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 
 598   // Emitting into the scratch buffer should not fail
 599   assert (!failing(), "Must not have pending failure. Reason is: %s", failure_reason());
 600 
 601   if (is_branch) // Restore label.
 602     n->as_MachBranch()->label_set(saveL, save_bnum);
 603 
 604   // End scratch_emit_size section.
 605   set_in_scratch_emit_size(false);
 606 
 607   return buf.insts_size();
 608 }
 609 
 610 
 611 // ============================================================================
 612 //------------------------------Compile standard-------------------------------
 613 debug_only( int Compile::_debug_idx = 100000; )
 614 
 615 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 616 // the continuation bci for on stack replacement.
 617 
 618 
 619 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
 620                   bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing )
 621                 : Phase(Compiler),
 622                   _env(ci_env),
 623                   _log(ci_env->log()),
 624                   _compile_id(ci_env->compile_id()),
 625                   _save_argument_registers(false),
 626                   _stub_name(NULL),
 627                   _stub_function(NULL),
 628                   _stub_entry_point(NULL),
 629                   _method(target),
 630                   _entry_bci(osr_bci),
 631                   _initial_gvn(NULL),
 632                   _for_igvn(NULL),
 633                   _warm_calls(NULL),
 634                   _subsume_loads(subsume_loads),
 635                   _do_escape_analysis(do_escape_analysis),
 636                   _eliminate_boxing(eliminate_boxing),
 637                   _failure_reason(NULL),
 638                   _code_buffer("Compile::Fill_buffer"),
 639                   _orig_pc_slot(0),
 640                   _orig_pc_slot_offset_in_bytes(0),
 641                   _has_method_handle_invokes(false),
 642                   _mach_constant_base_node(NULL),
 643                   _node_bundling_limit(0),
 644                   _node_bundling_base(NULL),
 645                   _java_calls(0),
 646                   _inner_loops(0),
 647                   _scratch_const_size(-1),
 648                   _in_scratch_emit_size(false),
 649                   _dead_node_list(comp_arena()),
 650                   _dead_node_count(0),
 651 #ifndef PRODUCT
 652                   _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
 653                   _in_dump_cnt(0),
 654                   _printer(IdealGraphPrinter::printer()),
 655 #endif
 656                   _congraph(NULL),
 657                   _comp_arena(mtCompiler),
 658                   _node_arena(mtCompiler),
 659                   _old_arena(mtCompiler),
 660                   _Compile_types(mtCompiler),
 661                   _replay_inline_data(NULL),
 662                   _late_inlines(comp_arena(), 2, 0, NULL),
 663                   _string_late_inlines(comp_arena(), 2, 0, NULL),
 664                   _boxing_late_inlines(comp_arena(), 2, 0, NULL),
 665                   _late_inlines_pos(0),
 666                   _number_of_mh_late_inlines(0),
 667                   _inlining_progress(false),
 668                   _inlining_incrementally(false),
 669                   _print_inlining_list(NULL),
 670                   _print_inlining_stream(NULL),
 671                   _print_inlining_idx(0),
 672                   _print_inlining_output(NULL),
 673                   _interpreter_frame_size(0),
 674                   _max_node_limit(MaxNodeLimit) {
 675   C = this;
 676 
 677   CompileWrapper cw(this);
 678 
 679   if (CITimeVerbose) {
 680     tty->print(" ");
 681     target->holder()->name()->print();
 682     tty->print(".");
 683     target->print_short_name();
 684     tty->print("  ");
 685   }
 686   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
 687   TraceTime t2(NULL, &_t_methodCompilation, CITime, false);
 688 
 689 #ifndef PRODUCT
 690   bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
 691   if (!print_opto_assembly) {
 692     bool print_assembly = (PrintAssembly || _method->should_print_assembly());
 693     if (print_assembly && !Disassembler::can_decode()) {
 694       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
 695       print_opto_assembly = true;
 696     }
 697   }
 698   set_print_assembly(print_opto_assembly);
 699   set_parsed_irreducible_loop(false);
 700 
 701   if (method()->has_option("ReplayInline")) {
 702     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 703   }
 704 #endif
 705   set_print_inlining(PrintInlining || method()->has_option("PrintInlining") NOT_PRODUCT( || PrintOptoInlining));
 706   set_print_intrinsics(PrintIntrinsics || method()->has_option("PrintIntrinsics"));
 707   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 708 
 709   if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
 710     // Make sure the method being compiled gets its own MDO,
 711     // so we can at least track the decompile_count().
 712     // Need MDO to record RTM code generation state.
 713     method()->ensure_method_data();
 714   }
 715 
 716   Init(::AliasLevel);
 717 
 718 
 719   print_compile_messages();
 720 
 721   _ilt = InlineTree::build_inline_tree_root();
 722 
 723   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 724   assert(num_alias_types() >= AliasIdxRaw, "");
 725 
 726 #define MINIMUM_NODE_HASH  1023
 727   // Node list that Iterative GVN will start with
 728   Unique_Node_List for_igvn(comp_arena());
 729   set_for_igvn(&for_igvn);
 730 
 731   // GVN that will be run immediately on new nodes
 732   uint estimated_size = method()->code_size()*4+64;
 733   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 734   PhaseGVN gvn(node_arena(), estimated_size);
 735   set_initial_gvn(&gvn);
 736 
 737   print_inlining_init();
 738   { // Scope for timing the parser
 739     TracePhase tp("parse", &timers[_t_parser]);
 740 
 741     // Put top into the hash table ASAP.
 742     initial_gvn()->transform_no_reclaim(top());
 743 
 744     // Set up tf(), start(), and find a CallGenerator.
 745     CallGenerator* cg = NULL;
 746     if (is_osr_compilation()) {
 747       const TypeTuple *domain = StartOSRNode::osr_domain();
 748       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 749       init_tf(TypeFunc::make(domain, range));
 750       StartNode* s = new StartOSRNode(root(), domain);
 751       initial_gvn()->set_type_bottom(s);
 752       init_start(s);
 753       cg = CallGenerator::for_osr(method(), entry_bci());
 754     } else {
 755       // Normal case.
 756       init_tf(TypeFunc::make(method()));
 757       StartNode* s = new StartNode(root(), tf()->domain());
 758       initial_gvn()->set_type_bottom(s);
 759       init_start(s);
 760       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
 761         // With java.lang.ref.reference.get() we must go through the
 762         // intrinsic when G1 is enabled - even when get() is the root
 763         // method of the compile - so that, if necessary, the value in
 764         // the referent field of the reference object gets recorded by
 765         // the pre-barrier code.
 766         // Specifically, if G1 is enabled, the value in the referent
 767         // field is recorded by the G1 SATB pre barrier. This will
 768         // result in the referent being marked live and the reference
 769         // object removed from the list of discovered references during
 770         // reference processing.
 771         cg = find_intrinsic(method(), false);
 772       }
 773       if (cg == NULL) {
 774         float past_uses = method()->interpreter_invocation_count();
 775         float expected_uses = past_uses;
 776         cg = CallGenerator::for_inline(method(), expected_uses);
 777       }
 778     }
 779     if (failing())  return;
 780     if (cg == NULL) {
 781       record_method_not_compilable_all_tiers("cannot parse method");
 782       return;
 783     }
 784     JVMState* jvms = build_start_state(start(), tf());
 785     if ((jvms = cg->generate(jvms)) == NULL) {
 786       if (!failure_reason_is(C2Compiler::retry_class_loading_during_parsing())) {
 787         record_method_not_compilable("method parse failed");
 788       }
 789       return;
 790     }
 791     GraphKit kit(jvms);
 792 
 793     if (!kit.stopped()) {
 794       // Accept return values, and transfer control we know not where.
 795       // This is done by a special, unique ReturnNode bound to root.
 796       return_values(kit.jvms());
 797     }
 798 
 799     if (kit.has_exceptions()) {
 800       // Any exceptions that escape from this call must be rethrown
 801       // to whatever caller is dynamically above us on the stack.
 802       // This is done by a special, unique RethrowNode bound to root.
 803       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 804     }
 805 
 806     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 807 
 808     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 809       inline_string_calls(true);
 810     }
 811 
 812     if (failing())  return;
 813 
 814     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
 815 
 816     // Remove clutter produced by parsing.
 817     if (!failing()) {
 818       ResourceMark rm;
 819       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 820     }
 821   }
 822 
 823   // Note:  Large methods are capped off in do_one_bytecode().
 824   if (failing())  return;
 825 
 826   // After parsing, node notes are no longer automagic.
 827   // They must be propagated by register_new_node_with_optimizer(),
 828   // clone(), or the like.
 829   set_default_node_notes(NULL);
 830 
 831   for (;;) {
 832     int successes = Inline_Warm();
 833     if (failing())  return;
 834     if (successes == 0)  break;
 835   }
 836 
 837   // Drain the list.
 838   Finish_Warm();
 839 #ifndef PRODUCT
 840   if (_printer && _printer->should_print(_method)) {
 841     _printer->print_inlining(this);
 842   }
 843 #endif
 844 
 845   if (failing())  return;
 846   NOT_PRODUCT( verify_graph_edges(); )
 847 
 848   // Now optimize
 849   Optimize();
 850   if (failing())  return;
 851   NOT_PRODUCT( verify_graph_edges(); )
 852 
 853 #ifndef PRODUCT
 854   if (PrintIdeal) {
 855     ttyLocker ttyl;  // keep the following output all in one block
 856     // This output goes directly to the tty, not the compiler log.
 857     // To enable tools to match it up with the compilation activity,
 858     // be sure to tag this tty output with the compile ID.
 859     if (xtty != NULL) {
 860       xtty->head("ideal compile_id='%d'%s", compile_id(),
 861                  is_osr_compilation()    ? " compile_kind='osr'" :
 862                  "");
 863     }
 864     root()->dump(9999);
 865     if (xtty != NULL) {
 866       xtty->tail("ideal");
 867     }
 868   }
 869 #endif
 870 
 871   NOT_PRODUCT( verify_barriers(); )
 872 
 873   // Dump compilation data to replay it.
 874   if (method()->has_option("DumpReplay")) {
 875     env()->dump_replay_data(_compile_id);
 876   }
 877   if (method()->has_option("DumpInline") && (ilt() != NULL)) {
 878     env()->dump_inline_data(_compile_id);
 879   }
 880 
 881   // Now that we know the size of all the monitors we can add a fixed slot
 882   // for the original deopt pc.
 883 
 884   _orig_pc_slot =  fixed_slots();
 885   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
 886   set_fixed_slots(next_slot);
 887 
 888   // Compute when to use implicit null checks. Used by matching trap based
 889   // nodes and NullCheck optimization.
 890   set_allowed_deopt_reasons();
 891 
 892   // Now generate code
 893   Code_Gen();
 894   if (failing())  return;
 895 
 896   // Check if we want to skip execution of all compiled code.
 897   {
 898 #ifndef PRODUCT
 899     if (OptoNoExecute) {
 900       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
 901       return;
 902     }
 903 #endif
 904     TracePhase tp("install_code", &timers[_t_registerMethod]);
 905 
 906     if (is_osr_compilation()) {
 907       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
 908       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
 909     } else {
 910       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
 911       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
 912     }
 913 
 914     env()->register_method(_method, _entry_bci,
 915                            &_code_offsets,
 916                            _orig_pc_slot_offset_in_bytes,
 917                            code_buffer(),
 918                            frame_size_in_words(), _oop_map_set,
 919                            &_handler_table, &_inc_table,
 920                            compiler,
 921                            env()->comp_level(),
 922                            has_unsafe_access(),
 923                            SharedRuntime::is_wide_vector(max_vector_size()),
 924                            rtm_state()
 925                            );
 926 
 927     if (log() != NULL) // Print code cache state into compiler log
 928       log()->code_cache_state();
 929   }
 930 }
 931 
 932 //------------------------------Compile----------------------------------------
 933 // Compile a runtime stub
 934 Compile::Compile( ciEnv* ci_env,
 935                   TypeFunc_generator generator,
 936                   address stub_function,
 937                   const char *stub_name,
 938                   int is_fancy_jump,
 939                   bool pass_tls,
 940                   bool save_arg_registers,
 941                   bool return_pc )
 942   : Phase(Compiler),
 943     _env(ci_env),
 944     _log(ci_env->log()),
 945     _compile_id(0),
 946     _save_argument_registers(save_arg_registers),
 947     _method(NULL),
 948     _stub_name(stub_name),
 949     _stub_function(stub_function),
 950     _stub_entry_point(NULL),
 951     _entry_bci(InvocationEntryBci),
 952     _initial_gvn(NULL),
 953     _for_igvn(NULL),
 954     _warm_calls(NULL),
 955     _orig_pc_slot(0),
 956     _orig_pc_slot_offset_in_bytes(0),
 957     _subsume_loads(true),
 958     _do_escape_analysis(false),
 959     _eliminate_boxing(false),
 960     _failure_reason(NULL),
 961     _code_buffer("Compile::Fill_buffer"),
 962     _has_method_handle_invokes(false),
 963     _mach_constant_base_node(NULL),
 964     _node_bundling_limit(0),
 965     _node_bundling_base(NULL),
 966     _java_calls(0),
 967     _inner_loops(0),
 968 #ifndef PRODUCT
 969     _trace_opto_output(TraceOptoOutput),
 970     _in_dump_cnt(0),
 971     _printer(NULL),
 972 #endif
 973     _comp_arena(mtCompiler),
 974     _node_arena(mtCompiler),
 975     _old_arena(mtCompiler),
 976     _Compile_types(mtCompiler),
 977     _dead_node_list(comp_arena()),
 978     _dead_node_count(0),
 979     _congraph(NULL),
 980     _replay_inline_data(NULL),
 981     _number_of_mh_late_inlines(0),
 982     _inlining_progress(false),
 983     _inlining_incrementally(false),
 984     _print_inlining_list(NULL),
 985     _print_inlining_stream(NULL),
 986     _print_inlining_idx(0),
 987     _print_inlining_output(NULL),
 988     _allowed_reasons(0),
 989     _interpreter_frame_size(0),
 990     _max_node_limit(MaxNodeLimit) {
 991   C = this;
 992 
 993   TraceTime t1(NULL, &_t_totalCompilation, CITime, false);
 994   TraceTime t2(NULL, &_t_stubCompilation, CITime, false);
 995 
 996 #ifndef PRODUCT
 997   set_print_assembly(PrintFrameConverterAssembly);
 998   set_parsed_irreducible_loop(false);
 999 #endif
1000   set_has_irreducible_loop(false); // no loops
1001 
1002   CompileWrapper cw(this);
1003   Init(/*AliasLevel=*/ 0);
1004   init_tf((*generator)());
1005 
1006   {
1007     // The following is a dummy for the sake of GraphKit::gen_stub
1008     Unique_Node_List for_igvn(comp_arena());
1009     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
1010     PhaseGVN gvn(Thread::current()->resource_area(),255);
1011     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
1012     gvn.transform_no_reclaim(top());
1013 
1014     GraphKit kit;
1015     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1016   }
1017 
1018   NOT_PRODUCT( verify_graph_edges(); )
1019   Code_Gen();
1020   if (failing())  return;
1021 
1022 
1023   // Entry point will be accessed using compile->stub_entry_point();
1024   if (code_buffer() == NULL) {
1025     Matcher::soft_match_failure();
1026   } else {
1027     if (PrintAssembly && (WizardMode || Verbose))
1028       tty->print_cr("### Stub::%s", stub_name);
1029 
1030     if (!failing()) {
1031       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
1032 
1033       // Make the NMethod
1034       // For now we mark the frame as never safe for profile stackwalking
1035       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
1036                                                       code_buffer(),
1037                                                       CodeOffsets::frame_never_safe,
1038                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
1039                                                       frame_size_in_words(),
1040                                                       _oop_map_set,
1041                                                       save_arg_registers);
1042       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
1043 
1044       _stub_entry_point = rs->entry_point();
1045     }
1046   }
1047 }
1048 
1049 //------------------------------Init-------------------------------------------
1050 // Prepare for a single compilation
1051 void Compile::Init(int aliaslevel) {
1052   _unique  = 0;
1053   _regalloc = NULL;
1054 
1055   _tf      = NULL;  // filled in later
1056   _top     = NULL;  // cached later
1057   _matcher = NULL;  // filled in later
1058   _cfg     = NULL;  // filled in later
1059 
1060   set_24_bit_selection_and_mode(Use24BitFP, false);
1061 
1062   _node_note_array = NULL;
1063   _default_node_notes = NULL;
1064   DEBUG_ONLY( _modified_nodes = NULL; ) // Used in Optimize()
1065 
1066   _immutable_memory = NULL; // filled in at first inquiry
1067 
1068   // Globally visible Nodes
1069   // First set TOP to NULL to give safe behavior during creation of RootNode
1070   set_cached_top_node(NULL);
1071   set_root(new RootNode());
1072   // Now that you have a Root to point to, create the real TOP
1073   set_cached_top_node( new ConNode(Type::TOP) );
1074   set_recent_alloc(NULL, NULL);
1075 
1076   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1077   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1078   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1079   env()->set_dependencies(new Dependencies(env()));
1080 
1081   _fixed_slots = 0;
1082   set_has_split_ifs(false);
1083   set_has_loops(has_method() && method()->has_loops()); // first approximation
1084   set_has_stringbuilder(false);
1085   set_has_boxed_value(false);
1086   _trap_can_recompile = false;  // no traps emitted yet
1087   _major_progress = true; // start out assuming good things will happen
1088   set_has_unsafe_access(false);
1089   set_max_vector_size(0);
1090   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1091   set_decompile_count(0);
1092 
1093   set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
1094   set_num_loop_opts(LoopOptsCount);
1095   set_do_inlining(Inline);
1096   set_max_inline_size(MaxInlineSize);
1097   set_freq_inline_size(FreqInlineSize);
1098   set_do_scheduling(OptoScheduling);
1099   set_do_count_invocations(false);
1100   set_do_method_data_update(false);
1101 
1102   set_do_vector_loop(false);
1103 
1104   bool do_vector = false;
1105   if (AllowVectorizeOnDemand) {
1106     if (has_method() && (method()->has_option("Vectorize") || method()->has_option("VectorizeDebug"))) {
1107       set_do_vector_loop(true);
1108     } else if (has_method() && method()->name() != 0 &&
1109                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1110       set_do_vector_loop(true);
1111     }
1112 #ifndef PRODUCT
1113     if (do_vector_loop() && Verbose) {
1114       tty->print("Compile::Init: do vectorized loops (SIMD like) for method %s\n",  method()->name()->as_quoted_ascii());
1115     }
1116 #endif
1117   }
1118 
1119   set_age_code(has_method() && method()->profile_aging());
1120   set_rtm_state(NoRTM); // No RTM lock eliding by default
1121   method_has_option_value("MaxNodeLimit", _max_node_limit);
1122 #if INCLUDE_RTM_OPT
1123   if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
1124     int rtm_state = method()->method_data()->rtm_state();
1125     if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
1126       // Don't generate RTM lock eliding code.
1127       set_rtm_state(NoRTM);
1128     } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
1129       // Generate RTM lock eliding code without abort ratio calculation code.
1130       set_rtm_state(UseRTM);
1131     } else if (UseRTMDeopt) {
1132       // Generate RTM lock eliding code and include abort ratio calculation
1133       // code if UseRTMDeopt is on.
1134       set_rtm_state(ProfileRTM);
1135     }
1136   }
1137 #endif
1138   if (debug_info()->recording_non_safepoints()) {
1139     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1140                         (comp_arena(), 8, 0, NULL));
1141     set_default_node_notes(Node_Notes::make(this));
1142   }
1143 
1144   // // -- Initialize types before each compile --
1145   // // Update cached type information
1146   // if( _method && _method->constants() )
1147   //   Type::update_loaded_types(_method, _method->constants());
1148 
1149   // Init alias_type map.
1150   if (!_do_escape_analysis && aliaslevel == 3)
1151     aliaslevel = 2;  // No unique types without escape analysis
1152   _AliasLevel = aliaslevel;
1153   const int grow_ats = 16;
1154   _max_alias_types = grow_ats;
1155   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1156   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1157   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1158   {
1159     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1160   }
1161   // Initialize the first few types.
1162   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1163   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1164   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1165   _num_alias_types = AliasIdxRaw+1;
1166   // Zero out the alias type cache.
1167   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1168   // A NULL adr_type hits in the cache right away.  Preload the right answer.
1169   probe_alias_cache(NULL)->_index = AliasIdxTop;
1170 
1171   _intrinsics = NULL;
1172   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1173   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1174   _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1175   register_library_intrinsics();
1176 }
1177 
1178 //---------------------------init_start----------------------------------------
1179 // Install the StartNode on this compile object.
1180 void Compile::init_start(StartNode* s) {
1181   if (failing())
1182     return; // already failing
1183   assert(s == start(), "");
1184 }
1185 
1186 /**
1187  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1188  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1189  * the ideal graph.
1190  */
1191 StartNode* Compile::start() const {
1192   assert (!failing(), "Must not have pending failure. Reason is: %s", failure_reason());
1193   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1194     Node* start = root()->fast_out(i);
1195     if (start->is_Start()) {
1196       return start->as_Start();
1197     }
1198   }
1199   fatal("Did not find Start node!");
1200   return NULL;
1201 }
1202 
1203 //-------------------------------immutable_memory-------------------------------------
1204 // Access immutable memory
1205 Node* Compile::immutable_memory() {
1206   if (_immutable_memory != NULL) {
1207     return _immutable_memory;
1208   }
1209   StartNode* s = start();
1210   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1211     Node *p = s->fast_out(i);
1212     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1213       _immutable_memory = p;
1214       return _immutable_memory;
1215     }
1216   }
1217   ShouldNotReachHere();
1218   return NULL;
1219 }
1220 
1221 //----------------------set_cached_top_node------------------------------------
1222 // Install the cached top node, and make sure Node::is_top works correctly.
1223 void Compile::set_cached_top_node(Node* tn) {
1224   if (tn != NULL)  verify_top(tn);
1225   Node* old_top = _top;
1226   _top = tn;
1227   // Calling Node::setup_is_top allows the nodes the chance to adjust
1228   // their _out arrays.
1229   if (_top != NULL)     _top->setup_is_top();
1230   if (old_top != NULL)  old_top->setup_is_top();
1231   assert(_top == NULL || top()->is_top(), "");
1232 }
1233 
1234 #ifdef ASSERT
1235 uint Compile::count_live_nodes_by_graph_walk() {
1236   Unique_Node_List useful(comp_arena());
1237   // Get useful node list by walking the graph.
1238   identify_useful_nodes(useful);
1239   return useful.size();
1240 }
1241 
1242 void Compile::print_missing_nodes() {
1243 
1244   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1245   if ((_log == NULL) && (! PrintIdealNodeCount)) {
1246     return;
1247   }
1248 
1249   // This is an expensive function. It is executed only when the user
1250   // specifies VerifyIdealNodeCount option or otherwise knows the
1251   // additional work that needs to be done to identify reachable nodes
1252   // by walking the flow graph and find the missing ones using
1253   // _dead_node_list.
1254 
1255   Unique_Node_List useful(comp_arena());
1256   // Get useful node list by walking the graph.
1257   identify_useful_nodes(useful);
1258 
1259   uint l_nodes = C->live_nodes();
1260   uint l_nodes_by_walk = useful.size();
1261 
1262   if (l_nodes != l_nodes_by_walk) {
1263     if (_log != NULL) {
1264       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1265       _log->stamp();
1266       _log->end_head();
1267     }
1268     VectorSet& useful_member_set = useful.member_set();
1269     int last_idx = l_nodes_by_walk;
1270     for (int i = 0; i < last_idx; i++) {
1271       if (useful_member_set.test(i)) {
1272         if (_dead_node_list.test(i)) {
1273           if (_log != NULL) {
1274             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1275           }
1276           if (PrintIdealNodeCount) {
1277             // Print the log message to tty
1278               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1279               useful.at(i)->dump();
1280           }
1281         }
1282       }
1283       else if (! _dead_node_list.test(i)) {
1284         if (_log != NULL) {
1285           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1286         }
1287         if (PrintIdealNodeCount) {
1288           // Print the log message to tty
1289           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1290         }
1291       }
1292     }
1293     if (_log != NULL) {
1294       _log->tail("mismatched_nodes");
1295     }
1296   }
1297 }
1298 void Compile::record_modified_node(Node* n) {
1299   if (_modified_nodes != NULL && !_inlining_incrementally &&
1300       n->outcnt() != 0 && !n->is_Con()) {
1301     _modified_nodes->push(n);
1302   }
1303 }
1304 
1305 void Compile::remove_modified_node(Node* n) {
1306   if (_modified_nodes != NULL) {
1307     _modified_nodes->remove(n);
1308   }
1309 }
1310 #endif
1311 
1312 #ifndef PRODUCT
1313 void Compile::verify_top(Node* tn) const {
1314   if (tn != NULL) {
1315     assert(tn->is_Con(), "top node must be a constant");
1316     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1317     assert(tn->in(0) != NULL, "must have live top node");
1318   }
1319 }
1320 #endif
1321 
1322 
1323 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1324 
1325 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1326   guarantee(arr != NULL, "");
1327   int num_blocks = arr->length();
1328   if (grow_by < num_blocks)  grow_by = num_blocks;
1329   int num_notes = grow_by * _node_notes_block_size;
1330   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1331   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1332   while (num_notes > 0) {
1333     arr->append(notes);
1334     notes     += _node_notes_block_size;
1335     num_notes -= _node_notes_block_size;
1336   }
1337   assert(num_notes == 0, "exact multiple, please");
1338 }
1339 
1340 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1341   if (source == NULL || dest == NULL)  return false;
1342 
1343   if (dest->is_Con())
1344     return false;               // Do not push debug info onto constants.
1345 
1346 #ifdef ASSERT
1347   // Leave a bread crumb trail pointing to the original node:
1348   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1349     dest->set_debug_orig(source);
1350   }
1351 #endif
1352 
1353   if (node_note_array() == NULL)
1354     return false;               // Not collecting any notes now.
1355 
1356   // This is a copy onto a pre-existing node, which may already have notes.
1357   // If both nodes have notes, do not overwrite any pre-existing notes.
1358   Node_Notes* source_notes = node_notes_at(source->_idx);
1359   if (source_notes == NULL || source_notes->is_clear())  return false;
1360   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1361   if (dest_notes == NULL || dest_notes->is_clear()) {
1362     return set_node_notes_at(dest->_idx, source_notes);
1363   }
1364 
1365   Node_Notes merged_notes = (*source_notes);
1366   // The order of operations here ensures that dest notes will win...
1367   merged_notes.update_from(dest_notes);
1368   return set_node_notes_at(dest->_idx, &merged_notes);
1369 }
1370 
1371 
1372 //--------------------------allow_range_check_smearing-------------------------
1373 // Gating condition for coalescing similar range checks.
1374 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1375 // single covering check that is at least as strong as any of them.
1376 // If the optimization succeeds, the simplified (strengthened) range check
1377 // will always succeed.  If it fails, we will deopt, and then give up
1378 // on the optimization.
1379 bool Compile::allow_range_check_smearing() const {
1380   // If this method has already thrown a range-check,
1381   // assume it was because we already tried range smearing
1382   // and it failed.
1383   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1384   return !already_trapped;
1385 }
1386 
1387 
1388 //------------------------------flatten_alias_type-----------------------------
1389 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1390   int offset = tj->offset();
1391   TypePtr::PTR ptr = tj->ptr();
1392 
1393   // Known instance (scalarizable allocation) alias only with itself.
1394   bool is_known_inst = tj->isa_oopptr() != NULL &&
1395                        tj->is_oopptr()->is_known_instance();
1396 
1397   // Process weird unsafe references.
1398   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1399     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1400     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1401     tj = TypeOopPtr::BOTTOM;
1402     ptr = tj->ptr();
1403     offset = tj->offset();
1404   }
1405 
1406   // Array pointers need some flattening
1407   const TypeAryPtr *ta = tj->isa_aryptr();
1408   if (ta && ta->is_stable()) {
1409     // Erase stability property for alias analysis.
1410     tj = ta = ta->cast_to_stable(false);
1411   }
1412   if( ta && is_known_inst ) {
1413     if ( offset != Type::OffsetBot &&
1414          offset > arrayOopDesc::length_offset_in_bytes() ) {
1415       offset = Type::OffsetBot; // Flatten constant access into array body only
1416       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
1417     }
1418   } else if( ta && _AliasLevel >= 2 ) {
1419     // For arrays indexed by constant indices, we flatten the alias
1420     // space to include all of the array body.  Only the header, klass
1421     // and array length can be accessed un-aliased.
1422     if( offset != Type::OffsetBot ) {
1423       if( ta->const_oop() ) { // MethodData* or Method*
1424         offset = Type::OffsetBot;   // Flatten constant access into array body
1425         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1426       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1427         // range is OK as-is.
1428         tj = ta = TypeAryPtr::RANGE;
1429       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1430         tj = TypeInstPtr::KLASS; // all klass loads look alike
1431         ta = TypeAryPtr::RANGE; // generic ignored junk
1432         ptr = TypePtr::BotPTR;
1433       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1434         tj = TypeInstPtr::MARK;
1435         ta = TypeAryPtr::RANGE; // generic ignored junk
1436         ptr = TypePtr::BotPTR;
1437       } else {                  // Random constant offset into array body
1438         offset = Type::OffsetBot;   // Flatten constant access into array body
1439         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
1440       }
1441     }
1442     // Arrays of fixed size alias with arrays of unknown size.
1443     if (ta->size() != TypeInt::POS) {
1444       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1445       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
1446     }
1447     // Arrays of known objects become arrays of unknown objects.
1448     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1449       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1450       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1451     }
1452     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1453       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1454       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1455     }
1456     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1457     // cannot be distinguished by bytecode alone.
1458     if (ta->elem() == TypeInt::BOOL) {
1459       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1460       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1461       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1462     }
1463     // During the 2nd round of IterGVN, NotNull castings are removed.
1464     // Make sure the Bottom and NotNull variants alias the same.
1465     // Also, make sure exact and non-exact variants alias the same.
1466     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
1467       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1468     }
1469   }
1470 
1471   // Oop pointers need some flattening
1472   const TypeInstPtr *to = tj->isa_instptr();
1473   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1474     ciInstanceKlass *k = to->klass()->as_instance_klass();
1475     if( ptr == TypePtr::Constant ) {
1476       if (to->klass() != ciEnv::current()->Class_klass() ||
1477           offset < k->size_helper() * wordSize) {
1478         // No constant oop pointers (such as Strings); they alias with
1479         // unknown strings.
1480         assert(!is_known_inst, "not scalarizable allocation");
1481         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1482       }
1483     } else if( is_known_inst ) {
1484       tj = to; // Keep NotNull and klass_is_exact for instance type
1485     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1486       // During the 2nd round of IterGVN, NotNull castings are removed.
1487       // Make sure the Bottom and NotNull variants alias the same.
1488       // Also, make sure exact and non-exact variants alias the same.
1489       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1490     }
1491     if (to->speculative() != NULL) {
1492       tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
1493     }
1494     // Canonicalize the holder of this field
1495     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1496       // First handle header references such as a LoadKlassNode, even if the
1497       // object's klass is unloaded at compile time (4965979).
1498       if (!is_known_inst) { // Do it only for non-instance types
1499         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
1500       }
1501     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1502       // Static fields are in the space above the normal instance
1503       // fields in the java.lang.Class instance.
1504       if (to->klass() != ciEnv::current()->Class_klass()) {
1505         to = NULL;
1506         tj = TypeOopPtr::BOTTOM;
1507         offset = tj->offset();
1508       }
1509     } else {
1510       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1511       if (!k->equals(canonical_holder) || tj->offset() != offset) {
1512         if( is_known_inst ) {
1513           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
1514         } else {
1515           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
1516         }
1517       }
1518     }
1519   }
1520 
1521   // Klass pointers to object array klasses need some flattening
1522   const TypeKlassPtr *tk = tj->isa_klassptr();
1523   if( tk ) {
1524     // If we are referencing a field within a Klass, we need
1525     // to assume the worst case of an Object.  Both exact and
1526     // inexact types must flatten to the same alias class so
1527     // use NotNull as the PTR.
1528     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1529 
1530       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1531                                    TypeKlassPtr::OBJECT->klass(),
1532                                    offset);
1533     }
1534 
1535     ciKlass* klass = tk->klass();
1536     if( klass->is_obj_array_klass() ) {
1537       ciKlass* k = TypeAryPtr::OOPS->klass();
1538       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
1539         k = TypeInstPtr::BOTTOM->klass();
1540       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1541     }
1542 
1543     // Check for precise loads from the primary supertype array and force them
1544     // to the supertype cache alias index.  Check for generic array loads from
1545     // the primary supertype array and also force them to the supertype cache
1546     // alias index.  Since the same load can reach both, we need to merge
1547     // these 2 disparate memories into the same alias class.  Since the
1548     // primary supertype array is read-only, there's no chance of confusion
1549     // where we bypass an array load and an array store.
1550     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1551     if (offset == Type::OffsetBot ||
1552         (offset >= primary_supers_offset &&
1553          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1554         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1555       offset = in_bytes(Klass::secondary_super_cache_offset());
1556       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1557     }
1558   }
1559 
1560   // Flatten all Raw pointers together.
1561   if (tj->base() == Type::RawPtr)
1562     tj = TypeRawPtr::BOTTOM;
1563 
1564   if (tj->base() == Type::AnyPtr)
1565     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1566 
1567   // Flatten all to bottom for now
1568   switch( _AliasLevel ) {
1569   case 0:
1570     tj = TypePtr::BOTTOM;
1571     break;
1572   case 1:                       // Flatten to: oop, static, field or array
1573     switch (tj->base()) {
1574     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
1575     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
1576     case Type::AryPtr:   // do not distinguish arrays at all
1577     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
1578     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1579     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
1580     default: ShouldNotReachHere();
1581     }
1582     break;
1583   case 2:                       // No collapsing at level 2; keep all splits
1584   case 3:                       // No collapsing at level 3; keep all splits
1585     break;
1586   default:
1587     Unimplemented();
1588   }
1589 
1590   offset = tj->offset();
1591   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1592 
1593   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1594           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1595           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1596           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1597           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1598           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1599           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
1600           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1601   assert( tj->ptr() != TypePtr::TopPTR &&
1602           tj->ptr() != TypePtr::AnyNull &&
1603           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1604 //    assert( tj->ptr() != TypePtr::Constant ||
1605 //            tj->base() == Type::RawPtr ||
1606 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1607 
1608   return tj;
1609 }
1610 
1611 void Compile::AliasType::Init(int i, const TypePtr* at) {
1612   _index = i;
1613   _adr_type = at;
1614   _field = NULL;
1615   _element = NULL;
1616   _is_rewritable = true; // default
1617   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1618   if (atoop != NULL && atoop->is_known_instance()) {
1619     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1620     _general_index = Compile::current()->get_alias_index(gt);
1621   } else {
1622     _general_index = 0;
1623   }
1624 }
1625 
1626 //---------------------------------print_on------------------------------------
1627 #ifndef PRODUCT
1628 void Compile::AliasType::print_on(outputStream* st) {
1629   if (index() < 10)
1630         st->print("@ <%d> ", index());
1631   else  st->print("@ <%d>",  index());
1632   st->print(is_rewritable() ? "   " : " RO");
1633   int offset = adr_type()->offset();
1634   if (offset == Type::OffsetBot)
1635         st->print(" +any");
1636   else  st->print(" +%-3d", offset);
1637   st->print(" in ");
1638   adr_type()->dump_on(st);
1639   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1640   if (field() != NULL && tjp) {
1641     if (tjp->klass()  != field()->holder() ||
1642         tjp->offset() != field()->offset_in_bytes()) {
1643       st->print(" != ");
1644       field()->print();
1645       st->print(" ***");
1646     }
1647   }
1648 }
1649 
1650 void print_alias_types() {
1651   Compile* C = Compile::current();
1652   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1653   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1654     C->alias_type(idx)->print_on(tty);
1655     tty->cr();
1656   }
1657 }
1658 #endif
1659 
1660 
1661 //----------------------------probe_alias_cache--------------------------------
1662 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1663   intptr_t key = (intptr_t) adr_type;
1664   key ^= key >> logAliasCacheSize;
1665   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1666 }
1667 
1668 
1669 //-----------------------------grow_alias_types--------------------------------
1670 void Compile::grow_alias_types() {
1671   const int old_ats  = _max_alias_types; // how many before?
1672   const int new_ats  = old_ats;          // how many more?
1673   const int grow_ats = old_ats+new_ats;  // how many now?
1674   _max_alias_types = grow_ats;
1675   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1676   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1677   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1678   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1679 }
1680 
1681 
1682 //--------------------------------find_alias_type------------------------------
1683 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1684   if (_AliasLevel == 0)
1685     return alias_type(AliasIdxBot);
1686 
1687   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1688   if (ace->_adr_type == adr_type) {
1689     return alias_type(ace->_index);
1690   }
1691 
1692   // Handle special cases.
1693   if (adr_type == NULL)             return alias_type(AliasIdxTop);
1694   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1695 
1696   // Do it the slow way.
1697   const TypePtr* flat = flatten_alias_type(adr_type);
1698 
1699 #ifdef ASSERT
1700   assert(flat == flatten_alias_type(flat), "idempotent");
1701   assert(flat != TypePtr::BOTTOM,     "cannot alias-analyze an untyped ptr");
1702   if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1703     const TypeOopPtr* foop = flat->is_oopptr();
1704     // Scalarizable allocations have exact klass always.
1705     bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1706     const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1707     assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
1708   }
1709   assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
1710 #endif
1711 
1712   int idx = AliasIdxTop;
1713   for (int i = 0; i < num_alias_types(); i++) {
1714     if (alias_type(i)->adr_type() == flat) {
1715       idx = i;
1716       break;
1717     }
1718   }
1719 
1720   if (idx == AliasIdxTop) {
1721     if (no_create)  return NULL;
1722     // Grow the array if necessary.
1723     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1724     // Add a new alias type.
1725     idx = _num_alias_types++;
1726     _alias_types[idx]->Init(idx, flat);
1727     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1728     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1729     if (flat->isa_instptr()) {
1730       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1731           && flat->is_instptr()->klass() == env()->Class_klass())
1732         alias_type(idx)->set_rewritable(false);
1733     }
1734     if (flat->isa_aryptr()) {
1735 #ifdef ASSERT
1736       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1737       // (T_BYTE has the weakest alignment and size restrictions...)
1738       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1739 #endif
1740       if (flat->offset() == TypePtr::OffsetBot) {
1741         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1742       }
1743     }
1744     if (flat->isa_klassptr()) {
1745       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1746         alias_type(idx)->set_rewritable(false);
1747       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1748         alias_type(idx)->set_rewritable(false);
1749       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1750         alias_type(idx)->set_rewritable(false);
1751       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1752         alias_type(idx)->set_rewritable(false);
1753     }
1754     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1755     // but the base pointer type is not distinctive enough to identify
1756     // references into JavaThread.)
1757 
1758     // Check for final fields.
1759     const TypeInstPtr* tinst = flat->isa_instptr();
1760     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1761       ciField* field;
1762       if (tinst->const_oop() != NULL &&
1763           tinst->klass() == ciEnv::current()->Class_klass() &&
1764           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1765         // static field
1766         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1767         field = k->get_field_by_offset(tinst->offset(), true);
1768       } else {
1769         ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1770         field = k->get_field_by_offset(tinst->offset(), false);
1771       }
1772       assert(field == NULL ||
1773              original_field == NULL ||
1774              (field->holder() == original_field->holder() &&
1775               field->offset() == original_field->offset() &&
1776               field->is_static() == original_field->is_static()), "wrong field?");
1777       // Set field() and is_rewritable() attributes.
1778       if (field != NULL)  alias_type(idx)->set_field(field);
1779     }
1780   }
1781 
1782   // Fill the cache for next time.
1783   ace->_adr_type = adr_type;
1784   ace->_index    = idx;
1785   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1786 
1787   // Might as well try to fill the cache for the flattened version, too.
1788   AliasCacheEntry* face = probe_alias_cache(flat);
1789   if (face->_adr_type == NULL) {
1790     face->_adr_type = flat;
1791     face->_index    = idx;
1792     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1793   }
1794 
1795   return alias_type(idx);
1796 }
1797 
1798 
1799 Compile::AliasType* Compile::alias_type(ciField* field) {
1800   const TypeOopPtr* t;
1801   if (field->is_static())
1802     t = TypeInstPtr::make(field->holder()->java_mirror());
1803   else
1804     t = TypeOopPtr::make_from_klass_raw(field->holder());
1805   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1806   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1807   return atp;
1808 }
1809 
1810 
1811 //------------------------------have_alias_type--------------------------------
1812 bool Compile::have_alias_type(const TypePtr* adr_type) {
1813   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1814   if (ace->_adr_type == adr_type) {
1815     return true;
1816   }
1817 
1818   // Handle special cases.
1819   if (adr_type == NULL)             return true;
1820   if (adr_type == TypePtr::BOTTOM)  return true;
1821 
1822   return find_alias_type(adr_type, true, NULL) != NULL;
1823 }
1824 
1825 //-----------------------------must_alias--------------------------------------
1826 // True if all values of the given address type are in the given alias category.
1827 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1828   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1829   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
1830   if (alias_idx == AliasIdxTop)         return false; // the empty category
1831   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1832 
1833   // the only remaining possible overlap is identity
1834   int adr_idx = get_alias_index(adr_type);
1835   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1836   assert(adr_idx == alias_idx ||
1837          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1838           && adr_type                       != TypeOopPtr::BOTTOM),
1839          "should not be testing for overlap with an unsafe pointer");
1840   return adr_idx == alias_idx;
1841 }
1842 
1843 //------------------------------can_alias--------------------------------------
1844 // True if any values of the given address type are in the given alias category.
1845 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1846   if (alias_idx == AliasIdxTop)         return false; // the empty category
1847   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
1848   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1849   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
1850 
1851   // the only remaining possible overlap is identity
1852   int adr_idx = get_alias_index(adr_type);
1853   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1854   return adr_idx == alias_idx;
1855 }
1856 
1857 
1858 
1859 //---------------------------pop_warm_call-------------------------------------
1860 WarmCallInfo* Compile::pop_warm_call() {
1861   WarmCallInfo* wci = _warm_calls;
1862   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
1863   return wci;
1864 }
1865 
1866 //----------------------------Inline_Warm--------------------------------------
1867 int Compile::Inline_Warm() {
1868   // If there is room, try to inline some more warm call sites.
1869   // %%% Do a graph index compaction pass when we think we're out of space?
1870   if (!InlineWarmCalls)  return 0;
1871 
1872   int calls_made_hot = 0;
1873   int room_to_grow   = NodeCountInliningCutoff - unique();
1874   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1875   int amount_grown   = 0;
1876   WarmCallInfo* call;
1877   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1878     int est_size = (int)call->size();
1879     if (est_size > (room_to_grow - amount_grown)) {
1880       // This one won't fit anyway.  Get rid of it.
1881       call->make_cold();
1882       continue;
1883     }
1884     call->make_hot();
1885     calls_made_hot++;
1886     amount_grown   += est_size;
1887     amount_to_grow -= est_size;
1888   }
1889 
1890   if (calls_made_hot > 0)  set_major_progress();
1891   return calls_made_hot;
1892 }
1893 
1894 
1895 //----------------------------Finish_Warm--------------------------------------
1896 void Compile::Finish_Warm() {
1897   if (!InlineWarmCalls)  return;
1898   if (failing())  return;
1899   if (warm_calls() == NULL)  return;
1900 
1901   // Clean up loose ends, if we are out of space for inlining.
1902   WarmCallInfo* call;
1903   while ((call = pop_warm_call()) != NULL) {
1904     call->make_cold();
1905   }
1906 }
1907 
1908 //---------------------cleanup_loop_predicates-----------------------
1909 // Remove the opaque nodes that protect the predicates so that all unused
1910 // checks and uncommon_traps will be eliminated from the ideal graph
1911 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
1912   if (predicate_count()==0) return;
1913   for (int i = predicate_count(); i > 0; i--) {
1914     Node * n = predicate_opaque1_node(i-1);
1915     assert(n->Opcode() == Op_Opaque1, "must be");
1916     igvn.replace_node(n, n->in(1));
1917   }
1918   assert(predicate_count()==0, "should be clean!");
1919 }
1920 
1921 // StringOpts and late inlining of string methods
1922 void Compile::inline_string_calls(bool parse_time) {
1923   {
1924     // remove useless nodes to make the usage analysis simpler
1925     ResourceMark rm;
1926     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
1927   }
1928 
1929   {
1930     ResourceMark rm;
1931     print_method(PHASE_BEFORE_STRINGOPTS, 3);
1932     PhaseStringOpts pso(initial_gvn(), for_igvn());
1933     print_method(PHASE_AFTER_STRINGOPTS, 3);
1934   }
1935 
1936   // now inline anything that we skipped the first time around
1937   if (!parse_time) {
1938     _late_inlines_pos = _late_inlines.length();
1939   }
1940 
1941   while (_string_late_inlines.length() > 0) {
1942     CallGenerator* cg = _string_late_inlines.pop();
1943     cg->do_late_inline();
1944     if (failing())  return;
1945   }
1946   _string_late_inlines.trunc_to(0);
1947 }
1948 
1949 // Late inlining of boxing methods
1950 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
1951   if (_boxing_late_inlines.length() > 0) {
1952     assert(has_boxed_value(), "inconsistent");
1953 
1954     PhaseGVN* gvn = initial_gvn();
1955     set_inlining_incrementally(true);
1956 
1957     assert( igvn._worklist.size() == 0, "should be done with igvn" );
1958     for_igvn()->clear();
1959     gvn->replace_with(&igvn);
1960 
1961     _late_inlines_pos = _late_inlines.length();
1962 
1963     while (_boxing_late_inlines.length() > 0) {
1964       CallGenerator* cg = _boxing_late_inlines.pop();
1965       cg->do_late_inline();
1966       if (failing())  return;
1967     }
1968     _boxing_late_inlines.trunc_to(0);
1969 
1970     {
1971       ResourceMark rm;
1972       PhaseRemoveUseless pru(gvn, for_igvn());
1973     }
1974 
1975     igvn = PhaseIterGVN(gvn);
1976     igvn.optimize();
1977 
1978     set_inlining_progress(false);
1979     set_inlining_incrementally(false);
1980   }
1981 }
1982 
1983 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
1984   assert(IncrementalInline, "incremental inlining should be on");
1985   PhaseGVN* gvn = initial_gvn();
1986 
1987   set_inlining_progress(false);
1988   for_igvn()->clear();
1989   gvn->replace_with(&igvn);
1990 
1991   {
1992     TracePhase tp("incrementalInline_inline", &timers[_t_incrInline_inline]);
1993     int i = 0;
1994     for (; i <_late_inlines.length() && !inlining_progress(); i++) {
1995       CallGenerator* cg = _late_inlines.at(i);
1996       _late_inlines_pos = i+1;
1997       cg->do_late_inline();
1998       if (failing())  return;
1999     }
2000     int j = 0;
2001     for (; i < _late_inlines.length(); i++, j++) {
2002       _late_inlines.at_put(j, _late_inlines.at(i));
2003     }
2004     _late_inlines.trunc_to(j);
2005   }
2006 
2007   {
2008     TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2009     ResourceMark rm;
2010     PhaseRemoveUseless pru(gvn, for_igvn());
2011   }
2012 
2013   {
2014     TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2015     igvn = PhaseIterGVN(gvn);
2016   }
2017 }
2018 
2019 // Perform incremental inlining until bound on number of live nodes is reached
2020 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2021   TracePhase tp("incrementalInline", &timers[_t_incrInline]);
2022 
2023   PhaseGVN* gvn = initial_gvn();
2024 
2025   set_inlining_incrementally(true);
2026   set_inlining_progress(true);
2027   uint low_live_nodes = 0;
2028 
2029   while(inlining_progress() && _late_inlines.length() > 0) {
2030 
2031     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2032       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2033         TracePhase tp("incrementalInline_ideal", &timers[_t_incrInline_ideal]);
2034         // PhaseIdealLoop is expensive so we only try it once we are
2035         // out of live nodes and we only try it again if the previous
2036         // helped got the number of nodes down significantly
2037         PhaseIdealLoop ideal_loop( igvn, false, true );
2038         if (failing())  return;
2039         low_live_nodes = live_nodes();
2040         _major_progress = true;
2041       }
2042 
2043       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2044         break;
2045       }
2046     }
2047 
2048     inline_incrementally_one(igvn);
2049 
2050     if (failing())  return;
2051 
2052     {
2053       TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2054       igvn.optimize();
2055     }
2056 
2057     if (failing())  return;
2058   }
2059 
2060   assert( igvn._worklist.size() == 0, "should be done with igvn" );
2061 
2062   if (_string_late_inlines.length() > 0) {
2063     assert(has_stringbuilder(), "inconsistent");
2064     for_igvn()->clear();
2065     initial_gvn()->replace_with(&igvn);
2066 
2067     inline_string_calls(false);
2068 
2069     if (failing())  return;
2070 
2071     {
2072       TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2073       ResourceMark rm;
2074       PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2075     }
2076 
2077     {
2078       TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2079       igvn = PhaseIterGVN(gvn);
2080       igvn.optimize();
2081     }
2082   }
2083 
2084   set_inlining_incrementally(false);
2085 }
2086 
2087 
2088 //------------------------------Optimize---------------------------------------
2089 // Given a graph, optimize it.
2090 void Compile::Optimize() {
2091   TracePhase tp("optimizer", &timers[_t_optimizer]);
2092 
2093 #ifndef PRODUCT
2094   if (env()->break_at_compile()) {
2095     BREAKPOINT;
2096   }
2097 
2098 #endif
2099 
2100   ResourceMark rm;
2101   int          loop_opts_cnt;
2102 
2103   print_inlining_reinit();
2104 
2105   NOT_PRODUCT( verify_graph_edges(); )
2106 
2107   print_method(PHASE_AFTER_PARSING);
2108 
2109  {
2110   // Iterative Global Value Numbering, including ideal transforms
2111   // Initialize IterGVN with types and values from parse-time GVN
2112   PhaseIterGVN igvn(initial_gvn());
2113 #ifdef ASSERT
2114   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2115 #endif
2116   {
2117     TracePhase tp("iterGVN", &timers[_t_iterGVN]);
2118     igvn.optimize();
2119   }
2120 
2121   print_method(PHASE_ITER_GVN1, 2);
2122 
2123   if (failing())  return;
2124 
2125   inline_incrementally(igvn);
2126 
2127   print_method(PHASE_INCREMENTAL_INLINE, 2);
2128 
2129   if (failing())  return;
2130 
2131   if (eliminate_boxing()) {
2132     // Inline valueOf() methods now.
2133     inline_boxing_calls(igvn);
2134 
2135     if (AlwaysIncrementalInline) {
2136       inline_incrementally(igvn);
2137     }
2138 
2139     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2140 
2141     if (failing())  return;
2142   }
2143 
2144   // Remove the speculative part of types and clean up the graph from
2145   // the extra CastPP nodes whose only purpose is to carry them. Do
2146   // that early so that optimizations are not disrupted by the extra
2147   // CastPP nodes.
2148   remove_speculative_types(igvn);
2149 
2150   // No more new expensive nodes will be added to the list from here
2151   // so keep only the actual candidates for optimizations.
2152   cleanup_expensive_nodes(igvn);
2153 
2154   // Perform escape analysis
2155   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2156     if (has_loops()) {
2157       // Cleanup graph (remove dead nodes).
2158       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2159       PhaseIdealLoop ideal_loop( igvn, false, true );
2160       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2161       if (failing())  return;
2162     }
2163     ConnectionGraph::do_analysis(this, &igvn);
2164 
2165     if (failing())  return;
2166 
2167     // Optimize out fields loads from scalar replaceable allocations.
2168     igvn.optimize();
2169     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2170 
2171     if (failing())  return;
2172 
2173     if (congraph() != NULL && macro_count() > 0) {
2174       TracePhase tp("macroEliminate", &timers[_t_macroEliminate]);
2175       PhaseMacroExpand mexp(igvn);
2176       mexp.eliminate_macro_nodes();
2177       igvn.set_delay_transform(false);
2178 
2179       igvn.optimize();
2180       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2181 
2182       if (failing())  return;
2183     }
2184   }
2185 
2186   // Loop transforms on the ideal graph.  Range Check Elimination,
2187   // peeling, unrolling, etc.
2188 
2189   // Set loop opts counter
2190   loop_opts_cnt = num_loop_opts();
2191   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2192     {
2193       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2194       PhaseIdealLoop ideal_loop( igvn, true );
2195       loop_opts_cnt--;
2196       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2197       if (failing())  return;
2198     }
2199     // Loop opts pass if partial peeling occurred in previous pass
2200     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
2201       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2202       PhaseIdealLoop ideal_loop( igvn, false );
2203       loop_opts_cnt--;
2204       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2205       if (failing())  return;
2206     }
2207     // Loop opts pass for loop-unrolling before CCP
2208     if(major_progress() && (loop_opts_cnt > 0)) {
2209       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2210       PhaseIdealLoop ideal_loop( igvn, false );
2211       loop_opts_cnt--;
2212       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2213     }
2214     if (!failing()) {
2215       // Verify that last round of loop opts produced a valid graph
2216       TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2217       PhaseIdealLoop::verify(igvn);
2218     }
2219   }
2220   if (failing())  return;
2221 
2222   // Conditional Constant Propagation;
2223   PhaseCCP ccp( &igvn );
2224   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2225   {
2226     TracePhase tp("ccp", &timers[_t_ccp]);
2227     ccp.do_transform();
2228   }
2229   print_method(PHASE_CPP1, 2);
2230 
2231   assert( true, "Break here to ccp.dump_old2new_map()");
2232 
2233   // Iterative Global Value Numbering, including ideal transforms
2234   {
2235     TracePhase tp("iterGVN2", &timers[_t_iterGVN2]);
2236     igvn = ccp;
2237     igvn.optimize();
2238   }
2239 
2240   print_method(PHASE_ITER_GVN2, 2);
2241 
2242   if (failing())  return;
2243 
2244   // Loop transforms on the ideal graph.  Range Check Elimination,
2245   // peeling, unrolling, etc.
2246   if(loop_opts_cnt > 0) {
2247     debug_only( int cnt = 0; );
2248     while(major_progress() && (loop_opts_cnt > 0)) {
2249       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2250       assert( cnt++ < 40, "infinite cycle in loop optimization" );
2251       PhaseIdealLoop ideal_loop( igvn, true);
2252       loop_opts_cnt--;
2253       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2254       if (failing())  return;
2255     }
2256   }
2257 
2258   {
2259     // Verify that all previous optimizations produced a valid graph
2260     // at least to this point, even if no loop optimizations were done.
2261     TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2262     PhaseIdealLoop::verify(igvn);
2263   }
2264 
2265   {
2266     TracePhase tp("macroExpand", &timers[_t_macroExpand]);
2267     PhaseMacroExpand  mex(igvn);
2268     if (mex.expand_macro_nodes()) {
2269       assert(failing(), "must bail out w/ explicit message");
2270       return;
2271     }
2272   }
2273 
2274   DEBUG_ONLY( _modified_nodes = NULL; )
2275  } // (End scope of igvn; run destructor if necessary for asserts.)
2276 
2277   process_print_inlining();
2278   // A method with only infinite loops has no edges entering loops from root
2279   {
2280     TracePhase tp("graphReshape", &timers[_t_graphReshaping]);
2281     if (final_graph_reshaping()) {
2282       assert(failing(), "must bail out w/ explicit message");
2283       return;
2284     }
2285   }
2286 
2287   print_method(PHASE_OPTIMIZE_FINISHED, 2);
2288 }
2289 
2290 
2291 //------------------------------Code_Gen---------------------------------------
2292 // Given a graph, generate code for it
2293 void Compile::Code_Gen() {
2294   if (failing()) {
2295     return;
2296   }
2297 
2298   // Perform instruction selection.  You might think we could reclaim Matcher
2299   // memory PDQ, but actually the Matcher is used in generating spill code.
2300   // Internals of the Matcher (including some VectorSets) must remain live
2301   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2302   // set a bit in reclaimed memory.
2303 
2304   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2305   // nodes.  Mapping is only valid at the root of each matched subtree.
2306   NOT_PRODUCT( verify_graph_edges(); )
2307 
2308   Matcher matcher;
2309   _matcher = &matcher;
2310   {
2311     TracePhase tp("matcher", &timers[_t_matcher]);
2312     matcher.match();
2313   }
2314   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2315   // nodes.  Mapping is only valid at the root of each matched subtree.
2316   NOT_PRODUCT( verify_graph_edges(); )
2317 
2318   // If you have too many nodes, or if matching has failed, bail out
2319   check_node_count(0, "out of nodes matching instructions");
2320   if (failing()) {
2321     return;
2322   }
2323 
2324   // Build a proper-looking CFG
2325   PhaseCFG cfg(node_arena(), root(), matcher);
2326   _cfg = &cfg;
2327   {
2328     TracePhase tp("scheduler", &timers[_t_scheduler]);
2329     bool success = cfg.do_global_code_motion();
2330     if (!success) {
2331       return;
2332     }
2333 
2334     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2335     NOT_PRODUCT( verify_graph_edges(); )
2336     debug_only( cfg.verify(); )
2337   }
2338 
2339   PhaseChaitin regalloc(unique(), cfg, matcher, false);
2340   _regalloc = &regalloc;
2341   {
2342     TracePhase tp("regalloc", &timers[_t_registerAllocation]);
2343     // Perform register allocation.  After Chaitin, use-def chains are
2344     // no longer accurate (at spill code) and so must be ignored.
2345     // Node->LRG->reg mappings are still accurate.
2346     _regalloc->Register_Allocate();
2347 
2348     // Bail out if the allocator builds too many nodes
2349     if (failing()) {
2350       return;
2351     }
2352   }
2353 
2354   // Prior to register allocation we kept empty basic blocks in case the
2355   // the allocator needed a place to spill.  After register allocation we
2356   // are not adding any new instructions.  If any basic block is empty, we
2357   // can now safely remove it.
2358   {
2359     TracePhase tp("blockOrdering", &timers[_t_blockOrdering]);
2360     cfg.remove_empty_blocks();
2361     if (do_freq_based_layout()) {
2362       PhaseBlockLayout layout(cfg);
2363     } else {
2364       cfg.set_loop_alignment();
2365     }
2366     cfg.fixup_flow();
2367   }
2368 
2369   // Apply peephole optimizations
2370   if( OptoPeephole ) {
2371     TracePhase tp("peephole", &timers[_t_peephole]);
2372     PhasePeephole peep( _regalloc, cfg);
2373     peep.do_transform();
2374   }
2375 
2376   // Do late expand if CPU requires this.
2377   if (Matcher::require_postalloc_expand) {
2378     TracePhase tp("postalloc_expand", &timers[_t_postalloc_expand]);
2379     cfg.postalloc_expand(_regalloc);
2380   }
2381 
2382   // Convert Nodes to instruction bits in a buffer
2383   {
2384     TraceTime tp("output", &timers[_t_output], CITime);
2385     Output();
2386   }
2387 
2388   print_method(PHASE_FINAL_CODE);
2389 
2390   // He's dead, Jim.
2391   _cfg     = (PhaseCFG*)0xdeadbeef;
2392   _regalloc = (PhaseChaitin*)0xdeadbeef;
2393 }
2394 
2395 
2396 //------------------------------dump_asm---------------------------------------
2397 // Dump formatted assembly
2398 #ifndef PRODUCT
2399 void Compile::dump_asm(int *pcs, uint pc_limit) {
2400   bool cut_short = false;
2401   tty->print_cr("#");
2402   tty->print("#  ");  _tf->dump();  tty->cr();
2403   tty->print_cr("#");
2404 
2405   // For all blocks
2406   int pc = 0x0;                 // Program counter
2407   char starts_bundle = ' ';
2408   _regalloc->dump_frame();
2409 
2410   Node *n = NULL;
2411   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
2412     if (VMThread::should_terminate()) {
2413       cut_short = true;
2414       break;
2415     }
2416     Block* block = _cfg->get_block(i);
2417     if (block->is_connector() && !Verbose) {
2418       continue;
2419     }
2420     n = block->head();
2421     if (pcs && n->_idx < pc_limit) {
2422       tty->print("%3.3x   ", pcs[n->_idx]);
2423     } else {
2424       tty->print("      ");
2425     }
2426     block->dump_head(_cfg);
2427     if (block->is_connector()) {
2428       tty->print_cr("        # Empty connector block");
2429     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
2430       tty->print_cr("        # Block is sole successor of call");
2431     }
2432 
2433     // For all instructions
2434     Node *delay = NULL;
2435     for (uint j = 0; j < block->number_of_nodes(); j++) {
2436       if (VMThread::should_terminate()) {
2437         cut_short = true;
2438         break;
2439       }
2440       n = block->get_node(j);
2441       if (valid_bundle_info(n)) {
2442         Bundle* bundle = node_bundling(n);
2443         if (bundle->used_in_unconditional_delay()) {
2444           delay = n;
2445           continue;
2446         }
2447         if (bundle->starts_bundle()) {
2448           starts_bundle = '+';
2449         }
2450       }
2451 
2452       if (WizardMode) {
2453         n->dump();
2454       }
2455 
2456       if( !n->is_Region() &&    // Dont print in the Assembly
2457           !n->is_Phi() &&       // a few noisely useless nodes
2458           !n->is_Proj() &&
2459           !n->is_MachTemp() &&
2460           !n->is_SafePointScalarObject() &&
2461           !n->is_Catch() &&     // Would be nice to print exception table targets
2462           !n->is_MergeMem() &&  // Not very interesting
2463           !n->is_top() &&       // Debug info table constants
2464           !(n->is_Con() && !n->is_Mach())// Debug info table constants
2465           ) {
2466         if (pcs && n->_idx < pc_limit)
2467           tty->print("%3.3x", pcs[n->_idx]);
2468         else
2469           tty->print("   ");
2470         tty->print(" %c ", starts_bundle);
2471         starts_bundle = ' ';
2472         tty->print("\t");
2473         n->format(_regalloc, tty);
2474         tty->cr();
2475       }
2476 
2477       // If we have an instruction with a delay slot, and have seen a delay,
2478       // then back up and print it
2479       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
2480         assert(delay != NULL, "no unconditional delay instruction");
2481         if (WizardMode) delay->dump();
2482 
2483         if (node_bundling(delay)->starts_bundle())
2484           starts_bundle = '+';
2485         if (pcs && n->_idx < pc_limit)
2486           tty->print("%3.3x", pcs[n->_idx]);
2487         else
2488           tty->print("   ");
2489         tty->print(" %c ", starts_bundle);
2490         starts_bundle = ' ';
2491         tty->print("\t");
2492         delay->format(_regalloc, tty);
2493         tty->cr();
2494         delay = NULL;
2495       }
2496 
2497       // Dump the exception table as well
2498       if( n->is_Catch() && (Verbose || WizardMode) ) {
2499         // Print the exception table for this offset
2500         _handler_table.print_subtable_for(pc);
2501       }
2502     }
2503 
2504     if (pcs && n->_idx < pc_limit)
2505       tty->print_cr("%3.3x", pcs[n->_idx]);
2506     else
2507       tty->cr();
2508 
2509     assert(cut_short || delay == NULL, "no unconditional delay branch");
2510 
2511   } // End of per-block dump
2512   tty->cr();
2513 
2514   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
2515 }
2516 #endif
2517 
2518 //------------------------------Final_Reshape_Counts---------------------------
2519 // This class defines counters to help identify when a method
2520 // may/must be executed using hardware with only 24-bit precision.
2521 struct Final_Reshape_Counts : public StackObj {
2522   int  _call_count;             // count non-inlined 'common' calls
2523   int  _float_count;            // count float ops requiring 24-bit precision
2524   int  _double_count;           // count double ops requiring more precision
2525   int  _java_call_count;        // count non-inlined 'java' calls
2526   int  _inner_loop_count;       // count loops which need alignment
2527   VectorSet _visited;           // Visitation flags
2528   Node_List _tests;             // Set of IfNodes & PCTableNodes
2529 
2530   Final_Reshape_Counts() :
2531     _call_count(0), _float_count(0), _double_count(0),
2532     _java_call_count(0), _inner_loop_count(0),
2533     _visited( Thread::current()->resource_area() ) { }
2534 
2535   void inc_call_count  () { _call_count  ++; }
2536   void inc_float_count () { _float_count ++; }
2537   void inc_double_count() { _double_count++; }
2538   void inc_java_call_count() { _java_call_count++; }
2539   void inc_inner_loop_count() { _inner_loop_count++; }
2540 
2541   int  get_call_count  () const { return _call_count  ; }
2542   int  get_float_count () const { return _float_count ; }
2543   int  get_double_count() const { return _double_count; }
2544   int  get_java_call_count() const { return _java_call_count; }
2545   int  get_inner_loop_count() const { return _inner_loop_count; }
2546 };
2547 
2548 #ifdef ASSERT
2549 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
2550   ciInstanceKlass *k = tp->klass()->as_instance_klass();
2551   // Make sure the offset goes inside the instance layout.
2552   return k->contains_field_offset(tp->offset());
2553   // Note that OffsetBot and OffsetTop are very negative.
2554 }
2555 #endif
2556 
2557 // Eliminate trivially redundant StoreCMs and accumulate their
2558 // precedence edges.
2559 void Compile::eliminate_redundant_card_marks(Node* n) {
2560   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
2561   if (n->in(MemNode::Address)->outcnt() > 1) {
2562     // There are multiple users of the same address so it might be
2563     // possible to eliminate some of the StoreCMs
2564     Node* mem = n->in(MemNode::Memory);
2565     Node* adr = n->in(MemNode::Address);
2566     Node* val = n->in(MemNode::ValueIn);
2567     Node* prev = n;
2568     bool done = false;
2569     // Walk the chain of StoreCMs eliminating ones that match.  As
2570     // long as it's a chain of single users then the optimization is
2571     // safe.  Eliminating partially redundant StoreCMs would require
2572     // cloning copies down the other paths.
2573     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
2574       if (adr == mem->in(MemNode::Address) &&
2575           val == mem->in(MemNode::ValueIn)) {
2576         // redundant StoreCM
2577         if (mem->req() > MemNode::OopStore) {
2578           // Hasn't been processed by this code yet.
2579           n->add_prec(mem->in(MemNode::OopStore));
2580         } else {
2581           // Already converted to precedence edge
2582           for (uint i = mem->req(); i < mem->len(); i++) {
2583             // Accumulate any precedence edges
2584             if (mem->in(i) != NULL) {
2585               n->add_prec(mem->in(i));
2586             }
2587           }
2588           // Everything above this point has been processed.
2589           done = true;
2590         }
2591         // Eliminate the previous StoreCM
2592         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
2593         assert(mem->outcnt() == 0, "should be dead");
2594         mem->disconnect_inputs(NULL, this);
2595       } else {
2596         prev = mem;
2597       }
2598       mem = prev->in(MemNode::Memory);
2599     }
2600   }
2601 }
2602 
2603 //------------------------------final_graph_reshaping_impl----------------------
2604 // Implement items 1-5 from final_graph_reshaping below.
2605 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
2606 
2607   if ( n->outcnt() == 0 ) return; // dead node
2608   uint nop = n->Opcode();
2609 
2610   // Check for 2-input instruction with "last use" on right input.
2611   // Swap to left input.  Implements item (2).
2612   if( n->req() == 3 &&          // two-input instruction
2613       n->in(1)->outcnt() > 1 && // left use is NOT a last use
2614       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
2615       n->in(2)->outcnt() == 1 &&// right use IS a last use
2616       !n->in(2)->is_Con() ) {   // right use is not a constant
2617     // Check for commutative opcode
2618     switch( nop ) {
2619     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
2620     case Op_MaxI:  case Op_MinI:
2621     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
2622     case Op_AndL:  case Op_XorL:  case Op_OrL:
2623     case Op_AndI:  case Op_XorI:  case Op_OrI: {
2624       // Move "last use" input to left by swapping inputs
2625       n->swap_edges(1, 2);
2626       break;
2627     }
2628     default:
2629       break;
2630     }
2631   }
2632 
2633 #ifdef ASSERT
2634   if( n->is_Mem() ) {
2635     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
2636     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
2637             // oop will be recorded in oop map if load crosses safepoint
2638             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
2639                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
2640             "raw memory operations should have control edge");
2641   }
2642 #endif
2643   // Count FPU ops and common calls, implements item (3)
2644   switch( nop ) {
2645   // Count all float operations that may use FPU
2646   case Op_AddF:
2647   case Op_SubF:
2648   case Op_MulF:
2649   case Op_DivF:
2650   case Op_NegF:
2651   case Op_ModF:
2652   case Op_ConvI2F:
2653   case Op_ConF:
2654   case Op_CmpF:
2655   case Op_CmpF3:
2656   // case Op_ConvL2F: // longs are split into 32-bit halves
2657     frc.inc_float_count();
2658     break;
2659 
2660   case Op_ConvF2D:
2661   case Op_ConvD2F:
2662     frc.inc_float_count();
2663     frc.inc_double_count();
2664     break;
2665 
2666   // Count all double operations that may use FPU
2667   case Op_AddD:
2668   case Op_SubD:
2669   case Op_MulD:
2670   case Op_DivD:
2671   case Op_NegD:
2672   case Op_ModD:
2673   case Op_ConvI2D:
2674   case Op_ConvD2I:
2675   // case Op_ConvL2D: // handled by leaf call
2676   // case Op_ConvD2L: // handled by leaf call
2677   case Op_ConD:
2678   case Op_CmpD:
2679   case Op_CmpD3:
2680     frc.inc_double_count();
2681     break;
2682   case Op_Opaque1:              // Remove Opaque Nodes before matching
2683   case Op_Opaque2:              // Remove Opaque Nodes before matching
2684   case Op_Opaque3:
2685     n->subsume_by(n->in(1), this);
2686     break;
2687   case Op_CallStaticJava:
2688   case Op_CallJava:
2689   case Op_CallDynamicJava:
2690     frc.inc_java_call_count(); // Count java call site;
2691   case Op_CallRuntime:
2692   case Op_CallLeaf:
2693   case Op_CallLeafNoFP: {
2694     assert( n->is_Call(), "" );
2695     CallNode *call = n->as_Call();
2696     // Count call sites where the FP mode bit would have to be flipped.
2697     // Do not count uncommon runtime calls:
2698     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
2699     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
2700     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
2701       frc.inc_call_count();   // Count the call site
2702     } else {                  // See if uncommon argument is shared
2703       Node *n = call->in(TypeFunc::Parms);
2704       int nop = n->Opcode();
2705       // Clone shared simple arguments to uncommon calls, item (1).
2706       if( n->outcnt() > 1 &&
2707           !n->is_Proj() &&
2708           nop != Op_CreateEx &&
2709           nop != Op_CheckCastPP &&
2710           nop != Op_DecodeN &&
2711           nop != Op_DecodeNKlass &&
2712           !n->is_Mem() ) {
2713         Node *x = n->clone();
2714         call->set_req( TypeFunc::Parms, x );
2715       }
2716     }
2717     break;
2718   }
2719 
2720   case Op_StoreD:
2721   case Op_LoadD:
2722   case Op_LoadD_unaligned:
2723     frc.inc_double_count();
2724     goto handle_mem;
2725   case Op_StoreF:
2726   case Op_LoadF:
2727     frc.inc_float_count();
2728     goto handle_mem;
2729 
2730   case Op_StoreCM:
2731     {
2732       // Convert OopStore dependence into precedence edge
2733       Node* prec = n->in(MemNode::OopStore);
2734       n->del_req(MemNode::OopStore);
2735       n->add_prec(prec);
2736       eliminate_redundant_card_marks(n);
2737     }
2738 
2739     // fall through
2740 
2741   case Op_StoreB:
2742   case Op_StoreC:
2743   case Op_StorePConditional:
2744   case Op_StoreI:
2745   case Op_StoreL:
2746   case Op_StoreIConditional:
2747   case Op_StoreLConditional:
2748   case Op_CompareAndSwapI:
2749   case Op_CompareAndSwapL:
2750   case Op_CompareAndSwapP:
2751   case Op_CompareAndSwapN:
2752   case Op_GetAndAddI:
2753   case Op_GetAndAddL:
2754   case Op_GetAndSetI:
2755   case Op_GetAndSetL:
2756   case Op_GetAndSetP:
2757   case Op_GetAndSetN:
2758   case Op_StoreP:
2759   case Op_StoreN:
2760   case Op_StoreNKlass:
2761   case Op_LoadB:
2762   case Op_LoadUB:
2763   case Op_LoadUS:
2764   case Op_LoadI:
2765   case Op_LoadKlass:
2766   case Op_LoadNKlass:
2767   case Op_LoadL:
2768   case Op_LoadL_unaligned:
2769   case Op_LoadPLocked:
2770   case Op_LoadP:
2771   case Op_LoadN:
2772   case Op_LoadRange:
2773   case Op_LoadS: {
2774   handle_mem:
2775 #ifdef ASSERT
2776     if( VerifyOptoOopOffsets ) {
2777       assert( n->is_Mem(), "" );
2778       MemNode *mem  = (MemNode*)n;
2779       // Check to see if address types have grounded out somehow.
2780       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
2781       assert( !tp || oop_offset_is_sane(tp), "" );
2782     }
2783 #endif
2784     break;
2785   }
2786 
2787   case Op_AddP: {               // Assert sane base pointers
2788     Node *addp = n->in(AddPNode::Address);
2789     assert( !addp->is_AddP() ||
2790             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
2791             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
2792             "Base pointers must match" );
2793 #ifdef _LP64
2794     if ((UseCompressedOops || UseCompressedClassPointers) &&
2795         addp->Opcode() == Op_ConP &&
2796         addp == n->in(AddPNode::Base) &&
2797         n->in(AddPNode::Offset)->is_Con()) {
2798       // Use addressing with narrow klass to load with offset on x86.
2799       // On sparc loading 32-bits constant and decoding it have less
2800       // instructions (4) then load 64-bits constant (7).
2801       // Do this transformation here since IGVN will convert ConN back to ConP.
2802       const Type* t = addp->bottom_type();
2803       if (t->isa_oopptr() || t->isa_klassptr()) {
2804         Node* nn = NULL;
2805 
2806         int op = t->isa_oopptr() ? Op_ConN : Op_ConNKlass;
2807 
2808         // Look for existing ConN node of the same exact type.
2809         Node* r  = root();
2810         uint cnt = r->outcnt();
2811         for (uint i = 0; i < cnt; i++) {
2812           Node* m = r->raw_out(i);
2813           if (m!= NULL && m->Opcode() == op &&
2814               m->bottom_type()->make_ptr() == t) {
2815             nn = m;
2816             break;
2817           }
2818         }
2819         if (nn != NULL) {
2820           // Decode a narrow oop to match address
2821           // [R12 + narrow_oop_reg<<3 + offset]
2822           if (t->isa_oopptr()) {
2823             nn = new DecodeNNode(nn, t);
2824           } else {
2825             nn = new DecodeNKlassNode(nn, t);
2826           }
2827           n->set_req(AddPNode::Base, nn);
2828           n->set_req(AddPNode::Address, nn);
2829           if (addp->outcnt() == 0) {
2830             addp->disconnect_inputs(NULL, this);
2831           }
2832         }
2833       }
2834     }
2835 #endif
2836     break;
2837   }
2838 
2839   case Op_CastPP: {
2840     // Remove CastPP nodes to gain more freedom during scheduling but
2841     // keep the dependency they encode as control or precedence edges
2842     // (if control is set already) on memory operations. Some CastPP
2843     // nodes don't have a control (don't carry a dependency): skip
2844     // those.
2845     if (n->in(0) != NULL) {
2846       ResourceMark rm;
2847       Unique_Node_List wq;
2848       wq.push(n);
2849       for (uint next = 0; next < wq.size(); ++next) {
2850         Node *m = wq.at(next);
2851         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
2852           Node* use = m->fast_out(i);
2853           if (use->is_Mem() || use->is_EncodeNarrowPtr()) {
2854             use->ensure_control_or_add_prec(n->in(0));
2855           } else if (use->in(0) == NULL) {
2856             switch(use->Opcode()) {
2857             case Op_AddP:
2858             case Op_DecodeN:
2859             case Op_DecodeNKlass:
2860             case Op_CheckCastPP:
2861             case Op_CastPP:
2862               wq.push(use);
2863               break;
2864             }
2865           }
2866         }
2867       }
2868     }
2869     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
2870     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
2871       Node* in1 = n->in(1);
2872       const Type* t = n->bottom_type();
2873       Node* new_in1 = in1->clone();
2874       new_in1->as_DecodeN()->set_type(t);
2875 
2876       if (!Matcher::narrow_oop_use_complex_address()) {
2877         //
2878         // x86, ARM and friends can handle 2 adds in addressing mode
2879         // and Matcher can fold a DecodeN node into address by using
2880         // a narrow oop directly and do implicit NULL check in address:
2881         //
2882         // [R12 + narrow_oop_reg<<3 + offset]
2883         // NullCheck narrow_oop_reg
2884         //
2885         // On other platforms (Sparc) we have to keep new DecodeN node and
2886         // use it to do implicit NULL check in address:
2887         //
2888         // decode_not_null narrow_oop_reg, base_reg
2889         // [base_reg + offset]
2890         // NullCheck base_reg
2891         //
2892         // Pin the new DecodeN node to non-null path on these platform (Sparc)
2893         // to keep the information to which NULL check the new DecodeN node
2894         // corresponds to use it as value in implicit_null_check().
2895         //
2896         new_in1->set_req(0, n->in(0));
2897       }
2898 
2899       n->subsume_by(new_in1, this);
2900       if (in1->outcnt() == 0) {
2901         in1->disconnect_inputs(NULL, this);
2902       }
2903     } else {
2904       n->subsume_by(n->in(1), this);
2905       if (n->outcnt() == 0) {
2906         n->disconnect_inputs(NULL, this);
2907       }
2908     }
2909     break;
2910   }
2911 #ifdef _LP64
2912   case Op_CmpP:
2913     // Do this transformation here to preserve CmpPNode::sub() and
2914     // other TypePtr related Ideal optimizations (for example, ptr nullness).
2915     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
2916       Node* in1 = n->in(1);
2917       Node* in2 = n->in(2);
2918       if (!in1->is_DecodeNarrowPtr()) {
2919         in2 = in1;
2920         in1 = n->in(2);
2921       }
2922       assert(in1->is_DecodeNarrowPtr(), "sanity");
2923 
2924       Node* new_in2 = NULL;
2925       if (in2->is_DecodeNarrowPtr()) {
2926         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
2927         new_in2 = in2->in(1);
2928       } else if (in2->Opcode() == Op_ConP) {
2929         const Type* t = in2->bottom_type();
2930         if (t == TypePtr::NULL_PTR) {
2931           assert(in1->is_DecodeN(), "compare klass to null?");
2932           // Don't convert CmpP null check into CmpN if compressed
2933           // oops implicit null check is not generated.
2934           // This will allow to generate normal oop implicit null check.
2935           if (Matcher::gen_narrow_oop_implicit_null_checks())
2936             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
2937           //
2938           // This transformation together with CastPP transformation above
2939           // will generated code for implicit NULL checks for compressed oops.
2940           //
2941           // The original code after Optimize()
2942           //
2943           //    LoadN memory, narrow_oop_reg
2944           //    decode narrow_oop_reg, base_reg
2945           //    CmpP base_reg, NULL
2946           //    CastPP base_reg // NotNull
2947           //    Load [base_reg + offset], val_reg
2948           //
2949           // after these transformations will be
2950           //
2951           //    LoadN memory, narrow_oop_reg
2952           //    CmpN narrow_oop_reg, NULL
2953           //    decode_not_null narrow_oop_reg, base_reg
2954           //    Load [base_reg + offset], val_reg
2955           //
2956           // and the uncommon path (== NULL) will use narrow_oop_reg directly
2957           // since narrow oops can be used in debug info now (see the code in
2958           // final_graph_reshaping_walk()).
2959           //
2960           // At the end the code will be matched to
2961           // on x86:
2962           //
2963           //    Load_narrow_oop memory, narrow_oop_reg
2964           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
2965           //    NullCheck narrow_oop_reg
2966           //
2967           // and on sparc:
2968           //
2969           //    Load_narrow_oop memory, narrow_oop_reg
2970           //    decode_not_null narrow_oop_reg, base_reg
2971           //    Load [base_reg + offset], val_reg
2972           //    NullCheck base_reg
2973           //
2974         } else if (t->isa_oopptr()) {
2975           new_in2 = ConNode::make(t->make_narrowoop());
2976         } else if (t->isa_klassptr()) {
2977           new_in2 = ConNode::make(t->make_narrowklass());
2978         }
2979       }
2980       if (new_in2 != NULL) {
2981         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
2982         n->subsume_by(cmpN, this);
2983         if (in1->outcnt() == 0) {
2984           in1->disconnect_inputs(NULL, this);
2985         }
2986         if (in2->outcnt() == 0) {
2987           in2->disconnect_inputs(NULL, this);
2988         }
2989       }
2990     }
2991     break;
2992 
2993   case Op_DecodeN:
2994   case Op_DecodeNKlass:
2995     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
2996     // DecodeN could be pinned when it can't be fold into
2997     // an address expression, see the code for Op_CastPP above.
2998     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
2999     break;
3000 
3001   case Op_EncodeP:
3002   case Op_EncodePKlass: {
3003     Node* in1 = n->in(1);
3004     if (in1->is_DecodeNarrowPtr()) {
3005       n->subsume_by(in1->in(1), this);
3006     } else if (in1->Opcode() == Op_ConP) {
3007       const Type* t = in1->bottom_type();
3008       if (t == TypePtr::NULL_PTR) {
3009         assert(t->isa_oopptr(), "null klass?");
3010         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
3011       } else if (t->isa_oopptr()) {
3012         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
3013       } else if (t->isa_klassptr()) {
3014         n->subsume_by(ConNode::make(t->make_narrowklass()), this);
3015       }
3016     }
3017     if (in1->outcnt() == 0) {
3018       in1->disconnect_inputs(NULL, this);
3019     }
3020     break;
3021   }
3022 
3023   case Op_Proj: {
3024     if (OptimizeStringConcat) {
3025       ProjNode* p = n->as_Proj();
3026       if (p->_is_io_use) {
3027         // Separate projections were used for the exception path which
3028         // are normally removed by a late inline.  If it wasn't inlined
3029         // then they will hang around and should just be replaced with
3030         // the original one.
3031         Node* proj = NULL;
3032         // Replace with just one
3033         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
3034           Node *use = i.get();
3035           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
3036             proj = use;
3037             break;
3038           }
3039         }
3040         assert(proj != NULL, "must be found");
3041         p->subsume_by(proj, this);
3042       }
3043     }
3044     break;
3045   }
3046 
3047   case Op_Phi:
3048     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3049       // The EncodeP optimization may create Phi with the same edges
3050       // for all paths. It is not handled well by Register Allocator.
3051       Node* unique_in = n->in(1);
3052       assert(unique_in != NULL, "");
3053       uint cnt = n->req();
3054       for (uint i = 2; i < cnt; i++) {
3055         Node* m = n->in(i);
3056         assert(m != NULL, "");
3057         if (unique_in != m)
3058           unique_in = NULL;
3059       }
3060       if (unique_in != NULL) {
3061         n->subsume_by(unique_in, this);
3062       }
3063     }
3064     break;
3065 
3066 #endif
3067 
3068   case Op_ModI:
3069     if (UseDivMod) {
3070       // Check if a%b and a/b both exist
3071       Node* d = n->find_similar(Op_DivI);
3072       if (d) {
3073         // Replace them with a fused divmod if supported
3074         if (Matcher::has_match_rule(Op_DivModI)) {
3075           DivModINode* divmod = DivModINode::make(n);
3076           d->subsume_by(divmod->div_proj(), this);
3077           n->subsume_by(divmod->mod_proj(), this);
3078         } else {
3079           // replace a%b with a-((a/b)*b)
3080           Node* mult = new MulINode(d, d->in(2));
3081           Node* sub  = new SubINode(d->in(1), mult);
3082           n->subsume_by(sub, this);
3083         }
3084       }
3085     }
3086     break;
3087 
3088   case Op_ModL:
3089     if (UseDivMod) {
3090       // Check if a%b and a/b both exist
3091       Node* d = n->find_similar(Op_DivL);
3092       if (d) {
3093         // Replace them with a fused divmod if supported
3094         if (Matcher::has_match_rule(Op_DivModL)) {
3095           DivModLNode* divmod = DivModLNode::make(n);
3096           d->subsume_by(divmod->div_proj(), this);
3097           n->subsume_by(divmod->mod_proj(), this);
3098         } else {
3099           // replace a%b with a-((a/b)*b)
3100           Node* mult = new MulLNode(d, d->in(2));
3101           Node* sub  = new SubLNode(d->in(1), mult);
3102           n->subsume_by(sub, this);
3103         }
3104       }
3105     }
3106     break;
3107 
3108   case Op_LoadVector:
3109   case Op_StoreVector:
3110     break;
3111 
3112   case Op_AddReductionVI:
3113   case Op_AddReductionVL:
3114   case Op_AddReductionVF:
3115   case Op_AddReductionVD:
3116   case Op_MulReductionVI:
3117   case Op_MulReductionVL:
3118   case Op_MulReductionVF:
3119   case Op_MulReductionVD:
3120     break;
3121 
3122   case Op_PackB:
3123   case Op_PackS:
3124   case Op_PackI:
3125   case Op_PackF:
3126   case Op_PackL:
3127   case Op_PackD:
3128     if (n->req()-1 > 2) {
3129       // Replace many operand PackNodes with a binary tree for matching
3130       PackNode* p = (PackNode*) n;
3131       Node* btp = p->binary_tree_pack(1, n->req());
3132       n->subsume_by(btp, this);
3133     }
3134     break;
3135   case Op_Loop:
3136   case Op_CountedLoop:
3137     if (n->as_Loop()->is_inner_loop()) {
3138       frc.inc_inner_loop_count();
3139     }
3140     break;
3141   case Op_LShiftI:
3142   case Op_RShiftI:
3143   case Op_URShiftI:
3144   case Op_LShiftL:
3145   case Op_RShiftL:
3146   case Op_URShiftL:
3147     if (Matcher::need_masked_shift_count) {
3148       // The cpu's shift instructions don't restrict the count to the
3149       // lower 5/6 bits. We need to do the masking ourselves.
3150       Node* in2 = n->in(2);
3151       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3152       const TypeInt* t = in2->find_int_type();
3153       if (t != NULL && t->is_con()) {
3154         juint shift = t->get_con();
3155         if (shift > mask) { // Unsigned cmp
3156           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3157         }
3158       } else {
3159         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
3160           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3161           n->set_req(2, shift);
3162         }
3163       }
3164       if (in2->outcnt() == 0) { // Remove dead node
3165         in2->disconnect_inputs(NULL, this);
3166       }
3167     }
3168     break;
3169   case Op_MemBarStoreStore:
3170   case Op_MemBarRelease:
3171     // Break the link with AllocateNode: it is no longer useful and
3172     // confuses register allocation.
3173     if (n->req() > MemBarNode::Precedent) {
3174       n->set_req(MemBarNode::Precedent, top());
3175     }
3176     break;
3177   default:
3178     assert( !n->is_Call(), "" );
3179     assert( !n->is_Mem(), "" );
3180     assert( nop != Op_ProfileBoolean, "should be eliminated during IGVN");
3181     break;
3182   }
3183 
3184   // Collect CFG split points
3185   if (n->is_MultiBranch())
3186     frc._tests.push(n);
3187 }
3188 
3189 //------------------------------final_graph_reshaping_walk---------------------
3190 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3191 // requires that the walk visits a node's inputs before visiting the node.
3192 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
3193   ResourceArea *area = Thread::current()->resource_area();
3194   Unique_Node_List sfpt(area);
3195 
3196   frc._visited.set(root->_idx); // first, mark node as visited
3197   uint cnt = root->req();
3198   Node *n = root;
3199   uint  i = 0;
3200   while (true) {
3201     if (i < cnt) {
3202       // Place all non-visited non-null inputs onto stack
3203       Node* m = n->in(i);
3204       ++i;
3205       if (m != NULL && !frc._visited.test_set(m->_idx)) {
3206         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
3207           // compute worst case interpreter size in case of a deoptimization
3208           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3209 
3210           sfpt.push(m);
3211         }
3212         cnt = m->req();
3213         nstack.push(n, i); // put on stack parent and next input's index
3214         n = m;
3215         i = 0;
3216       }
3217     } else {
3218       // Now do post-visit work
3219       final_graph_reshaping_impl( n, frc );
3220       if (nstack.is_empty())
3221         break;             // finished
3222       n = nstack.node();   // Get node from stack
3223       cnt = n->req();
3224       i = nstack.index();
3225       nstack.pop();        // Shift to the next node on stack
3226     }
3227   }
3228 
3229   // Skip next transformation if compressed oops are not used.
3230   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3231       (!UseCompressedOops && !UseCompressedClassPointers))
3232     return;
3233 
3234   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3235   // It could be done for an uncommon traps or any safepoints/calls
3236   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3237   while (sfpt.size() > 0) {
3238     n = sfpt.pop();
3239     JVMState *jvms = n->as_SafePoint()->jvms();
3240     assert(jvms != NULL, "sanity");
3241     int start = jvms->debug_start();
3242     int end   = n->req();
3243     bool is_uncommon = (n->is_CallStaticJava() &&
3244                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
3245     for (int j = start; j < end; j++) {
3246       Node* in = n->in(j);
3247       if (in->is_DecodeNarrowPtr()) {
3248         bool safe_to_skip = true;
3249         if (!is_uncommon ) {
3250           // Is it safe to skip?
3251           for (uint i = 0; i < in->outcnt(); i++) {
3252             Node* u = in->raw_out(i);
3253             if (!u->is_SafePoint() ||
3254                  u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
3255               safe_to_skip = false;
3256             }
3257           }
3258         }
3259         if (safe_to_skip) {
3260           n->set_req(j, in->in(1));
3261         }
3262         if (in->outcnt() == 0) {
3263           in->disconnect_inputs(NULL, this);
3264         }
3265       }
3266     }
3267   }
3268 }
3269 
3270 //------------------------------final_graph_reshaping--------------------------
3271 // Final Graph Reshaping.
3272 //
3273 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3274 //     and not commoned up and forced early.  Must come after regular
3275 //     optimizations to avoid GVN undoing the cloning.  Clone constant
3276 //     inputs to Loop Phis; these will be split by the allocator anyways.
3277 //     Remove Opaque nodes.
3278 // (2) Move last-uses by commutative operations to the left input to encourage
3279 //     Intel update-in-place two-address operations and better register usage
3280 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
3281 //     calls canonicalizing them back.
3282 // (3) Count the number of double-precision FP ops, single-precision FP ops
3283 //     and call sites.  On Intel, we can get correct rounding either by
3284 //     forcing singles to memory (requires extra stores and loads after each
3285 //     FP bytecode) or we can set a rounding mode bit (requires setting and
3286 //     clearing the mode bit around call sites).  The mode bit is only used
3287 //     if the relative frequency of single FP ops to calls is low enough.
3288 //     This is a key transform for SPEC mpeg_audio.
3289 // (4) Detect infinite loops; blobs of code reachable from above but not
3290 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
3291 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
3292 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
3293 //     Detection is by looking for IfNodes where only 1 projection is
3294 //     reachable from below or CatchNodes missing some targets.
3295 // (5) Assert for insane oop offsets in debug mode.
3296 
3297 bool Compile::final_graph_reshaping() {
3298   // an infinite loop may have been eliminated by the optimizer,
3299   // in which case the graph will be empty.
3300   if (root()->req() == 1) {
3301     record_method_not_compilable("trivial infinite loop");
3302     return true;
3303   }
3304 
3305   // Expensive nodes have their control input set to prevent the GVN
3306   // from freely commoning them. There's no GVN beyond this point so
3307   // no need to keep the control input. We want the expensive nodes to
3308   // be freely moved to the least frequent code path by gcm.
3309   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
3310   for (int i = 0; i < expensive_count(); i++) {
3311     _expensive_nodes->at(i)->set_req(0, NULL);
3312   }
3313 
3314   Final_Reshape_Counts frc;
3315 
3316   // Visit everybody reachable!
3317   // Allocate stack of size C->unique()/2 to avoid frequent realloc
3318   Node_Stack nstack(live_nodes() >> 1);
3319   final_graph_reshaping_walk(nstack, root(), frc);
3320 
3321   // Check for unreachable (from below) code (i.e., infinite loops).
3322   for( uint i = 0; i < frc._tests.size(); i++ ) {
3323     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
3324     // Get number of CFG targets.
3325     // Note that PCTables include exception targets after calls.
3326     uint required_outcnt = n->required_outcnt();
3327     if (n->outcnt() != required_outcnt) {
3328       // Check for a few special cases.  Rethrow Nodes never take the
3329       // 'fall-thru' path, so expected kids is 1 less.
3330       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
3331         if (n->in(0)->in(0)->is_Call()) {
3332           CallNode *call = n->in(0)->in(0)->as_Call();
3333           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
3334             required_outcnt--;      // Rethrow always has 1 less kid
3335           } else if (call->req() > TypeFunc::Parms &&
3336                      call->is_CallDynamicJava()) {
3337             // Check for null receiver. In such case, the optimizer has
3338             // detected that the virtual call will always result in a null
3339             // pointer exception. The fall-through projection of this CatchNode
3340             // will not be populated.
3341             Node *arg0 = call->in(TypeFunc::Parms);
3342             if (arg0->is_Type() &&
3343                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
3344               required_outcnt--;
3345             }
3346           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
3347                      call->req() > TypeFunc::Parms+1 &&
3348                      call->is_CallStaticJava()) {
3349             // Check for negative array length. In such case, the optimizer has
3350             // detected that the allocation attempt will always result in an
3351             // exception. There is no fall-through projection of this CatchNode .
3352             Node *arg1 = call->in(TypeFunc::Parms+1);
3353             if (arg1->is_Type() &&
3354                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
3355               required_outcnt--;
3356             }
3357           }
3358         }
3359       }
3360       // Recheck with a better notion of 'required_outcnt'
3361       if (n->outcnt() != required_outcnt) {
3362         record_method_not_compilable("malformed control flow");
3363         return true;            // Not all targets reachable!
3364       }
3365     }
3366     // Check that I actually visited all kids.  Unreached kids
3367     // must be infinite loops.
3368     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
3369       if (!frc._visited.test(n->fast_out(j)->_idx)) {
3370         record_method_not_compilable("infinite loop");
3371         return true;            // Found unvisited kid; must be unreach
3372       }
3373   }
3374 
3375   // If original bytecodes contained a mixture of floats and doubles
3376   // check if the optimizer has made it homogenous, item (3).
3377   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
3378       frc.get_float_count() > 32 &&
3379       frc.get_double_count() == 0 &&
3380       (10 * frc.get_call_count() < frc.get_float_count()) ) {
3381     set_24_bit_selection_and_mode( false,  true );
3382   }
3383 
3384   set_java_calls(frc.get_java_call_count());
3385   set_inner_loops(frc.get_inner_loop_count());
3386 
3387   // No infinite loops, no reason to bail out.
3388   return false;
3389 }
3390 
3391 //-----------------------------too_many_traps----------------------------------
3392 // Report if there are too many traps at the current method and bci.
3393 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
3394 bool Compile::too_many_traps(ciMethod* method,
3395                              int bci,
3396                              Deoptimization::DeoptReason reason) {
3397   ciMethodData* md = method->method_data();
3398   if (md->is_empty()) {
3399     // Assume the trap has not occurred, or that it occurred only
3400     // because of a transient condition during start-up in the interpreter.
3401     return false;
3402   }
3403   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3404   if (md->has_trap_at(bci, m, reason) != 0) {
3405     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
3406     // Also, if there are multiple reasons, or if there is no per-BCI record,
3407     // assume the worst.
3408     if (log())
3409       log()->elem("observe trap='%s' count='%d'",
3410                   Deoptimization::trap_reason_name(reason),
3411                   md->trap_count(reason));
3412     return true;
3413   } else {
3414     // Ignore method/bci and see if there have been too many globally.
3415     return too_many_traps(reason, md);
3416   }
3417 }
3418 
3419 // Less-accurate variant which does not require a method and bci.
3420 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
3421                              ciMethodData* logmd) {
3422   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
3423     // Too many traps globally.
3424     // Note that we use cumulative trap_count, not just md->trap_count.
3425     if (log()) {
3426       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
3427       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
3428                   Deoptimization::trap_reason_name(reason),
3429                   mcount, trap_count(reason));
3430     }
3431     return true;
3432   } else {
3433     // The coast is clear.
3434     return false;
3435   }
3436 }
3437 
3438 //--------------------------too_many_recompiles--------------------------------
3439 // Report if there are too many recompiles at the current method and bci.
3440 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
3441 // Is not eager to return true, since this will cause the compiler to use
3442 // Action_none for a trap point, to avoid too many recompilations.
3443 bool Compile::too_many_recompiles(ciMethod* method,
3444                                   int bci,
3445                                   Deoptimization::DeoptReason reason) {
3446   ciMethodData* md = method->method_data();
3447   if (md->is_empty()) {
3448     // Assume the trap has not occurred, or that it occurred only
3449     // because of a transient condition during start-up in the interpreter.
3450     return false;
3451   }
3452   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
3453   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
3454   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
3455   Deoptimization::DeoptReason per_bc_reason
3456     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
3457   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3458   if ((per_bc_reason == Deoptimization::Reason_none
3459        || md->has_trap_at(bci, m, reason) != 0)
3460       // The trap frequency measure we care about is the recompile count:
3461       && md->trap_recompiled_at(bci, m)
3462       && md->overflow_recompile_count() >= bc_cutoff) {
3463     // Do not emit a trap here if it has already caused recompilations.
3464     // Also, if there are multiple reasons, or if there is no per-BCI record,
3465     // assume the worst.
3466     if (log())
3467       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
3468                   Deoptimization::trap_reason_name(reason),
3469                   md->trap_count(reason),
3470                   md->overflow_recompile_count());
3471     return true;
3472   } else if (trap_count(reason) != 0
3473              && decompile_count() >= m_cutoff) {
3474     // Too many recompiles globally, and we have seen this sort of trap.
3475     // Use cumulative decompile_count, not just md->decompile_count.
3476     if (log())
3477       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
3478                   Deoptimization::trap_reason_name(reason),
3479                   md->trap_count(reason), trap_count(reason),
3480                   md->decompile_count(), decompile_count());
3481     return true;
3482   } else {
3483     // The coast is clear.
3484     return false;
3485   }
3486 }
3487 
3488 // Compute when not to trap. Used by matching trap based nodes and
3489 // NullCheck optimization.
3490 void Compile::set_allowed_deopt_reasons() {
3491   _allowed_reasons = 0;
3492   if (is_method_compilation()) {
3493     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
3494       assert(rs < BitsPerInt, "recode bit map");
3495       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
3496         _allowed_reasons |= nth_bit(rs);
3497       }
3498     }
3499   }
3500 }
3501 
3502 #ifndef PRODUCT
3503 //------------------------------verify_graph_edges---------------------------
3504 // Walk the Graph and verify that there is a one-to-one correspondence
3505 // between Use-Def edges and Def-Use edges in the graph.
3506 void Compile::verify_graph_edges(bool no_dead_code) {
3507   if (VerifyGraphEdges) {
3508     ResourceArea *area = Thread::current()->resource_area();
3509     Unique_Node_List visited(area);
3510     // Call recursive graph walk to check edges
3511     _root->verify_edges(visited);
3512     if (no_dead_code) {
3513       // Now make sure that no visited node is used by an unvisited node.
3514       bool dead_nodes = false;
3515       Unique_Node_List checked(area);
3516       while (visited.size() > 0) {
3517         Node* n = visited.pop();
3518         checked.push(n);
3519         for (uint i = 0; i < n->outcnt(); i++) {
3520           Node* use = n->raw_out(i);
3521           if (checked.member(use))  continue;  // already checked
3522           if (visited.member(use))  continue;  // already in the graph
3523           if (use->is_Con())        continue;  // a dead ConNode is OK
3524           // At this point, we have found a dead node which is DU-reachable.
3525           if (!dead_nodes) {
3526             tty->print_cr("*** Dead nodes reachable via DU edges:");
3527             dead_nodes = true;
3528           }
3529           use->dump(2);
3530           tty->print_cr("---");
3531           checked.push(use);  // No repeats; pretend it is now checked.
3532         }
3533       }
3534       assert(!dead_nodes, "using nodes must be reachable from root");
3535     }
3536   }
3537 }
3538 
3539 // Verify GC barriers consistency
3540 // Currently supported:
3541 // - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
3542 void Compile::verify_barriers() {
3543   if (UseG1GC) {
3544     // Verify G1 pre-barriers
3545     const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active());
3546 
3547     ResourceArea *area = Thread::current()->resource_area();
3548     Unique_Node_List visited(area);
3549     Node_List worklist(area);
3550     // We're going to walk control flow backwards starting from the Root
3551     worklist.push(_root);
3552     while (worklist.size() > 0) {
3553       Node* x = worklist.pop();
3554       if (x == NULL || x == top()) continue;
3555       if (visited.member(x)) {
3556         continue;
3557       } else {
3558         visited.push(x);
3559       }
3560 
3561       if (x->is_Region()) {
3562         for (uint i = 1; i < x->req(); i++) {
3563           worklist.push(x->in(i));
3564         }
3565       } else {
3566         worklist.push(x->in(0));
3567         // We are looking for the pattern:
3568         //                            /->ThreadLocal
3569         // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
3570         //              \->ConI(0)
3571         // We want to verify that the If and the LoadB have the same control
3572         // See GraphKit::g1_write_barrier_pre()
3573         if (x->is_If()) {
3574           IfNode *iff = x->as_If();
3575           if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
3576             CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
3577             if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
3578                 && cmp->in(1)->is_Load()) {
3579               LoadNode* load = cmp->in(1)->as_Load();
3580               if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
3581                   && load->in(2)->in(3)->is_Con()
3582                   && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
3583 
3584                 Node* if_ctrl = iff->in(0);
3585                 Node* load_ctrl = load->in(0);
3586 
3587                 if (if_ctrl != load_ctrl) {
3588                   // Skip possible CProj->NeverBranch in infinite loops
3589                   if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
3590                       && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
3591                     if_ctrl = if_ctrl->in(0)->in(0);
3592                   }
3593                 }
3594                 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
3595               }
3596             }
3597           }
3598         }
3599       }
3600     }
3601   }
3602 }
3603 
3604 #endif
3605 
3606 // The Compile object keeps track of failure reasons separately from the ciEnv.
3607 // This is required because there is not quite a 1-1 relation between the
3608 // ciEnv and its compilation task and the Compile object.  Note that one
3609 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
3610 // to backtrack and retry without subsuming loads.  Other than this backtracking
3611 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
3612 // by the logic in C2Compiler.
3613 void Compile::record_failure(const char* reason) {
3614   if (log() != NULL) {
3615     log()->elem("failure reason='%s' phase='compile'", reason);
3616   }
3617   if (_failure_reason == NULL) {
3618     // Record the first failure reason.
3619     _failure_reason = reason;
3620   }
3621 
3622   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
3623     C->print_method(PHASE_FAILURE);
3624   }
3625   _root = NULL;  // flush the graph, too
3626 }
3627 
3628 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator)
3629   : TraceTime(name, accumulator, CITime, CITimeVerbose),
3630     _phase_name(name), _dolog(CITimeVerbose)
3631 {
3632   if (_dolog) {
3633     C = Compile::current();
3634     _log = C->log();
3635   } else {
3636     C = NULL;
3637     _log = NULL;
3638   }
3639   if (_log != NULL) {
3640     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3641     _log->stamp();
3642     _log->end_head();
3643   }
3644 }
3645 
3646 Compile::TracePhase::~TracePhase() {
3647 
3648   C = Compile::current();
3649   if (_dolog) {
3650     _log = C->log();
3651   } else {
3652     _log = NULL;
3653   }
3654 
3655 #ifdef ASSERT
3656   if (PrintIdealNodeCount) {
3657     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
3658                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
3659   }
3660 
3661   if (VerifyIdealNodeCount) {
3662     Compile::current()->print_missing_nodes();
3663   }
3664 #endif
3665 
3666   if (_log != NULL) {
3667     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3668   }
3669 }
3670 
3671 //=============================================================================
3672 // Two Constant's are equal when the type and the value are equal.
3673 bool Compile::Constant::operator==(const Constant& other) {
3674   if (type()          != other.type()         )  return false;
3675   if (can_be_reused() != other.can_be_reused())  return false;
3676   // For floating point values we compare the bit pattern.
3677   switch (type()) {
3678   case T_FLOAT:   return (_v._value.i == other._v._value.i);
3679   case T_LONG:
3680   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
3681   case T_OBJECT:
3682   case T_ADDRESS: return (_v._value.l == other._v._value.l);
3683   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
3684   case T_METADATA: return (_v._metadata == other._v._metadata);
3685   default: ShouldNotReachHere();
3686   }
3687   return false;
3688 }
3689 
3690 static int type_to_size_in_bytes(BasicType t) {
3691   switch (t) {
3692   case T_LONG:    return sizeof(jlong  );
3693   case T_FLOAT:   return sizeof(jfloat );
3694   case T_DOUBLE:  return sizeof(jdouble);
3695   case T_METADATA: return sizeof(Metadata*);
3696     // We use T_VOID as marker for jump-table entries (labels) which
3697     // need an internal word relocation.
3698   case T_VOID:
3699   case T_ADDRESS:
3700   case T_OBJECT:  return sizeof(jobject);
3701   }
3702 
3703   ShouldNotReachHere();
3704   return -1;
3705 }
3706 
3707 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
3708   // sort descending
3709   if (a->freq() > b->freq())  return -1;
3710   if (a->freq() < b->freq())  return  1;
3711   return 0;
3712 }
3713 
3714 void Compile::ConstantTable::calculate_offsets_and_size() {
3715   // First, sort the array by frequencies.
3716   _constants.sort(qsort_comparator);
3717 
3718 #ifdef ASSERT
3719   // Make sure all jump-table entries were sorted to the end of the
3720   // array (they have a negative frequency).
3721   bool found_void = false;
3722   for (int i = 0; i < _constants.length(); i++) {
3723     Constant con = _constants.at(i);
3724     if (con.type() == T_VOID)
3725       found_void = true;  // jump-tables
3726     else
3727       assert(!found_void, "wrong sorting");
3728   }
3729 #endif
3730 
3731   int offset = 0;
3732   for (int i = 0; i < _constants.length(); i++) {
3733     Constant* con = _constants.adr_at(i);
3734 
3735     // Align offset for type.
3736     int typesize = type_to_size_in_bytes(con->type());
3737     offset = align_size_up(offset, typesize);
3738     con->set_offset(offset);   // set constant's offset
3739 
3740     if (con->type() == T_VOID) {
3741       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
3742       offset = offset + typesize * n->outcnt();  // expand jump-table
3743     } else {
3744       offset = offset + typesize;
3745     }
3746   }
3747 
3748   // Align size up to the next section start (which is insts; see
3749   // CodeBuffer::align_at_start).
3750   assert(_size == -1, "already set?");
3751   _size = align_size_up(offset, CodeEntryAlignment);
3752 }
3753 
3754 void Compile::ConstantTable::emit(CodeBuffer& cb) {
3755   MacroAssembler _masm(&cb);
3756   for (int i = 0; i < _constants.length(); i++) {
3757     Constant con = _constants.at(i);
3758     address constant_addr;
3759     switch (con.type()) {
3760     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
3761     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
3762     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
3763     case T_OBJECT: {
3764       jobject obj = con.get_jobject();
3765       int oop_index = _masm.oop_recorder()->find_index(obj);
3766       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
3767       break;
3768     }
3769     case T_ADDRESS: {
3770       address addr = (address) con.get_jobject();
3771       constant_addr = _masm.address_constant(addr);
3772       break;
3773     }
3774     // We use T_VOID as marker for jump-table entries (labels) which
3775     // need an internal word relocation.
3776     case T_VOID: {
3777       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
3778       // Fill the jump-table with a dummy word.  The real value is
3779       // filled in later in fill_jump_table.
3780       address dummy = (address) n;
3781       constant_addr = _masm.address_constant(dummy);
3782       // Expand jump-table
3783       for (uint i = 1; i < n->outcnt(); i++) {
3784         address temp_addr = _masm.address_constant(dummy + i);
3785         assert(temp_addr, "consts section too small");
3786       }
3787       break;
3788     }
3789     case T_METADATA: {
3790       Metadata* obj = con.get_metadata();
3791       int metadata_index = _masm.oop_recorder()->find_index(obj);
3792       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
3793       break;
3794     }
3795     default: ShouldNotReachHere();
3796     }
3797     assert(constant_addr, "consts section too small");
3798     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
3799             "must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset()));
3800   }
3801 }
3802 
3803 int Compile::ConstantTable::find_offset(Constant& con) const {
3804   int idx = _constants.find(con);
3805   assert(idx != -1, "constant must be in constant table");
3806   int offset = _constants.at(idx).offset();
3807   assert(offset != -1, "constant table not emitted yet?");
3808   return offset;
3809 }
3810 
3811 void Compile::ConstantTable::add(Constant& con) {
3812   if (con.can_be_reused()) {
3813     int idx = _constants.find(con);
3814     if (idx != -1 && _constants.at(idx).can_be_reused()) {
3815       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
3816       return;
3817     }
3818   }
3819   (void) _constants.append(con);
3820 }
3821 
3822 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
3823   Block* b = Compile::current()->cfg()->get_block_for_node(n);
3824   Constant con(type, value, b->_freq);
3825   add(con);
3826   return con;
3827 }
3828 
3829 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
3830   Constant con(metadata);
3831   add(con);
3832   return con;
3833 }
3834 
3835 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
3836   jvalue value;
3837   BasicType type = oper->type()->basic_type();
3838   switch (type) {
3839   case T_LONG:    value.j = oper->constantL(); break;
3840   case T_FLOAT:   value.f = oper->constantF(); break;
3841   case T_DOUBLE:  value.d = oper->constantD(); break;
3842   case T_OBJECT:
3843   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
3844   case T_METADATA: return add((Metadata*)oper->constant()); break;
3845   default: guarantee(false, "unhandled type: %s", type2name(type));
3846   }
3847   return add(n, type, value);
3848 }
3849 
3850 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
3851   jvalue value;
3852   // We can use the node pointer here to identify the right jump-table
3853   // as this method is called from Compile::Fill_buffer right before
3854   // the MachNodes are emitted and the jump-table is filled (means the
3855   // MachNode pointers do not change anymore).
3856   value.l = (jobject) n;
3857   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
3858   add(con);
3859   return con;
3860 }
3861 
3862 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
3863   // If called from Compile::scratch_emit_size do nothing.
3864   if (Compile::current()->in_scratch_emit_size())  return;
3865 
3866   assert(labels.is_nonempty(), "must be");
3867   assert((uint) labels.length() == n->outcnt(), "must be equal: %d == %d", labels.length(), n->outcnt());
3868 
3869   // Since MachConstantNode::constant_offset() also contains
3870   // table_base_offset() we need to subtract the table_base_offset()
3871   // to get the plain offset into the constant table.
3872   int offset = n->constant_offset() - table_base_offset();
3873 
3874   MacroAssembler _masm(&cb);
3875   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
3876 
3877   for (uint i = 0; i < n->outcnt(); i++) {
3878     address* constant_addr = &jump_table_base[i];
3879     assert(*constant_addr == (((address) n) + i), "all jump-table entries must contain adjusted node pointer: " INTPTR_FORMAT " == " INTPTR_FORMAT, p2i(*constant_addr), p2i(((address) n) + i));
3880     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
3881     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
3882   }
3883 }
3884 
3885 //----------------------------static_subtype_check-----------------------------
3886 // Shortcut important common cases when superklass is exact:
3887 // (0) superklass is java.lang.Object (can occur in reflective code)
3888 // (1) subklass is already limited to a subtype of superklass => always ok
3889 // (2) subklass does not overlap with superklass => always fail
3890 // (3) superklass has NO subtypes and we can check with a simple compare.
3891 int Compile::static_subtype_check(ciKlass* superk, ciKlass* subk) {
3892   if (StressReflectiveCode) {
3893     return SSC_full_test;       // Let caller generate the general case.
3894   }
3895 
3896   if (superk == env()->Object_klass()) {
3897     return SSC_always_true;     // (0) this test cannot fail
3898   }
3899 
3900   ciType* superelem = superk;
3901   if (superelem->is_array_klass())
3902     superelem = superelem->as_array_klass()->base_element_type();
3903 
3904   if (!subk->is_interface()) {  // cannot trust static interface types yet
3905     if (subk->is_subtype_of(superk)) {
3906       return SSC_always_true;   // (1) false path dead; no dynamic test needed
3907     }
3908     if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
3909         !superk->is_subtype_of(subk)) {
3910       return SSC_always_false;
3911     }
3912   }
3913 
3914   // If casting to an instance klass, it must have no subtypes
3915   if (superk->is_interface()) {
3916     // Cannot trust interfaces yet.
3917     // %%% S.B. superk->nof_implementors() == 1
3918   } else if (superelem->is_instance_klass()) {
3919     ciInstanceKlass* ik = superelem->as_instance_klass();
3920     if (!ik->has_subklass() && !ik->is_interface()) {
3921       if (!ik->is_final()) {
3922         // Add a dependency if there is a chance of a later subclass.
3923         dependencies()->assert_leaf_type(ik);
3924       }
3925       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
3926     }
3927   } else {
3928     // A primitive array type has no subtypes.
3929     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
3930   }
3931 
3932   return SSC_full_test;
3933 }
3934 
3935 Node* Compile::conv_I2X_index(PhaseGVN *phase, Node* idx, const TypeInt* sizetype) {
3936 #ifdef _LP64
3937   // The scaled index operand to AddP must be a clean 64-bit value.
3938   // Java allows a 32-bit int to be incremented to a negative
3939   // value, which appears in a 64-bit register as a large
3940   // positive number.  Using that large positive number as an
3941   // operand in pointer arithmetic has bad consequences.
3942   // On the other hand, 32-bit overflow is rare, and the possibility
3943   // can often be excluded, if we annotate the ConvI2L node with
3944   // a type assertion that its value is known to be a small positive
3945   // number.  (The prior range check has ensured this.)
3946   // This assertion is used by ConvI2LNode::Ideal.
3947   int index_max = max_jint - 1;  // array size is max_jint, index is one less
3948   if (sizetype != NULL)  index_max = sizetype->_hi - 1;
3949   const TypeLong* lidxtype = TypeLong::make(CONST64(0), index_max, Type::WidenMax);
3950   idx = phase->transform(new ConvI2LNode(idx, lidxtype));
3951 #endif
3952   return idx;
3953 }
3954 
3955 // The message about the current inlining is accumulated in
3956 // _print_inlining_stream and transfered into the _print_inlining_list
3957 // once we know whether inlining succeeds or not. For regular
3958 // inlining, messages are appended to the buffer pointed by
3959 // _print_inlining_idx in the _print_inlining_list. For late inlining,
3960 // a new buffer is added after _print_inlining_idx in the list. This
3961 // way we can update the inlining message for late inlining call site
3962 // when the inlining is attempted again.
3963 void Compile::print_inlining_init() {
3964   if (print_inlining() || print_intrinsics()) {
3965     _print_inlining_stream = new stringStream();
3966     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
3967   }
3968 }
3969 
3970 void Compile::print_inlining_reinit() {
3971   if (print_inlining() || print_intrinsics()) {
3972     // Re allocate buffer when we change ResourceMark
3973     _print_inlining_stream = new stringStream();
3974   }
3975 }
3976 
3977 void Compile::print_inlining_reset() {
3978   _print_inlining_stream->reset();
3979 }
3980 
3981 void Compile::print_inlining_commit() {
3982   assert(print_inlining() || print_intrinsics(), "PrintInlining off?");
3983   // Transfer the message from _print_inlining_stream to the current
3984   // _print_inlining_list buffer and clear _print_inlining_stream.
3985   _print_inlining_list->at(_print_inlining_idx).ss()->write(_print_inlining_stream->as_string(), _print_inlining_stream->size());
3986   print_inlining_reset();
3987 }
3988 
3989 void Compile::print_inlining_push() {
3990   // Add new buffer to the _print_inlining_list at current position
3991   _print_inlining_idx++;
3992   _print_inlining_list->insert_before(_print_inlining_idx, PrintInliningBuffer());
3993 }
3994 
3995 Compile::PrintInliningBuffer& Compile::print_inlining_current() {
3996   return _print_inlining_list->at(_print_inlining_idx);
3997 }
3998 
3999 void Compile::print_inlining_update(CallGenerator* cg) {
4000   if (print_inlining() || print_intrinsics()) {
4001     if (!cg->is_late_inline()) {
4002       if (print_inlining_current().cg() != NULL) {
4003         print_inlining_push();
4004       }
4005       print_inlining_commit();
4006     } else {
4007       if (print_inlining_current().cg() != cg &&
4008           (print_inlining_current().cg() != NULL ||
4009            print_inlining_current().ss()->size() != 0)) {
4010         print_inlining_push();
4011       }
4012       print_inlining_commit();
4013       print_inlining_current().set_cg(cg);
4014     }
4015   }
4016 }
4017 
4018 void Compile::print_inlining_move_to(CallGenerator* cg) {
4019   // We resume inlining at a late inlining call site. Locate the
4020   // corresponding inlining buffer so that we can update it.
4021   if (print_inlining()) {
4022     for (int i = 0; i < _print_inlining_list->length(); i++) {
4023       if (_print_inlining_list->adr_at(i)->cg() == cg) {
4024         _print_inlining_idx = i;
4025         return;
4026       }
4027     }
4028     ShouldNotReachHere();
4029   }
4030 }
4031 
4032 void Compile::print_inlining_update_delayed(CallGenerator* cg) {
4033   if (print_inlining()) {
4034     assert(_print_inlining_stream->size() > 0, "missing inlining msg");
4035     assert(print_inlining_current().cg() == cg, "wrong entry");
4036     // replace message with new message
4037     _print_inlining_list->at_put(_print_inlining_idx, PrintInliningBuffer());
4038     print_inlining_commit();
4039     print_inlining_current().set_cg(cg);
4040   }
4041 }
4042 
4043 void Compile::print_inlining_assert_ready() {
4044   assert(!_print_inlining || _print_inlining_stream->size() == 0, "loosing data");
4045 }
4046 
4047 void Compile::process_print_inlining() {
4048   bool do_print_inlining = print_inlining() || print_intrinsics();
4049   if (do_print_inlining || log() != NULL) {
4050     // Print inlining message for candidates that we couldn't inline
4051     // for lack of space
4052     for (int i = 0; i < _late_inlines.length(); i++) {
4053       CallGenerator* cg = _late_inlines.at(i);
4054       if (!cg->is_mh_late_inline()) {
4055         const char* msg = "live nodes > LiveNodeCountInliningCutoff";
4056         if (do_print_inlining) {
4057           cg->print_inlining_late(msg);
4058         }
4059         log_late_inline_failure(cg, msg);
4060       }
4061     }
4062   }
4063   if (do_print_inlining) {
4064     ResourceMark rm;
4065     stringStream ss;
4066     for (int i = 0; i < _print_inlining_list->length(); i++) {
4067       ss.print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
4068     }
4069     size_t end = ss.size();
4070     _print_inlining_output = NEW_ARENA_ARRAY(comp_arena(), char, end+1);
4071     strncpy(_print_inlining_output, ss.base(), end+1);
4072     _print_inlining_output[end] = 0;
4073   }
4074 }
4075 
4076 void Compile::dump_print_inlining() {
4077   if (_print_inlining_output != NULL) {
4078     tty->print_raw(_print_inlining_output);
4079   }
4080 }
4081 
4082 void Compile::log_late_inline(CallGenerator* cg) {
4083   if (log() != NULL) {
4084     log()->head("late_inline method='%d'  inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
4085                 cg->unique_id());
4086     JVMState* p = cg->call_node()->jvms();
4087     while (p != NULL) {
4088       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4089       p = p->caller();
4090     }
4091     log()->tail("late_inline");
4092   }
4093 }
4094 
4095 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4096   log_late_inline(cg);
4097   if (log() != NULL) {
4098     log()->inline_fail(msg);
4099   }
4100 }
4101 
4102 void Compile::log_inline_id(CallGenerator* cg) {
4103   if (log() != NULL) {
4104     // The LogCompilation tool needs a unique way to identify late
4105     // inline call sites. This id must be unique for this call site in
4106     // this compilation. Try to have it unique across compilations as
4107     // well because it can be convenient when grepping through the log
4108     // file.
4109     // Distinguish OSR compilations from others in case CICountOSR is
4110     // on.
4111     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4112     cg->set_unique_id(id);
4113     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4114   }
4115 }
4116 
4117 void Compile::log_inline_failure(const char* msg) {
4118   if (C->log() != NULL) {
4119     C->log()->inline_fail(msg);
4120   }
4121 }
4122 
4123 
4124 // Dump inlining replay data to the stream.
4125 // Don't change thread state and acquire any locks.
4126 void Compile::dump_inline_data(outputStream* out) {
4127   InlineTree* inl_tree = ilt();
4128   if (inl_tree != NULL) {
4129     out->print(" inline %d", inl_tree->count());
4130     inl_tree->dump_replay_data(out);
4131   }
4132 }
4133 
4134 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4135   if (n1->Opcode() < n2->Opcode())      return -1;
4136   else if (n1->Opcode() > n2->Opcode()) return 1;
4137 
4138   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
4139   for (uint i = 1; i < n1->req(); i++) {
4140     if (n1->in(i) < n2->in(i))      return -1;
4141     else if (n1->in(i) > n2->in(i)) return 1;
4142   }
4143 
4144   return 0;
4145 }
4146 
4147 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4148   Node* n1 = *n1p;
4149   Node* n2 = *n2p;
4150 
4151   return cmp_expensive_nodes(n1, n2);
4152 }
4153 
4154 void Compile::sort_expensive_nodes() {
4155   if (!expensive_nodes_sorted()) {
4156     _expensive_nodes->sort(cmp_expensive_nodes);
4157   }
4158 }
4159 
4160 bool Compile::expensive_nodes_sorted() const {
4161   for (int i = 1; i < _expensive_nodes->length(); i++) {
4162     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
4163       return false;
4164     }
4165   }
4166   return true;
4167 }
4168 
4169 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4170   if (_expensive_nodes->length() == 0) {
4171     return false;
4172   }
4173 
4174   assert(OptimizeExpensiveOps, "optimization off?");
4175 
4176   // Take this opportunity to remove dead nodes from the list
4177   int j = 0;
4178   for (int i = 0; i < _expensive_nodes->length(); i++) {
4179     Node* n = _expensive_nodes->at(i);
4180     if (!n->is_unreachable(igvn)) {
4181       assert(n->is_expensive(), "should be expensive");
4182       _expensive_nodes->at_put(j, n);
4183       j++;
4184     }
4185   }
4186   _expensive_nodes->trunc_to(j);
4187 
4188   // Then sort the list so that similar nodes are next to each other
4189   // and check for at least two nodes of identical kind with same data
4190   // inputs.
4191   sort_expensive_nodes();
4192 
4193   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
4194     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
4195       return true;
4196     }
4197   }
4198 
4199   return false;
4200 }
4201 
4202 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4203   if (_expensive_nodes->length() == 0) {
4204     return;
4205   }
4206 
4207   assert(OptimizeExpensiveOps, "optimization off?");
4208 
4209   // Sort to bring similar nodes next to each other and clear the
4210   // control input of nodes for which there's only a single copy.
4211   sort_expensive_nodes();
4212 
4213   int j = 0;
4214   int identical = 0;
4215   int i = 0;
4216   bool modified = false;
4217   for (; i < _expensive_nodes->length()-1; i++) {
4218     assert(j <= i, "can't write beyond current index");
4219     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
4220       identical++;
4221       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4222       continue;
4223     }
4224     if (identical > 0) {
4225       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4226       identical = 0;
4227     } else {
4228       Node* n = _expensive_nodes->at(i);
4229       igvn.replace_input_of(n, 0, NULL);
4230       igvn.hash_insert(n);
4231       modified = true;
4232     }
4233   }
4234   if (identical > 0) {
4235     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4236   } else if (_expensive_nodes->length() >= 1) {
4237     Node* n = _expensive_nodes->at(i);
4238     igvn.replace_input_of(n, 0, NULL);
4239     igvn.hash_insert(n);
4240     modified = true;
4241   }
4242   _expensive_nodes->trunc_to(j);
4243   if (modified) {
4244     igvn.optimize();
4245   }
4246 }
4247 
4248 void Compile::add_expensive_node(Node * n) {
4249   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
4250   assert(n->is_expensive(), "expensive nodes with non-null control here only");
4251   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4252   if (OptimizeExpensiveOps) {
4253     _expensive_nodes->append(n);
4254   } else {
4255     // Clear control input and let IGVN optimize expensive nodes if
4256     // OptimizeExpensiveOps is off.
4257     n->set_req(0, NULL);
4258   }
4259 }
4260 
4261 /**
4262  * Remove the speculative part of types and clean up the graph
4263  */
4264 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4265   if (UseTypeSpeculation) {
4266     Unique_Node_List worklist;
4267     worklist.push(root());
4268     int modified = 0;
4269     // Go over all type nodes that carry a speculative type, drop the
4270     // speculative part of the type and enqueue the node for an igvn
4271     // which may optimize it out.
4272     for (uint next = 0; next < worklist.size(); ++next) {
4273       Node *n  = worklist.at(next);
4274       if (n->is_Type()) {
4275         TypeNode* tn = n->as_Type();
4276         const Type* t = tn->type();
4277         const Type* t_no_spec = t->remove_speculative();
4278         if (t_no_spec != t) {
4279           bool in_hash = igvn.hash_delete(n);
4280           assert(in_hash, "node should be in igvn hash table");
4281           tn->set_type(t_no_spec);
4282           igvn.hash_insert(n);
4283           igvn._worklist.push(n); // give it a chance to go away
4284           modified++;
4285         }
4286       }
4287       uint max = n->len();
4288       for( uint i = 0; i < max; ++i ) {
4289         Node *m = n->in(i);
4290         if (not_a_node(m))  continue;
4291         worklist.push(m);
4292       }
4293     }
4294     // Drop the speculative part of all types in the igvn's type table
4295     igvn.remove_speculative_types();
4296     if (modified > 0) {
4297       igvn.optimize();
4298     }
4299 #ifdef ASSERT
4300     // Verify that after the IGVN is over no speculative type has resurfaced
4301     worklist.clear();
4302     worklist.push(root());
4303     for (uint next = 0; next < worklist.size(); ++next) {
4304       Node *n  = worklist.at(next);
4305       const Type* t = igvn.type_or_null(n);
4306       assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
4307       if (n->is_Type()) {
4308         t = n->as_Type()->type();
4309         assert(t == t->remove_speculative(), "no more speculative types");
4310       }
4311       uint max = n->len();
4312       for( uint i = 0; i < max; ++i ) {
4313         Node *m = n->in(i);
4314         if (not_a_node(m))  continue;
4315         worklist.push(m);
4316       }
4317     }
4318     igvn.check_no_speculative_types();
4319 #endif
4320   }
4321 }
4322 
4323 // Auxiliary method to support randomized stressing/fuzzing.
4324 //
4325 // This method can be called the arbitrary number of times, with current count
4326 // as the argument. The logic allows selecting a single candidate from the
4327 // running list of candidates as follows:
4328 //    int count = 0;
4329 //    Cand* selected = null;
4330 //    while(cand = cand->next()) {
4331 //      if (randomized_select(++count)) {
4332 //        selected = cand;
4333 //      }
4334 //    }
4335 //
4336 // Including count equalizes the chances any candidate is "selected".
4337 // This is useful when we don't have the complete list of candidates to choose
4338 // from uniformly. In this case, we need to adjust the randomicity of the
4339 // selection, or else we will end up biasing the selection towards the latter
4340 // candidates.
4341 //
4342 // Quick back-envelope calculation shows that for the list of n candidates
4343 // the equal probability for the candidate to persist as "best" can be
4344 // achieved by replacing it with "next" k-th candidate with the probability
4345 // of 1/k. It can be easily shown that by the end of the run, the
4346 // probability for any candidate is converged to 1/n, thus giving the
4347 // uniform distribution among all the candidates.
4348 //
4349 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
4350 #define RANDOMIZED_DOMAIN_POW 29
4351 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
4352 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
4353 bool Compile::randomized_select(int count) {
4354   assert(count > 0, "only positive");
4355   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
4356 }
4357 
4358 const char*   CloneMap::debug_option_name = "CloneMapDebug";
4359 CloneMap&     Compile::clone_map()                 { return _clone_map; }
4360 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
4361 
4362 void NodeCloneInfo::dump() const {
4363   tty->print(" {%d:%d} ", idx(), gen());
4364 }
4365 
4366 void CloneMap::clone(Node* old, Node* nnn, int gen) {
4367   uint64_t val = value(old->_idx);
4368   NodeCloneInfo cio(val);
4369   assert(val != 0, "old node should be in the map");
4370   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
4371   insert(nnn->_idx, cin.get());
4372 #ifndef PRODUCT
4373   if (is_debug()) {
4374     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
4375   }
4376 #endif
4377 }
4378 
4379 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
4380   NodeCloneInfo cio(value(old->_idx));
4381   if (cio.get() == 0) {
4382     cio.set(old->_idx, 0);
4383     insert(old->_idx, cio.get());
4384 #ifndef PRODUCT
4385     if (is_debug()) {
4386       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
4387     }
4388 #endif
4389   }
4390   clone(old, nnn, gen);
4391 }
4392 
4393 int CloneMap::max_gen() const {
4394   int g = 0;
4395   DictI di(_dict);
4396   for(; di.test(); ++di) {
4397     int t = gen(di._key);
4398     if (g < t) {
4399       g = t;
4400 #ifndef PRODUCT
4401       if (is_debug()) {
4402         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
4403       }
4404 #endif
4405     }
4406   }
4407   return g;
4408 }
4409 
4410 void CloneMap::dump(node_idx_t key) const {
4411   uint64_t val = value(key);
4412   if (val != 0) {
4413     NodeCloneInfo ni(val);
4414     ni.dump();
4415   }
4416 }