);
2878           n->set_req(AddPNode::Address, nn);
2879           if (addp->outcnt() == 0) {
2880             addp->disconnect_inputs(NULL, this);
2881           }
2882         }
2883       }
2884     }
2885 #endif
2886     break;
2887   }
2888 
2889 #ifdef _LP64
2890   case Op_CastPP:
2891     if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
2892       Node* in1 = n->in(1);
2893       const Type* t = n->bottom_type();
2894       Node* new_in1 = in1->clone();
2895       new_in1->as_DecodeN()->set_type(t);
2896 
2897       if (!Matcher::narrow_oop_use_complex_address()) {
2898         //
2899         // x86, ARM and friends can handle 2 adds in addressing mode
2900         // and Matcher can fold a DecodeN node into address by using
2901         // a narrow oop directly and do implicit NULL check in address:
2902         //
2903         // [R12 + narrow_oop_reg<<3 + offset]
2904         // NullCheck narrow_oop_reg
2905         //
2906         // On other platforms (Sparc) we have to keep new DecodeN node and
2907         // use it to do implicit NULL check in address:
2908         //
2909         // decode_not_null narrow_oop_reg, base_reg
2910         // [base_reg + offset]
2911         // NullCheck base_reg
2912         //
2913         // Pin the new DecodeN node to non-null path on these platform (Sparc)
2914         // to keep the information to which NULL check the new DecodeN node
2915         // corresponds to use it as value in implicit_null_check().
2916         //
2917         new_in1->set_req(0, n->in(0));
2918       }
2919 
2920       n->subsume_by(new_in1, this);
2921       if (in1->outcnt() == 0) {
2922         in1->disconnect_inputs(NULL, this);
2923       }
2924     }
2925     break;
2926 
2927   case Op_CmpP:
2928     // Do this transformation here to preserve CmpPNode::sub() and
2929     // other TypePtr related Ideal optimizations (for example, ptr nullness).
2930     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
2931       Node* in1 = n->in(1);
2932       Node* in2 = n->in(2);
2933       if (!in1->is_DecodeNarrowPtr()) {
2934         in2 = in1;
2935         in1 = n->in(2);
2936       }
2937       assert(in1->is_DecodeNarrowPtr(), "sanity");
2938 
2939       Node* new_in2 = NULL;
2940       if (in2->is_DecodeNarrowPtr()) {
2941         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
2942         new_in2 = in2->in(1);
2943       } else if (in2->Opcode() == Op_ConP) {
2944         const Type* t = in2->bottom_type();
2945         if (t == TypePtr::NULL_PTR) {
2946           assert(in1->is_DecodeN(), "compare klass to null?");
2947           // Don't convert CmpP null check into CmpN if compressed
2948           // oops implicit null check is not generated.
2949           // This will allow to generate normal oop implicit null check.
2950           if (Matcher::gen_narrow_oop_implicit_null_checks())
2951             new_in2 = ConNode::make(this, TypeNarrowOop::NULL_PTR);
2952           //
2953           // This transformation together with CastPP transformation above
2954           // will generated code for implicit NULL checks for compressed oops.
2955           //
2956           // The original code after Optimize()
2957           //
2958           //    LoadN memory, narrow_oop_reg
2959           //    decode narrow_oop_reg, base_reg
2960           //    CmpP base_reg, NULL
2961           //    CastPP base_reg // NotNull
2962           //    Load [base_reg + offset], val_reg
2963           //
2964           // after these transformations will be
2965           //
2966           //    LoadN memory, narrow_oop_reg
2967           //    CmpN narrow_oop_reg, NULL
2968           //    decode_not_null narrow_oop_reg, base_reg
2969           //    Load [base_reg + offset], val_reg
2970           //
2971           // and the uncommon path (== NULL) will use narrow_oop_reg directly
2972           // since narrow oops can be used in debug info now (see the code in
2973           // final_graph_reshaping_walk()).
2974           //
2975           // At the end the code will be matched to
2976           // on x86:
2977           //
2978           //    Load_narrow_oop memory, narrow_oop_reg
2979           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
2980           //    NullCheck narrow_oop_reg
2981           //
2982           // and on sparc:
2983           //
2984           //    Load_narrow_oop memory, narrow_oop_reg
2985           //    decode_not_null narrow_oop_reg, base_reg
2986           //    Load [base_reg + offset], val_reg
2987           //    NullCheck base_reg
2988           //
2989         } else if (t->isa_oopptr()) {
2990           new_in2 = ConNode::make(this, t->make_narrowoop());
2991         } else if (t->isa_klassptr()) {
2992           new_in2 = ConNode::make(this, t->make_narrowklass());
2993         }
2994       }
2995       if (new_in2 != NULL) {
2996         Node* cmpN = new (this) CmpNNode(in1->in(1), new_in2);
2997         n->subsume_by(cmpN, this);
2998         if (in1->outcnt() == 0) {
2999           in1->disconnect_inputs(NULL, this);
3000         }
3001         if (in2->outcnt() == 0) {
3002           in2->disconnect_inputs(NULL, this);
3003         }
3004       }
3005     }
3006     break;
3007 
3008   case Op_DecodeN:
3009   case Op_DecodeNKlass:
3010     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
3011     // DecodeN could be pinned when it can't be fold into
3012     // an address expression, see the code for Op_CastPP above.
3013     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
3014     break;
3015 
3016   case Op_EncodeP:
3017   case Op_EncodePKlass: {
3018     Node* in1 = n->in(1);
3019     if (in1->is_DecodeNarrowPtr()) {
3020       n->subsume_by(in1->in(1), this);
3021     } else if (in1->Opcode() == Op_ConP) {
3022       const Type* t = in1->bottom_type();
3023       if (t == TypePtr::NULL_PTR) {
3024         assert(t->isa_oopptr(), "null klass?");
3025         n->subsume_by(ConNode::make(this, TypeNarrowOop::NULL_PTR), this);
3026       } else if (t->isa_oopptr()) {
3027         n->subsume_by(ConNode::make(this, t->make_narrowoop()), this);
3028       } else if (t->isa_klassptr()) {
3029         n->subsume_by(ConNode::make(this, t->make_narrowklass()), this);
3030       }
3031     }
3032     if (in1->outcnt() == 0) {
3033       in1->disconnect_inputs(NULL, this);
3034     }
3035     break;
3036   }
3037 
3038   case Op_Proj: {
3039     if (OptimizeStringConcat) {
3040       ProjNode* p = n->as_Proj();
3041       if (p->_is_io_use) {
3042         // Separate projections were used for the exception path which
3043         // are normally removed by a late inline.  If it wasn't inlined
3044         // then they will hang around and should just be replaced with
3045         // the original one.
3046         Node* proj = NULL;
3047         // Replace with just one
3048         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
3049           Node *use = i.get();
3050           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
3051             proj = use;
3052             break;
3053           }
3054         }
3055         assert(proj != NULL || p->_con == TypeFunc::I_O, "io may be dropped at an infinite loop");
3056         if (proj != NULL) {
3057           p->subsume_by(proj, this);
3058         }
3059       }
3060     }
3061     break;
3062   }
3063 
3064   case Op_Phi:
3065     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3066       // The EncodeP optimization may create Phi with the same edges
3067       // for all paths. It is not handled well by Register Allocator.
3068       Node* unique_in = n->in(1);
3069       assert(unique_in != NULL, "");
3070       uint cnt = n->req();
3071       for (uint i = 2; i < cnt; i++) {
3072         Node* m = n->in(i);
3073         assert(m != NULL, "");
3074         if (unique_in != m)
3075           unique_in = NULL;
3076       }
3077       if (unique_in != NULL) {
3078         n->subsume_by(unique_in, this);
3079       }
3080     }
3081     break;
3082 
3083 #endif
3084 
3085 #ifdef ASSERT
3086   case Op_CastII:
3087     // Verify that all range check dependent CastII nodes were removed.
3088     if (n->isa_CastII()->has_range_check()) {
3089       n->dump(3);
3090       assert(false, "Range check dependent CastII node was not removed");
3091     }
3092     break;
3093 #endif
3094 
3095   case Op_ModI:
3096     if (UseDivMod) {
3097       // Check if a%b and a/b both exist
3098       Node* d = n->find_similar(Op_DivI);
3099       if (d) {
3100         // Replace them with a fused divmod if supported
3101         if (Matcher::has_match_rule(Op_DivModI)) {
3102           DivModINode* divmod = DivModINode::make(this, n);
3103           d->subsume_by(divmod->div_proj(), this);
3104           n->subsume_by(divmod->mod_proj(), this);
3105         } else {
3106           // replace a%b with a-((a/b)*b)
3107           Node* mult = new (this) MulINode(d, d->in(2));
3108           Node* sub  = new (this) SubINode(d->in(1), mult);
3109           n->subsume_by(sub, this);
3110         }
3111       }
3112     }
3113     break;
3114 
3115   case Op_ModL:
3116     if (UseDivMod) {
3117       // Check if a%b and a/b both exist
3118       Node* d = n->find_similar(Op_DivL);
3119       if (d) {
3120         // Replace them with a fused divmod if supported
3121         if (Matcher::has_match_rule(Op_DivModL)) {
3122           DivModLNode* divmod = DivModLNode::make(this, n);
3123           d->subsume_by(divmod->div_proj(), this);
3124           n->subsume_by(divmod->mod_proj(), this);
3125         } else {
3126           // replace a%b with a-((a/b)*b)
3127           Node* mult = new (this) MulLNode(d, d->in(2));
3128           Node* sub  = new (this) SubLNode(d->in(1), mult);
3129           n->subsume_by(sub, this);
3130         }
3131       }
3132     }
3133     break;
3134 
3135   case Op_LoadVector:
3136   case Op_StoreVector:
3137     break;
3138 
3139   case Op_PackB:
3140   case Op_PackS:
3141   case Op_PackI:
3142   case Op_PackF:
3143   case Op_PackL:
3144   case Op_PackD:
3145     if (n->req()-1 > 2) {
3146       // Replace many operand PackNodes with a binary tree for matching
3147       PackNode* p = (PackNode*) n;
3148       Node* btp = p->binary_tree_pack(this, 1, n->req());
3149       n->subsume_by(btp, this);
3150     }
3151     break;
3152   case Op_Loop:
3153   case Op_CountedLoop:
3154     if (n->as_Loop()->is_inner_loop()) {
3155       frc.inc_inner_loop_count();
3156     }
3157     break;
3158   case Op_LShiftI:
3159   case Op_RShiftI:
3160   case Op_URShiftI:
3161   case Op_LShiftL:
3162   case Op_RShiftL:
3163   case Op_URShiftL:
3164     if (Matcher::need_masked_shift_count) {
3165       // The cpu's shift instructions don't restrict the count to the
3166       // lower 5/6 bits. We need to do the masking ourselves.
3167       Node* in2 = n->in(2);
3168       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3169       const TypeInt* t = in2->find_int_type();
3170       if (t != NULL && t->is_con()) {
3171         juint shift = t->get_con();
3172         if (shift > mask) { // Unsigned cmp
3173           n->set_req(2, ConNode::make(this, TypeInt::make(shift & mask)));
3174         }
3175       } else {
3176         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
3177           Node* shift = new (this) AndINode(in2, ConNode::make(this, TypeInt::make(mask)));
3178           n->set_req(2, shift);
3179         }
3180       }
3181       if (in2->outcnt() == 0) { // Remove dead node
3182         in2->disconnect_inputs(NULL, this);
3183       }
3184     }
3185     break;
3186   case Op_MemBarStoreStore:
3187   case Op_MemBarRelease:
3188     // Break the link with AllocateNode: it is no longer useful and
3189     // confuses register allocation.
3190     if (n->req() > MemBarNode::Precedent) {
3191       n->set_req(MemBarNode::Precedent, top());
3192     }
3193     break;
3194   default:
3195     assert( !n->is_Call(), "" );
3196     assert( !n->is_Mem(), "" );
3197     assert( nop != Op_ProfileBoolean, "should be eliminated during IGVN");
3198     break;
3199   }
3200 
3201   // Collect CFG split points
3202   if (n->is_MultiBranch())
3203     frc._tests.push(n);
3204 }
3205 
3206 //------------------------------final_graph_reshaping_walk---------------------
3207 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3208 // requires that the walk visits a node's inputs before visiting the node.
3209 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
3210   ResourceArea *area = Thread::current()->resource_area();
3211   Unique_Node_List sfpt(area);
3212 
3213   frc._visited.set(root->_idx); // first, mark node as visited
3214   uint cnt = root->req();
3215   Node *n = root;
3216   uint  i = 0;
3217   while (true) {
3218     if (i < cnt) {
3219       // Place all non-visited non-null inputs onto stack
3220       Node* m = n->in(i);
3221       ++i;
3222       if (m != NULL && !frc._visited.test_set(m->_idx)) {
3223         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
3224           // compute worst case interpreter size in case of a deoptimization
3225           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3226 
3227           sfpt.push(m);
3228         }
3229         cnt = m->req();
3230         nstack.push(n, i); // put on stack parent and next input's index
3231         n = m;
3232         i = 0;
3233       }
3234     } else {
3235       // Now do post-visit work
3236       final_graph_reshaping_impl( n, frc );
3237       if (nstack.is_empty())
3238         break;             // finished
3239       n = nstack.node();   // Get node from stack
3240       cnt = n->req();
3241       i = nstack.index();
3242       nstack.pop();        // Shift to the next node on stack
3243     }
3244   }
3245 
3246   // Skip next transformation if compressed oops are not used.
3247   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3248       (!UseCompressedOops && !UseCompressedClassPointers))
3249     return;
3250 
3251   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3252   // It could be done for an uncommon traps or any safepoints/calls
3253   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3254   while (sfpt.size() > 0) {
3255     n = sfpt.pop();
3256     JVMState *jvms = n->as_SafePoint()->jvms();
3257     assert(jvms != NULL, "sanity");
3258     int start = jvms->debug_start();
3259     int end   = n->req();
3260     bool is_uncommon = (n->is_CallStaticJava() &&
3261                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
3262     for (int j = start; j < end; j++) {
3263       Node* in = n->in(j);
3264       if (in->is_DecodeNarrowPtr()) {
3265         bool safe_to_skip = true;
3266         if (!is_uncommon ) {
3267           // Is it safe to skip?
3268           for (uint i = 0; i < in->outcnt(); i++) {
3269             Node* u = in->raw_out(i);
3270             if (!u->is_SafePoint() ||
3271                  u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
3272               safe_to_skip = false;
3273             }
3274           }
3275         }
3276         if (safe_to_skip) {
3277           n->set_req(j, in->in(1));
3278         }
3279         if (in->outcnt() == 0) {
3280           in->disconnect_inputs(NULL, this);
3281         }
3282       }
3283     }
3284   }
3285 }
3286 
3287 //------------------------------final_graph_reshaping--------------------------
3288 // Final Graph Reshaping.
3289 //
3290 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3291 //     and not commoned up and forced early.  Must come after regular
3292 //     optimizations to avoid GVN undoing the cloning.  Clone constant
3293 //     inputs to Loop Phis; these will be split by the allocator anyways.
3294 //     Remove Opaque nodes.
3295 // (2) Move last-uses by commutative operations to the left input to encourage
3296 //     Intel update-in-place two-address operations and better register usage
3297 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
3298 //     calls canonicalizing them back.
3299 // (3) Count the number of double-precision FP ops, single-precision FP ops
3300 //     and call sites.  On Intel, we can get correct rounding either by
3301 //     forcing singles to memory (requires extra stores and loads after each
3302 //     FP bytecode) or we can set a rounding mode bit (requires setting and
3303 //     clearing the mode bit around call sites).  The mode bit is only used
3304 //     if the relative frequency of single FP ops to calls is low enough.
3305 //     This is a key transform for SPEC mpeg_audio.
3306 // (4) Detect infinite loops; blobs of code reachable from above but not
3307 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
3308 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
3309 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
3310 //     Detection is by looking for IfNodes where only 1 projection is
3311 //     reachable from below or CatchNodes missing some targets.
3312 // (5) Assert for insane oop offsets in debug mode.
3313 
3314 bool Compile::final_graph_reshaping() {
3315   // an infinite loop may have been eliminated by the optimizer,
3316   // in which case the graph will be empty.
3317   if (root()->req() == 1) {
3318     record_method_not_compilable("trivial infinite loop");
3319     return true;
3320   }
3321 
3322   // Expensive nodes have their control input set to prevent the GVN
3323   // from freely commoning them. There's no GVN beyond this point so
3324   // no need to keep the control input. We want the expensive nodes to
3325   // be freely moved to the least frequent code path by gcm.
3326   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
3327   for (int i = 0; i < expensive_count(); i++) {
3328     _expensive_nodes->at(i)->set_req(0, NULL);
3329   }
3330 
3331   Final_Reshape_Counts frc;
3332 
3333   // Visit everybody reachable!
3334   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
3335   Node_Stack nstack(live_nodes() >> 1);
3336   final_graph_reshaping_walk(nstack, root(), frc);
3337 
3338   // Check for unreachable (from below) code (i.e., infinite loops).
3339   for( uint i = 0; i < frc._tests.size(); i++ ) {
3340     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
3341     // Get number of CFG targets.
3342     // Note that PCTables include exception targets after calls.
3343     uint required_outcnt = n->required_outcnt();
3344     if (n->outcnt() != required_outcnt) {
3345       // Check for a few special cases.  Rethrow Nodes never take the
3346       // 'fall-thru' path, so expected kids is 1 less.
3347       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
3348         if (n->in(0)->in(0)->is_Call()) {
3349           CallNode *call = n->in(0)->in(0)->as_Call();
3350           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
3351             required_outcnt--;      // Rethrow always has 1 less kid
3352           } else if (call->req() > TypeFunc::Parms &&
3353                      call->is_CallDynamicJava()) {
3354             // Check for null receiver. In such case, the optimizer has
3355             // detected that the virtual call will always result in a null
3356             // pointer exception. The fall-through projection of this CatchNode
3357             // will not be populated.
3358             Node *arg0 = call->in(TypeFunc::Parms);
3359             if (arg0->is_Type() &&
3360                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
3361               required_outcnt--;
3362             }
3363           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
3364                      call->req() > TypeFunc::Parms+1 &&
3365                      call->is_CallStaticJava()) {
3366             // Check for negative array length. In such case, the optimizer has
3367             // detected that the allocation attempt will always result in an
3368             // exception. There is no fall-through projection of this CatchNode .
3369             Node *arg1 = call->in(TypeFunc::Parms+1);
3370             if (arg1->is_Type() &&
3371                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
3372               required_outcnt--;
3373             }
3374           }
3375         }
3376       }
3377       // Recheck with a better notion of 'required_outcnt'
3378       if (n->outcnt() != required_outcnt) {
3379         record_method_not_compilable("malformed control flow");
3380         return true;            // Not all targets reachable!
3381       }
3382     }
3383     // Check that I actually visited all kids.  Unreached kids
3384     // must be infinite loops.
3385     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
3386       if (!frc._visited.test(n->fast_out(j)->_idx)) {
3387         record_method_not_compilable("infinite loop");
3388         return true;            // Found unvisited kid; must be unreach
3389       }
3390   }
3391 
3392   // If original bytecodes contained a mixture of floats and doubles
3393   // check if the optimizer has made it homogenous, item (3).
3394   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
3395       frc.get_float_count() > 32 &&
3396       frc.get_double_count() == 0 &&
3397       (10 * frc.get_call_count() < frc.get_float_count()) ) {
3398     set_24_bit_selection_and_mode( false,  true );
3399   }
3400 
3401   set_java_calls(frc.get_java_call_count());
3402   set_inner_loops(frc.get_inner_loop_count());
3403 
3404   // No infinite loops, no reason to bail out.
3405   return false;
3406 }
3407 
3408 //-----------------------------too_many_traps----------------------------------
3409 // Report if there are too many traps at the current method and bci.
3410 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
3411 bool Compile::too_many_traps(ciMethod* method,
3412                              int bci,
3413                              Deoptimization::DeoptReason reason) {
3414   ciMethodData* md = method->method_data();
3415   if (md->is_empty()) {
3416     // Assume the trap has not occurred, or that it occurred only
3417     // because of a transient condition during start-up in the interpreter.
3418     return false;
3419   }
3420   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3421   if (md->has_trap_at(bci, m, reason) != 0) {
3422     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
3423     // Also, if there are multiple reasons, or if there is no per-BCI record,
3424     // assume the worst.
3425     if (log())
3426       log()->elem("observe trap='%s' count='%d'",
3427                   Deoptimization::trap_reason_name(reason),
3428                   md->trap_count(reason));
3429     return true;
3430   } else {
3431     // Ignore method/bci and see if there have been too many globally.
3432     return too_many_traps(reason, md);
3433   }
3434 }
3435 
3436 // Less-accurate variant which does not require a method and bci.
3437 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
3438                              ciMethodData* logmd) {
3439   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
3440     // Too many traps globally.
3441     // Note that we use cumulative trap_count, not just md->trap_count.
3442     if (log()) {
3443       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
3444       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
3445                   Deoptimization::trap_reason_name(reason),
3446                   mcount, trap_count(reason));
3447     }
3448     return true;
3449   } else {
3450     // The coast is clear.
3451     return false;
3452   }
3453 }
3454 
3455 //--------------------------too_many_recompiles--------------------------------
3456 // Report if there are too many recompiles at the current method and bci.
3457 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
3458 // Is not eager to return true, since this will cause the compiler to use
3459 // Action_none for a trap point, to avoid too many recompilations.
3460 bool Compile::too_many_recompiles(ciMethod* method,
3461                                   int bci,
3462                                   Deoptimization::DeoptReason reason) {
3463   ciMethodData* md = method->method_data();
3464   if (md->is_empty()) {
3465     // Assume the trap has not occurred, or that it occurred only
3466     // because of a transient condition during start-up in the interpreter.
3467     return false;
3468   }
3469   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
3470   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
3471   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
3472   Deoptimization::DeoptReason per_bc_reason
3473     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
3474   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3475   if ((per_bc_reason == Deoptimization::Reason_none
3476        || md->has_trap_at(bci, m, reason) != 0)
3477       // The trap frequency measure we care about is the recompile count:
3478       && md->trap_recompiled_at(bci, m)
3479       && md->overflow_recompile_count() >= bc_cutoff) {
3480     // Do not emit a trap here if it has already caused recompilations.
3481     // Also, if there are multiple reasons, or if there is no per-BCI record,
3482     // assume the worst.
3483     if (log())
3484       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
3485                   Deoptimization::trap_reason_name(reason),
3486                   md->trap_count(reason),
3487                   md->overflow_recompile_count());
3488     return true;
3489   } else if (trap_count(reason) != 0
3490              && decompile_count() >= m_cutoff) {
3491     // Too many recompiles globally, and we have seen this sort of trap.
3492     // Use cumulative decompile_count, not just md->decompile_count.
3493     if (log())
3494       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
3495                   Deoptimization::trap_reason_name(reason),
3496                   md->trap_count(reason), trap_count(reason),
3497                   md->decompile_count(), decompile_count());
3498     return true;
3499   } else {
3500     // The coast is clear.
3501     return false;
3502   }
3503 }
3504 
3505 // Compute when not to trap. Used by matching trap based nodes and
3506 // NullCheck optimization.
3507 void Compile::set_allowed_deopt_reasons() {
3508   _allowed_reasons = 0;
3509   if (is_method_compilation()) {
3510     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
3511       assert(rs < BitsPerInt, "recode bit map");
3512       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
3513         _allowed_reasons |= nth_bit(rs);
3514       }
3515     }
3516   }
3517 }
3518 
3519 #ifndef PRODUCT
3520 //------------------------------verify_graph_edges---------------------------
3521 // Walk the Graph and verify that there is a one-to-one correspondence
3522 // between Use-Def edges and Def-Use edges in the graph.
3523 void Compile::verify_graph_edges(bool no_dead_code) {
3524   if (VerifyGraphEdges) {
3525     ResourceArea *area = Thread::current()->resource_area();
3526     Unique_Node_List visited(area);
3527     // Call recursive graph walk to check edges
3528     _root->verify_edges(visited);
3529     if (no_dead_code) {
3530       // Now make sure that no visited node is used by an unvisited node.
3531       bool dead_nodes = false;
3532       Unique_Node_List checked(area);
3533       while (visited.size() > 0) {
3534         Node* n = visited.pop();
3535         checked.push(n);
3536         for (uint i = 0; i < n->outcnt(); i++) {
3537           Node* use = n->raw_out(i);
3538           if (checked.member(use))  continue;  // already checked
3539           if (visited.member(use))  continue;  // already in the graph
3540           if (use->is_Con())        continue;  // a dead ConNode is OK
3541           // At this point, we have found a dead node which is DU-reachable.
3542           if (!dead_nodes) {
3543             tty->print_cr("*** Dead nodes reachable via DU edges:");
3544             dead_nodes = true;
3545           }
3546           use->dump(2);
3547           tty->print_cr("---");
3548           checked.push(use);  // No repeats; pretend it is now checked.
3549         }
3550       }
3551       assert(!dead_nodes, "using nodes must be reachable from root");
3552     }
3553   }
3554 }
3555 
3556 // Verify GC barriers consistency
3557 // Currently supported:
3558 // - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
3559 void Compile::verify_barriers() {
3560   if (UseG1GC) {
3561     // Verify G1 pre-barriers
3562     const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active());
3563 
3564     ResourceArea *area = Thread::current()->resource_area();
3565     Unique_Node_List visited(area);
3566     Node_List worklist(area);
3567     // We're going to walk control flow backwards starting from the Root
3568     worklist.push(_root);
3569     while (worklist.size() > 0) {
3570       Node* x = worklist.pop();
3571       if (x == NULL || x == top()) continue;
3572       if (visited.member(x)) {
3573         continue;
3574       } else {
3575         visited.push(x);
3576       }
3577 
3578       if (x->is_Region()) {
3579         for (uint i = 1; i < x->req(); i++) {
3580           worklist.push(x->in(i));
3581         }
3582       } else {
3583         worklist.push(x->in(0));
3584         // We are looking for the pattern:
3585         //                            /->ThreadLocal
3586         // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
3587         //              \->ConI(0)
3588         // We want to verify that the If and the LoadB have the same control
3589         // See GraphKit::g1_write_barrier_pre()
3590         if (x->is_If()) {
3591           IfNode *iff = x->as_If();
3592           if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
3593             CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
3594             if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
3595                 && cmp->in(1)->is_Load()) {
3596               LoadNode* load = cmp->in(1)->as_Load();
3597               if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
3598                   && load->in(2)->in(3)->is_Con()
3599                   && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
3600 
3601                 Node* if_ctrl = iff->in(0);
3602                 Node* load_ctrl = load->in(0);
3603 
3604                 if (if_ctrl != load_ctrl) {
3605                   // Skip possible CProj->NeverBranch in infinite loops
3606                   if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
3607                       && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
3608                     if_ctrl = if_ctrl->in(0)->in(0);
3609                   }
3610                 }
3611                 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
3612               }
3613             }
3614           }
3615         }
3616       }
3617     }
3618   }
3619 }
3620 
3621 #endif
3622 
3623 // The Compile object keeps track of failure reasons separately from the ciEnv.
3624 // This is required because there is not quite a 1-1 relation between the
3625 // ciEnv and its compilation task and the Compile object.  Note that one
3626 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
3627 // to backtrack and retry without subsuming loads.  Other than this backtracking
3628 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
3629 // by the logic in C2Compiler.
3630 void Compile::record_failure(const char* reason) {
3631   if (log() != NULL) {
3632     log()->elem("failure reason='%s' phase='compile'", reason);
3633   }
3634   if (_failure_reason == NULL) {
3635     // Record the first failure reason.
3636     _failure_reason = reason;
3637   }
3638 
3639   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
3640     C->print_method(PHASE_FAILURE);
3641   }
3642   _root = NULL;  // flush the graph, too
3643 }
3644 
3645 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
3646   : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false),
3647     _phase_name(name), _dolog(dolog)
3648 {
3649   if (dolog) {
3650     C = Compile::current();
3651     _log = C->log();
3652   } else {
3653     C = NULL;
3654     _log = NULL;
3655   }
3656   if (_log != NULL) {
3657     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3658     _log->stamp();
3659     _log->end_head();
3660   }
3661 }
3662 
3663 Compile::TracePhase::~TracePhase() {
3664 
3665   C = Compile::current();
3666   if (_dolog) {
3667     _log = C->log();
3668   } else {
3669     _log = NULL;
3670   }
3671 
3672 #ifdef ASSERT
3673   if (PrintIdealNodeCount) {
3674     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
3675                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
3676   }
3677 
3678   if (VerifyIdealNodeCount) {
3679     Compile::current()->print_missing_nodes();
3680   }
3681 #endif
3682 
3683   if (_log != NULL) {
3684     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3685   }
3686 }
3687 
3688 //=============================================================================
3689 // Two Constant's are equal when the type and the value are equal.
3690 bool Compile::Constant::operator==(const Constant& other) {
3691   if (type()          != other.type()         )  return false;
3692   if (can_be_reused() != other.can_be_reused())  return false;
3693   // For floating point values we compare the bit pattern.
3694   switch (type()) {
3695   case T_FLOAT:   return (_v._value.i == other._v._value.i);
3696   case T_LONG:
3697   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
3698   case T_OBJECT:
3699   case T_ADDRESS: return (_v._value.l == other._v._value.l);
3700   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
3701   case T_METADATA: return (_v._metadata == other._v._metadata);
3702   default: ShouldNotReachHere();
3703   }
3704   return false;
3705 }
3706 
3707 static int type_to_size_in_bytes(BasicType t) {
3708   switch (t) {
3709   case T_LONG:    return sizeof(jlong  );
3710   case T_FLOAT:   return sizeof(jfloat );
3711   case T_DOUBLE:  return sizeof(jdouble);
3712   case T_METADATA: return sizeof(Metadata*);
3713     // We use T_VOID as marker for jump-table entries (labels) which
3714     // need an internal word relocation.
3715   case T_VOID:
3716   case T_ADDRESS:
3717   case T_OBJECT:  return sizeof(jobject);
3718   }
3719 
3720   ShouldNotReachHere();
3721   return -1;
3722 }
3723 
3724 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
3725   // sort descending
3726   if (a->freq() > b->freq())  return -1;
3727   if (a->freq() < b->freq())  return  1;
3728   return 0;
3729 }
3730 
3731 void Compile::ConstantTable::calculate_offsets_and_size() {
3732   // First, sort the array by frequencies.
3733   _constants.sort(qsort_comparator);
3734 
3735 #ifdef ASSERT
3736   // Make sure all jump-table entries were sorted to the end of the
3737   // array (they have a negative frequency).
3738   bool found_void = false;
3739   for (int i = 0; i < _constants.length(); i++) {
3740     Constant con = _constants.at(i);
3741     if (con.type() == T_VOID)
3742       found_void = true;  // jump-tables
3743     else
3744       assert(!found_void, "wrong sorting");
3745   }
3746 #endif
3747 
3748   int offset = 0;
3749   for (int i = 0; i < _constants.length(); i++) {
3750     Constant* con = _constants.adr_at(i);
3751 
3752     // Align offset for type.
3753     int typesize = type_to_size_in_bytes(con->type());
3754     offset = align_size_up(offset, typesize);
3755     con->set_offset(offset);   // set constant's offset
3756 
3757     if (con->type() == T_VOID) {
3758       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
3759       offset = offset + typesize * n->outcnt();  // expand jump-table
3760     } else {
3761       offset = offset + typesize;
3762     }
3763   }
3764 
3765   // Align size up to the next section start (which is insts; see
3766   // CodeBuffer::align_at_start).
3767   assert(_size == -1, "already set?");
3768   _size = align_size_up(offset, CodeEntryAlignment);
3769 }
3770 
3771 void Compile::ConstantTable::emit(CodeBuffer& cb) {
3772   MacroAssembler _masm(&cb);
3773   for (int i = 0; i < _constants.length(); i++) {
3774     Constant con = _constants.at(i);
3775     address constant_addr = NULL;
3776     switch (con.type()) {
3777     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
3778     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
3779     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
3780     case T_OBJECT: {
3781       jobject obj = con.get_jobject();
3782       int oop_index = _masm.oop_recorder()->find_index(obj);
3783       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
3784       break;
3785     }
3786     case T_ADDRESS: {
3787       address addr = (address) con.get_jobject();
3788       constant_addr = _masm.address_constant(addr);
3789       break;
3790     }
3791     // We use T_VOID as marker for jump-table entries (labels) which
3792     // need an internal word relocation.
3793     case T_VOID: {
3794       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
3795       // Fill the jump-table with a dummy word.  The real value is
3796       // filled in later in fill_jump_table.
3797       address dummy = (address) n;
3798       constant_addr = _masm.address_constant(dummy);
3799       // Expand jump-table
3800       for (uint i = 1; i < n->outcnt(); i++) {
3801         address temp_addr = _masm.address_constant(dummy + i);
3802         assert(temp_addr, "consts section too small");
3803       }
3804       break;
3805     }
3806     case T_METADATA: {
3807       Metadata* obj = con.get_metadata();
3808       int metadata_index = _masm.oop_recorder()->find_index(obj);
3809       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
3810       break;
3811     }
3812     default: ShouldNotReachHere();
3813     }
3814     assert(constant_addr, "consts section too small");
3815     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
3816             err_msg_res("must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset())));
3817   }
3818 }
3819 
3820 int Compile::ConstantTable::find_offset(Constant& con) const {
3821   int idx = _constants.find(con);
3822   assert(idx != -1, "constant must be in constant table");
3823   int offset = _constants.at(idx).offset();
3824   assert(offset != -1, "constant table not emitted yet?");
3825   return offset;
3826 }
3827 
3828 void Compile::ConstantTable::add(Constant& con) {
3829   if (con.can_be_reused()) {
3830     int idx = _constants.find(con);
3831     if (idx != -1 && _constants.at(idx).can_be_reused()) {
3832       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
3833       return;
3834     }
3835   }
3836   (void) _constants.append(con);
3837 }
3838 
3839 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
3840   Block* b = Compile::current()->cfg()->get_block_for_node(n);
3841   Constant con(type, value, b->_freq);
3842   add(con);
3843   return con;
3844 }
3845 
3846 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
3847   Constant con(metadata);
3848   add(con);
3849   return con;
3850 }
3851 
3852 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
3853   jvalue value;
3854   BasicType type = oper->type()->basic_type();
3855   switch (type) {
3856   case T_LONG:    value.j = oper->constantL(); break;
3857   case T_FLOAT:   value.f = oper->constantF(); break;
3858   case T_DOUBLE:  value.d = oper->constantD(); break;
3859   case T_OBJECT:
3860   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
3861   case T_METADATA: return add((Metadata*)oper->constant()); break;
3862   default: guarantee(false, err_msg_res("unhandled type: %s", type2name(type)));
3863   }
3864   return add(n, type, value);
3865 }
3866 
3867 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
3868   jvalue value;
3869   // We can use the node pointer here to identify the right jump-table
3870   // as this method is called from Compile::Fill_buffer right before
3871   // the MachNodes are emitted and the jump-table is filled (means the
3872   // MachNode pointers do not change anymore).
3873   value.l = (jobject) n;
3874   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
3875   add(con);
3876   return con;
3877 }
3878 
3879 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
3880   // If called from Compile::scratch_emit_size do nothing.
3881   if (Compile::current()->in_scratch_emit_size())  return;
3882 
3883   assert(labels.is_nonempty(), "must be");
3884   assert((uint) labels.length() == n->outcnt(), err_msg_res("must be equal: %d == %d", labels.length(), n->outcnt()));
3885 
3886   // Since MachConstantNode::constant_offset() also contains
3887   // table_base_offset() we need to subtract the table_base_offset()
3888   // to get the plain offset into the constant table.
3889   int offset = n->constant_offset() - table_base_offset();
3890 
3891   MacroAssembler _masm(&cb);
3892   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
3893 
3894   for (uint i = 0; i < n->outcnt(); i++) {
3895     address* constant_addr = &jump_table_base[i];
3896     assert(*constant_addr == (((address) n) + i), err_msg_res("all jump-table entries must contain adjusted node pointer: " INTPTR_FORMAT " == " INTPTR_FORMAT, p2i(*constant_addr), p2i(((address) n) + i)));
3897     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
3898     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
3899   }
3900 }
3901 
3902 void Compile::dump_inlining() {
3903   if (print_inlining() || print_intrinsics()) {
3904     // Print inlining message for candidates that we couldn't inline
3905     // for lack of space or non constant receiver
3906     for (int i = 0; i < _late_inlines.length(); i++) {
3907       CallGenerator* cg = _late_inlines.at(i);
3908       cg->print_inlining_late("live nodes > LiveNodeCountInliningCutoff");
3909     }
3910     Unique_Node_List useful;
3911     useful.push(root());
3912     for (uint next = 0; next < useful.size(); ++next) {
3913       Node* n  = useful.at(next);
3914       if (n->is_Call() && n->as_Call()->generator() != NULL && n->as_Call()->generator()->call_node() == n) {
3915         CallNode* call = n->as_Call();
3916         CallGenerator* cg = call->generator();
3917         cg->print_inlining_late("receiver not constant");
3918       }
3919       uint max = n->len();
3920       for ( uint i = 0; i < max; ++i ) {
3921         Node *m = n->in(i);
3922         if ( m == NULL ) continue;
3923         useful.push(m);
3924       }
3925     }
3926     for (int i = 0; i < _print_inlining_list->length(); i++) {
3927       tty->print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
3928     }
3929   }
3930 }
3931 
3932 // Dump inlining replay data to the stream.
3933 // Don't change thread state and acquire any locks.
3934 void Compile::dump_inline_data(outputStream* out) {
3935   InlineTree* inl_tree = ilt();
3936   if (inl_tree != NULL) {
3937     out->print(" inline %d", inl_tree->count());
3938     inl_tree->dump_replay_data(out);
3939   }
3940 }
3941 
3942 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
3943   if (n1->Opcode() < n2->Opcode())      return -1;
3944   else if (n1->Opcode() > n2->Opcode()) return 1;
3945 
3946   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()));
3947   for (uint i = 1; i < n1->req(); i++) {
3948     if (n1->in(i) < n2->in(i))      return -1;
3949     else if (n1->in(i) > n2->in(i)) return 1;
3950   }
3951 
3952   return 0;
3953 }
3954 
3955 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
3956   Node* n1 = *n1p;
3957   Node* n2 = *n2p;
3958 
3959   return cmp_expensive_nodes(n1, n2);
3960 }
3961 
3962 void Compile::sort_expensive_nodes() {
3963   if (!expensive_nodes_sorted()) {
3964     _expensive_nodes->sort(cmp_expensive_nodes);
3965   }
3966 }
3967 
3968 bool Compile::expensive_nodes_sorted() const {
3969   for (int i = 1; i < _expensive_nodes->length(); i++) {
3970     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
3971       return false;
3972     }
3973   }
3974   return true;
3975 }
3976 
3977 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
3978   if (_expensive_nodes->length() == 0) {
3979     return false;
3980   }
3981 
3982   assert(OptimizeExpensiveOps, "optimization off?");
3983 
3984   // Take this opportunity to remove dead nodes from the list
3985   int j = 0;
3986   for (int i = 0; i < _expensive_nodes->length(); i++) {
3987     Node* n = _expensive_nodes->at(i);
3988     if (!n->is_unreachable(igvn)) {
3989       assert(n->is_expensive(), "should be expensive");
3990       _expensive_nodes->at_put(j, n);
3991       j++;
3992     }
3993   }
3994   _expensive_nodes->trunc_to(j);
3995 
3996   // Then sort the list so that similar nodes are next to each other
3997   // and check for at least two nodes of identical kind with same data
3998   // inputs.
3999   sort_expensive_nodes();
4000 
4001   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
4002     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
4003       return true;
4004     }
4005   }
4006 
4007   return false;
4008 }
4009 
4010 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4011   if (_expensive_nodes->length() == 0) {
4012     return;
4013   }
4014 
4015   assert(OptimizeExpensiveOps, "optimization off?");
4016 
4017   // Sort to bring similar nodes next to each other and clear the
4018   // control input of nodes for which there's only a single copy.
4019   sort_expensive_nodes();
4020 
4021   int j = 0;
4022   int identical = 0;
4023   int i = 0;
4024   for (; i < _expensive_nodes->length()-1; i++) {
4025     assert(j <= i, "can't write beyond current index");
4026     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
4027       identical++;
4028       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4029       continue;
4030     }
4031     if (identical > 0) {
4032       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4033       identical = 0;
4034     } else {
4035       Node* n = _expensive_nodes->at(i);
4036       igvn.hash_delete(n);
4037       n->set_req(0, NULL);
4038       igvn.hash_insert(n);
4039     }
4040   }
4041   if (identical > 0) {
4042     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4043   } else if (_expensive_nodes->length() >= 1) {
4044     Node* n = _expensive_nodes->at(i);
4045     igvn.hash_delete(n);
4046     n->set_req(0, NULL);
4047     igvn.hash_insert(n);
4048   }
4049   _expensive_nodes->trunc_to(j);
4050 }
4051 
4052 void Compile::add_expensive_node(Node * n) {
4053   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
4054   assert(n->is_expensive(), "expensive nodes with non-null control here only");
4055   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4056   if (OptimizeExpensiveOps) {
4057     _expensive_nodes->append(n);
4058   } else {
4059     // Clear control input and let IGVN optimize expensive nodes if
4060     // OptimizeExpensiveOps is off.
4061     n->set_req(0, NULL);
4062   }
4063 }
4064 
4065 /**
4066  * Remove the speculative part of types and clean up the graph
4067  */
4068 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4069   if (UseTypeSpeculation) {
4070     Unique_Node_List worklist;
4071     worklist.push(root());
4072     int modified = 0;
4073     // Go over all type nodes that carry a speculative type, drop the
4074     // speculative part of the type and enqueue the node for an igvn
4075     // which may optimize it out.
4076     for (uint next = 0; next < worklist.size(); ++next) {
4077       Node *n  = worklist.at(next);
4078       if (n->is_Type()) {
4079         TypeNode* tn = n->as_Type();
4080         const Type* t = tn->type();
4081         const Type* t_no_spec = t->remove_speculative();
4082         if (t_no_spec != t) {
4083           bool in_hash = igvn.hash_delete(n);
4084           assert(in_hash, "node should be in igvn hash table");
4085           tn->set_type(t_no_spec);
4086           igvn.hash_insert(n);
4087           igvn._worklist.push(n); // give it a chance to go away
4088           modified++;
4089         }
4090       }
4091       uint max = n->len();
4092       for( uint i = 0; i < max; ++i ) {
4093         Node *m = n->in(i);
4094         if (not_a_node(m))  continue;
4095         worklist.push(m);
4096       }
4097     }
4098     // Drop the speculative part of all types in the igvn's type table
4099     igvn.remove_speculative_types();
4100     if (modified > 0) {
4101       igvn.optimize();
4102     }
4103 #ifdef ASSERT
4104     // Verify that after the IGVN is over no speculative type has resurfaced
4105     worklist.clear();
4106     worklist.push(root());
4107     for (uint next = 0; next < worklist.size(); ++next) {
4108       Node *n  = worklist.at(next);
4109       const Type* t = igvn.type_or_null(n);
4110       assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
4111       if (n->is_Type()) {
4112         t = n->as_Type()->type();
4113         assert(t == t->remove_speculative(), "no more speculative types");
4114       }
4115       uint max = n->len();
4116       for( uint i = 0; i < max; ++i ) {
4117         Node *m = n->in(i);
4118         if (not_a_node(m))  continue;
4119         worklist.push(m);
4120       }
4121     }
4122     igvn.check_no_speculative_types();
4123 #endif
4124   }
4125 }
4126 
4127 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
4128 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl) {
4129   if (ctrl != NULL) {
4130     // Express control dependency by a CastII node with a narrow type.
4131     value = new (phase->C) CastIINode(value, itype, false, true /* range check dependency */);
4132     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4133     // node from floating above the range check during loop optimizations. Otherwise, the
4134     // ConvI2L node may be eliminated independently of the range check, causing the data path
4135     // to become TOP while the control path is still there (although it's unreachable).
4136     value->set_req(0, ctrl);
4137     // Save CastII node to remove it after loop optimizations.
4138     phase->C->add_range_check_cast(value);
4139     value = phase->transform(value);
4140   }
4141   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4142   return phase->transform(new (phase->C) ConvI2LNode(value, ltype));
4143 }
4144 
4145 // Auxiliary method to support randomized stressing/fuzzing.
4146 //
4147 // This method can be called the arbitrary number of times, with current count
4148 // as the argument. The logic allows selecting a single candidate from the
4149 // running list of candidates as follows:
4150 //    int count = 0;
4151 //    Cand* selected = null;
4152 //    while(cand = cand->next()) {
4153 //      if (randomized_select(++count)) {
4154 //        selected = cand;
4155 //      }
4156 //    }
4157 //
4158 // Including count equalizes the chances any candidate is "selected".
4159 // This is useful when we don't have the complete list of candidates to choose
4160 // from uniformly. In this case, we need to adjust the randomicity of the
4161 // selection, or else we will end up biasing the selection towards the latter
4162 // candidates.
4163 //
4164 // Quick back-envelope calculation shows that for the list of n candidates
4165 // the equal probability for the candidate to persist as "best" can be
4166 // achieved by replacing it with "next" k-th candidate with the probability
4167 // of 1/k. It can be easily shown that by the end of the run, the
4168 // probability for any candidate is converged to 1/n, thus giving the
4169 // uniform distribution among all the candidates.
4170 //
4171 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
4172 #define RANDOMIZED_DOMAIN_POW 29
4173 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
4174 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
4175 bool Compile::randomized_select(int count) {
4176   assert(count > 0, "only positive");
4177   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
4178 }