1 /*
   2  * Copyright (c) 1997, 2015, 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/compileBroker.hpp"
  33 #include "compiler/compileLog.hpp"
  34 #include "compiler/disassembler.hpp"
  35 #include "compiler/oopMap.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/convertnode.hpp"
  46 #include "opto/divnode.hpp"
  47 #include "opto/escape.hpp"
  48 #include "opto/idealGraphPrinter.hpp"
  49 #include "opto/loopnode.hpp"
  50 #include "opto/machnode.hpp"
  51 #include "opto/macro.hpp"
  52 #include "opto/matcher.hpp"
  53 #include "opto/mathexactnode.hpp"
  54 #include "opto/memnode.hpp"
  55 #include "opto/mulnode.hpp"
  56 #include "opto/narrowptrnode.hpp"
  57 #include "opto/node.hpp"
  58 #include "opto/opcodes.hpp"
  59 #include "opto/output.hpp"
  60 #include "opto/parse.hpp"
  61 #include "opto/phaseX.hpp"
  62 #include "opto/rootnode.hpp"
  63 #include "opto/runtime.hpp"
  64 #include "opto/stringopts.hpp"
  65 #include "opto/type.hpp"
  66 #include "opto/vectornode.hpp"
  67 #include "runtime/arguments.hpp"
  68 #include "runtime/sharedRuntime.hpp"
  69 #include "runtime/signature.hpp"
  70 #include "runtime/stubRoutines.hpp"
  71 #include "runtime/timer.hpp"
  72 #include "utilities/copy.hpp"
  73 
  74 
  75 // -------------------- Compile::mach_constant_base_node -----------------------
  76 // Constant table base node singleton.
  77 MachConstantBaseNode* Compile::mach_constant_base_node() {
  78   if (_mach_constant_base_node == NULL) {
  79     _mach_constant_base_node = new MachConstantBaseNode();
  80     _mach_constant_base_node->add_req(C->root());
  81   }
  82   return _mach_constant_base_node;
  83 }
  84 
  85 
  86 /// Support for intrinsics.
  87 
  88 // Return the index at which m must be inserted (or already exists).
  89 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
  90 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual) {
  91 #ifdef ASSERT
  92   for (int i = 1; i < _intrinsics->length(); i++) {
  93     CallGenerator* cg1 = _intrinsics->at(i-1);
  94     CallGenerator* cg2 = _intrinsics->at(i);
  95     assert(cg1->method() != cg2->method()
  96            ? cg1->method()     < cg2->method()
  97            : cg1->is_virtual() < cg2->is_virtual(),
  98            "compiler intrinsics list must stay sorted");
  99   }
 100 #endif
 101   // Binary search sorted list, in decreasing intervals [lo, hi].
 102   int lo = 0, hi = _intrinsics->length()-1;
 103   while (lo <= hi) {
 104     int mid = (uint)(hi + lo) / 2;
 105     ciMethod* mid_m = _intrinsics->at(mid)->method();
 106     if (m < mid_m) {
 107       hi = mid-1;
 108     } else if (m > mid_m) {
 109       lo = mid+1;
 110     } else {
 111       // look at minor sort key
 112       bool mid_virt = _intrinsics->at(mid)->is_virtual();
 113       if (is_virtual < mid_virt) {
 114         hi = mid-1;
 115       } else if (is_virtual > mid_virt) {
 116         lo = mid+1;
 117       } else {
 118         return mid;  // exact match
 119       }
 120     }
 121   }
 122   return lo;  // inexact match
 123 }
 124 
 125 void Compile::register_intrinsic(CallGenerator* cg) {
 126   if (_intrinsics == NULL) {
 127     _intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
 128   }
 129   // This code is stolen from ciObjectFactory::insert.
 130   // Really, GrowableArray should have methods for
 131   // insert_at, remove_at, and binary_search.
 132   int len = _intrinsics->length();
 133   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual());
 134   if (index == len) {
 135     _intrinsics->append(cg);
 136   } else {
 137 #ifdef ASSERT
 138     CallGenerator* oldcg = _intrinsics->at(index);
 139     assert(oldcg->method() != cg->method() || oldcg->is_virtual() != cg->is_virtual(), "don't register twice");
 140 #endif
 141     _intrinsics->append(_intrinsics->at(len-1));
 142     int pos;
 143     for (pos = len-2; pos >= index; pos--) {
 144       _intrinsics->at_put(pos+1,_intrinsics->at(pos));
 145     }
 146     _intrinsics->at_put(index, cg);
 147   }
 148   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 149 }
 150 
 151 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
 152   assert(m->is_loaded(), "don't try this on unloaded methods");
 153   if (_intrinsics != NULL) {
 154     int index = intrinsic_insertion_index(m, is_virtual);
 155     if (index < _intrinsics->length()
 156         && _intrinsics->at(index)->method() == m
 157         && _intrinsics->at(index)->is_virtual() == is_virtual) {
 158       return _intrinsics->at(index);
 159     }
 160   }
 161   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 162   if (m->intrinsic_id() != vmIntrinsics::_none &&
 163       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 164     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 165     if (cg != NULL) {
 166       // Save it for next time:
 167       register_intrinsic(cg);
 168       return cg;
 169     } else {
 170       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 171     }
 172   }
 173   return NULL;
 174 }
 175 
 176 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
 177 // in library_call.cpp.
 178 
 179 
 180 #ifndef PRODUCT
 181 // statistics gathering...
 182 
 183 juint  Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
 184 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
 185 
 186 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 187   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 188   int oflags = _intrinsic_hist_flags[id];
 189   assert(flags != 0, "what happened?");
 190   if (is_virtual) {
 191     flags |= _intrinsic_virtual;
 192   }
 193   bool changed = (flags != oflags);
 194   if ((flags & _intrinsic_worked) != 0) {
 195     juint count = (_intrinsic_hist_count[id] += 1);
 196     if (count == 1) {
 197       changed = true;           // first time
 198     }
 199     // increment the overall count also:
 200     _intrinsic_hist_count[vmIntrinsics::_none] += 1;
 201   }
 202   if (changed) {
 203     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 204       // Something changed about the intrinsic's virtuality.
 205       if ((flags & _intrinsic_virtual) != 0) {
 206         // This is the first use of this intrinsic as a virtual call.
 207         if (oflags != 0) {
 208           // We already saw it as a non-virtual, so note both cases.
 209           flags |= _intrinsic_both;
 210         }
 211       } else if ((oflags & _intrinsic_both) == 0) {
 212         // This is the first use of this intrinsic as a non-virtual
 213         flags |= _intrinsic_both;
 214       }
 215     }
 216     _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
 217   }
 218   // update the overall flags also:
 219   _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
 220   return changed;
 221 }
 222 
 223 static char* format_flags(int flags, char* buf) {
 224   buf[0] = 0;
 225   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 226   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 227   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 228   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 229   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 230   if (buf[0] == 0)  strcat(buf, ",");
 231   assert(buf[0] == ',', "must be");
 232   return &buf[1];
 233 }
 234 
 235 void Compile::print_intrinsic_statistics() {
 236   char flagsbuf[100];
 237   ttyLocker ttyl;
 238   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
 239   tty->print_cr("Compiler intrinsic usage:");
 240   juint total = _intrinsic_hist_count[vmIntrinsics::_none];
 241   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 242   #define PRINT_STAT_LINE(name, c, f) \
 243     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 244   for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
 245     vmIntrinsics::ID id = (vmIntrinsics::ID) index;
 246     int   flags = _intrinsic_hist_flags[id];
 247     juint count = _intrinsic_hist_count[id];
 248     if ((flags | count) != 0) {
 249       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 250     }
 251   }
 252   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
 253   if (xtty != NULL)  xtty->tail("statistics");
 254 }
 255 
 256 void Compile::print_statistics() {
 257   { ttyLocker ttyl;
 258     if (xtty != NULL)  xtty->head("statistics type='opto'");
 259     Parse::print_statistics();
 260     PhaseCCP::print_statistics();
 261     PhaseRegAlloc::print_statistics();
 262     Scheduling::print_statistics();
 263     PhasePeephole::print_statistics();
 264     PhaseIdealLoop::print_statistics();
 265     if (xtty != NULL)  xtty->tail("statistics");
 266   }
 267   if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
 268     // put this under its own <statistics> element.
 269     print_intrinsic_statistics();
 270   }
 271 }
 272 #endif //PRODUCT
 273 
 274 // Support for bundling info
 275 Bundle* Compile::node_bundling(const Node *n) {
 276   assert(valid_bundle_info(n), "oob");
 277   return &_node_bundling_base[n->_idx];
 278 }
 279 
 280 bool Compile::valid_bundle_info(const Node *n) {
 281   return (_node_bundling_limit > n->_idx);
 282 }
 283 
 284 
 285 void Compile::gvn_replace_by(Node* n, Node* nn) {
 286   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 287     Node* use = n->last_out(i);
 288     bool is_in_table = initial_gvn()->hash_delete(use);
 289     uint uses_found = 0;
 290     for (uint j = 0; j < use->len(); j++) {
 291       if (use->in(j) == n) {
 292         if (j < use->req())
 293           use->set_req(j, nn);
 294         else
 295           use->set_prec(j, nn);
 296         uses_found++;
 297       }
 298     }
 299     if (is_in_table) {
 300       // reinsert into table
 301       initial_gvn()->hash_find_insert(use);
 302     }
 303     record_for_igvn(use);
 304     i -= uses_found;    // we deleted 1 or more copies of this edge
 305   }
 306 }
 307 
 308 
 309 static inline bool not_a_node(const Node* n) {
 310   if (n == NULL)                   return true;
 311   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
 312   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
 313   return false;
 314 }
 315 
 316 // Identify all nodes that are reachable from below, useful.
 317 // Use breadth-first pass that records state in a Unique_Node_List,
 318 // recursive traversal is slower.
 319 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 320   int estimated_worklist_size = unique();
 321   useful.map( estimated_worklist_size, NULL );  // preallocate space
 322 
 323   // Initialize worklist
 324   if (root() != NULL)     { useful.push(root()); }
 325   // If 'top' is cached, declare it useful to preserve cached node
 326   if( cached_top_node() ) { useful.push(cached_top_node()); }
 327 
 328   // Push all useful nodes onto the list, breadthfirst
 329   for( uint next = 0; next < useful.size(); ++next ) {
 330     assert( next < unique(), "Unique useful nodes < total nodes");
 331     Node *n  = useful.at(next);
 332     uint max = n->len();
 333     for( uint i = 0; i < max; ++i ) {
 334       Node *m = n->in(i);
 335       if (not_a_node(m))  continue;
 336       useful.push(m);
 337     }
 338   }
 339 }
 340 
 341 // Update dead_node_list with any missing dead nodes using useful
 342 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 343 void Compile::update_dead_node_list(Unique_Node_List &useful) {
 344   uint max_idx = unique();
 345   VectorSet& useful_node_set = useful.member_set();
 346 
 347   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
 348     // If node with index node_idx is not in useful set,
 349     // mark it as dead in dead node list.
 350     if (! useful_node_set.test(node_idx) ) {
 351       record_dead_node(node_idx);
 352     }
 353   }
 354 }
 355 
 356 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
 357   int shift = 0;
 358   for (int i = 0; i < inlines->length(); i++) {
 359     CallGenerator* cg = inlines->at(i);
 360     CallNode* call = cg->call_node();
 361     if (shift > 0) {
 362       inlines->at_put(i-shift, cg);
 363     }
 364     if (!useful.member(call)) {
 365       shift++;
 366     }
 367   }
 368   inlines->trunc_to(inlines->length()-shift);
 369 }
 370 
 371 // Disconnect all useless nodes by disconnecting those at the boundary.
 372 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
 373   uint next = 0;
 374   while (next < useful.size()) {
 375     Node *n = useful.at(next++);
 376     if (n->is_SafePoint()) {
 377       // We're done with a parsing phase. Replaced nodes are not valid
 378       // beyond that point.
 379       n->as_SafePoint()->delete_replaced_nodes();
 380     }
 381     // Use raw traversal of out edges since this code removes out edges
 382     int max = n->outcnt();
 383     for (int j = 0; j < max; ++j) {
 384       Node* child = n->raw_out(j);
 385       if (! useful.member(child)) {
 386         assert(!child->is_top() || child != top(),
 387                "If top is cached in Compile object it is in useful list");
 388         // Only need to remove this out-edge to the useless node
 389         n->raw_del_out(j);
 390         --j;
 391         --max;
 392       }
 393     }
 394     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 395       record_for_igvn(n->unique_out());
 396     }
 397   }
 398   // Remove useless macro and predicate opaq nodes
 399   for (int i = C->macro_count()-1; i >= 0; i--) {
 400     Node* n = C->macro_node(i);
 401     if (!useful.member(n)) {
 402       remove_macro_node(n);
 403     }
 404   }
 405   // Remove useless expensive node
 406   for (int i = C->expensive_count()-1; i >= 0; i--) {
 407     Node* n = C->expensive_node(i);
 408     if (!useful.member(n)) {
 409       remove_expensive_node(n);
 410     }
 411   }
 412   // clean up the late inline lists
 413   remove_useless_late_inlines(&_string_late_inlines, useful);
 414   remove_useless_late_inlines(&_boxing_late_inlines, useful);
 415   remove_useless_late_inlines(&_late_inlines, useful);
 416   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
 417 }
 418 
 419 //------------------------------frame_size_in_words-----------------------------
 420 // frame_slots in units of words
 421 int Compile::frame_size_in_words() const {
 422   // shift is 0 in LP32 and 1 in LP64
 423   const int shift = (LogBytesPerWord - LogBytesPerInt);
 424   int words = _frame_slots >> shift;
 425   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
 426   return words;
 427 }
 428 
 429 // To bang the stack of this compiled method we use the stack size
 430 // that the interpreter would need in case of a deoptimization. This
 431 // removes the need to bang the stack in the deoptimization blob which
 432 // in turn simplifies stack overflow handling.
 433 int Compile::bang_size_in_bytes() const {
 434   return MAX2(frame_size_in_bytes() + os::extra_bang_size_in_bytes(), _interpreter_frame_size);
 435 }
 436 
 437 // ============================================================================
 438 //------------------------------CompileWrapper---------------------------------
 439 class CompileWrapper : public StackObj {
 440   Compile *const _compile;
 441  public:
 442   CompileWrapper(Compile* compile);
 443 
 444   ~CompileWrapper();
 445 };
 446 
 447 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 448   // the Compile* pointer is stored in the current ciEnv:
 449   ciEnv* env = compile->env();
 450   assert(env == ciEnv::current(), "must already be a ciEnv active");
 451   assert(env->compiler_data() == NULL, "compile already active?");
 452   env->set_compiler_data(compile);
 453   assert(compile == Compile::current(), "sanity");
 454 
 455   compile->set_type_dict(NULL);
 456   compile->set_clone_map(new Dict(cmpkey, hashkey, _compile->comp_arena()));
 457   compile->clone_map().set_clone_idx(0);
 458   compile->set_type_hwm(NULL);
 459   compile->set_type_last_size(0);
 460   compile->set_last_tf(NULL, NULL);
 461   compile->set_indexSet_arena(NULL);
 462   compile->set_indexSet_free_block_list(NULL);
 463   compile->init_type_arena();
 464   Type::Initialize(compile);
 465   _compile->set_scratch_buffer_blob(NULL);
 466   _compile->begin_method();
 467   _compile->clone_map().set_debug(_compile->has_method() && _compile->method_has_option(_compile->clone_map().debug_option_name));
 468 }
 469 CompileWrapper::~CompileWrapper() {
 470   _compile->end_method();
 471   if (_compile->scratch_buffer_blob() != NULL)
 472     BufferBlob::free(_compile->scratch_buffer_blob());
 473   _compile->env()->set_compiler_data(NULL);
 474 }
 475 
 476 
 477 //----------------------------print_compile_messages---------------------------
 478 void Compile::print_compile_messages() {
 479 #ifndef PRODUCT
 480   // Check if recompiling
 481   if (_subsume_loads == false && PrintOpto) {
 482     // Recompiling without allowing machine instructions to subsume loads
 483     tty->print_cr("*********************************************************");
 484     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 485     tty->print_cr("*********************************************************");
 486   }
 487   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
 488     // Recompiling without escape analysis
 489     tty->print_cr("*********************************************************");
 490     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 491     tty->print_cr("*********************************************************");
 492   }
 493   if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
 494     // Recompiling without boxing elimination
 495     tty->print_cr("*********************************************************");
 496     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
 497     tty->print_cr("*********************************************************");
 498   }
 499   if (env()->break_at_compile()) {
 500     // Open the debugger when compiling this method.
 501     tty->print("### Breaking when compiling: ");
 502     method()->print_short_name();
 503     tty->cr();
 504     BREAKPOINT;
 505   }
 506 
 507   if( PrintOpto ) {
 508     if (is_osr_compilation()) {
 509       tty->print("[OSR]%3d", _compile_id);
 510     } else {
 511       tty->print("%3d", _compile_id);
 512     }
 513   }
 514 #endif
 515 }
 516 
 517 
 518 //-----------------------init_scratch_buffer_blob------------------------------
 519 // Construct a temporary BufferBlob and cache it for this compile.
 520 void Compile::init_scratch_buffer_blob(int const_size) {
 521   // If there is already a scratch buffer blob allocated and the
 522   // constant section is big enough, use it.  Otherwise free the
 523   // current and allocate a new one.
 524   BufferBlob* blob = scratch_buffer_blob();
 525   if ((blob != NULL) && (const_size <= _scratch_const_size)) {
 526     // Use the current blob.
 527   } else {
 528     if (blob != NULL) {
 529       BufferBlob::free(blob);
 530     }
 531 
 532     ResourceMark rm;
 533     _scratch_const_size = const_size;
 534     int size = (MAX_inst_size + MAX_stubs_size + _scratch_const_size);
 535     blob = BufferBlob::create("Compile::scratch_buffer", size);
 536     // Record the buffer blob for next time.
 537     set_scratch_buffer_blob(blob);
 538     // Have we run out of code space?
 539     if (scratch_buffer_blob() == NULL) {
 540       // Let CompilerBroker disable further compilations.
 541       record_failure("Not enough space for scratch buffer in CodeCache");
 542       return;
 543     }
 544   }
 545 
 546   // Initialize the relocation buffers
 547   relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
 548   set_scratch_locs_memory(locs_buf);
 549 }
 550 
 551 
 552 //-----------------------scratch_emit_size-------------------------------------
 553 // Helper function that computes size by emitting code
 554 uint Compile::scratch_emit_size(const Node* n) {
 555   // Start scratch_emit_size section.
 556   set_in_scratch_emit_size(true);
 557 
 558   // Emit into a trash buffer and count bytes emitted.
 559   // This is a pretty expensive way to compute a size,
 560   // but it works well enough if seldom used.
 561   // All common fixed-size instructions are given a size
 562   // method by the AD file.
 563   // Note that the scratch buffer blob and locs memory are
 564   // allocated at the beginning of the compile task, and
 565   // may be shared by several calls to scratch_emit_size.
 566   // The allocation of the scratch buffer blob is particularly
 567   // expensive, since it has to grab the code cache lock.
 568   BufferBlob* blob = this->scratch_buffer_blob();
 569   assert(blob != NULL, "Initialize BufferBlob at start");
 570   assert(blob->size() > MAX_inst_size, "sanity");
 571   relocInfo* locs_buf = scratch_locs_memory();
 572   address blob_begin = blob->content_begin();
 573   address blob_end   = (address)locs_buf;
 574   assert(blob->content_contains(blob_end), "sanity");
 575   CodeBuffer buf(blob_begin, blob_end - blob_begin);
 576   buf.initialize_consts_size(_scratch_const_size);
 577   buf.initialize_stubs_size(MAX_stubs_size);
 578   assert(locs_buf != NULL, "sanity");
 579   int lsize = MAX_locs_size / 3;
 580   buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
 581   buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
 582   buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
 583 
 584   // Do the emission.
 585 
 586   Label fakeL; // Fake label for branch instructions.
 587   Label*   saveL = NULL;
 588   uint save_bnum = 0;
 589   bool is_branch = n->is_MachBranch();
 590   if (is_branch) {
 591     MacroAssembler masm(&buf);
 592     masm.bind(fakeL);
 593     n->as_MachBranch()->save_label(&saveL, &save_bnum);
 594     n->as_MachBranch()->label_set(&fakeL, 0);
 595   }
 596   n->emit(buf, this->regalloc());
 597   if (is_branch) // Restore label.
 598     n->as_MachBranch()->label_set(saveL, save_bnum);
 599 
 600   // End scratch_emit_size section.
 601   set_in_scratch_emit_size(false);
 602 
 603   return buf.insts_size();
 604 }
 605 
 606 
 607 // ============================================================================
 608 //------------------------------Compile standard-------------------------------
 609 debug_only( int Compile::_debug_idx = 100000; )
 610 
 611 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 612 // the continuation bci for on stack replacement.
 613 
 614 
 615 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
 616                   bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing )
 617                 : Phase(Compiler),
 618                   _env(ci_env),
 619                   _log(ci_env->log()),
 620                   _compile_id(ci_env->compile_id()),
 621                   _save_argument_registers(false),
 622                   _stub_name(NULL),
 623                   _stub_function(NULL),
 624                   _stub_entry_point(NULL),
 625                   _method(target),
 626                   _entry_bci(osr_bci),
 627                   _initial_gvn(NULL),
 628                   _for_igvn(NULL),
 629                   _warm_calls(NULL),
 630                   _subsume_loads(subsume_loads),
 631                   _do_escape_analysis(do_escape_analysis),
 632                   _eliminate_boxing(eliminate_boxing),
 633                   _failure_reason(NULL),
 634                   _code_buffer("Compile::Fill_buffer"),
 635                   _orig_pc_slot(0),
 636                   _orig_pc_slot_offset_in_bytes(0),
 637                   _has_method_handle_invokes(false),
 638                   _mach_constant_base_node(NULL),
 639                   _node_bundling_limit(0),
 640                   _node_bundling_base(NULL),
 641                   _java_calls(0),
 642                   _inner_loops(0),
 643                   _scratch_const_size(-1),
 644                   _in_scratch_emit_size(false),
 645                   _dead_node_list(comp_arena()),
 646                   _dead_node_count(0),
 647 #ifndef PRODUCT
 648                   _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
 649                   _in_dump_cnt(0),
 650                   _printer(IdealGraphPrinter::printer()),
 651 #endif
 652                   _congraph(NULL),
 653                   _comp_arena(mtCompiler),
 654                   _node_arena(mtCompiler),
 655                   _old_arena(mtCompiler),
 656                   _Compile_types(mtCompiler),
 657                   _replay_inline_data(NULL),
 658                   _late_inlines(comp_arena(), 2, 0, NULL),
 659                   _string_late_inlines(comp_arena(), 2, 0, NULL),
 660                   _boxing_late_inlines(comp_arena(), 2, 0, NULL),
 661                   _late_inlines_pos(0),
 662                   _number_of_mh_late_inlines(0),
 663                   _inlining_progress(false),
 664                   _inlining_incrementally(false),
 665                   _print_inlining_list(NULL),
 666                   _print_inlining_stream(NULL),
 667                   _print_inlining_idx(0),
 668                   _print_inlining_output(NULL),
 669                   _interpreter_frame_size(0),
 670                   _max_node_limit(MaxNodeLimit) {
 671   C = this;
 672 
 673   CompileWrapper cw(this);
 674 
 675   if (CITimeVerbose) {
 676     tty->print(" ");
 677     target->holder()->name()->print();
 678     tty->print(".");
 679     target->print_short_name();
 680     tty->print("  ");
 681   }
 682   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
 683   TraceTime t2(NULL, &_t_methodCompilation, CITime, false);
 684 
 685 #ifndef PRODUCT
 686   bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
 687   if (!print_opto_assembly) {
 688     bool print_assembly = (PrintAssembly || _method->should_print_assembly());
 689     if (print_assembly && !Disassembler::can_decode()) {
 690       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
 691       print_opto_assembly = true;
 692     }
 693   }
 694   set_print_assembly(print_opto_assembly);
 695   set_parsed_irreducible_loop(false);
 696 
 697   if (method()->has_option("ReplayInline")) {
 698     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 699   }
 700 #endif
 701   set_print_inlining(PrintInlining || method()->has_option("PrintInlining") NOT_PRODUCT( || PrintOptoInlining));
 702   set_print_intrinsics(PrintIntrinsics || method()->has_option("PrintIntrinsics"));
 703   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 704 
 705   if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
 706     // Make sure the method being compiled gets its own MDO,
 707     // so we can at least track the decompile_count().
 708     // Need MDO to record RTM code generation state.
 709     method()->ensure_method_data();
 710   }
 711 
 712   Init(::AliasLevel);
 713 
 714 
 715   print_compile_messages();
 716 
 717   _ilt = InlineTree::build_inline_tree_root();
 718 
 719   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 720   assert(num_alias_types() >= AliasIdxRaw, "");
 721 
 722 #define MINIMUM_NODE_HASH  1023
 723   // Node list that Iterative GVN will start with
 724   Unique_Node_List for_igvn(comp_arena());
 725   set_for_igvn(&for_igvn);
 726 
 727   // GVN that will be run immediately on new nodes
 728   uint estimated_size = method()->code_size()*4+64;
 729   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 730   PhaseGVN gvn(node_arena(), estimated_size);
 731   set_initial_gvn(&gvn);
 732 
 733   print_inlining_init();
 734   { // Scope for timing the parser
 735     TracePhase tp("parse", &timers[_t_parser]);
 736 
 737     // Put top into the hash table ASAP.
 738     initial_gvn()->transform_no_reclaim(top());
 739 
 740     // Set up tf(), start(), and find a CallGenerator.
 741     CallGenerator* cg = NULL;
 742     if (is_osr_compilation()) {
 743       const TypeTuple *domain = StartOSRNode::osr_domain();
 744       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 745       init_tf(TypeFunc::make(domain, range));
 746       StartNode* s = new StartOSRNode(root(), domain);
 747       initial_gvn()->set_type_bottom(s);
 748       init_start(s);
 749       cg = CallGenerator::for_osr(method(), entry_bci());
 750     } else {
 751       // Normal case.
 752       init_tf(TypeFunc::make(method()));
 753       StartNode* s = new StartNode(root(), tf()->domain());
 754       initial_gvn()->set_type_bottom(s);
 755       init_start(s);
 756       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
 757         // With java.lang.ref.reference.get() we must go through the
 758         // intrinsic when G1 is enabled - even when get() is the root
 759         // method of the compile - so that, if necessary, the value in
 760         // the referent field of the reference object gets recorded by
 761         // the pre-barrier code.
 762         // Specifically, if G1 is enabled, the value in the referent
 763         // field is recorded by the G1 SATB pre barrier. This will
 764         // result in the referent being marked live and the reference
 765         // object removed from the list of discovered references during
 766         // reference processing.
 767         cg = find_intrinsic(method(), false);
 768       }
 769       if (cg == NULL) {
 770         float past_uses = method()->interpreter_invocation_count();
 771         float expected_uses = past_uses;
 772         cg = CallGenerator::for_inline(method(), expected_uses);
 773       }
 774     }
 775     if (failing())  return;
 776     if (cg == NULL) {
 777       record_method_not_compilable_all_tiers("cannot parse method");
 778       return;
 779     }
 780     JVMState* jvms = build_start_state(start(), tf());
 781     if ((jvms = cg->generate(jvms)) == NULL) {
 782       if (!failure_reason_is(C2Compiler::retry_class_loading_during_parsing())) {
 783         record_method_not_compilable("method parse failed");
 784       }
 785       return;
 786     }
 787     GraphKit kit(jvms);
 788 
 789     if (!kit.stopped()) {
 790       // Accept return values, and transfer control we know not where.
 791       // This is done by a special, unique ReturnNode bound to root.
 792       return_values(kit.jvms());
 793     }
 794 
 795     if (kit.has_exceptions()) {
 796       // Any exceptions that escape from this call must be rethrown
 797       // to whatever caller is dynamically above us on the stack.
 798       // This is done by a special, unique RethrowNode bound to root.
 799       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 800     }
 801 
 802     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 803 
 804     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 805       inline_string_calls(true);
 806     }
 807 
 808     if (failing())  return;
 809 
 810     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
 811 
 812     // Remove clutter produced by parsing.
 813     if (!failing()) {
 814       ResourceMark rm;
 815       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 816     }
 817   }
 818 
 819   // Note:  Large methods are capped off in do_one_bytecode().
 820   if (failing())  return;
 821 
 822   // After parsing, node notes are no longer automagic.
 823   // They must be propagated by register_new_node_with_optimizer(),
 824   // clone(), or the like.
 825   set_default_node_notes(NULL);
 826 
 827   for (;;) {
 828     int successes = Inline_Warm();
 829     if (failing())  return;
 830     if (successes == 0)  break;
 831   }
 832 
 833   // Drain the list.
 834   Finish_Warm();
 835 #ifndef PRODUCT
 836   if (_printer && _printer->should_print(_method)) {
 837     _printer->print_inlining(this);
 838   }
 839 #endif
 840 
 841   if (failing())  return;
 842   NOT_PRODUCT( verify_graph_edges(); )
 843 
 844   // Now optimize
 845   Optimize();
 846   if (failing())  return;
 847   NOT_PRODUCT( verify_graph_edges(); )
 848 
 849 #ifndef PRODUCT
 850   if (PrintIdeal) {
 851     ttyLocker ttyl;  // keep the following output all in one block
 852     // This output goes directly to the tty, not the compiler log.
 853     // To enable tools to match it up with the compilation activity,
 854     // be sure to tag this tty output with the compile ID.
 855     if (xtty != NULL) {
 856       xtty->head("ideal compile_id='%d'%s", compile_id(),
 857                  is_osr_compilation()    ? " compile_kind='osr'" :
 858                  "");
 859     }
 860     root()->dump(9999);
 861     if (xtty != NULL) {
 862       xtty->tail("ideal");
 863     }
 864   }
 865 #endif
 866 
 867   NOT_PRODUCT( verify_barriers(); )
 868 
 869   // Dump compilation data to replay it.
 870   if (method()->has_option("DumpReplay")) {
 871     env()->dump_replay_data(_compile_id);
 872   }
 873   if (method()->has_option("DumpInline") && (ilt() != NULL)) {
 874     env()->dump_inline_data(_compile_id);
 875   }
 876 
 877   // Now that we know the size of all the monitors we can add a fixed slot
 878   // for the original deopt pc.
 879 
 880   _orig_pc_slot =  fixed_slots();
 881   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
 882   set_fixed_slots(next_slot);
 883 
 884   // Compute when to use implicit null checks. Used by matching trap based
 885   // nodes and NullCheck optimization.
 886   set_allowed_deopt_reasons();
 887 
 888   // Now generate code
 889   Code_Gen();
 890   if (failing())  return;
 891 
 892   // Check if we want to skip execution of all compiled code.
 893   {
 894 #ifndef PRODUCT
 895     if (OptoNoExecute) {
 896       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
 897       return;
 898     }
 899 #endif
 900     TracePhase tp("install_code", &timers[_t_registerMethod]);
 901 
 902     if (is_osr_compilation()) {
 903       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
 904       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
 905     } else {
 906       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
 907       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
 908     }
 909 
 910     env()->register_method(_method, _entry_bci,
 911                            &_code_offsets,
 912                            _orig_pc_slot_offset_in_bytes,
 913                            code_buffer(),
 914                            frame_size_in_words(), _oop_map_set,
 915                            &_handler_table, &_inc_table,
 916                            compiler,
 917                            env()->comp_level(),
 918                            has_unsafe_access(),
 919                            SharedRuntime::is_wide_vector(max_vector_size()),
 920                            rtm_state()
 921                            );
 922 
 923     if (log() != NULL) // Print code cache state into compiler log
 924       log()->code_cache_state();
 925   }
 926 }
 927 
 928 //------------------------------Compile----------------------------------------
 929 // Compile a runtime stub
 930 Compile::Compile( ciEnv* ci_env,
 931                   TypeFunc_generator generator,
 932                   address stub_function,
 933                   const char *stub_name,
 934                   int is_fancy_jump,
 935                   bool pass_tls,
 936                   bool save_arg_registers,
 937                   bool return_pc )
 938   : Phase(Compiler),
 939     _env(ci_env),
 940     _log(ci_env->log()),
 941     _compile_id(0),
 942     _save_argument_registers(save_arg_registers),
 943     _method(NULL),
 944     _stub_name(stub_name),
 945     _stub_function(stub_function),
 946     _stub_entry_point(NULL),
 947     _entry_bci(InvocationEntryBci),
 948     _initial_gvn(NULL),
 949     _for_igvn(NULL),
 950     _warm_calls(NULL),
 951     _orig_pc_slot(0),
 952     _orig_pc_slot_offset_in_bytes(0),
 953     _subsume_loads(true),
 954     _do_escape_analysis(false),
 955     _eliminate_boxing(false),
 956     _failure_reason(NULL),
 957     _code_buffer("Compile::Fill_buffer"),
 958     _has_method_handle_invokes(false),
 959     _mach_constant_base_node(NULL),
 960     _node_bundling_limit(0),
 961     _node_bundling_base(NULL),
 962     _java_calls(0),
 963     _inner_loops(0),
 964 #ifndef PRODUCT
 965     _trace_opto_output(TraceOptoOutput),
 966     _in_dump_cnt(0),
 967     _printer(NULL),
 968 #endif
 969     _comp_arena(mtCompiler),
 970     _node_arena(mtCompiler),
 971     _old_arena(mtCompiler),
 972     _Compile_types(mtCompiler),
 973     _dead_node_list(comp_arena()),
 974     _dead_node_count(0),
 975     _congraph(NULL),
 976     _replay_inline_data(NULL),
 977     _number_of_mh_late_inlines(0),
 978     _inlining_progress(false),
 979     _inlining_incrementally(false),
 980     _print_inlining_list(NULL),
 981     _print_inlining_stream(NULL),
 982     _print_inlining_idx(0),
 983     _print_inlining_output(NULL),
 984     _allowed_reasons(0),
 985     _interpreter_frame_size(0),
 986     _max_node_limit(MaxNodeLimit) {
 987   C = this;
 988 
 989   TraceTime t1(NULL, &_t_totalCompilation, CITime, false);
 990   TraceTime t2(NULL, &_t_stubCompilation, CITime, false);
 991 
 992 #ifndef PRODUCT
 993   set_print_assembly(PrintFrameConverterAssembly);
 994   set_parsed_irreducible_loop(false);
 995 #endif
 996   set_has_irreducible_loop(false); // no loops
 997 
 998   CompileWrapper cw(this);
 999   Init(/*AliasLevel=*/ 0);
1000   init_tf((*generator)());
1001 
1002   {
1003     // The following is a dummy for the sake of GraphKit::gen_stub
1004     Unique_Node_List for_igvn(comp_arena());
1005     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
1006     PhaseGVN gvn(Thread::current()->resource_area(),255);
1007     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
1008     gvn.transform_no_reclaim(top());
1009 
1010     GraphKit kit;
1011     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1012   }
1013 
1014   NOT_PRODUCT( verify_graph_edges(); )
1015   Code_Gen();
1016   if (failing())  return;
1017 
1018 
1019   // Entry point will be accessed using compile->stub_entry_point();
1020   if (code_buffer() == NULL) {
1021     Matcher::soft_match_failure();
1022   } else {
1023     if (PrintAssembly && (WizardMode || Verbose))
1024       tty->print_cr("### Stub::%s", stub_name);
1025 
1026     if (!failing()) {
1027       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
1028 
1029       // Make the NMethod
1030       // For now we mark the frame as never safe for profile stackwalking
1031       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
1032                                                       code_buffer(),
1033                                                       CodeOffsets::frame_never_safe,
1034                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
1035                                                       frame_size_in_words(),
1036                                                       _oop_map_set,
1037                                                       save_arg_registers);
1038       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
1039 
1040       _stub_entry_point = rs->entry_point();
1041     }
1042   }
1043 }
1044 
1045 //------------------------------Init-------------------------------------------
1046 // Prepare for a single compilation
1047 void Compile::Init(int aliaslevel) {
1048   _unique  = 0;
1049   _regalloc = NULL;
1050 
1051   _tf      = NULL;  // filled in later
1052   _top     = NULL;  // cached later
1053   _matcher = NULL;  // filled in later
1054   _cfg     = NULL;  // filled in later
1055 
1056   set_24_bit_selection_and_mode(Use24BitFP, false);
1057 
1058   _node_note_array = NULL;
1059   _default_node_notes = NULL;
1060   DEBUG_ONLY( _modified_nodes = NULL; ) // Used in Optimize()
1061 
1062   _immutable_memory = NULL; // filled in at first inquiry
1063 
1064   // Globally visible Nodes
1065   // First set TOP to NULL to give safe behavior during creation of RootNode
1066   set_cached_top_node(NULL);
1067   set_root(new RootNode());
1068   // Now that you have a Root to point to, create the real TOP
1069   set_cached_top_node( new ConNode(Type::TOP) );
1070   set_recent_alloc(NULL, NULL);
1071 
1072   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1073   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1074   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1075   env()->set_dependencies(new Dependencies(env()));
1076 
1077   _fixed_slots = 0;
1078   set_has_split_ifs(false);
1079   set_has_loops(has_method() && method()->has_loops()); // first approximation
1080   set_has_stringbuilder(false);
1081   set_has_boxed_value(false);
1082   _trap_can_recompile = false;  // no traps emitted yet
1083   _major_progress = true; // start out assuming good things will happen
1084   set_has_unsafe_access(false);
1085   set_max_vector_size(0);
1086   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1087   set_decompile_count(0);
1088 
1089   set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
1090   set_num_loop_opts(LoopOptsCount);
1091   set_do_inlining(Inline);
1092   set_max_inline_size(MaxInlineSize);
1093   set_freq_inline_size(FreqInlineSize);
1094   set_do_scheduling(OptoScheduling);
1095   set_do_count_invocations(false);
1096   set_do_method_data_update(false);
1097 
1098   set_do_vector_loop(false);
1099 
1100   bool do_vector = false;
1101   if (AllowVectorizeOnDemand) {
1102     if (has_method() && (method()->has_option("Vectorize") || method()->has_option("VectorizeDebug"))) {
1103       set_do_vector_loop(true);
1104     } else if (has_method() && method()->name() != 0 &&
1105                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1106       set_do_vector_loop(true);
1107     }
1108 #ifndef PRODUCT
1109     if (do_vector_loop() && Verbose) {
1110       tty->print("Compile::Init: do vectorized loops (SIMD like) for method %s\n",  method()->name()->as_quoted_ascii());
1111     }
1112 #endif
1113   }
1114 
1115   set_age_code(has_method() && method()->profile_aging());
1116   set_rtm_state(NoRTM); // No RTM lock eliding by default
1117   method_has_option_value("MaxNodeLimit", _max_node_limit);
1118 #if INCLUDE_RTM_OPT
1119   if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
1120     int rtm_state = method()->method_data()->rtm_state();
1121     if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
1122       // Don't generate RTM lock eliding code.
1123       set_rtm_state(NoRTM);
1124     } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
1125       // Generate RTM lock eliding code without abort ratio calculation code.
1126       set_rtm_state(UseRTM);
1127     } else if (UseRTMDeopt) {
1128       // Generate RTM lock eliding code and include abort ratio calculation
1129       // code if UseRTMDeopt is on.
1130       set_rtm_state(ProfileRTM);
1131     }
1132   }
1133 #endif
1134   if (debug_info()->recording_non_safepoints()) {
1135     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1136                         (comp_arena(), 8, 0, NULL));
1137     set_default_node_notes(Node_Notes::make(this));
1138   }
1139 
1140   // // -- Initialize types before each compile --
1141   // // Update cached type information
1142   // if( _method && _method->constants() )
1143   //   Type::update_loaded_types(_method, _method->constants());
1144 
1145   // Init alias_type map.
1146   if (!_do_escape_analysis && aliaslevel == 3)
1147     aliaslevel = 2;  // No unique types without escape analysis
1148   _AliasLevel = aliaslevel;
1149   const int grow_ats = 16;
1150   _max_alias_types = grow_ats;
1151   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1152   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1153   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1154   {
1155     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1156   }
1157   // Initialize the first few types.
1158   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1159   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1160   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1161   _num_alias_types = AliasIdxRaw+1;
1162   // Zero out the alias type cache.
1163   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1164   // A NULL adr_type hits in the cache right away.  Preload the right answer.
1165   probe_alias_cache(NULL)->_index = AliasIdxTop;
1166 
1167   _intrinsics = NULL;
1168   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1169   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1170   _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1171   register_library_intrinsics();
1172 }
1173 
1174 //---------------------------init_start----------------------------------------
1175 // Install the StartNode on this compile object.
1176 void Compile::init_start(StartNode* s) {
1177   if (failing())
1178     return; // already failing
1179   assert(s == start(), "");
1180 }
1181 
1182 /**
1183  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1184  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1185  * the ideal graph.
1186  */
1187 StartNode* Compile::start() const {
1188   assert (!failing(), err_msg_res("Must not have pending failure. Reason is: %s", failure_reason()));
1189   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1190     Node* start = root()->fast_out(i);
1191     if (start->is_Start()) {
1192       return start->as_Start();
1193     }
1194   }
1195   fatal("Did not find Start node!");
1196   return NULL;
1197 }
1198 
1199 //-------------------------------immutable_memory-------------------------------------
1200 // Access immutable memory
1201 Node* Compile::immutable_memory() {
1202   if (_immutable_memory != NULL) {
1203     return _immutable_memory;
1204   }
1205   StartNode* s = start();
1206   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1207     Node *p = s->fast_out(i);
1208     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1209       _immutable_memory = p;
1210       return _immutable_memory;
1211     }
1212   }
1213   ShouldNotReachHere();
1214   return NULL;
1215 }
1216 
1217 //----------------------set_cached_top_node------------------------------------
1218 // Install the cached top node, and make sure Node::is_top works correctly.
1219 void Compile::set_cached_top_node(Node* tn) {
1220   if (tn != NULL)  verify_top(tn);
1221   Node* old_top = _top;
1222   _top = tn;
1223   // Calling Node::setup_is_top allows the nodes the chance to adjust
1224   // their _out arrays.
1225   if (_top != NULL)     _top->setup_is_top();
1226   if (old_top != NULL)  old_top->setup_is_top();
1227   assert(_top == NULL || top()->is_top(), "");
1228 }
1229 
1230 #ifdef ASSERT
1231 uint Compile::count_live_nodes_by_graph_walk() {
1232   Unique_Node_List useful(comp_arena());
1233   // Get useful node list by walking the graph.
1234   identify_useful_nodes(useful);
1235   return useful.size();
1236 }
1237 
1238 void Compile::print_missing_nodes() {
1239 
1240   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1241   if ((_log == NULL) && (! PrintIdealNodeCount)) {
1242     return;
1243   }
1244 
1245   // This is an expensive function. It is executed only when the user
1246   // specifies VerifyIdealNodeCount option or otherwise knows the
1247   // additional work that needs to be done to identify reachable nodes
1248   // by walking the flow graph and find the missing ones using
1249   // _dead_node_list.
1250 
1251   Unique_Node_List useful(comp_arena());
1252   // Get useful node list by walking the graph.
1253   identify_useful_nodes(useful);
1254 
1255   uint l_nodes = C->live_nodes();
1256   uint l_nodes_by_walk = useful.size();
1257 
1258   if (l_nodes != l_nodes_by_walk) {
1259     if (_log != NULL) {
1260       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1261       _log->stamp();
1262       _log->end_head();
1263     }
1264     VectorSet& useful_member_set = useful.member_set();
1265     int last_idx = l_nodes_by_walk;
1266     for (int i = 0; i < last_idx; i++) {
1267       if (useful_member_set.test(i)) {
1268         if (_dead_node_list.test(i)) {
1269           if (_log != NULL) {
1270             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1271           }
1272           if (PrintIdealNodeCount) {
1273             // Print the log message to tty
1274               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1275               useful.at(i)->dump();
1276           }
1277         }
1278       }
1279       else if (! _dead_node_list.test(i)) {
1280         if (_log != NULL) {
1281           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1282         }
1283         if (PrintIdealNodeCount) {
1284           // Print the log message to tty
1285           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1286         }
1287       }
1288     }
1289     if (_log != NULL) {
1290       _log->tail("mismatched_nodes");
1291     }
1292   }
1293 }
1294 void Compile::record_modified_node(Node* n) {
1295   if (_modified_nodes != NULL && !_inlining_incrementally &&
1296       n->outcnt() != 0 && !n->is_Con()) {
1297     _modified_nodes->push(n);
1298   }
1299 }
1300 
1301 void Compile::remove_modified_node(Node* n) {
1302   if (_modified_nodes != NULL) {
1303     _modified_nodes->remove(n);
1304   }
1305 }
1306 #endif
1307 
1308 #ifndef PRODUCT
1309 void Compile::verify_top(Node* tn) const {
1310   if (tn != NULL) {
1311     assert(tn->is_Con(), "top node must be a constant");
1312     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1313     assert(tn->in(0) != NULL, "must have live top node");
1314   }
1315 }
1316 #endif
1317 
1318 
1319 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1320 
1321 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1322   guarantee(arr != NULL, "");
1323   int num_blocks = arr->length();
1324   if (grow_by < num_blocks)  grow_by = num_blocks;
1325   int num_notes = grow_by * _node_notes_block_size;
1326   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1327   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1328   while (num_notes > 0) {
1329     arr->append(notes);
1330     notes     += _node_notes_block_size;
1331     num_notes -= _node_notes_block_size;
1332   }
1333   assert(num_notes == 0, "exact multiple, please");
1334 }
1335 
1336 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1337   if (source == NULL || dest == NULL)  return false;
1338 
1339   if (dest->is_Con())
1340     return false;               // Do not push debug info onto constants.
1341 
1342 #ifdef ASSERT
1343   // Leave a bread crumb trail pointing to the original node:
1344   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1345     dest->set_debug_orig(source);
1346   }
1347 #endif
1348 
1349   if (node_note_array() == NULL)
1350     return false;               // Not collecting any notes now.
1351 
1352   // This is a copy onto a pre-existing node, which may already have notes.
1353   // If both nodes have notes, do not overwrite any pre-existing notes.
1354   Node_Notes* source_notes = node_notes_at(source->_idx);
1355   if (source_notes == NULL || source_notes->is_clear())  return false;
1356   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1357   if (dest_notes == NULL || dest_notes->is_clear()) {
1358     return set_node_notes_at(dest->_idx, source_notes);
1359   }
1360 
1361   Node_Notes merged_notes = (*source_notes);
1362   // The order of operations here ensures that dest notes will win...
1363   merged_notes.update_from(dest_notes);
1364   return set_node_notes_at(dest->_idx, &merged_notes);
1365 }
1366 
1367 
1368 //--------------------------allow_range_check_smearing-------------------------
1369 // Gating condition for coalescing similar range checks.
1370 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1371 // single covering check that is at least as strong as any of them.
1372 // If the optimization succeeds, the simplified (strengthened) range check
1373 // will always succeed.  If it fails, we will deopt, and then give up
1374 // on the optimization.
1375 bool Compile::allow_range_check_smearing() const {
1376   // If this method has already thrown a range-check,
1377   // assume it was because we already tried range smearing
1378   // and it failed.
1379   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1380   return !already_trapped;
1381 }
1382 
1383 
1384 //------------------------------flatten_alias_type-----------------------------
1385 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1386   int offset = tj->offset();
1387   TypePtr::PTR ptr = tj->ptr();
1388 
1389   // Known instance (scalarizable allocation) alias only with itself.
1390   bool is_known_inst = tj->isa_oopptr() != NULL &&
1391                        tj->is_oopptr()->is_known_instance();
1392 
1393   // Process weird unsafe references.
1394   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1395     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1396     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1397     tj = TypeOopPtr::BOTTOM;
1398     ptr = tj->ptr();
1399     offset = tj->offset();
1400   }
1401 
1402   // Array pointers need some flattening
1403   const TypeAryPtr *ta = tj->isa_aryptr();
1404   if (ta && ta->is_stable()) {
1405     // Erase stability property for alias analysis.
1406     tj = ta = ta->cast_to_stable(false);
1407   }
1408   if( ta && is_known_inst ) {
1409     if ( offset != Type::OffsetBot &&
1410          offset > arrayOopDesc::length_offset_in_bytes() ) {
1411       offset = Type::OffsetBot; // Flatten constant access into array body only
1412       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
1413     }
1414   } else if( ta && _AliasLevel >= 2 ) {
1415     // For arrays indexed by constant indices, we flatten the alias
1416     // space to include all of the array body.  Only the header, klass
1417     // and array length can be accessed un-aliased.
1418     if( offset != Type::OffsetBot ) {
1419       if( ta->const_oop() ) { // MethodData* or Method*
1420         offset = Type::OffsetBot;   // Flatten constant access into array body
1421         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1422       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1423         // range is OK as-is.
1424         tj = ta = TypeAryPtr::RANGE;
1425       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1426         tj = TypeInstPtr::KLASS; // all klass loads look alike
1427         ta = TypeAryPtr::RANGE; // generic ignored junk
1428         ptr = TypePtr::BotPTR;
1429       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1430         tj = TypeInstPtr::MARK;
1431         ta = TypeAryPtr::RANGE; // generic ignored junk
1432         ptr = TypePtr::BotPTR;
1433       } else {                  // Random constant offset into array body
1434         offset = Type::OffsetBot;   // Flatten constant access into array body
1435         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
1436       }
1437     }
1438     // Arrays of fixed size alias with arrays of unknown size.
1439     if (ta->size() != TypeInt::POS) {
1440       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1441       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
1442     }
1443     // Arrays of known objects become arrays of unknown objects.
1444     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1445       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1446       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1447     }
1448     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1449       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1450       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1451     }
1452     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1453     // cannot be distinguished by bytecode alone.
1454     if (ta->elem() == TypeInt::BOOL) {
1455       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1456       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1457       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1458     }
1459     // During the 2nd round of IterGVN, NotNull castings are removed.
1460     // Make sure the Bottom and NotNull variants alias the same.
1461     // Also, make sure exact and non-exact variants alias the same.
1462     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
1463       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1464     }
1465   }
1466 
1467   // Oop pointers need some flattening
1468   const TypeInstPtr *to = tj->isa_instptr();
1469   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1470     ciInstanceKlass *k = to->klass()->as_instance_klass();
1471     if( ptr == TypePtr::Constant ) {
1472       if (to->klass() != ciEnv::current()->Class_klass() ||
1473           offset < k->size_helper() * wordSize) {
1474         // No constant oop pointers (such as Strings); they alias with
1475         // unknown strings.
1476         assert(!is_known_inst, "not scalarizable allocation");
1477         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1478       }
1479     } else if( is_known_inst ) {
1480       tj = to; // Keep NotNull and klass_is_exact for instance type
1481     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1482       // During the 2nd round of IterGVN, NotNull castings are removed.
1483       // Make sure the Bottom and NotNull variants alias the same.
1484       // Also, make sure exact and non-exact variants alias the same.
1485       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1486     }
1487     if (to->speculative() != NULL) {
1488       tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
1489     }
1490     // Canonicalize the holder of this field
1491     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1492       // First handle header references such as a LoadKlassNode, even if the
1493       // object's klass is unloaded at compile time (4965979).
1494       if (!is_known_inst) { // Do it only for non-instance types
1495         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
1496       }
1497     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1498       // Static fields are in the space above the normal instance
1499       // fields in the java.lang.Class instance.
1500       if (to->klass() != ciEnv::current()->Class_klass()) {
1501         to = NULL;
1502         tj = TypeOopPtr::BOTTOM;
1503         offset = tj->offset();
1504       }
1505     } else {
1506       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1507       if (!k->equals(canonical_holder) || tj->offset() != offset) {
1508         if( is_known_inst ) {
1509           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
1510         } else {
1511           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
1512         }
1513       }
1514     }
1515   }
1516 
1517   // Klass pointers to object array klasses need some flattening
1518   const TypeKlassPtr *tk = tj->isa_klassptr();
1519   if( tk ) {
1520     // If we are referencing a field within a Klass, we need
1521     // to assume the worst case of an Object.  Both exact and
1522     // inexact types must flatten to the same alias class so
1523     // use NotNull as the PTR.
1524     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1525 
1526       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1527                                    TypeKlassPtr::OBJECT->klass(),
1528                                    offset);
1529     }
1530 
1531     ciKlass* klass = tk->klass();
1532     if( klass->is_obj_array_klass() ) {
1533       ciKlass* k = TypeAryPtr::OOPS->klass();
1534       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
1535         k = TypeInstPtr::BOTTOM->klass();
1536       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1537     }
1538 
1539     // Check for precise loads from the primary supertype array and force them
1540     // to the supertype cache alias index.  Check for generic array loads from
1541     // the primary supertype array and also force them to the supertype cache
1542     // alias index.  Since the same load can reach both, we need to merge
1543     // these 2 disparate memories into the same alias class.  Since the
1544     // primary supertype array is read-only, there's no chance of confusion
1545     // where we bypass an array load and an array store.
1546     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1547     if (offset == Type::OffsetBot ||
1548         (offset >= primary_supers_offset &&
1549          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1550         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1551       offset = in_bytes(Klass::secondary_super_cache_offset());
1552       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1553     }
1554   }
1555 
1556   // Flatten all Raw pointers together.
1557   if (tj->base() == Type::RawPtr)
1558     tj = TypeRawPtr::BOTTOM;
1559 
1560   if (tj->base() == Type::AnyPtr)
1561     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1562 
1563   // Flatten all to bottom for now
1564   switch( _AliasLevel ) {
1565   case 0:
1566     tj = TypePtr::BOTTOM;
1567     break;
1568   case 1:                       // Flatten to: oop, static, field or array
1569     switch (tj->base()) {
1570     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
1571     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
1572     case Type::AryPtr:   // do not distinguish arrays at all
1573     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
1574     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1575     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
1576     default: ShouldNotReachHere();
1577     }
1578     break;
1579   case 2:                       // No collapsing at level 2; keep all splits
1580   case 3:                       // No collapsing at level 3; keep all splits
1581     break;
1582   default:
1583     Unimplemented();
1584   }
1585 
1586   offset = tj->offset();
1587   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1588 
1589   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1590           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1591           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1592           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1593           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1594           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1595           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
1596           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1597   assert( tj->ptr() != TypePtr::TopPTR &&
1598           tj->ptr() != TypePtr::AnyNull &&
1599           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1600 //    assert( tj->ptr() != TypePtr::Constant ||
1601 //            tj->base() == Type::RawPtr ||
1602 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1603 
1604   return tj;
1605 }
1606 
1607 void Compile::AliasType::Init(int i, const TypePtr* at) {
1608   _index = i;
1609   _adr_type = at;
1610   _field = NULL;
1611   _element = NULL;
1612   _is_rewritable = true; // default
1613   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1614   if (atoop != NULL && atoop->is_known_instance()) {
1615     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1616     _general_index = Compile::current()->get_alias_index(gt);
1617   } else {
1618     _general_index = 0;
1619   }
1620 }
1621 
1622 //---------------------------------print_on------------------------------------
1623 #ifndef PRODUCT
1624 void Compile::AliasType::print_on(outputStream* st) {
1625   if (index() < 10)
1626         st->print("@ <%d> ", index());
1627   else  st->print("@ <%d>",  index());
1628   st->print(is_rewritable() ? "   " : " RO");
1629   int offset = adr_type()->offset();
1630   if (offset == Type::OffsetBot)
1631         st->print(" +any");
1632   else  st->print(" +%-3d", offset);
1633   st->print(" in ");
1634   adr_type()->dump_on(st);
1635   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1636   if (field() != NULL && tjp) {
1637     if (tjp->klass()  != field()->holder() ||
1638         tjp->offset() != field()->offset_in_bytes()) {
1639       st->print(" != ");
1640       field()->print();
1641       st->print(" ***");
1642     }
1643   }
1644 }
1645 
1646 void print_alias_types() {
1647   Compile* C = Compile::current();
1648   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1649   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1650     C->alias_type(idx)->print_on(tty);
1651     tty->cr();
1652   }
1653 }
1654 #endif
1655 
1656 
1657 //----------------------------probe_alias_cache--------------------------------
1658 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1659   intptr_t key = (intptr_t) adr_type;
1660   key ^= key >> logAliasCacheSize;
1661   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1662 }
1663 
1664 
1665 //-----------------------------grow_alias_types--------------------------------
1666 void Compile::grow_alias_types() {
1667   const int old_ats  = _max_alias_types; // how many before?
1668   const int new_ats  = old_ats;          // how many more?
1669   const int grow_ats = old_ats+new_ats;  // how many now?
1670   _max_alias_types = grow_ats;
1671   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1672   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1673   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1674   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1675 }
1676 
1677 
1678 //--------------------------------find_alias_type------------------------------
1679 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1680   if (_AliasLevel == 0)
1681     return alias_type(AliasIdxBot);
1682 
1683   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1684   if (ace->_adr_type == adr_type) {
1685     return alias_type(ace->_index);
1686   }
1687 
1688   // Handle special cases.
1689   if (adr_type == NULL)             return alias_type(AliasIdxTop);
1690   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1691 
1692   // Do it the slow way.
1693   const TypePtr* flat = flatten_alias_type(adr_type);
1694 
1695 #ifdef ASSERT
1696   assert(flat == flatten_alias_type(flat), "idempotent");
1697   assert(flat != TypePtr::BOTTOM,     "cannot alias-analyze an untyped ptr");
1698   if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1699     const TypeOopPtr* foop = flat->is_oopptr();
1700     // Scalarizable allocations have exact klass always.
1701     bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1702     const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1703     assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
1704   }
1705   assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
1706 #endif
1707 
1708   int idx = AliasIdxTop;
1709   for (int i = 0; i < num_alias_types(); i++) {
1710     if (alias_type(i)->adr_type() == flat) {
1711       idx = i;
1712       break;
1713     }
1714   }
1715 
1716   if (idx == AliasIdxTop) {
1717     if (no_create)  return NULL;
1718     // Grow the array if necessary.
1719     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1720     // Add a new alias type.
1721     idx = _num_alias_types++;
1722     _alias_types[idx]->Init(idx, flat);
1723     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1724     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1725     if (flat->isa_instptr()) {
1726       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1727           && flat->is_instptr()->klass() == env()->Class_klass())
1728         alias_type(idx)->set_rewritable(false);
1729     }
1730     if (flat->isa_aryptr()) {
1731 #ifdef ASSERT
1732       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1733       // (T_BYTE has the weakest alignment and size restrictions...)
1734       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1735 #endif
1736       if (flat->offset() == TypePtr::OffsetBot) {
1737         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1738       }
1739     }
1740     if (flat->isa_klassptr()) {
1741       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1742         alias_type(idx)->set_rewritable(false);
1743       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1744         alias_type(idx)->set_rewritable(false);
1745       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1746         alias_type(idx)->set_rewritable(false);
1747       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1748         alias_type(idx)->set_rewritable(false);
1749     }
1750     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1751     // but the base pointer type is not distinctive enough to identify
1752     // references into JavaThread.)
1753 
1754     // Check for final fields.
1755     const TypeInstPtr* tinst = flat->isa_instptr();
1756     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1757       ciField* field;
1758       if (tinst->const_oop() != NULL &&
1759           tinst->klass() == ciEnv::current()->Class_klass() &&
1760           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1761         // static field
1762         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1763         field = k->get_field_by_offset(tinst->offset(), true);
1764       } else {
1765         ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1766         field = k->get_field_by_offset(tinst->offset(), false);
1767       }
1768       assert(field == NULL ||
1769              original_field == NULL ||
1770              (field->holder() == original_field->holder() &&
1771               field->offset() == original_field->offset() &&
1772               field->is_static() == original_field->is_static()), "wrong field?");
1773       // Set field() and is_rewritable() attributes.
1774       if (field != NULL)  alias_type(idx)->set_field(field);
1775     }
1776   }
1777 
1778   // Fill the cache for next time.
1779   ace->_adr_type = adr_type;
1780   ace->_index    = idx;
1781   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1782 
1783   // Might as well try to fill the cache for the flattened version, too.
1784   AliasCacheEntry* face = probe_alias_cache(flat);
1785   if (face->_adr_type == NULL) {
1786     face->_adr_type = flat;
1787     face->_index    = idx;
1788     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1789   }
1790 
1791   return alias_type(idx);
1792 }
1793 
1794 
1795 Compile::AliasType* Compile::alias_type(ciField* field) {
1796   const TypeOopPtr* t;
1797   if (field->is_static())
1798     t = TypeInstPtr::make(field->holder()->java_mirror());
1799   else
1800     t = TypeOopPtr::make_from_klass_raw(field->holder());
1801   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1802   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1803   return atp;
1804 }
1805 
1806 
1807 //------------------------------have_alias_type--------------------------------
1808 bool Compile::have_alias_type(const TypePtr* adr_type) {
1809   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1810   if (ace->_adr_type == adr_type) {
1811     return true;
1812   }
1813 
1814   // Handle special cases.
1815   if (adr_type == NULL)             return true;
1816   if (adr_type == TypePtr::BOTTOM)  return true;
1817 
1818   return find_alias_type(adr_type, true, NULL) != NULL;
1819 }
1820 
1821 //-----------------------------must_alias--------------------------------------
1822 // True if all values of the given address type are in the given alias category.
1823 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1824   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1825   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
1826   if (alias_idx == AliasIdxTop)         return false; // the empty category
1827   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1828 
1829   // the only remaining possible overlap is identity
1830   int adr_idx = get_alias_index(adr_type);
1831   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1832   assert(adr_idx == alias_idx ||
1833          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1834           && adr_type                       != TypeOopPtr::BOTTOM),
1835          "should not be testing for overlap with an unsafe pointer");
1836   return adr_idx == alias_idx;
1837 }
1838 
1839 //------------------------------can_alias--------------------------------------
1840 // True if any values of the given address type are in the given alias category.
1841 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1842   if (alias_idx == AliasIdxTop)         return false; // the empty category
1843   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
1844   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1845   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
1846 
1847   // the only remaining possible overlap is identity
1848   int adr_idx = get_alias_index(adr_type);
1849   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1850   return adr_idx == alias_idx;
1851 }
1852 
1853 
1854 
1855 //---------------------------pop_warm_call-------------------------------------
1856 WarmCallInfo* Compile::pop_warm_call() {
1857   WarmCallInfo* wci = _warm_calls;
1858   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
1859   return wci;
1860 }
1861 
1862 //----------------------------Inline_Warm--------------------------------------
1863 int Compile::Inline_Warm() {
1864   // If there is room, try to inline some more warm call sites.
1865   // %%% Do a graph index compaction pass when we think we're out of space?
1866   if (!InlineWarmCalls)  return 0;
1867 
1868   int calls_made_hot = 0;
1869   int room_to_grow   = NodeCountInliningCutoff - unique();
1870   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1871   int amount_grown   = 0;
1872   WarmCallInfo* call;
1873   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1874     int est_size = (int)call->size();
1875     if (est_size > (room_to_grow - amount_grown)) {
1876       // This one won't fit anyway.  Get rid of it.
1877       call->make_cold();
1878       continue;
1879     }
1880     call->make_hot();
1881     calls_made_hot++;
1882     amount_grown   += est_size;
1883     amount_to_grow -= est_size;
1884   }
1885 
1886   if (calls_made_hot > 0)  set_major_progress();
1887   return calls_made_hot;
1888 }
1889 
1890 
1891 //----------------------------Finish_Warm--------------------------------------
1892 void Compile::Finish_Warm() {
1893   if (!InlineWarmCalls)  return;
1894   if (failing())  return;
1895   if (warm_calls() == NULL)  return;
1896 
1897   // Clean up loose ends, if we are out of space for inlining.
1898   WarmCallInfo* call;
1899   while ((call = pop_warm_call()) != NULL) {
1900     call->make_cold();
1901   }
1902 }
1903 
1904 //---------------------cleanup_loop_predicates-----------------------
1905 // Remove the opaque nodes that protect the predicates so that all unused
1906 // checks and uncommon_traps will be eliminated from the ideal graph
1907 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
1908   if (predicate_count()==0) return;
1909   for (int i = predicate_count(); i > 0; i--) {
1910     Node * n = predicate_opaque1_node(i-1);
1911     assert(n->Opcode() == Op_Opaque1, "must be");
1912     igvn.replace_node(n, n->in(1));
1913   }
1914   assert(predicate_count()==0, "should be clean!");
1915 }
1916 
1917 // StringOpts and late inlining of string methods
1918 void Compile::inline_string_calls(bool parse_time) {
1919   {
1920     // remove useless nodes to make the usage analysis simpler
1921     ResourceMark rm;
1922     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
1923   }
1924 
1925   {
1926     ResourceMark rm;
1927     print_method(PHASE_BEFORE_STRINGOPTS, 3);
1928     PhaseStringOpts pso(initial_gvn(), for_igvn());
1929     print_method(PHASE_AFTER_STRINGOPTS, 3);
1930   }
1931 
1932   // now inline anything that we skipped the first time around
1933   if (!parse_time) {
1934     _late_inlines_pos = _late_inlines.length();
1935   }
1936 
1937   while (_string_late_inlines.length() > 0) {
1938     CallGenerator* cg = _string_late_inlines.pop();
1939     cg->do_late_inline();
1940     if (failing())  return;
1941   }
1942   _string_late_inlines.trunc_to(0);
1943 }
1944 
1945 // Late inlining of boxing methods
1946 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
1947   if (_boxing_late_inlines.length() > 0) {
1948     assert(has_boxed_value(), "inconsistent");
1949 
1950     PhaseGVN* gvn = initial_gvn();
1951     set_inlining_incrementally(true);
1952 
1953     assert( igvn._worklist.size() == 0, "should be done with igvn" );
1954     for_igvn()->clear();
1955     gvn->replace_with(&igvn);
1956 
1957     _late_inlines_pos = _late_inlines.length();
1958 
1959     while (_boxing_late_inlines.length() > 0) {
1960       CallGenerator* cg = _boxing_late_inlines.pop();
1961       cg->do_late_inline();
1962       if (failing())  return;
1963     }
1964     _boxing_late_inlines.trunc_to(0);
1965 
1966     {
1967       ResourceMark rm;
1968       PhaseRemoveUseless pru(gvn, for_igvn());
1969     }
1970 
1971     igvn = PhaseIterGVN(gvn);
1972     igvn.optimize();
1973 
1974     set_inlining_progress(false);
1975     set_inlining_incrementally(false);
1976   }
1977 }
1978 
1979 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
1980   assert(IncrementalInline, "incremental inlining should be on");
1981   PhaseGVN* gvn = initial_gvn();
1982 
1983   set_inlining_progress(false);
1984   for_igvn()->clear();
1985   gvn->replace_with(&igvn);
1986 
1987   {
1988     TracePhase tp("incrementalInline_inline", &timers[_t_incrInline_inline]);
1989     int i = 0;
1990     for (; i <_late_inlines.length() && !inlining_progress(); i++) {
1991       CallGenerator* cg = _late_inlines.at(i);
1992       _late_inlines_pos = i+1;
1993       cg->do_late_inline();
1994       if (failing())  return;
1995     }
1996     int j = 0;
1997     for (; i < _late_inlines.length(); i++, j++) {
1998       _late_inlines.at_put(j, _late_inlines.at(i));
1999     }
2000     _late_inlines.trunc_to(j);
2001   }
2002 
2003   {
2004     TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2005     ResourceMark rm;
2006     PhaseRemoveUseless pru(gvn, for_igvn());
2007   }
2008 
2009   {
2010     TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2011     igvn = PhaseIterGVN(gvn);
2012   }
2013 }
2014 
2015 // Perform incremental inlining until bound on number of live nodes is reached
2016 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2017   TracePhase tp("incrementalInline", &timers[_t_incrInline]);
2018 
2019   PhaseGVN* gvn = initial_gvn();
2020 
2021   set_inlining_incrementally(true);
2022   set_inlining_progress(true);
2023   uint low_live_nodes = 0;
2024 
2025   while(inlining_progress() && _late_inlines.length() > 0) {
2026 
2027     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2028       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2029         TracePhase tp("incrementalInline_ideal", &timers[_t_incrInline_ideal]);
2030         // PhaseIdealLoop is expensive so we only try it once we are
2031         // out of live nodes and we only try it again if the previous
2032         // helped got the number of nodes down significantly
2033         PhaseIdealLoop ideal_loop( igvn, false, true );
2034         if (failing())  return;
2035         low_live_nodes = live_nodes();
2036         _major_progress = true;
2037       }
2038 
2039       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2040         break;
2041       }
2042     }
2043 
2044     inline_incrementally_one(igvn);
2045 
2046     if (failing())  return;
2047 
2048     {
2049       TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2050       igvn.optimize();
2051     }
2052 
2053     if (failing())  return;
2054   }
2055 
2056   assert( igvn._worklist.size() == 0, "should be done with igvn" );
2057 
2058   if (_string_late_inlines.length() > 0) {
2059     assert(has_stringbuilder(), "inconsistent");
2060     for_igvn()->clear();
2061     initial_gvn()->replace_with(&igvn);
2062 
2063     inline_string_calls(false);
2064 
2065     if (failing())  return;
2066 
2067     {
2068       TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2069       ResourceMark rm;
2070       PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2071     }
2072 
2073     {
2074       TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2075       igvn = PhaseIterGVN(gvn);
2076       igvn.optimize();
2077     }
2078   }
2079 
2080   set_inlining_incrementally(false);
2081 }
2082 
2083 
2084 //------------------------------Optimize---------------------------------------
2085 // Given a graph, optimize it.
2086 void Compile::Optimize() {
2087   TracePhase tp("optimizer", &timers[_t_optimizer]);
2088 
2089 #ifndef PRODUCT
2090   if (env()->break_at_compile()) {
2091     BREAKPOINT;
2092   }
2093 
2094 #endif
2095 
2096   ResourceMark rm;
2097   int          loop_opts_cnt;
2098 
2099   print_inlining_reinit();
2100 
2101   NOT_PRODUCT( verify_graph_edges(); )
2102 
2103   print_method(PHASE_AFTER_PARSING);
2104 
2105  {
2106   // Iterative Global Value Numbering, including ideal transforms
2107   // Initialize IterGVN with types and values from parse-time GVN
2108   PhaseIterGVN igvn(initial_gvn());
2109 #ifdef ASSERT
2110   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2111 #endif
2112   {
2113     TracePhase tp("iterGVN", &timers[_t_iterGVN]);
2114     igvn.optimize();
2115   }
2116 
2117   print_method(PHASE_ITER_GVN1, 2);
2118 
2119   if (failing())  return;
2120 
2121   inline_incrementally(igvn);
2122 
2123   print_method(PHASE_INCREMENTAL_INLINE, 2);
2124 
2125   if (failing())  return;
2126 
2127   if (eliminate_boxing()) {
2128     // Inline valueOf() methods now.
2129     inline_boxing_calls(igvn);
2130 
2131     if (AlwaysIncrementalInline) {
2132       inline_incrementally(igvn);
2133     }
2134 
2135     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2136 
2137     if (failing())  return;
2138   }
2139 
2140   // Remove the speculative part of types and clean up the graph from
2141   // the extra CastPP nodes whose only purpose is to carry them. Do
2142   // that early so that optimizations are not disrupted by the extra
2143   // CastPP nodes.
2144   remove_speculative_types(igvn);
2145 
2146   // No more new expensive nodes will be added to the list from here
2147   // so keep only the actual candidates for optimizations.
2148   cleanup_expensive_nodes(igvn);
2149 
2150   // Perform escape analysis
2151   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2152     if (has_loops()) {
2153       // Cleanup graph (remove dead nodes).
2154       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2155       PhaseIdealLoop ideal_loop( igvn, false, true );
2156       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2157       if (failing())  return;
2158     }
2159     ConnectionGraph::do_analysis(this, &igvn);
2160 
2161     if (failing())  return;
2162 
2163     // Optimize out fields loads from scalar replaceable allocations.
2164     igvn.optimize();
2165     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2166 
2167     if (failing())  return;
2168 
2169     if (congraph() != NULL && macro_count() > 0) {
2170       TracePhase tp("macroEliminate", &timers[_t_macroEliminate]);
2171       PhaseMacroExpand mexp(igvn);
2172       mexp.eliminate_macro_nodes();
2173       igvn.set_delay_transform(false);
2174 
2175       igvn.optimize();
2176       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2177 
2178       if (failing())  return;
2179     }
2180   }
2181 
2182   // Loop transforms on the ideal graph.  Range Check Elimination,
2183   // peeling, unrolling, etc.
2184 
2185   // Set loop opts counter
2186   loop_opts_cnt = num_loop_opts();
2187   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2188     {
2189       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2190       PhaseIdealLoop ideal_loop( igvn, true );
2191       loop_opts_cnt--;
2192       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2193       if (failing())  return;
2194     }
2195     // Loop opts pass if partial peeling occurred in previous pass
2196     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
2197       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2198       PhaseIdealLoop ideal_loop( igvn, false );
2199       loop_opts_cnt--;
2200       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2201       if (failing())  return;
2202     }
2203     // Loop opts pass for loop-unrolling before CCP
2204     if(major_progress() && (loop_opts_cnt > 0)) {
2205       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2206       PhaseIdealLoop ideal_loop( igvn, false );
2207       loop_opts_cnt--;
2208       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2209     }
2210     if (!failing()) {
2211       // Verify that last round of loop opts produced a valid graph
2212       TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2213       PhaseIdealLoop::verify(igvn);
2214     }
2215   }
2216   if (failing())  return;
2217 
2218   // Conditional Constant Propagation;
2219   PhaseCCP ccp( &igvn );
2220   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2221   {
2222     TracePhase tp("ccp", &timers[_t_ccp]);
2223     ccp.do_transform();
2224   }
2225   print_method(PHASE_CPP1, 2);
2226 
2227   assert( true, "Break here to ccp.dump_old2new_map()");
2228 
2229   // Iterative Global Value Numbering, including ideal transforms
2230   {
2231     TracePhase tp("iterGVN2", &timers[_t_iterGVN2]);
2232     igvn = ccp;
2233     igvn.optimize();
2234   }
2235 
2236   print_method(PHASE_ITER_GVN2, 2);
2237 
2238   if (failing())  return;
2239 
2240   // Loop transforms on the ideal graph.  Range Check Elimination,
2241   // peeling, unrolling, etc.
2242   if(loop_opts_cnt > 0) {
2243     debug_only( int cnt = 0; );
2244     while(major_progress() && (loop_opts_cnt > 0)) {
2245       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2246       assert( cnt++ < 40, "infinite cycle in loop optimization" );
2247       PhaseIdealLoop ideal_loop( igvn, true);
2248       loop_opts_cnt--;
2249       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2250       if (failing())  return;
2251     }
2252   }
2253 
2254   {
2255     // Verify that all previous optimizations produced a valid graph
2256     // at least to this point, even if no loop optimizations were done.
2257     TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2258     PhaseIdealLoop::verify(igvn);
2259   }
2260 
2261   {
2262     TracePhase tp("macroExpand", &timers[_t_macroExpand]);
2263     PhaseMacroExpand  mex(igvn);
2264     if (mex.expand_macro_nodes()) {
2265       assert(failing(), "must bail out w/ explicit message");
2266       return;
2267     }
2268   }
2269 
2270   DEBUG_ONLY( _modified_nodes = NULL; )
2271  } // (End scope of igvn; run destructor if necessary for asserts.)
2272 
2273   process_print_inlining();
2274   // A method with only infinite loops has no edges entering loops from root
2275   {
2276     TracePhase tp("graphReshape", &timers[_t_graphReshaping]);
2277     if (final_graph_reshaping()) {
2278       assert(failing(), "must bail out w/ explicit message");
2279       return;
2280     }
2281   }
2282 
2283   print_method(PHASE_OPTIMIZE_FINISHED, 2);
2284 }
2285 
2286 
2287 //------------------------------Code_Gen---------------------------------------
2288 // Given a graph, generate code for it
2289 void Compile::Code_Gen() {
2290   if (failing()) {
2291     return;
2292   }
2293 
2294   // Perform instruction selection.  You might think we could reclaim Matcher
2295   // memory PDQ, but actually the Matcher is used in generating spill code.
2296   // Internals of the Matcher (including some VectorSets) must remain live
2297   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2298   // set a bit in reclaimed memory.
2299 
2300   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2301   // nodes.  Mapping is only valid at the root of each matched subtree.
2302   NOT_PRODUCT( verify_graph_edges(); )
2303 
2304   Matcher matcher;
2305   _matcher = &matcher;
2306   {
2307     TracePhase tp("matcher", &timers[_t_matcher]);
2308     matcher.match();
2309   }
2310   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2311   // nodes.  Mapping is only valid at the root of each matched subtree.
2312   NOT_PRODUCT( verify_graph_edges(); )
2313 
2314   // If you have too many nodes, or if matching has failed, bail out
2315   check_node_count(0, "out of nodes matching instructions");
2316   if (failing()) {
2317     return;
2318   }
2319 
2320   // Build a proper-looking CFG
2321   PhaseCFG cfg(node_arena(), root(), matcher);
2322   _cfg = &cfg;
2323   {
2324     TracePhase tp("scheduler", &timers[_t_scheduler]);
2325     bool success = cfg.do_global_code_motion();
2326     if (!success) {
2327       return;
2328     }
2329 
2330     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2331     NOT_PRODUCT( verify_graph_edges(); )
2332     debug_only( cfg.verify(); )
2333   }
2334 
2335   PhaseChaitin regalloc(unique(), cfg, matcher);
2336   _regalloc = &regalloc;
2337   {
2338     TracePhase tp("regalloc", &timers[_t_registerAllocation]);
2339     // Perform register allocation.  After Chaitin, use-def chains are
2340     // no longer accurate (at spill code) and so must be ignored.
2341     // Node->LRG->reg mappings are still accurate.
2342     _regalloc->Register_Allocate();
2343 
2344     // Bail out if the allocator builds too many nodes
2345     if (failing()) {
2346       return;
2347     }
2348   }
2349 
2350   // Prior to register allocation we kept empty basic blocks in case the
2351   // the allocator needed a place to spill.  After register allocation we
2352   // are not adding any new instructions.  If any basic block is empty, we
2353   // can now safely remove it.
2354   {
2355     TracePhase tp("blockOrdering", &timers[_t_blockOrdering]);
2356     cfg.remove_empty_blocks();
2357     if (do_freq_based_layout()) {
2358       PhaseBlockLayout layout(cfg);
2359     } else {
2360       cfg.set_loop_alignment();
2361     }
2362     cfg.fixup_flow();
2363   }
2364 
2365   // Apply peephole optimizations
2366   if( OptoPeephole ) {
2367     TracePhase tp("peephole", &timers[_t_peephole]);
2368     PhasePeephole peep( _regalloc, cfg);
2369     peep.do_transform();
2370   }
2371 
2372   // Do late expand if CPU requires this.
2373   if (Matcher::require_postalloc_expand) {
2374     TracePhase tp("postalloc_expand", &timers[_t_postalloc_expand]);
2375     cfg.postalloc_expand(_regalloc);
2376   }
2377 
2378   // Convert Nodes to instruction bits in a buffer
2379   {
2380     TraceTime tp("output", &timers[_t_output], CITime);
2381     Output();
2382   }
2383 
2384   print_method(PHASE_FINAL_CODE);
2385 
2386   // He's dead, Jim.
2387   _cfg     = (PhaseCFG*)0xdeadbeef;
2388   _regalloc = (PhaseChaitin*)0xdeadbeef;
2389 }
2390 
2391 
2392 //------------------------------dump_asm---------------------------------------
2393 // Dump formatted assembly
2394 #ifndef PRODUCT
2395 void Compile::dump_asm(int *pcs, uint pc_limit) {
2396   bool cut_short = false;
2397   tty->print_cr("#");
2398   tty->print("#  ");  _tf->dump();  tty->cr();
2399   tty->print_cr("#");
2400 
2401   // For all blocks
2402   int pc = 0x0;                 // Program counter
2403   char starts_bundle = ' ';
2404   _regalloc->dump_frame();
2405 
2406   Node *n = NULL;
2407   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
2408     if (VMThread::should_terminate()) {
2409       cut_short = true;
2410       break;
2411     }
2412     Block* block = _cfg->get_block(i);
2413     if (block->is_connector() && !Verbose) {
2414       continue;
2415     }
2416     n = block->head();
2417     if (pcs && n->_idx < pc_limit) {
2418       tty->print("%3.3x   ", pcs[n->_idx]);
2419     } else {
2420       tty->print("      ");
2421     }
2422     block->dump_head(_cfg);
2423     if (block->is_connector()) {
2424       tty->print_cr("        # Empty connector block");
2425     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
2426       tty->print_cr("        # Block is sole successor of call");
2427     }
2428 
2429     // For all instructions
2430     Node *delay = NULL;
2431     for (uint j = 0; j < block->number_of_nodes(); j++) {
2432       if (VMThread::should_terminate()) {
2433         cut_short = true;
2434         break;
2435       }
2436       n = block->get_node(j);
2437       if (valid_bundle_info(n)) {
2438         Bundle* bundle = node_bundling(n);
2439         if (bundle->used_in_unconditional_delay()) {
2440           delay = n;
2441           continue;
2442         }
2443         if (bundle->starts_bundle()) {
2444           starts_bundle = '+';
2445         }
2446       }
2447 
2448       if (WizardMode) {
2449         n->dump();
2450       }
2451 
2452       if( !n->is_Region() &&    // Dont print in the Assembly
2453           !n->is_Phi() &&       // a few noisely useless nodes
2454           !n->is_Proj() &&
2455           !n->is_MachTemp() &&
2456           !n->is_SafePointScalarObject() &&
2457           !n->is_Catch() &&     // Would be nice to print exception table targets
2458           !n->is_MergeMem() &&  // Not very interesting
2459           !n->is_top() &&       // Debug info table constants
2460           !(n->is_Con() && !n->is_Mach())// Debug info table constants
2461           ) {
2462         if (pcs && n->_idx < pc_limit)
2463           tty->print("%3.3x", pcs[n->_idx]);
2464         else
2465           tty->print("   ");
2466         tty->print(" %c ", starts_bundle);
2467         starts_bundle = ' ';
2468         tty->print("\t");
2469         n->format(_regalloc, tty);
2470         tty->cr();
2471       }
2472 
2473       // If we have an instruction with a delay slot, and have seen a delay,
2474       // then back up and print it
2475       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
2476         assert(delay != NULL, "no unconditional delay instruction");
2477         if (WizardMode) delay->dump();
2478 
2479         if (node_bundling(delay)->starts_bundle())
2480           starts_bundle = '+';
2481         if (pcs && n->_idx < pc_limit)
2482           tty->print("%3.3x", pcs[n->_idx]);
2483         else
2484           tty->print("   ");
2485         tty->print(" %c ", starts_bundle);
2486         starts_bundle = ' ';
2487         tty->print("\t");
2488         delay->format(_regalloc, tty);
2489         tty->cr();
2490         delay = NULL;
2491       }
2492 
2493       // Dump the exception table as well
2494       if( n->is_Catch() && (Verbose || WizardMode) ) {
2495         // Print the exception table for this offset
2496         _handler_table.print_subtable_for(pc);
2497       }
2498     }
2499 
2500     if (pcs && n->_idx < pc_limit)
2501       tty->print_cr("%3.3x", pcs[n->_idx]);
2502     else
2503       tty->cr();
2504 
2505     assert(cut_short || delay == NULL, "no unconditional delay branch");
2506 
2507   } // End of per-block dump
2508   tty->cr();
2509 
2510   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
2511 }
2512 #endif
2513 
2514 //------------------------------Final_Reshape_Counts---------------------------
2515 // This class defines counters to help identify when a method
2516 // may/must be executed using hardware with only 24-bit precision.
2517 struct Final_Reshape_Counts : public StackObj {
2518   int  _call_count;             // count non-inlined 'common' calls
2519   int  _float_count;            // count float ops requiring 24-bit precision
2520   int  _double_count;           // count double ops requiring more precision
2521   int  _java_call_count;        // count non-inlined 'java' calls
2522   int  _inner_loop_count;       // count loops which need alignment
2523   VectorSet _visited;           // Visitation flags
2524   Node_List _tests;             // Set of IfNodes & PCTableNodes
2525 
2526   Final_Reshape_Counts() :
2527     _call_count(0), _float_count(0), _double_count(0),
2528     _java_call_count(0), _inner_loop_count(0),
2529     _visited( Thread::current()->resource_area() ) { }
2530 
2531   void inc_call_count  () { _call_count  ++; }
2532   void inc_float_count () { _float_count ++; }
2533   void inc_double_count() { _double_count++; }
2534   void inc_java_call_count() { _java_call_count++; }
2535   void inc_inner_loop_count() { _inner_loop_count++; }
2536 
2537   int  get_call_count  () const { return _call_count  ; }
2538   int  get_float_count () const { return _float_count ; }
2539   int  get_double_count() const { return _double_count; }
2540   int  get_java_call_count() const { return _java_call_count; }
2541   int  get_inner_loop_count() const { return _inner_loop_count; }
2542 };
2543 
2544 #ifdef ASSERT
2545 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
2546   ciInstanceKlass *k = tp->klass()->as_instance_klass();
2547   // Make sure the offset goes inside the instance layout.
2548   return k->contains_field_offset(tp->offset());
2549   // Note that OffsetBot and OffsetTop are very negative.
2550 }
2551 #endif
2552 
2553 // Eliminate trivially redundant StoreCMs and accumulate their
2554 // precedence edges.
2555 void Compile::eliminate_redundant_card_marks(Node* n) {
2556   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
2557   if (n->in(MemNode::Address)->outcnt() > 1) {
2558     // There are multiple users of the same address so it might be
2559     // possible to eliminate some of the StoreCMs
2560     Node* mem = n->in(MemNode::Memory);
2561     Node* adr = n->in(MemNode::Address);
2562     Node* val = n->in(MemNode::ValueIn);
2563     Node* prev = n;
2564     bool done = false;
2565     // Walk the chain of StoreCMs eliminating ones that match.  As
2566     // long as it's a chain of single users then the optimization is
2567     // safe.  Eliminating partially redundant StoreCMs would require
2568     // cloning copies down the other paths.
2569     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
2570       if (adr == mem->in(MemNode::Address) &&
2571           val == mem->in(MemNode::ValueIn)) {
2572         // redundant StoreCM
2573         if (mem->req() > MemNode::OopStore) {
2574           // Hasn't been processed by this code yet.
2575           n->add_prec(mem->in(MemNode::OopStore));
2576         } else {
2577           // Already converted to precedence edge
2578           for (uint i = mem->req(); i < mem->len(); i++) {
2579             // Accumulate any precedence edges
2580             if (mem->in(i) != NULL) {
2581               n->add_prec(mem->in(i));
2582             }
2583           }
2584           // Everything above this point has been processed.
2585           done = true;
2586         }
2587         // Eliminate the previous StoreCM
2588         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
2589         assert(mem->outcnt() == 0, "should be dead");
2590         mem->disconnect_inputs(NULL, this);
2591       } else {
2592         prev = mem;
2593       }
2594       mem = prev->in(MemNode::Memory);
2595     }
2596   }
2597 }
2598 
2599 //------------------------------final_graph_reshaping_impl----------------------
2600 // Implement items 1-5 from final_graph_reshaping below.
2601 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
2602 
2603   if ( n->outcnt() == 0 ) return; // dead node
2604   uint nop = n->Opcode();
2605 
2606   // Check for 2-input instruction with "last use" on right input.
2607   // Swap to left input.  Implements item (2).
2608   if( n->req() == 3 &&          // two-input instruction
2609       n->in(1)->outcnt() > 1 && // left use is NOT a last use
2610       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
2611       n->in(2)->outcnt() == 1 &&// right use IS a last use
2612       !n->in(2)->is_Con() ) {   // right use is not a constant
2613     // Check for commutative opcode
2614     switch( nop ) {
2615     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
2616     case Op_MaxI:  case Op_MinI:
2617     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
2618     case Op_AndL:  case Op_XorL:  case Op_OrL:
2619     case Op_AndI:  case Op_XorI:  case Op_OrI: {
2620       // Move "last use" input to left by swapping inputs
2621       n->swap_edges(1, 2);
2622       break;
2623     }
2624     default:
2625       break;
2626     }
2627   }
2628 
2629 #ifdef ASSERT
2630   if( n->is_Mem() ) {
2631     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
2632     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
2633             // oop will be recorded in oop map if load crosses safepoint
2634             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
2635                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
2636             "raw memory operations should have control edge");
2637   }
2638 #endif
2639   // Count FPU ops and common calls, implements item (3)
2640   switch( nop ) {
2641   // Count all float operations that may use FPU
2642   case Op_AddF:
2643   case Op_SubF:
2644   case Op_MulF:
2645   case Op_DivF:
2646   case Op_NegF:
2647   case Op_ModF:
2648   case Op_ConvI2F:
2649   case Op_ConF:
2650   case Op_CmpF:
2651   case Op_CmpF3:
2652   // case Op_ConvL2F: // longs are split into 32-bit halves
2653     frc.inc_float_count();
2654     break;
2655 
2656   case Op_ConvF2D:
2657   case Op_ConvD2F:
2658     frc.inc_float_count();
2659     frc.inc_double_count();
2660     break;
2661 
2662   // Count all double operations that may use FPU
2663   case Op_AddD:
2664   case Op_SubD:
2665   case Op_MulD:
2666   case Op_DivD:
2667   case Op_NegD:
2668   case Op_ModD:
2669   case Op_ConvI2D:
2670   case Op_ConvD2I:
2671   // case Op_ConvL2D: // handled by leaf call
2672   // case Op_ConvD2L: // handled by leaf call
2673   case Op_ConD:
2674   case Op_CmpD:
2675   case Op_CmpD3:
2676     frc.inc_double_count();
2677     break;
2678   case Op_Opaque1:              // Remove Opaque Nodes before matching
2679   case Op_Opaque2:              // Remove Opaque Nodes before matching
2680   case Op_Opaque3:
2681     n->subsume_by(n->in(1), this);
2682     break;
2683   case Op_CallStaticJava:
2684   case Op_CallJava:
2685   case Op_CallDynamicJava:
2686     frc.inc_java_call_count(); // Count java call site;
2687   case Op_CallRuntime:
2688   case Op_CallLeaf:
2689   case Op_CallLeafNoFP: {
2690     assert( n->is_Call(), "" );
2691     CallNode *call = n->as_Call();
2692     // Count call sites where the FP mode bit would have to be flipped.
2693     // Do not count uncommon runtime calls:
2694     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
2695     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
2696     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
2697       frc.inc_call_count();   // Count the call site
2698     } else {                  // See if uncommon argument is shared
2699       Node *n = call->in(TypeFunc::Parms);
2700       int nop = n->Opcode();
2701       // Clone shared simple arguments to uncommon calls, item (1).
2702       if( n->outcnt() > 1 &&
2703           !n->is_Proj() &&
2704           nop != Op_CreateEx &&
2705           nop != Op_CheckCastPP &&
2706           nop != Op_DecodeN &&
2707           nop != Op_DecodeNKlass &&
2708           !n->is_Mem() ) {
2709         Node *x = n->clone();
2710         call->set_req( TypeFunc::Parms, x );
2711       }
2712     }
2713     break;
2714   }
2715 
2716   case Op_StoreD:
2717   case Op_LoadD:
2718   case Op_LoadD_unaligned:
2719     frc.inc_double_count();
2720     goto handle_mem;
2721   case Op_StoreF:
2722   case Op_LoadF:
2723     frc.inc_float_count();
2724     goto handle_mem;
2725 
2726   case Op_StoreCM:
2727     {
2728       // Convert OopStore dependence into precedence edge
2729       Node* prec = n->in(MemNode::OopStore);
2730       n->del_req(MemNode::OopStore);
2731       n->add_prec(prec);
2732       eliminate_redundant_card_marks(n);
2733     }
2734 
2735     // fall through
2736 
2737   case Op_StoreB:
2738   case Op_StoreC:
2739   case Op_StorePConditional:
2740   case Op_StoreI:
2741   case Op_StoreL:
2742   case Op_StoreIConditional:
2743   case Op_StoreLConditional:
2744   case Op_CompareAndSwapI:
2745   case Op_CompareAndSwapL:
2746   case Op_CompareAndSwapP:
2747   case Op_CompareAndSwapN:
2748   case Op_GetAndAddI:
2749   case Op_GetAndAddL:
2750   case Op_GetAndSetI:
2751   case Op_GetAndSetL:
2752   case Op_GetAndSetP:
2753   case Op_GetAndSetN:
2754   case Op_StoreP:
2755   case Op_StoreN:
2756   case Op_StoreNKlass:
2757   case Op_LoadB:
2758   case Op_LoadUB:
2759   case Op_LoadUS:
2760   case Op_LoadI:
2761   case Op_LoadKlass:
2762   case Op_LoadNKlass:
2763   case Op_LoadL:
2764   case Op_LoadL_unaligned:
2765   case Op_LoadPLocked:
2766   case Op_LoadP:
2767   case Op_LoadN:
2768   case Op_LoadRange:
2769   case Op_LoadS: {
2770   handle_mem:
2771 #ifdef ASSERT
2772     if( VerifyOptoOopOffsets ) {
2773       assert( n->is_Mem(), "" );
2774       MemNode *mem  = (MemNode*)n;
2775       // Check to see if address types have grounded out somehow.
2776       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
2777       assert( !tp || oop_offset_is_sane(tp), "" );
2778     }
2779 #endif
2780     break;
2781   }
2782 
2783   case Op_AddP: {               // Assert sane base pointers
2784     Node *addp = n->in(AddPNode::Address);
2785     assert( !addp->is_AddP() ||
2786             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
2787             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
2788             "Base pointers must match" );
2789 #ifdef _LP64
2790     if ((UseCompressedOops || UseCompressedClassPointers) &&
2791         addp->Opcode() == Op_ConP &&
2792         addp == n->in(AddPNode::Base) &&
2793         n->in(AddPNode::Offset)->is_Con()) {
2794       // Use addressing with narrow klass to load with offset on x86.
2795       // On sparc loading 32-bits constant and decoding it have less
2796       // instructions (4) then load 64-bits constant (7).
2797       // Do this transformation here since IGVN will convert ConN back to ConP.
2798       const Type* t = addp->bottom_type();
2799       if (t->isa_oopptr() || t->isa_klassptr()) {
2800         Node* nn = NULL;
2801 
2802         int op = t->isa_oopptr() ? Op_ConN : Op_ConNKlass;
2803 
2804         // Look for existing ConN node of the same exact type.
2805         Node* r  = root();
2806         uint cnt = r->outcnt();
2807         for (uint i = 0; i < cnt; i++) {
2808           Node* m = r->raw_out(i);
2809           if (m!= NULL && m->Opcode() == op &&
2810               m->bottom_type()->make_ptr() == t) {
2811             nn = m;
2812             break;
2813           }
2814         }
2815         if (nn != NULL) {
2816           // Decode a narrow oop to match address
2817           // [R12 + narrow_oop_reg<<3 + offset]
2818           if (t->isa_oopptr()) {
2819             nn = new DecodeNNode(nn, t);
2820           } else {
2821             nn = new DecodeNKlassNode(nn, t);
2822           }
2823           n->set_req(AddPNode::Base, nn);
2824           n->set_req(AddPNode::Address, nn);
2825           if (addp->outcnt() == 0) {
2826             addp->disconnect_inputs(NULL, this);
2827           }
2828         }
2829       }
2830     }
2831 #endif
2832     break;
2833   }
2834 
2835   case Op_CastPP: {
2836     // Remove CastPP nodes to gain more freedom during scheduling but
2837     // keep the dependency they encode as control or precedence edges
2838     // (if control is set already) on memory operations. Some CastPP
2839     // nodes don't have a control (don't carry a dependency): skip
2840     // those.
2841     if (n->in(0) != NULL) {
2842       ResourceMark rm;
2843       Unique_Node_List wq;
2844       wq.push(n);
2845       for (uint next = 0; next < wq.size(); ++next) {
2846         Node *m = wq.at(next);
2847         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
2848           Node* use = m->fast_out(i);
2849           if (use->is_Mem() || use->is_EncodeNarrowPtr()) {
2850             use->ensure_control_or_add_prec(n->in(0));
2851           } else if (use->in(0) == NULL) {
2852             switch(use->Opcode()) {
2853             case Op_AddP:
2854             case Op_DecodeN:
2855             case Op_DecodeNKlass:
2856             case Op_CheckCastPP:
2857             case Op_CastPP:
2858               wq.push(use);
2859               break;
2860             }
2861           }
2862         }
2863       }
2864     }
2865     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
2866     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
2867       Node* in1 = n->in(1);
2868       const Type* t = n->bottom_type();
2869       Node* new_in1 = in1->clone();
2870       new_in1->as_DecodeN()->set_type(t);
2871 
2872       if (!Matcher::narrow_oop_use_complex_address()) {
2873         //
2874         // x86, ARM and friends can handle 2 adds in addressing mode
2875         // and Matcher can fold a DecodeN node into address by using
2876         // a narrow oop directly and do implicit NULL check in address:
2877         //
2878         // [R12 + narrow_oop_reg<<3 + offset]
2879         // NullCheck narrow_oop_reg
2880         //
2881         // On other platforms (Sparc) we have to keep new DecodeN node and
2882         // use it to do implicit NULL check in address:
2883         //
2884         // decode_not_null narrow_oop_reg, base_reg
2885         // [base_reg + offset]
2886         // NullCheck base_reg
2887         //
2888         // Pin the new DecodeN node to non-null path on these platform (Sparc)
2889         // to keep the information to which NULL check the new DecodeN node
2890         // corresponds to use it as value in implicit_null_check().
2891         //
2892         new_in1->set_req(0, n->in(0));
2893       }
2894 
2895       n->subsume_by(new_in1, this);
2896       if (in1->outcnt() == 0) {
2897         in1->disconnect_inputs(NULL, this);
2898       }
2899     } else {
2900       n->subsume_by(n->in(1), this);
2901       if (n->outcnt() == 0) {
2902         n->disconnect_inputs(NULL, this);
2903       }
2904     }
2905     break;
2906   }
2907 #ifdef _LP64
2908   case Op_CmpP:
2909     // Do this transformation here to preserve CmpPNode::sub() and
2910     // other TypePtr related Ideal optimizations (for example, ptr nullness).
2911     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
2912       Node* in1 = n->in(1);
2913       Node* in2 = n->in(2);
2914       if (!in1->is_DecodeNarrowPtr()) {
2915         in2 = in1;
2916         in1 = n->in(2);
2917       }
2918       assert(in1->is_DecodeNarrowPtr(), "sanity");
2919 
2920       Node* new_in2 = NULL;
2921       if (in2->is_DecodeNarrowPtr()) {
2922         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
2923         new_in2 = in2->in(1);
2924       } else if (in2->Opcode() == Op_ConP) {
2925         const Type* t = in2->bottom_type();
2926         if (t == TypePtr::NULL_PTR) {
2927           assert(in1->is_DecodeN(), "compare klass to null?");
2928           // Don't convert CmpP null check into CmpN if compressed
2929           // oops implicit null check is not generated.
2930           // This will allow to generate normal oop implicit null check.
2931           if (Matcher::gen_narrow_oop_implicit_null_checks())
2932             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
2933           //
2934           // This transformation together with CastPP transformation above
2935           // will generated code for implicit NULL checks for compressed oops.
2936           //
2937           // The original code after Optimize()
2938           //
2939           //    LoadN memory, narrow_oop_reg
2940           //    decode narrow_oop_reg, base_reg
2941           //    CmpP base_reg, NULL
2942           //    CastPP base_reg // NotNull
2943           //    Load [base_reg + offset], val_reg
2944           //
2945           // after these transformations will be
2946           //
2947           //    LoadN memory, narrow_oop_reg
2948           //    CmpN narrow_oop_reg, NULL
2949           //    decode_not_null narrow_oop_reg, base_reg
2950           //    Load [base_reg + offset], val_reg
2951           //
2952           // and the uncommon path (== NULL) will use narrow_oop_reg directly
2953           // since narrow oops can be used in debug info now (see the code in
2954           // final_graph_reshaping_walk()).
2955           //
2956           // At the end the code will be matched to
2957           // on x86:
2958           //
2959           //    Load_narrow_oop memory, narrow_oop_reg
2960           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
2961           //    NullCheck narrow_oop_reg
2962           //
2963           // and on sparc:
2964           //
2965           //    Load_narrow_oop memory, narrow_oop_reg
2966           //    decode_not_null narrow_oop_reg, base_reg
2967           //    Load [base_reg + offset], val_reg
2968           //    NullCheck base_reg
2969           //
2970         } else if (t->isa_oopptr()) {
2971           new_in2 = ConNode::make(t->make_narrowoop());
2972         } else if (t->isa_klassptr()) {
2973           new_in2 = ConNode::make(t->make_narrowklass());
2974         }
2975       }
2976       if (new_in2 != NULL) {
2977         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
2978         n->subsume_by(cmpN, this);
2979         if (in1->outcnt() == 0) {
2980           in1->disconnect_inputs(NULL, this);
2981         }
2982         if (in2->outcnt() == 0) {
2983           in2->disconnect_inputs(NULL, this);
2984         }
2985       }
2986     }
2987     break;
2988 
2989   case Op_DecodeN:
2990   case Op_DecodeNKlass:
2991     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
2992     // DecodeN could be pinned when it can't be fold into
2993     // an address expression, see the code for Op_CastPP above.
2994     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
2995     break;
2996 
2997   case Op_EncodeP:
2998   case Op_EncodePKlass: {
2999     Node* in1 = n->in(1);
3000     if (in1->is_DecodeNarrowPtr()) {
3001       n->subsume_by(in1->in(1), this);
3002     } else if (in1->Opcode() == Op_ConP) {
3003       const Type* t = in1->bottom_type();
3004       if (t == TypePtr::NULL_PTR) {
3005         assert(t->isa_oopptr(), "null klass?");
3006         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
3007       } else if (t->isa_oopptr()) {
3008         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
3009       } else if (t->isa_klassptr()) {
3010         n->subsume_by(ConNode::make(t->make_narrowklass()), this);
3011       }
3012     }
3013     if (in1->outcnt() == 0) {
3014       in1->disconnect_inputs(NULL, this);
3015     }
3016     break;
3017   }
3018 
3019   case Op_Proj: {
3020     if (OptimizeStringConcat) {
3021       ProjNode* p = n->as_Proj();
3022       if (p->_is_io_use) {
3023         // Separate projections were used for the exception path which
3024         // are normally removed by a late inline.  If it wasn't inlined
3025         // then they will hang around and should just be replaced with
3026         // the original one.
3027         Node* proj = NULL;
3028         // Replace with just one
3029         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
3030           Node *use = i.get();
3031           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
3032             proj = use;
3033             break;
3034           }
3035         }
3036         assert(proj != NULL, "must be found");
3037         p->subsume_by(proj, this);
3038       }
3039     }
3040     break;
3041   }
3042 
3043   case Op_Phi:
3044     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3045       // The EncodeP optimization may create Phi with the same edges
3046       // for all paths. It is not handled well by Register Allocator.
3047       Node* unique_in = n->in(1);
3048       assert(unique_in != NULL, "");
3049       uint cnt = n->req();
3050       for (uint i = 2; i < cnt; i++) {
3051         Node* m = n->in(i);
3052         assert(m != NULL, "");
3053         if (unique_in != m)
3054           unique_in = NULL;
3055       }
3056       if (unique_in != NULL) {
3057         n->subsume_by(unique_in, this);
3058       }
3059     }
3060     break;
3061 
3062 #endif
3063 
3064   case Op_ModI:
3065     if (UseDivMod) {
3066       // Check if a%b and a/b both exist
3067       Node* d = n->find_similar(Op_DivI);
3068       if (d) {
3069         // Replace them with a fused divmod if supported
3070         if (Matcher::has_match_rule(Op_DivModI)) {
3071           DivModINode* divmod = DivModINode::make(n);
3072           d->subsume_by(divmod->div_proj(), this);
3073           n->subsume_by(divmod->mod_proj(), this);
3074         } else {
3075           // replace a%b with a-((a/b)*b)
3076           Node* mult = new MulINode(d, d->in(2));
3077           Node* sub  = new SubINode(d->in(1), mult);
3078           n->subsume_by(sub, this);
3079         }
3080       }
3081     }
3082     break;
3083 
3084   case Op_ModL:
3085     if (UseDivMod) {
3086       // Check if a%b and a/b both exist
3087       Node* d = n->find_similar(Op_DivL);
3088       if (d) {
3089         // Replace them with a fused divmod if supported
3090         if (Matcher::has_match_rule(Op_DivModL)) {
3091           DivModLNode* divmod = DivModLNode::make(n);
3092           d->subsume_by(divmod->div_proj(), this);
3093           n->subsume_by(divmod->mod_proj(), this);
3094         } else {
3095           // replace a%b with a-((a/b)*b)
3096           Node* mult = new MulLNode(d, d->in(2));
3097           Node* sub  = new SubLNode(d->in(1), mult);
3098           n->subsume_by(sub, this);
3099         }
3100       }
3101     }
3102     break;
3103 
3104   case Op_LoadVector:
3105   case Op_StoreVector:
3106     break;
3107 
3108   case Op_AddReductionVI:
3109   case Op_AddReductionVL:
3110   case Op_AddReductionVF:
3111   case Op_AddReductionVD:
3112   case Op_MulReductionVI:
3113   case Op_MulReductionVF:
3114   case Op_MulReductionVD:
3115     break;
3116 
3117   case Op_PackB:
3118   case Op_PackS:
3119   case Op_PackI:
3120   case Op_PackF:
3121   case Op_PackL:
3122   case Op_PackD:
3123     if (n->req()-1 > 2) {
3124       // Replace many operand PackNodes with a binary tree for matching
3125       PackNode* p = (PackNode*) n;
3126       Node* btp = p->binary_tree_pack(1, n->req());
3127       n->subsume_by(btp, this);
3128     }
3129     break;
3130   case Op_Loop:
3131   case Op_CountedLoop:
3132     if (n->as_Loop()->is_inner_loop()) {
3133       frc.inc_inner_loop_count();
3134     }
3135     break;
3136   case Op_LShiftI:
3137   case Op_RShiftI:
3138   case Op_URShiftI:
3139   case Op_LShiftL:
3140   case Op_RShiftL:
3141   case Op_URShiftL:
3142     if (Matcher::need_masked_shift_count) {
3143       // The cpu's shift instructions don't restrict the count to the
3144       // lower 5/6 bits. We need to do the masking ourselves.
3145       Node* in2 = n->in(2);
3146       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3147       const TypeInt* t = in2->find_int_type();
3148       if (t != NULL && t->is_con()) {
3149         juint shift = t->get_con();
3150         if (shift > mask) { // Unsigned cmp
3151           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3152         }
3153       } else {
3154         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
3155           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3156           n->set_req(2, shift);
3157         }
3158       }
3159       if (in2->outcnt() == 0) { // Remove dead node
3160         in2->disconnect_inputs(NULL, this);
3161       }
3162     }
3163     break;
3164   case Op_MemBarStoreStore:
3165   case Op_MemBarRelease:
3166     // Break the link with AllocateNode: it is no longer useful and
3167     // confuses register allocation.
3168     if (n->req() > MemBarNode::Precedent) {
3169       n->set_req(MemBarNode::Precedent, top());
3170     }
3171     break;
3172   default:
3173     assert( !n->is_Call(), "" );
3174     assert( !n->is_Mem(), "" );
3175     assert( nop != Op_ProfileBoolean, "should be eliminated during IGVN");
3176     break;
3177   }
3178 
3179   // Collect CFG split points
3180   if (n->is_MultiBranch())
3181     frc._tests.push(n);
3182 }
3183 
3184 //------------------------------final_graph_reshaping_walk---------------------
3185 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3186 // requires that the walk visits a node's inputs before visiting the node.
3187 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
3188   ResourceArea *area = Thread::current()->resource_area();
3189   Unique_Node_List sfpt(area);
3190 
3191   frc._visited.set(root->_idx); // first, mark node as visited
3192   uint cnt = root->req();
3193   Node *n = root;
3194   uint  i = 0;
3195   while (true) {
3196     if (i < cnt) {
3197       // Place all non-visited non-null inputs onto stack
3198       Node* m = n->in(i);
3199       ++i;
3200       if (m != NULL && !frc._visited.test_set(m->_idx)) {
3201         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
3202           // compute worst case interpreter size in case of a deoptimization
3203           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3204 
3205           sfpt.push(m);
3206         }
3207         cnt = m->req();
3208         nstack.push(n, i); // put on stack parent and next input's index
3209         n = m;
3210         i = 0;
3211       }
3212     } else {
3213       // Now do post-visit work
3214       final_graph_reshaping_impl( n, frc );
3215       if (nstack.is_empty())
3216         break;             // finished
3217       n = nstack.node();   // Get node from stack
3218       cnt = n->req();
3219       i = nstack.index();
3220       nstack.pop();        // Shift to the next node on stack
3221     }
3222   }
3223 
3224   // Skip next transformation if compressed oops are not used.
3225   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3226       (!UseCompressedOops && !UseCompressedClassPointers))
3227     return;
3228 
3229   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3230   // It could be done for an uncommon traps or any safepoints/calls
3231   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3232   while (sfpt.size() > 0) {
3233     n = sfpt.pop();
3234     JVMState *jvms = n->as_SafePoint()->jvms();
3235     assert(jvms != NULL, "sanity");
3236     int start = jvms->debug_start();
3237     int end   = n->req();
3238     bool is_uncommon = (n->is_CallStaticJava() &&
3239                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
3240     for (int j = start; j < end; j++) {
3241       Node* in = n->in(j);
3242       if (in->is_DecodeNarrowPtr()) {
3243         bool safe_to_skip = true;
3244         if (!is_uncommon ) {
3245           // Is it safe to skip?
3246           for (uint i = 0; i < in->outcnt(); i++) {
3247             Node* u = in->raw_out(i);
3248             if (!u->is_SafePoint() ||
3249                  u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
3250               safe_to_skip = false;
3251             }
3252           }
3253         }
3254         if (safe_to_skip) {
3255           n->set_req(j, in->in(1));
3256         }
3257         if (in->outcnt() == 0) {
3258           in->disconnect_inputs(NULL, this);
3259         }
3260       }
3261     }
3262   }
3263 }
3264 
3265 //------------------------------final_graph_reshaping--------------------------
3266 // Final Graph Reshaping.
3267 //
3268 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3269 //     and not commoned up and forced early.  Must come after regular
3270 //     optimizations to avoid GVN undoing the cloning.  Clone constant
3271 //     inputs to Loop Phis; these will be split by the allocator anyways.
3272 //     Remove Opaque nodes.
3273 // (2) Move last-uses by commutative operations to the left input to encourage
3274 //     Intel update-in-place two-address operations and better register usage
3275 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
3276 //     calls canonicalizing them back.
3277 // (3) Count the number of double-precision FP ops, single-precision FP ops
3278 //     and call sites.  On Intel, we can get correct rounding either by
3279 //     forcing singles to memory (requires extra stores and loads after each
3280 //     FP bytecode) or we can set a rounding mode bit (requires setting and
3281 //     clearing the mode bit around call sites).  The mode bit is only used
3282 //     if the relative frequency of single FP ops to calls is low enough.
3283 //     This is a key transform for SPEC mpeg_audio.
3284 // (4) Detect infinite loops; blobs of code reachable from above but not
3285 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
3286 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
3287 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
3288 //     Detection is by looking for IfNodes where only 1 projection is
3289 //     reachable from below or CatchNodes missing some targets.
3290 // (5) Assert for insane oop offsets in debug mode.
3291 
3292 bool Compile::final_graph_reshaping() {
3293   // an infinite loop may have been eliminated by the optimizer,
3294   // in which case the graph will be empty.
3295   if (root()->req() == 1) {
3296     record_method_not_compilable("trivial infinite loop");
3297     return true;
3298   }
3299 
3300   // Expensive nodes have their control input set to prevent the GVN
3301   // from freely commoning them. There's no GVN beyond this point so
3302   // no need to keep the control input. We want the expensive nodes to
3303   // be freely moved to the least frequent code path by gcm.
3304   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
3305   for (int i = 0; i < expensive_count(); i++) {
3306     _expensive_nodes->at(i)->set_req(0, NULL);
3307   }
3308 
3309   Final_Reshape_Counts frc;
3310 
3311   // Visit everybody reachable!
3312   // Allocate stack of size C->unique()/2 to avoid frequent realloc
3313   Node_Stack nstack(unique() >> 1);
3314   final_graph_reshaping_walk(nstack, root(), frc);
3315 
3316   // Check for unreachable (from below) code (i.e., infinite loops).
3317   for( uint i = 0; i < frc._tests.size(); i++ ) {
3318     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
3319     // Get number of CFG targets.
3320     // Note that PCTables include exception targets after calls.
3321     uint required_outcnt = n->required_outcnt();
3322     if (n->outcnt() != required_outcnt) {
3323       // Check for a few special cases.  Rethrow Nodes never take the
3324       // 'fall-thru' path, so expected kids is 1 less.
3325       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
3326         if (n->in(0)->in(0)->is_Call()) {
3327           CallNode *call = n->in(0)->in(0)->as_Call();
3328           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
3329             required_outcnt--;      // Rethrow always has 1 less kid
3330           } else if (call->req() > TypeFunc::Parms &&
3331                      call->is_CallDynamicJava()) {
3332             // Check for null receiver. In such case, the optimizer has
3333             // detected that the virtual call will always result in a null
3334             // pointer exception. The fall-through projection of this CatchNode
3335             // will not be populated.
3336             Node *arg0 = call->in(TypeFunc::Parms);
3337             if (arg0->is_Type() &&
3338                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
3339               required_outcnt--;
3340             }
3341           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
3342                      call->req() > TypeFunc::Parms+1 &&
3343                      call->is_CallStaticJava()) {
3344             // Check for negative array length. In such case, the optimizer has
3345             // detected that the allocation attempt will always result in an
3346             // exception. There is no fall-through projection of this CatchNode .
3347             Node *arg1 = call->in(TypeFunc::Parms+1);
3348             if (arg1->is_Type() &&
3349                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
3350               required_outcnt--;
3351             }
3352           }
3353         }
3354       }
3355       // Recheck with a better notion of 'required_outcnt'
3356       if (n->outcnt() != required_outcnt) {
3357         record_method_not_compilable("malformed control flow");
3358         return true;            // Not all targets reachable!
3359       }
3360     }
3361     // Check that I actually visited all kids.  Unreached kids
3362     // must be infinite loops.
3363     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
3364       if (!frc._visited.test(n->fast_out(j)->_idx)) {
3365         record_method_not_compilable("infinite loop");
3366         return true;            // Found unvisited kid; must be unreach
3367       }
3368   }
3369 
3370   // If original bytecodes contained a mixture of floats and doubles
3371   // check if the optimizer has made it homogenous, item (3).
3372   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
3373       frc.get_float_count() > 32 &&
3374       frc.get_double_count() == 0 &&
3375       (10 * frc.get_call_count() < frc.get_float_count()) ) {
3376     set_24_bit_selection_and_mode( false,  true );
3377   }
3378 
3379   set_java_calls(frc.get_java_call_count());
3380   set_inner_loops(frc.get_inner_loop_count());
3381 
3382   // No infinite loops, no reason to bail out.
3383   return false;
3384 }
3385 
3386 //-----------------------------too_many_traps----------------------------------
3387 // Report if there are too many traps at the current method and bci.
3388 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
3389 bool Compile::too_many_traps(ciMethod* method,
3390                              int bci,
3391                              Deoptimization::DeoptReason reason) {
3392   if (method->has_injected_profile()) {
3393     return false;
3394   }
3395   ciMethodData* md = method->method_data();
3396   if (md->is_empty()) {
3397     // Assume the trap has not occurred, or that it occurred only
3398     // because of a transient condition during start-up in the interpreter.
3399     return false;
3400   }
3401   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3402   if (md->has_trap_at(bci, m, reason) != 0) {
3403     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
3404     // Also, if there are multiple reasons, or if there is no per-BCI record,
3405     // assume the worst.
3406     if (log())
3407       log()->elem("observe trap='%s' count='%d'",
3408                   Deoptimization::trap_reason_name(reason),
3409                   md->trap_count(reason));
3410     return true;
3411   } else {
3412     // Ignore method/bci and see if there have been too many globally.
3413     return too_many_traps(reason, md);
3414   }
3415 }
3416 
3417 // Less-accurate variant which does not require a method and bci.
3418 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
3419                              ciMethodData* logmd) {
3420   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
3421     // Too many traps globally.
3422     // Note that we use cumulative trap_count, not just md->trap_count.
3423     if (log()) {
3424       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
3425       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
3426                   Deoptimization::trap_reason_name(reason),
3427                   mcount, trap_count(reason));
3428     }
3429     return true;
3430   } else {
3431     // The coast is clear.
3432     return false;
3433   }
3434 }
3435 
3436 //--------------------------too_many_recompiles--------------------------------
3437 // Report if there are too many recompiles at the current method and bci.
3438 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
3439 // Is not eager to return true, since this will cause the compiler to use
3440 // Action_none for a trap point, to avoid too many recompilations.
3441 bool Compile::too_many_recompiles(ciMethod* method,
3442                                   int bci,
3443                                   Deoptimization::DeoptReason reason) {
3444   if (method->has_injected_profile()) {
3445     return false;
3446   }
3447   ciMethodData* md = method->method_data();
3448   if (md->is_empty()) {
3449     // Assume the trap has not occurred, or that it occurred only
3450     // because of a transient condition during start-up in the interpreter.
3451     return false;
3452   }
3453   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
3454   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
3455   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
3456   Deoptimization::DeoptReason per_bc_reason
3457     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
3458   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3459   if ((per_bc_reason == Deoptimization::Reason_none
3460        || md->has_trap_at(bci, m, reason) != 0)
3461       // The trap frequency measure we care about is the recompile count:
3462       && md->trap_recompiled_at(bci, m)
3463       && md->overflow_recompile_count() >= bc_cutoff) {
3464     // Do not emit a trap here if it has already caused recompilations.
3465     // Also, if there are multiple reasons, or if there is no per-BCI record,
3466     // assume the worst.
3467     if (log())
3468       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
3469                   Deoptimization::trap_reason_name(reason),
3470                   md->trap_count(reason),
3471                   md->overflow_recompile_count());
3472     return true;
3473   } else if (trap_count(reason) != 0
3474              && decompile_count() >= m_cutoff) {
3475     // Too many recompiles globally, and we have seen this sort of trap.
3476     // Use cumulative decompile_count, not just md->decompile_count.
3477     if (log())
3478       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
3479                   Deoptimization::trap_reason_name(reason),
3480                   md->trap_count(reason), trap_count(reason),
3481                   md->decompile_count(), decompile_count());
3482     return true;
3483   } else {
3484     // The coast is clear.
3485     return false;
3486   }
3487 }
3488 
3489 // Compute when not to trap. Used by matching trap based nodes and
3490 // NullCheck optimization.
3491 void Compile::set_allowed_deopt_reasons() {
3492   _allowed_reasons = 0;
3493   if (is_method_compilation()) {
3494     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
3495       assert(rs < BitsPerInt, "recode bit map");
3496       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
3497         _allowed_reasons |= nth_bit(rs);
3498       }
3499     }
3500   }
3501 }
3502 
3503 #ifndef PRODUCT
3504 //------------------------------verify_graph_edges---------------------------
3505 // Walk the Graph and verify that there is a one-to-one correspondence
3506 // between Use-Def edges and Def-Use edges in the graph.
3507 void Compile::verify_graph_edges(bool no_dead_code) {
3508   if (VerifyGraphEdges) {
3509     ResourceArea *area = Thread::current()->resource_area();
3510     Unique_Node_List visited(area);
3511     // Call recursive graph walk to check edges
3512     _root->verify_edges(visited);
3513     if (no_dead_code) {
3514       // Now make sure that no visited node is used by an unvisited node.
3515       bool dead_nodes = false;
3516       Unique_Node_List checked(area);
3517       while (visited.size() > 0) {
3518         Node* n = visited.pop();
3519         checked.push(n);
3520         for (uint i = 0; i < n->outcnt(); i++) {
3521           Node* use = n->raw_out(i);
3522           if (checked.member(use))  continue;  // already checked
3523           if (visited.member(use))  continue;  // already in the graph
3524           if (use->is_Con())        continue;  // a dead ConNode is OK
3525           // At this point, we have found a dead node which is DU-reachable.
3526           if (!dead_nodes) {
3527             tty->print_cr("*** Dead nodes reachable via DU edges:");
3528             dead_nodes = true;
3529           }
3530           use->dump(2);
3531           tty->print_cr("---");
3532           checked.push(use);  // No repeats; pretend it is now checked.
3533         }
3534       }
3535       assert(!dead_nodes, "using nodes must be reachable from root");
3536     }
3537   }
3538 }
3539 
3540 // Verify GC barriers consistency
3541 // Currently supported:
3542 // - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
3543 void Compile::verify_barriers() {
3544   if (UseG1GC) {
3545     // Verify G1 pre-barriers
3546     const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active());
3547 
3548     ResourceArea *area = Thread::current()->resource_area();
3549     Unique_Node_List visited(area);
3550     Node_List worklist(area);
3551     // We're going to walk control flow backwards starting from the Root
3552     worklist.push(_root);
3553     while (worklist.size() > 0) {
3554       Node* x = worklist.pop();
3555       if (x == NULL || x == top()) continue;
3556       if (visited.member(x)) {
3557         continue;
3558       } else {
3559         visited.push(x);
3560       }
3561 
3562       if (x->is_Region()) {
3563         for (uint i = 1; i < x->req(); i++) {
3564           worklist.push(x->in(i));
3565         }
3566       } else {
3567         worklist.push(x->in(0));
3568         // We are looking for the pattern:
3569         //                            /->ThreadLocal
3570         // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
3571         //              \->ConI(0)
3572         // We want to verify that the If and the LoadB have the same control
3573         // See GraphKit::g1_write_barrier_pre()
3574         if (x->is_If()) {
3575           IfNode *iff = x->as_If();
3576           if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
3577             CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
3578             if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
3579                 && cmp->in(1)->is_Load()) {
3580               LoadNode* load = cmp->in(1)->as_Load();
3581               if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
3582                   && load->in(2)->in(3)->is_Con()
3583                   && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
3584 
3585                 Node* if_ctrl = iff->in(0);
3586                 Node* load_ctrl = load->in(0);
3587 
3588                 if (if_ctrl != load_ctrl) {
3589                   // Skip possible CProj->NeverBranch in infinite loops
3590                   if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
3591                       && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
3592                     if_ctrl = if_ctrl->in(0)->in(0);
3593                   }
3594                 }
3595                 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
3596               }
3597             }
3598           }
3599         }
3600       }
3601     }
3602   }
3603 }
3604 
3605 #endif
3606 
3607 // The Compile object keeps track of failure reasons separately from the ciEnv.
3608 // This is required because there is not quite a 1-1 relation between the
3609 // ciEnv and its compilation task and the Compile object.  Note that one
3610 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
3611 // to backtrack and retry without subsuming loads.  Other than this backtracking
3612 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
3613 // by the logic in C2Compiler.
3614 void Compile::record_failure(const char* reason) {
3615   if (log() != NULL) {
3616     log()->elem("failure reason='%s' phase='compile'", reason);
3617   }
3618   if (_failure_reason == NULL) {
3619     // Record the first failure reason.
3620     _failure_reason = reason;
3621   }
3622 
3623   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
3624     C->print_method(PHASE_FAILURE);
3625   }
3626   _root = NULL;  // flush the graph, too
3627 }
3628 
3629 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator)
3630   : TraceTime(name, accumulator, CITime, CITimeVerbose),
3631     _phase_name(name), _dolog(CITimeVerbose)
3632 {
3633   if (_dolog) {
3634     C = Compile::current();
3635     _log = C->log();
3636   } else {
3637     C = NULL;
3638     _log = NULL;
3639   }
3640   if (_log != NULL) {
3641     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3642     _log->stamp();
3643     _log->end_head();
3644   }
3645 }
3646 
3647 Compile::TracePhase::~TracePhase() {
3648 
3649   C = Compile::current();
3650   if (_dolog) {
3651     _log = C->log();
3652   } else {
3653     _log = NULL;
3654   }
3655 
3656 #ifdef ASSERT
3657   if (PrintIdealNodeCount) {
3658     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
3659                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
3660   }
3661 
3662   if (VerifyIdealNodeCount) {
3663     Compile::current()->print_missing_nodes();
3664   }
3665 #endif
3666 
3667   if (_log != NULL) {
3668     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3669   }
3670 }
3671 
3672 //=============================================================================
3673 // Two Constant's are equal when the type and the value are equal.
3674 bool Compile::Constant::operator==(const Constant& other) {
3675   if (type()          != other.type()         )  return false;
3676   if (can_be_reused() != other.can_be_reused())  return false;
3677   // For floating point values we compare the bit pattern.
3678   switch (type()) {
3679   case T_FLOAT:   return (_v._value.i == other._v._value.i);
3680   case T_LONG:
3681   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
3682   case T_OBJECT:
3683   case T_ADDRESS: return (_v._value.l == other._v._value.l);
3684   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
3685   case T_METADATA: return (_v._metadata == other._v._metadata);
3686   default: ShouldNotReachHere();
3687   }
3688   return false;
3689 }
3690 
3691 static int type_to_size_in_bytes(BasicType t) {
3692   switch (t) {
3693   case T_LONG:    return sizeof(jlong  );
3694   case T_FLOAT:   return sizeof(jfloat );
3695   case T_DOUBLE:  return sizeof(jdouble);
3696   case T_METADATA: return sizeof(Metadata*);
3697     // We use T_VOID as marker for jump-table entries (labels) which
3698     // need an internal word relocation.
3699   case T_VOID:
3700   case T_ADDRESS:
3701   case T_OBJECT:  return sizeof(jobject);
3702   }
3703 
3704   ShouldNotReachHere();
3705   return -1;
3706 }
3707 
3708 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
3709   // sort descending
3710   if (a->freq() > b->freq())  return -1;
3711   if (a->freq() < b->freq())  return  1;
3712   return 0;
3713 }
3714 
3715 void Compile::ConstantTable::calculate_offsets_and_size() {
3716   // First, sort the array by frequencies.
3717   _constants.sort(qsort_comparator);
3718 
3719 #ifdef ASSERT
3720   // Make sure all jump-table entries were sorted to the end of the
3721   // array (they have a negative frequency).
3722   bool found_void = false;
3723   for (int i = 0; i < _constants.length(); i++) {
3724     Constant con = _constants.at(i);
3725     if (con.type() == T_VOID)
3726       found_void = true;  // jump-tables
3727     else
3728       assert(!found_void, "wrong sorting");
3729   }
3730 #endif
3731 
3732   int offset = 0;
3733   for (int i = 0; i < _constants.length(); i++) {
3734     Constant* con = _constants.adr_at(i);
3735 
3736     // Align offset for type.
3737     int typesize = type_to_size_in_bytes(con->type());
3738     offset = align_size_up(offset, typesize);
3739     con->set_offset(offset);   // set constant's offset
3740 
3741     if (con->type() == T_VOID) {
3742       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
3743       offset = offset + typesize * n->outcnt();  // expand jump-table
3744     } else {
3745       offset = offset + typesize;
3746     }
3747   }
3748 
3749   // Align size up to the next section start (which is insts; see
3750   // CodeBuffer::align_at_start).
3751   assert(_size == -1, "already set?");
3752   _size = align_size_up(offset, CodeEntryAlignment);
3753 }
3754 
3755 void Compile::ConstantTable::emit(CodeBuffer& cb) {
3756   MacroAssembler _masm(&cb);
3757   for (int i = 0; i < _constants.length(); i++) {
3758     Constant con = _constants.at(i);
3759     address constant_addr;
3760     switch (con.type()) {
3761     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
3762     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
3763     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
3764     case T_OBJECT: {
3765       jobject obj = con.get_jobject();
3766       int oop_index = _masm.oop_recorder()->find_index(obj);
3767       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
3768       break;
3769     }
3770     case T_ADDRESS: {
3771       address addr = (address) con.get_jobject();
3772       constant_addr = _masm.address_constant(addr);
3773       break;
3774     }
3775     // We use T_VOID as marker for jump-table entries (labels) which
3776     // need an internal word relocation.
3777     case T_VOID: {
3778       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
3779       // Fill the jump-table with a dummy word.  The real value is
3780       // filled in later in fill_jump_table.
3781       address dummy = (address) n;
3782       constant_addr = _masm.address_constant(dummy);
3783       // Expand jump-table
3784       for (uint i = 1; i < n->outcnt(); i++) {
3785         address temp_addr = _masm.address_constant(dummy + i);
3786         assert(temp_addr, "consts section too small");
3787       }
3788       break;
3789     }
3790     case T_METADATA: {
3791       Metadata* obj = con.get_metadata();
3792       int metadata_index = _masm.oop_recorder()->find_index(obj);
3793       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
3794       break;
3795     }
3796     default: ShouldNotReachHere();
3797     }
3798     assert(constant_addr, "consts section too small");
3799     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
3800             err_msg_res("must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset())));
3801   }
3802 }
3803 
3804 int Compile::ConstantTable::find_offset(Constant& con) const {
3805   int idx = _constants.find(con);
3806   assert(idx != -1, "constant must be in constant table");
3807   int offset = _constants.at(idx).offset();
3808   assert(offset != -1, "constant table not emitted yet?");
3809   return offset;
3810 }
3811 
3812 void Compile::ConstantTable::add(Constant& con) {
3813   if (con.can_be_reused()) {
3814     int idx = _constants.find(con);
3815     if (idx != -1 && _constants.at(idx).can_be_reused()) {
3816       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
3817       return;
3818     }
3819   }
3820   (void) _constants.append(con);
3821 }
3822 
3823 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
3824   Block* b = Compile::current()->cfg()->get_block_for_node(n);
3825   Constant con(type, value, b->_freq);
3826   add(con);
3827   return con;
3828 }
3829 
3830 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
3831   Constant con(metadata);
3832   add(con);
3833   return con;
3834 }
3835 
3836 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
3837   jvalue value;
3838   BasicType type = oper->type()->basic_type();
3839   switch (type) {
3840   case T_LONG:    value.j = oper->constantL(); break;
3841   case T_FLOAT:   value.f = oper->constantF(); break;
3842   case T_DOUBLE:  value.d = oper->constantD(); break;
3843   case T_OBJECT:
3844   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
3845   case T_METADATA: return add((Metadata*)oper->constant()); break;
3846   default: guarantee(false, err_msg_res("unhandled type: %s", type2name(type)));
3847   }
3848   return add(n, type, value);
3849 }
3850 
3851 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
3852   jvalue value;
3853   // We can use the node pointer here to identify the right jump-table
3854   // as this method is called from Compile::Fill_buffer right before
3855   // the MachNodes are emitted and the jump-table is filled (means the
3856   // MachNode pointers do not change anymore).
3857   value.l = (jobject) n;
3858   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
3859   add(con);
3860   return con;
3861 }
3862 
3863 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
3864   // If called from Compile::scratch_emit_size do nothing.
3865   if (Compile::current()->in_scratch_emit_size())  return;
3866 
3867   assert(labels.is_nonempty(), "must be");
3868   assert((uint) labels.length() == n->outcnt(), err_msg_res("must be equal: %d == %d", labels.length(), n->outcnt()));
3869 
3870   // Since MachConstantNode::constant_offset() also contains
3871   // table_base_offset() we need to subtract the table_base_offset()
3872   // to get the plain offset into the constant table.
3873   int offset = n->constant_offset() - table_base_offset();
3874 
3875   MacroAssembler _masm(&cb);
3876   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
3877 
3878   for (uint i = 0; i < n->outcnt(); i++) {
3879     address* constant_addr = &jump_table_base[i];
3880     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)));
3881     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
3882     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
3883   }
3884 }
3885 
3886 //----------------------------static_subtype_check-----------------------------
3887 // Shortcut important common cases when superklass is exact:
3888 // (0) superklass is java.lang.Object (can occur in reflective code)
3889 // (1) subklass is already limited to a subtype of superklass => always ok
3890 // (2) subklass does not overlap with superklass => always fail
3891 // (3) superklass has NO subtypes and we can check with a simple compare.
3892 int Compile::static_subtype_check(ciKlass* superk, ciKlass* subk) {
3893   if (StressReflectiveCode) {
3894     return SSC_full_test;       // Let caller generate the general case.
3895   }
3896 
3897   if (superk == env()->Object_klass()) {
3898     return SSC_always_true;     // (0) this test cannot fail
3899   }
3900 
3901   ciType* superelem = superk;
3902   if (superelem->is_array_klass())
3903     superelem = superelem->as_array_klass()->base_element_type();
3904 
3905   if (!subk->is_interface()) {  // cannot trust static interface types yet
3906     if (subk->is_subtype_of(superk)) {
3907       return SSC_always_true;   // (1) false path dead; no dynamic test needed
3908     }
3909     if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
3910         !superk->is_subtype_of(subk)) {
3911       return SSC_always_false;
3912     }
3913   }
3914 
3915   // If casting to an instance klass, it must have no subtypes
3916   if (superk->is_interface()) {
3917     // Cannot trust interfaces yet.
3918     // %%% S.B. superk->nof_implementors() == 1
3919   } else if (superelem->is_instance_klass()) {
3920     ciInstanceKlass* ik = superelem->as_instance_klass();
3921     if (!ik->has_subklass() && !ik->is_interface()) {
3922       if (!ik->is_final()) {
3923         // Add a dependency if there is a chance of a later subclass.
3924         dependencies()->assert_leaf_type(ik);
3925       }
3926       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
3927     }
3928   } else {
3929     // A primitive array type has no subtypes.
3930     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
3931   }
3932 
3933   return SSC_full_test;
3934 }
3935 
3936 Node* Compile::conv_I2X_index(PhaseGVN *phase, Node* idx, const TypeInt* sizetype) {
3937 #ifdef _LP64
3938   // The scaled index operand to AddP must be a clean 64-bit value.
3939   // Java allows a 32-bit int to be incremented to a negative
3940   // value, which appears in a 64-bit register as a large
3941   // positive number.  Using that large positive number as an
3942   // operand in pointer arithmetic has bad consequences.
3943   // On the other hand, 32-bit overflow is rare, and the possibility
3944   // can often be excluded, if we annotate the ConvI2L node with
3945   // a type assertion that its value is known to be a small positive
3946   // number.  (The prior range check has ensured this.)
3947   // This assertion is used by ConvI2LNode::Ideal.
3948   int index_max = max_jint - 1;  // array size is max_jint, index is one less
3949   if (sizetype != NULL)  index_max = sizetype->_hi - 1;
3950   const TypeLong* lidxtype = TypeLong::make(CONST64(0), index_max, Type::WidenMax);
3951   idx = phase->transform(new ConvI2LNode(idx, lidxtype));
3952 #endif
3953   return idx;
3954 }
3955 
3956 // The message about the current inlining is accumulated in
3957 // _print_inlining_stream and transfered into the _print_inlining_list
3958 // once we know whether inlining succeeds or not. For regular
3959 // inlining, messages are appended to the buffer pointed by
3960 // _print_inlining_idx in the _print_inlining_list. For late inlining,
3961 // a new buffer is added after _print_inlining_idx in the list. This
3962 // way we can update the inlining message for late inlining call site
3963 // when the inlining is attempted again.
3964 void Compile::print_inlining_init() {
3965   if (print_inlining() || print_intrinsics()) {
3966     _print_inlining_stream = new stringStream();
3967     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
3968   }
3969 }
3970 
3971 void Compile::print_inlining_reinit() {
3972   if (print_inlining() || print_intrinsics()) {
3973     // Re allocate buffer when we change ResourceMark
3974     _print_inlining_stream = new stringStream();
3975   }
3976 }
3977 
3978 void Compile::print_inlining_reset() {
3979   _print_inlining_stream->reset();
3980 }
3981 
3982 void Compile::print_inlining_commit() {
3983   assert(print_inlining() || print_intrinsics(), "PrintInlining off?");
3984   // Transfer the message from _print_inlining_stream to the current
3985   // _print_inlining_list buffer and clear _print_inlining_stream.
3986   _print_inlining_list->at(_print_inlining_idx).ss()->write(_print_inlining_stream->as_string(), _print_inlining_stream->size());
3987   print_inlining_reset();
3988 }
3989 
3990 void Compile::print_inlining_push() {
3991   // Add new buffer to the _print_inlining_list at current position
3992   _print_inlining_idx++;
3993   _print_inlining_list->insert_before(_print_inlining_idx, PrintInliningBuffer());
3994 }
3995 
3996 Compile::PrintInliningBuffer& Compile::print_inlining_current() {
3997   return _print_inlining_list->at(_print_inlining_idx);
3998 }
3999 
4000 void Compile::print_inlining_update(CallGenerator* cg) {
4001   if (print_inlining() || print_intrinsics()) {
4002     if (!cg->is_late_inline()) {
4003       if (print_inlining_current().cg() != NULL) {
4004         print_inlining_push();
4005       }
4006       print_inlining_commit();
4007     } else {
4008       if (print_inlining_current().cg() != cg &&
4009           (print_inlining_current().cg() != NULL ||
4010            print_inlining_current().ss()->size() != 0)) {
4011         print_inlining_push();
4012       }
4013       print_inlining_commit();
4014       print_inlining_current().set_cg(cg);
4015     }
4016   }
4017 }
4018 
4019 void Compile::print_inlining_move_to(CallGenerator* cg) {
4020   // We resume inlining at a late inlining call site. Locate the
4021   // corresponding inlining buffer so that we can update it.
4022   if (print_inlining()) {
4023     for (int i = 0; i < _print_inlining_list->length(); i++) {
4024       if (_print_inlining_list->adr_at(i)->cg() == cg) {
4025         _print_inlining_idx = i;
4026         return;
4027       }
4028     }
4029     ShouldNotReachHere();
4030   }
4031 }
4032 
4033 void Compile::print_inlining_update_delayed(CallGenerator* cg) {
4034   if (print_inlining()) {
4035     assert(_print_inlining_stream->size() > 0, "missing inlining msg");
4036     assert(print_inlining_current().cg() == cg, "wrong entry");
4037     // replace message with new message
4038     _print_inlining_list->at_put(_print_inlining_idx, PrintInliningBuffer());
4039     print_inlining_commit();
4040     print_inlining_current().set_cg(cg);
4041   }
4042 }
4043 
4044 void Compile::print_inlining_assert_ready() {
4045   assert(!_print_inlining || _print_inlining_stream->size() == 0, "loosing data");
4046 }
4047 
4048 void Compile::process_print_inlining() {
4049   bool do_print_inlining = print_inlining() || print_intrinsics();
4050   if (do_print_inlining || log() != NULL) {
4051     // Print inlining message for candidates that we couldn't inline
4052     // for lack of space
4053     for (int i = 0; i < _late_inlines.length(); i++) {
4054       CallGenerator* cg = _late_inlines.at(i);
4055       if (!cg->is_mh_late_inline()) {
4056         const char* msg = "live nodes > LiveNodeCountInliningCutoff";
4057         if (do_print_inlining) {
4058           cg->print_inlining_late(msg);
4059         }
4060         log_late_inline_failure(cg, msg);
4061       }
4062     }
4063   }
4064   if (do_print_inlining) {
4065     ResourceMark rm;
4066     stringStream ss;
4067     for (int i = 0; i < _print_inlining_list->length(); i++) {
4068       ss.print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
4069     }
4070     size_t end = ss.size();
4071     _print_inlining_output = NEW_ARENA_ARRAY(comp_arena(), char, end+1);
4072     strncpy(_print_inlining_output, ss.base(), end+1);
4073     _print_inlining_output[end] = 0;
4074   }
4075 }
4076 
4077 void Compile::dump_print_inlining() {
4078   if (_print_inlining_output != NULL) {
4079     tty->print_raw(_print_inlining_output);
4080   }
4081 }
4082 
4083 void Compile::log_late_inline(CallGenerator* cg) {
4084   if (log() != NULL) {
4085     log()->head("late_inline method='%d'  inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
4086                 cg->unique_id());
4087     JVMState* p = cg->call_node()->jvms();
4088     while (p != NULL) {
4089       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4090       p = p->caller();
4091     }
4092     log()->tail("late_inline");
4093   }
4094 }
4095 
4096 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4097   log_late_inline(cg);
4098   if (log() != NULL) {
4099     log()->inline_fail(msg);
4100   }
4101 }
4102 
4103 void Compile::log_inline_id(CallGenerator* cg) {
4104   if (log() != NULL) {
4105     // The LogCompilation tool needs a unique way to identify late
4106     // inline call sites. This id must be unique for this call site in
4107     // this compilation. Try to have it unique across compilations as
4108     // well because it can be convenient when grepping through the log
4109     // file.
4110     // Distinguish OSR compilations from others in case CICountOSR is
4111     // on.
4112     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4113     cg->set_unique_id(id);
4114     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4115   }
4116 }
4117 
4118 void Compile::log_inline_failure(const char* msg) {
4119   if (C->log() != NULL) {
4120     C->log()->inline_fail(msg);
4121   }
4122 }
4123 
4124 
4125 // Dump inlining replay data to the stream.
4126 // Don't change thread state and acquire any locks.
4127 void Compile::dump_inline_data(outputStream* out) {
4128   InlineTree* inl_tree = ilt();
4129   if (inl_tree != NULL) {
4130     out->print(" inline %d", inl_tree->count());
4131     inl_tree->dump_replay_data(out);
4132   }
4133 }
4134 
4135 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4136   if (n1->Opcode() < n2->Opcode())      return -1;
4137   else if (n1->Opcode() > n2->Opcode()) return 1;
4138 
4139   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()));
4140   for (uint i = 1; i < n1->req(); i++) {
4141     if (n1->in(i) < n2->in(i))      return -1;
4142     else if (n1->in(i) > n2->in(i)) return 1;
4143   }
4144 
4145   return 0;
4146 }
4147 
4148 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4149   Node* n1 = *n1p;
4150   Node* n2 = *n2p;
4151 
4152   return cmp_expensive_nodes(n1, n2);
4153 }
4154 
4155 void Compile::sort_expensive_nodes() {
4156   if (!expensive_nodes_sorted()) {
4157     _expensive_nodes->sort(cmp_expensive_nodes);
4158   }
4159 }
4160 
4161 bool Compile::expensive_nodes_sorted() const {
4162   for (int i = 1; i < _expensive_nodes->length(); i++) {
4163     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
4164       return false;
4165     }
4166   }
4167   return true;
4168 }
4169 
4170 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4171   if (_expensive_nodes->length() == 0) {
4172     return false;
4173   }
4174 
4175   assert(OptimizeExpensiveOps, "optimization off?");
4176 
4177   // Take this opportunity to remove dead nodes from the list
4178   int j = 0;
4179   for (int i = 0; i < _expensive_nodes->length(); i++) {
4180     Node* n = _expensive_nodes->at(i);
4181     if (!n->is_unreachable(igvn)) {
4182       assert(n->is_expensive(), "should be expensive");
4183       _expensive_nodes->at_put(j, n);
4184       j++;
4185     }
4186   }
4187   _expensive_nodes->trunc_to(j);
4188 
4189   // Then sort the list so that similar nodes are next to each other
4190   // and check for at least two nodes of identical kind with same data
4191   // inputs.
4192   sort_expensive_nodes();
4193 
4194   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
4195     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
4196       return true;
4197     }
4198   }
4199 
4200   return false;
4201 }
4202 
4203 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4204   if (_expensive_nodes->length() == 0) {
4205     return;
4206   }
4207 
4208   assert(OptimizeExpensiveOps, "optimization off?");
4209 
4210   // Sort to bring similar nodes next to each other and clear the
4211   // control input of nodes for which there's only a single copy.
4212   sort_expensive_nodes();
4213 
4214   int j = 0;
4215   int identical = 0;
4216   int i = 0;
4217   bool modified = false;
4218   for (; i < _expensive_nodes->length()-1; i++) {
4219     assert(j <= i, "can't write beyond current index");
4220     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
4221       identical++;
4222       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4223       continue;
4224     }
4225     if (identical > 0) {
4226       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4227       identical = 0;
4228     } else {
4229       Node* n = _expensive_nodes->at(i);
4230       igvn.replace_input_of(n, 0, NULL);
4231       igvn.hash_insert(n);
4232       modified = true;
4233     }
4234   }
4235   if (identical > 0) {
4236     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4237   } else if (_expensive_nodes->length() >= 1) {
4238     Node* n = _expensive_nodes->at(i);
4239     igvn.replace_input_of(n, 0, NULL);
4240     igvn.hash_insert(n);
4241     modified = true;
4242   }
4243   _expensive_nodes->trunc_to(j);
4244   if (modified) {
4245     igvn.optimize();
4246   }
4247 }
4248 
4249 void Compile::add_expensive_node(Node * n) {
4250   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
4251   assert(n->is_expensive(), "expensive nodes with non-null control here only");
4252   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4253   if (OptimizeExpensiveOps) {
4254     _expensive_nodes->append(n);
4255   } else {
4256     // Clear control input and let IGVN optimize expensive nodes if
4257     // OptimizeExpensiveOps is off.
4258     n->set_req(0, NULL);
4259   }
4260 }
4261 
4262 /**
4263  * Remove the speculative part of types and clean up the graph
4264  */
4265 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4266   if (UseTypeSpeculation) {
4267     Unique_Node_List worklist;
4268     worklist.push(root());
4269     int modified = 0;
4270     // Go over all type nodes that carry a speculative type, drop the
4271     // speculative part of the type and enqueue the node for an igvn
4272     // which may optimize it out.
4273     for (uint next = 0; next < worklist.size(); ++next) {
4274       Node *n  = worklist.at(next);
4275       if (n->is_Type()) {
4276         TypeNode* tn = n->as_Type();
4277         const Type* t = tn->type();
4278         const Type* t_no_spec = t->remove_speculative();
4279         if (t_no_spec != t) {
4280           bool in_hash = igvn.hash_delete(n);
4281           assert(in_hash, "node should be in igvn hash table");
4282           tn->set_type(t_no_spec);
4283           igvn.hash_insert(n);
4284           igvn._worklist.push(n); // give it a chance to go away
4285           modified++;
4286         }
4287       }
4288       uint max = n->len();
4289       for( uint i = 0; i < max; ++i ) {
4290         Node *m = n->in(i);
4291         if (not_a_node(m))  continue;
4292         worklist.push(m);
4293       }
4294     }
4295     // Drop the speculative part of all types in the igvn's type table
4296     igvn.remove_speculative_types();
4297     if (modified > 0) {
4298       igvn.optimize();
4299     }
4300 #ifdef ASSERT
4301     // Verify that after the IGVN is over no speculative type has resurfaced
4302     worklist.clear();
4303     worklist.push(root());
4304     for (uint next = 0; next < worklist.size(); ++next) {
4305       Node *n  = worklist.at(next);
4306       const Type* t = igvn.type_or_null(n);
4307       assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
4308       if (n->is_Type()) {
4309         t = n->as_Type()->type();
4310         assert(t == t->remove_speculative(), "no more speculative types");
4311       }
4312       uint max = n->len();
4313       for( uint i = 0; i < max; ++i ) {
4314         Node *m = n->in(i);
4315         if (not_a_node(m))  continue;
4316         worklist.push(m);
4317       }
4318     }
4319     igvn.check_no_speculative_types();
4320 #endif
4321   }
4322 }
4323 
4324 // Auxiliary method to support randomized stressing/fuzzing.
4325 //
4326 // This method can be called the arbitrary number of times, with current count
4327 // as the argument. The logic allows selecting a single candidate from the
4328 // running list of candidates as follows:
4329 //    int count = 0;
4330 //    Cand* selected = null;
4331 //    while(cand = cand->next()) {
4332 //      if (randomized_select(++count)) {
4333 //        selected = cand;
4334 //      }
4335 //    }
4336 //
4337 // Including count equalizes the chances any candidate is "selected".
4338 // This is useful when we don't have the complete list of candidates to choose
4339 // from uniformly. In this case, we need to adjust the randomicity of the
4340 // selection, or else we will end up biasing the selection towards the latter
4341 // candidates.
4342 //
4343 // Quick back-envelope calculation shows that for the list of n candidates
4344 // the equal probability for the candidate to persist as "best" can be
4345 // achieved by replacing it with "next" k-th candidate with the probability
4346 // of 1/k. It can be easily shown that by the end of the run, the
4347 // probability for any candidate is converged to 1/n, thus giving the
4348 // uniform distribution among all the candidates.
4349 //
4350 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
4351 #define RANDOMIZED_DOMAIN_POW 29
4352 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
4353 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
4354 bool Compile::randomized_select(int count) {
4355   assert(count > 0, "only positive");
4356   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
4357 }
4358 
4359 const char*   CloneMap::debug_option_name = "CloneMapDebug";
4360 CloneMap&     Compile::clone_map()                 { return _clone_map; }
4361 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
4362 
4363 void NodeCloneInfo::dump() const {
4364   tty->print(" {%d:%d} ", idx(), gen());
4365 }
4366 
4367 void CloneMap::clone(Node* old, Node* nnn, int gen) {
4368   uint64_t val = value(old->_idx);
4369   NodeCloneInfo cio(val);
4370   assert(val != 0, "old node should be in the map");
4371   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
4372   insert(nnn->_idx, cin.get());
4373 #ifndef PRODUCT
4374   if (is_debug()) {
4375     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
4376   }
4377 #endif
4378 }
4379 
4380 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
4381   NodeCloneInfo cio(value(old->_idx));
4382   if (cio.get() == 0) {
4383     cio.set(old->_idx, 0);
4384     insert(old->_idx, cio.get());
4385 #ifndef PRODUCT
4386     if (is_debug()) {
4387       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
4388     }
4389 #endif
4390   }
4391   clone(old, nnn, gen);
4392 }
4393 
4394 int CloneMap::max_gen() const {
4395   int g = 0;
4396   DictI di(_dict);
4397   for(; di.test(); ++di) {
4398     int t = gen(di._key);
4399     if (g < t) {
4400       g = t;
4401 #ifndef PRODUCT
4402       if (is_debug()) {
4403         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
4404       }
4405 #endif
4406     }
4407   }
4408   return g;
4409 }
4410 
4411 void CloneMap::dump(node_idx_t key) const {
4412   uint64_t val = value(key);
4413   if (val != 0) {
4414     NodeCloneInfo ni(val);
4415     ni.dump();
4416   }
4417 }