1 /*
   2  * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "compiler/compileLog.hpp"
  27 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
  28 #include "gc_implementation/g1/heapRegion.hpp"
  29 #include "gc_interface/collectedHeap.hpp"
  30 #include "memory/barrierSet.hpp"
  31 #include "memory/cardTableModRefBS.hpp"
  32 #include "opto/addnode.hpp"
  33 #include "opto/castnode.hpp"
  34 #include "opto/convertnode.hpp"
  35 #include "opto/graphKit.hpp"
  36 #include "opto/idealKit.hpp"
  37 #include "opto/intrinsicnode.hpp"
  38 #include "opto/locknode.hpp"
  39 #include "opto/machnode.hpp"
  40 #include "opto/opaquenode.hpp"
  41 #include "opto/parse.hpp"
  42 #include "opto/rootnode.hpp"
  43 #include "opto/runtime.hpp"
  44 #include "runtime/deoptimization.hpp"
  45 #include "runtime/sharedRuntime.hpp"
  46 
  47 //----------------------------GraphKit-----------------------------------------
  48 // Main utility constructor.
  49 GraphKit::GraphKit(JVMState* jvms)
  50   : Phase(Phase::Parser),
  51     _env(C->env()),
  52     _gvn(*C->initial_gvn())
  53 {
  54   _exceptions = jvms->map()->next_exception();
  55   if (_exceptions != NULL)  jvms->map()->set_next_exception(NULL);
  56   set_jvms(jvms);
  57 }
  58 
  59 // Private constructor for parser.
  60 GraphKit::GraphKit()
  61   : Phase(Phase::Parser),
  62     _env(C->env()),
  63     _gvn(*C->initial_gvn())
  64 {
  65   _exceptions = NULL;
  66   set_map(NULL);
  67   debug_only(_sp = -99);
  68   debug_only(set_bci(-99));
  69 }
  70 
  71 
  72 
  73 //---------------------------clean_stack---------------------------------------
  74 // Clear away rubbish from the stack area of the JVM state.
  75 // This destroys any arguments that may be waiting on the stack.
  76 void GraphKit::clean_stack(int from_sp) {
  77   SafePointNode* map      = this->map();
  78   JVMState*      jvms     = this->jvms();
  79   int            stk_size = jvms->stk_size();
  80   int            stkoff   = jvms->stkoff();
  81   Node*          top      = this->top();
  82   for (int i = from_sp; i < stk_size; i++) {
  83     if (map->in(stkoff + i) != top) {
  84       map->set_req(stkoff + i, top);
  85     }
  86   }
  87 }
  88 
  89 
  90 //--------------------------------sync_jvms-----------------------------------
  91 // Make sure our current jvms agrees with our parse state.
  92 JVMState* GraphKit::sync_jvms() const {
  93   JVMState* jvms = this->jvms();
  94   jvms->set_bci(bci());       // Record the new bci in the JVMState
  95   jvms->set_sp(sp());         // Record the new sp in the JVMState
  96   assert(jvms_in_sync(), "jvms is now in sync");
  97   return jvms;
  98 }
  99 
 100 //--------------------------------sync_jvms_for_reexecute---------------------
 101 // Make sure our current jvms agrees with our parse state.  This version
 102 // uses the reexecute_sp for reexecuting bytecodes.
 103 JVMState* GraphKit::sync_jvms_for_reexecute() {
 104   JVMState* jvms = this->jvms();
 105   jvms->set_bci(bci());          // Record the new bci in the JVMState
 106   jvms->set_sp(reexecute_sp());  // Record the new sp in the JVMState
 107   return jvms;
 108 }
 109 
 110 #ifdef ASSERT
 111 bool GraphKit::jvms_in_sync() const {
 112   Parse* parse = is_Parse();
 113   if (parse == NULL) {
 114     if (bci() !=      jvms()->bci())          return false;
 115     if (sp()  != (int)jvms()->sp())           return false;
 116     return true;
 117   }
 118   if (jvms()->method() != parse->method())    return false;
 119   if (jvms()->bci()    != parse->bci())       return false;
 120   int jvms_sp = jvms()->sp();
 121   if (jvms_sp          != parse->sp())        return false;
 122   int jvms_depth = jvms()->depth();
 123   if (jvms_depth       != parse->depth())     return false;
 124   return true;
 125 }
 126 
 127 // Local helper checks for special internal merge points
 128 // used to accumulate and merge exception states.
 129 // They are marked by the region's in(0) edge being the map itself.
 130 // Such merge points must never "escape" into the parser at large,
 131 // until they have been handed to gvn.transform.
 132 static bool is_hidden_merge(Node* reg) {
 133   if (reg == NULL)  return false;
 134   if (reg->is_Phi()) {
 135     reg = reg->in(0);
 136     if (reg == NULL)  return false;
 137   }
 138   return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root();
 139 }
 140 
 141 void GraphKit::verify_map() const {
 142   if (map() == NULL)  return;  // null map is OK
 143   assert(map()->req() <= jvms()->endoff(), "no extra garbage on map");
 144   assert(!map()->has_exceptions(),    "call add_exception_states_from 1st");
 145   assert(!is_hidden_merge(control()), "call use_exception_state, not set_map");
 146 }
 147 
 148 void GraphKit::verify_exception_state(SafePointNode* ex_map) {
 149   assert(ex_map->next_exception() == NULL, "not already part of a chain");
 150   assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop");
 151 }
 152 #endif
 153 
 154 //---------------------------stop_and_kill_map---------------------------------
 155 // Set _map to NULL, signalling a stop to further bytecode execution.
 156 // First smash the current map's control to a constant, to mark it dead.
 157 void GraphKit::stop_and_kill_map() {
 158   SafePointNode* dead_map = stop();
 159   if (dead_map != NULL) {
 160     dead_map->disconnect_inputs(NULL, C); // Mark the map as killed.
 161     assert(dead_map->is_killed(), "must be so marked");
 162   }
 163 }
 164 
 165 
 166 //--------------------------------stopped--------------------------------------
 167 // Tell if _map is NULL, or control is top.
 168 bool GraphKit::stopped() {
 169   if (map() == NULL)           return true;
 170   else if (control() == top()) return true;
 171   else                         return false;
 172 }
 173 
 174 
 175 //-----------------------------has_ex_handler----------------------------------
 176 // Tell if this method or any caller method has exception handlers.
 177 bool GraphKit::has_ex_handler() {
 178   for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) {
 179     if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) {
 180       return true;
 181     }
 182   }
 183   return false;
 184 }
 185 
 186 //------------------------------save_ex_oop------------------------------------
 187 // Save an exception without blowing stack contents or other JVM state.
 188 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) {
 189   assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again");
 190   ex_map->add_req(ex_oop);
 191   debug_only(verify_exception_state(ex_map));
 192 }
 193 
 194 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) {
 195   assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there");
 196   Node* ex_oop = ex_map->in(ex_map->req()-1);
 197   if (clear_it)  ex_map->del_req(ex_map->req()-1);
 198   return ex_oop;
 199 }
 200 
 201 //-----------------------------saved_ex_oop------------------------------------
 202 // Recover a saved exception from its map.
 203 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) {
 204   return common_saved_ex_oop(ex_map, false);
 205 }
 206 
 207 //--------------------------clear_saved_ex_oop---------------------------------
 208 // Erase a previously saved exception from its map.
 209 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) {
 210   return common_saved_ex_oop(ex_map, true);
 211 }
 212 
 213 #ifdef ASSERT
 214 //---------------------------has_saved_ex_oop----------------------------------
 215 // Erase a previously saved exception from its map.
 216 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) {
 217   return ex_map->req() == ex_map->jvms()->endoff()+1;
 218 }
 219 #endif
 220 
 221 //-------------------------make_exception_state--------------------------------
 222 // Turn the current JVM state into an exception state, appending the ex_oop.
 223 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) {
 224   sync_jvms();
 225   SafePointNode* ex_map = stop();  // do not manipulate this map any more
 226   set_saved_ex_oop(ex_map, ex_oop);
 227   return ex_map;
 228 }
 229 
 230 
 231 //--------------------------add_exception_state--------------------------------
 232 // Add an exception to my list of exceptions.
 233 void GraphKit::add_exception_state(SafePointNode* ex_map) {
 234   if (ex_map == NULL || ex_map->control() == top()) {
 235     return;
 236   }
 237 #ifdef ASSERT
 238   verify_exception_state(ex_map);
 239   if (has_exceptions()) {
 240     assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place");
 241   }
 242 #endif
 243 
 244   // If there is already an exception of exactly this type, merge with it.
 245   // In particular, null-checks and other low-level exceptions common up here.
 246   Node*       ex_oop  = saved_ex_oop(ex_map);
 247   const Type* ex_type = _gvn.type(ex_oop);
 248   if (ex_oop == top()) {
 249     // No action needed.
 250     return;
 251   }
 252   assert(ex_type->isa_instptr(), "exception must be an instance");
 253   for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) {
 254     const Type* ex_type2 = _gvn.type(saved_ex_oop(e2));
 255     // We check sp also because call bytecodes can generate exceptions
 256     // both before and after arguments are popped!
 257     if (ex_type2 == ex_type
 258         && e2->_jvms->sp() == ex_map->_jvms->sp()) {
 259       combine_exception_states(ex_map, e2);
 260       return;
 261     }
 262   }
 263 
 264   // No pre-existing exception of the same type.  Chain it on the list.
 265   push_exception_state(ex_map);
 266 }
 267 
 268 //-----------------------add_exception_states_from-----------------------------
 269 void GraphKit::add_exception_states_from(JVMState* jvms) {
 270   SafePointNode* ex_map = jvms->map()->next_exception();
 271   if (ex_map != NULL) {
 272     jvms->map()->set_next_exception(NULL);
 273     for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) {
 274       next_map = ex_map->next_exception();
 275       ex_map->set_next_exception(NULL);
 276       add_exception_state(ex_map);
 277     }
 278   }
 279 }
 280 
 281 //-----------------------transfer_exceptions_into_jvms-------------------------
 282 JVMState* GraphKit::transfer_exceptions_into_jvms() {
 283   if (map() == NULL) {
 284     // We need a JVMS to carry the exceptions, but the map has gone away.
 285     // Create a scratch JVMS, cloned from any of the exception states...
 286     if (has_exceptions()) {
 287       _map = _exceptions;
 288       _map = clone_map();
 289       _map->set_next_exception(NULL);
 290       clear_saved_ex_oop(_map);
 291       debug_only(verify_map());
 292     } else {
 293       // ...or created from scratch
 294       JVMState* jvms = new (C) JVMState(_method, NULL);
 295       jvms->set_bci(_bci);
 296       jvms->set_sp(_sp);
 297       jvms->set_map(new (C) SafePointNode(TypeFunc::Parms, jvms));
 298       set_jvms(jvms);
 299       for (uint i = 0; i < map()->req(); i++)  map()->init_req(i, top());
 300       set_all_memory(top());
 301       while (map()->req() < jvms->endoff())  map()->add_req(top());
 302     }
 303     // (This is a kludge, in case you didn't notice.)
 304     set_control(top());
 305   }
 306   JVMState* jvms = sync_jvms();
 307   assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet");
 308   jvms->map()->set_next_exception(_exceptions);
 309   _exceptions = NULL;   // done with this set of exceptions
 310   return jvms;
 311 }
 312 
 313 static inline void add_n_reqs(Node* dstphi, Node* srcphi) {
 314   assert(is_hidden_merge(dstphi), "must be a special merge node");
 315   assert(is_hidden_merge(srcphi), "must be a special merge node");
 316   uint limit = srcphi->req();
 317   for (uint i = PhiNode::Input; i < limit; i++) {
 318     dstphi->add_req(srcphi->in(i));
 319   }
 320 }
 321 static inline void add_one_req(Node* dstphi, Node* src) {
 322   assert(is_hidden_merge(dstphi), "must be a special merge node");
 323   assert(!is_hidden_merge(src), "must not be a special merge node");
 324   dstphi->add_req(src);
 325 }
 326 
 327 //-----------------------combine_exception_states------------------------------
 328 // This helper function combines exception states by building phis on a
 329 // specially marked state-merging region.  These regions and phis are
 330 // untransformed, and can build up gradually.  The region is marked by
 331 // having a control input of its exception map, rather than NULL.  Such
 332 // regions do not appear except in this function, and in use_exception_state.
 333 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) {
 334   if (failing())  return;  // dying anyway...
 335   JVMState* ex_jvms = ex_map->_jvms;
 336   assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains");
 337   assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals");
 338   assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes");
 339   assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS");
 340   assert(ex_jvms->scloff() == phi_map->_jvms->scloff(), "matching scalar replaced objects");
 341   assert(ex_map->req() == phi_map->req(), "matching maps");
 342   uint tos = ex_jvms->stkoff() + ex_jvms->sp();
 343   Node*         hidden_merge_mark = root();
 344   Node*         region  = phi_map->control();
 345   MergeMemNode* phi_mem = phi_map->merged_memory();
 346   MergeMemNode* ex_mem  = ex_map->merged_memory();
 347   if (region->in(0) != hidden_merge_mark) {
 348     // The control input is not (yet) a specially-marked region in phi_map.
 349     // Make it so, and build some phis.
 350     region = new (C) RegionNode(2);
 351     _gvn.set_type(region, Type::CONTROL);
 352     region->set_req(0, hidden_merge_mark);  // marks an internal ex-state
 353     region->init_req(1, phi_map->control());
 354     phi_map->set_control(region);
 355     Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO);
 356     record_for_igvn(io_phi);
 357     _gvn.set_type(io_phi, Type::ABIO);
 358     phi_map->set_i_o(io_phi);
 359     for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) {
 360       Node* m = mms.memory();
 361       Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C));
 362       record_for_igvn(m_phi);
 363       _gvn.set_type(m_phi, Type::MEMORY);
 364       mms.set_memory(m_phi);
 365     }
 366   }
 367 
 368   // Either or both of phi_map and ex_map might already be converted into phis.
 369   Node* ex_control = ex_map->control();
 370   // if there is special marking on ex_map also, we add multiple edges from src
 371   bool add_multiple = (ex_control->in(0) == hidden_merge_mark);
 372   // how wide was the destination phi_map, originally?
 373   uint orig_width = region->req();
 374 
 375   if (add_multiple) {
 376     add_n_reqs(region, ex_control);
 377     add_n_reqs(phi_map->i_o(), ex_map->i_o());
 378   } else {
 379     // ex_map has no merges, so we just add single edges everywhere
 380     add_one_req(region, ex_control);
 381     add_one_req(phi_map->i_o(), ex_map->i_o());
 382   }
 383   for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) {
 384     if (mms.is_empty()) {
 385       // get a copy of the base memory, and patch some inputs into it
 386       const TypePtr* adr_type = mms.adr_type(C);
 387       Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
 388       assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
 389       mms.set_memory(phi);
 390       // Prepare to append interesting stuff onto the newly sliced phi:
 391       while (phi->req() > orig_width)  phi->del_req(phi->req()-1);
 392     }
 393     // Append stuff from ex_map:
 394     if (add_multiple) {
 395       add_n_reqs(mms.memory(), mms.memory2());
 396     } else {
 397       add_one_req(mms.memory(), mms.memory2());
 398     }
 399   }
 400   uint limit = ex_map->req();
 401   for (uint i = TypeFunc::Parms; i < limit; i++) {
 402     // Skip everything in the JVMS after tos.  (The ex_oop follows.)
 403     if (i == tos)  i = ex_jvms->monoff();
 404     Node* src = ex_map->in(i);
 405     Node* dst = phi_map->in(i);
 406     if (src != dst) {
 407       PhiNode* phi;
 408       if (dst->in(0) != region) {
 409         dst = phi = PhiNode::make(region, dst, _gvn.type(dst));
 410         record_for_igvn(phi);
 411         _gvn.set_type(phi, phi->type());
 412         phi_map->set_req(i, dst);
 413         // Prepare to append interesting stuff onto the new phi:
 414         while (dst->req() > orig_width)  dst->del_req(dst->req()-1);
 415       } else {
 416         assert(dst->is_Phi(), "nobody else uses a hidden region");
 417         phi = dst->as_Phi();
 418       }
 419       if (add_multiple && src->in(0) == ex_control) {
 420         // Both are phis.
 421         add_n_reqs(dst, src);
 422       } else {
 423         while (dst->req() < region->req())  add_one_req(dst, src);
 424       }
 425       const Type* srctype = _gvn.type(src);
 426       if (phi->type() != srctype) {
 427         const Type* dsttype = phi->type()->meet_speculative(srctype);
 428         if (phi->type() != dsttype) {
 429           phi->set_type(dsttype);
 430           _gvn.set_type(phi, dsttype);
 431         }
 432       }
 433     }
 434   }
 435 }
 436 
 437 //--------------------------use_exception_state--------------------------------
 438 Node* GraphKit::use_exception_state(SafePointNode* phi_map) {
 439   if (failing()) { stop(); return top(); }
 440   Node* region = phi_map->control();
 441   Node* hidden_merge_mark = root();
 442   assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation");
 443   Node* ex_oop = clear_saved_ex_oop(phi_map);
 444   if (region->in(0) == hidden_merge_mark) {
 445     // Special marking for internal ex-states.  Process the phis now.
 446     region->set_req(0, region);  // now it's an ordinary region
 447     set_jvms(phi_map->jvms());   // ...so now we can use it as a map
 448     // Note: Setting the jvms also sets the bci and sp.
 449     set_control(_gvn.transform(region));
 450     uint tos = jvms()->stkoff() + sp();
 451     for (uint i = 1; i < tos; i++) {
 452       Node* x = phi_map->in(i);
 453       if (x->in(0) == region) {
 454         assert(x->is_Phi(), "expected a special phi");
 455         phi_map->set_req(i, _gvn.transform(x));
 456       }
 457     }
 458     for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
 459       Node* x = mms.memory();
 460       if (x->in(0) == region) {
 461         assert(x->is_Phi(), "nobody else uses a hidden region");
 462         mms.set_memory(_gvn.transform(x));
 463       }
 464     }
 465     if (ex_oop->in(0) == region) {
 466       assert(ex_oop->is_Phi(), "expected a special phi");
 467       ex_oop = _gvn.transform(ex_oop);
 468     }
 469   } else {
 470     set_jvms(phi_map->jvms());
 471   }
 472 
 473   assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared");
 474   assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared");
 475   return ex_oop;
 476 }
 477 
 478 //---------------------------------java_bc-------------------------------------
 479 Bytecodes::Code GraphKit::java_bc() const {
 480   ciMethod* method = this->method();
 481   int       bci    = this->bci();
 482   if (method != NULL && bci != InvocationEntryBci)
 483     return method->java_code_at_bci(bci);
 484   else
 485     return Bytecodes::_illegal;
 486 }
 487 
 488 void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
 489                                                           bool must_throw) {
 490     // if the exception capability is set, then we will generate code
 491     // to check the JavaThread.should_post_on_exceptions flag to see
 492     // if we actually need to report exception events (for this
 493     // thread).  If we don't need to report exception events, we will
 494     // take the normal fast path provided by add_exception_events.  If
 495     // exception event reporting is enabled for this thread, we will
 496     // take the uncommon_trap in the BuildCutout below.
 497 
 498     // first must access the should_post_on_exceptions_flag in this thread's JavaThread
 499     Node* jthread = _gvn.transform(new (C) ThreadLocalNode());
 500     Node* adr = basic_plus_adr(top(), jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset()));
 501     Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw, MemNode::unordered);
 502 
 503     // Test the should_post_on_exceptions_flag vs. 0
 504     Node* chk = _gvn.transform( new (C) CmpINode(should_post_flag, intcon(0)) );
 505     Node* tst = _gvn.transform( new (C) BoolNode(chk, BoolTest::eq) );
 506 
 507     // Branch to slow_path if should_post_on_exceptions_flag was true
 508     { BuildCutout unless(this, tst, PROB_MAX);
 509       // Do not try anything fancy if we're notifying the VM on every throw.
 510       // Cf. case Bytecodes::_athrow in parse2.cpp.
 511       uncommon_trap(reason, Deoptimization::Action_none,
 512                     (ciKlass*)NULL, (char*)NULL, must_throw);
 513     }
 514 
 515 }
 516 
 517 //------------------------------builtin_throw----------------------------------
 518 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) {
 519   bool must_throw = true;
 520 
 521   if (env()->jvmti_can_post_on_exceptions()) {
 522     // check if we must post exception events, take uncommon trap if so
 523     uncommon_trap_if_should_post_on_exceptions(reason, must_throw);
 524     // here if should_post_on_exceptions is false
 525     // continue on with the normal codegen
 526   }
 527 
 528   // If this particular condition has not yet happened at this
 529   // bytecode, then use the uncommon trap mechanism, and allow for
 530   // a future recompilation if several traps occur here.
 531   // If the throw is hot, try to use a more complicated inline mechanism
 532   // which keeps execution inside the compiled code.
 533   bool treat_throw_as_hot = false;
 534   ciMethodData* md = method()->method_data();
 535 
 536   if (ProfileTraps) {
 537     if (too_many_traps(reason)) {
 538       treat_throw_as_hot = true;
 539     }
 540     // (If there is no MDO at all, assume it is early in
 541     // execution, and that any deopts are part of the
 542     // startup transient, and don't need to be remembered.)
 543 
 544     // Also, if there is a local exception handler, treat all throws
 545     // as hot if there has been at least one in this method.
 546     if (C->trap_count(reason) != 0
 547         && method()->method_data()->trap_count(reason) != 0
 548         && has_ex_handler()) {
 549         treat_throw_as_hot = true;
 550     }
 551   }
 552 
 553   // If this throw happens frequently, an uncommon trap might cause
 554   // a performance pothole.  If there is a local exception handler,
 555   // and if this particular bytecode appears to be deoptimizing often,
 556   // let us handle the throw inline, with a preconstructed instance.
 557   // Note:   If the deopt count has blown up, the uncommon trap
 558   // runtime is going to flush this nmethod, not matter what.
 559   if (treat_throw_as_hot
 560       && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) {
 561     // If the throw is local, we use a pre-existing instance and
 562     // punt on the backtrace.  This would lead to a missing backtrace
 563     // (a repeat of 4292742) if the backtrace object is ever asked
 564     // for its backtrace.
 565     // Fixing this remaining case of 4292742 requires some flavor of
 566     // escape analysis.  Leave that for the future.
 567     ciInstance* ex_obj = NULL;
 568     switch (reason) {
 569     case Deoptimization::Reason_null_check:
 570       ex_obj = env()->NullPointerException_instance();
 571       break;
 572     case Deoptimization::Reason_div0_check:
 573       ex_obj = env()->ArithmeticException_instance();
 574       break;
 575     case Deoptimization::Reason_range_check:
 576       ex_obj = env()->ArrayIndexOutOfBoundsException_instance();
 577       break;
 578     case Deoptimization::Reason_class_check:
 579       if (java_bc() == Bytecodes::_aastore) {
 580         ex_obj = env()->ArrayStoreException_instance();
 581       } else {
 582         ex_obj = env()->ClassCastException_instance();
 583       }
 584       break;
 585     }
 586     if (failing()) { stop(); return; }  // exception allocation might fail
 587     if (ex_obj != NULL) {
 588       // Cheat with a preallocated exception object.
 589       if (C->log() != NULL)
 590         C->log()->elem("hot_throw preallocated='1' reason='%s'",
 591                        Deoptimization::trap_reason_name(reason));
 592       const TypeInstPtr* ex_con  = TypeInstPtr::make(ex_obj);
 593       Node*              ex_node = _gvn.transform( ConNode::make(C, ex_con) );
 594 
 595       // Clear the detail message of the preallocated exception object.
 596       // Weblogic sometimes mutates the detail message of exceptions
 597       // using reflection.
 598       int offset = java_lang_Throwable::get_detailMessage_offset();
 599       const TypePtr* adr_typ = ex_con->add_offset(offset);
 600 
 601       Node *adr = basic_plus_adr(ex_node, ex_node, offset);
 602       const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass());
 603       // Conservatively release stores of object references.
 604       Node *store = store_oop_to_object(control(), ex_node, adr, adr_typ, null(), val_type, T_OBJECT, MemNode::release);
 605 
 606       add_exception_state(make_exception_state(ex_node));
 607       return;
 608     }
 609   }
 610 
 611   // %%% Maybe add entry to OptoRuntime which directly throws the exc.?
 612   // It won't be much cheaper than bailing to the interp., since we'll
 613   // have to pass up all the debug-info, and the runtime will have to
 614   // create the stack trace.
 615 
 616   // Usual case:  Bail to interpreter.
 617   // Reserve the right to recompile if we haven't seen anything yet.
 618 
 619   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? C->method() : NULL;
 620   Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile;
 621   if (treat_throw_as_hot
 622       && (method()->method_data()->trap_recompiled_at(bci(), m)
 623           || C->too_many_traps(reason))) {
 624     // We cannot afford to take more traps here.  Suffer in the interpreter.
 625     if (C->log() != NULL)
 626       C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'",
 627                      Deoptimization::trap_reason_name(reason),
 628                      C->trap_count(reason));
 629     action = Deoptimization::Action_none;
 630   }
 631 
 632   // "must_throw" prunes the JVM state to include only the stack, if there
 633   // are no local exception handlers.  This should cut down on register
 634   // allocation time and code size, by drastically reducing the number
 635   // of in-edges on the call to the uncommon trap.
 636 
 637   uncommon_trap(reason, action, (ciKlass*)NULL, (char*)NULL, must_throw);
 638 }
 639 
 640 
 641 //----------------------------PreserveJVMState---------------------------------
 642 PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) {
 643   debug_only(kit->verify_map());
 644   _kit    = kit;
 645   _map    = kit->map();   // preserve the map
 646   _sp     = kit->sp();
 647   kit->set_map(clone_map ? kit->clone_map() : NULL);
 648   Compile::current()->inc_preserve_jvm_state();
 649 #ifdef ASSERT
 650   _bci    = kit->bci();
 651   Parse* parser = kit->is_Parse();
 652   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 653   _block  = block;
 654 #endif
 655 }
 656 PreserveJVMState::~PreserveJVMState() {
 657   GraphKit* kit = _kit;
 658 #ifdef ASSERT
 659   assert(kit->bci() == _bci, "bci must not shift");
 660   Parse* parser = kit->is_Parse();
 661   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 662   assert(block == _block,    "block must not shift");
 663 #endif
 664   kit->set_map(_map);
 665   kit->set_sp(_sp);
 666   Compile::current()->dec_preserve_jvm_state();
 667 }
 668 
 669 
 670 //-----------------------------BuildCutout-------------------------------------
 671 BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt)
 672   : PreserveJVMState(kit)
 673 {
 674   assert(p->is_Con() || p->is_Bool(), "test must be a bool");
 675   SafePointNode* outer_map = _map;   // preserved map is caller's
 676   SafePointNode* inner_map = kit->map();
 677   IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt);
 678   outer_map->set_control(kit->gvn().transform( new (kit->C) IfTrueNode(iff) ));
 679   inner_map->set_control(kit->gvn().transform( new (kit->C) IfFalseNode(iff) ));
 680 }
 681 BuildCutout::~BuildCutout() {
 682   GraphKit* kit = _kit;
 683   assert(kit->stopped(), "cutout code must stop, throw, return, etc.");
 684 }
 685 
 686 //---------------------------PreserveReexecuteState----------------------------
 687 PreserveReexecuteState::PreserveReexecuteState(GraphKit* kit) {
 688   assert(!kit->stopped(), "must call stopped() before");
 689   _kit    =    kit;
 690   _sp     =    kit->sp();
 691   _reexecute = kit->jvms()->_reexecute;
 692 }
 693 PreserveReexecuteState::~PreserveReexecuteState() {
 694   if (_kit->stopped()) return;
 695   _kit->jvms()->_reexecute = _reexecute;
 696   _kit->set_sp(_sp);
 697 }
 698 
 699 //------------------------------clone_map--------------------------------------
 700 // Implementation of PreserveJVMState
 701 //
 702 // Only clone_map(...) here. If this function is only used in the
 703 // PreserveJVMState class we may want to get rid of this extra
 704 // function eventually and do it all there.
 705 
 706 SafePointNode* GraphKit::clone_map() {
 707   if (map() == NULL)  return NULL;
 708 
 709   // Clone the memory edge first
 710   Node* mem = MergeMemNode::make(C, map()->memory());
 711   gvn().set_type_bottom(mem);
 712 
 713   SafePointNode *clonemap = (SafePointNode*)map()->clone();
 714   JVMState* jvms = this->jvms();
 715   JVMState* clonejvms = jvms->clone_shallow(C);
 716   clonemap->set_memory(mem);
 717   clonemap->set_jvms(clonejvms);
 718   clonejvms->set_map(clonemap);
 719   record_for_igvn(clonemap);
 720   gvn().set_type_bottom(clonemap);
 721   return clonemap;
 722 }
 723 
 724 
 725 //-----------------------------set_map_clone-----------------------------------
 726 void GraphKit::set_map_clone(SafePointNode* m) {
 727   _map = m;
 728   _map = clone_map();
 729   _map->set_next_exception(NULL);
 730   debug_only(verify_map());
 731 }
 732 
 733 
 734 //----------------------------kill_dead_locals---------------------------------
 735 // Detect any locals which are known to be dead, and force them to top.
 736 void GraphKit::kill_dead_locals() {
 737   // Consult the liveness information for the locals.  If any
 738   // of them are unused, then they can be replaced by top().  This
 739   // should help register allocation time and cut down on the size
 740   // of the deoptimization information.
 741 
 742   // This call is made from many of the bytecode handling
 743   // subroutines called from the Big Switch in do_one_bytecode.
 744   // Every bytecode which might include a slow path is responsible
 745   // for killing its dead locals.  The more consistent we
 746   // are about killing deads, the fewer useless phis will be
 747   // constructed for them at various merge points.
 748 
 749   // bci can be -1 (InvocationEntryBci).  We return the entry
 750   // liveness for the method.
 751 
 752   if (method() == NULL || method()->code_size() == 0) {
 753     // We are building a graph for a call to a native method.
 754     // All locals are live.
 755     return;
 756   }
 757 
 758   ResourceMark rm;
 759 
 760   // Consult the liveness information for the locals.  If any
 761   // of them are unused, then they can be replaced by top().  This
 762   // should help register allocation time and cut down on the size
 763   // of the deoptimization information.
 764   MethodLivenessResult live_locals = method()->liveness_at_bci(bci());
 765 
 766   int len = (int)live_locals.size();
 767   assert(len <= jvms()->loc_size(), "too many live locals");
 768   for (int local = 0; local < len; local++) {
 769     if (!live_locals.at(local)) {
 770       set_local(local, top());
 771     }
 772   }
 773 }
 774 
 775 #ifdef ASSERT
 776 //-------------------------dead_locals_are_killed------------------------------
 777 // Return true if all dead locals are set to top in the map.
 778 // Used to assert "clean" debug info at various points.
 779 bool GraphKit::dead_locals_are_killed() {
 780   if (method() == NULL || method()->code_size() == 0) {
 781     // No locals need to be dead, so all is as it should be.
 782     return true;
 783   }
 784 
 785   // Make sure somebody called kill_dead_locals upstream.
 786   ResourceMark rm;
 787   for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
 788     if (jvms->loc_size() == 0)  continue;  // no locals to consult
 789     SafePointNode* map = jvms->map();
 790     ciMethod* method = jvms->method();
 791     int       bci    = jvms->bci();
 792     if (jvms == this->jvms()) {
 793       bci = this->bci();  // it might not yet be synched
 794     }
 795     MethodLivenessResult live_locals = method->liveness_at_bci(bci);
 796     int len = (int)live_locals.size();
 797     if (!live_locals.is_valid() || len == 0)
 798       // This method is trivial, or is poisoned by a breakpoint.
 799       return true;
 800     assert(len == jvms->loc_size(), "live map consistent with locals map");
 801     for (int local = 0; local < len; local++) {
 802       if (!live_locals.at(local) && map->local(jvms, local) != top()) {
 803         if (PrintMiscellaneous && (Verbose || WizardMode)) {
 804           tty->print_cr("Zombie local %d: ", local);
 805           jvms->dump();
 806         }
 807         return false;
 808       }
 809     }
 810   }
 811   return true;
 812 }
 813 
 814 #endif //ASSERT
 815 
 816 // Helper function for enforcing certain bytecodes to reexecute if
 817 // deoptimization happens
 818 static bool should_reexecute_implied_by_bytecode(JVMState *jvms, bool is_anewarray) {
 819   ciMethod* cur_method = jvms->method();
 820   int       cur_bci   = jvms->bci();
 821   if (cur_method != NULL && cur_bci != InvocationEntryBci) {
 822     Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci);
 823     return Interpreter::bytecode_should_reexecute(code) ||
 824            is_anewarray && code == Bytecodes::_multianewarray;
 825     // Reexecute _multianewarray bytecode which was replaced with
 826     // sequence of [a]newarray. See Parse::do_multianewarray().
 827     //
 828     // Note: interpreter should not have it set since this optimization
 829     // is limited by dimensions and guarded by flag so in some cases
 830     // multianewarray() runtime calls will be generated and
 831     // the bytecode should not be reexecutes (stack will not be reset).
 832   } else
 833     return false;
 834 }
 835 
 836 // Helper function for adding JVMState and debug information to node
 837 void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) {
 838   // Add the safepoint edges to the call (or other safepoint).
 839 
 840   // Make sure dead locals are set to top.  This
 841   // should help register allocation time and cut down on the size
 842   // of the deoptimization information.
 843   assert(dead_locals_are_killed(), "garbage in debug info before safepoint");
 844 
 845   // Walk the inline list to fill in the correct set of JVMState's
 846   // Also fill in the associated edges for each JVMState.
 847 
 848   // If the bytecode needs to be reexecuted we need to put
 849   // the arguments back on the stack.
 850   const bool should_reexecute = jvms()->should_reexecute();
 851   JVMState* youngest_jvms = should_reexecute ? sync_jvms_for_reexecute() : sync_jvms();
 852 
 853   // NOTE: set_bci (called from sync_jvms) might reset the reexecute bit to
 854   // undefined if the bci is different.  This is normal for Parse but it
 855   // should not happen for LibraryCallKit because only one bci is processed.
 856   assert(!is_LibraryCallKit() || (jvms()->should_reexecute() == should_reexecute),
 857          "in LibraryCallKit the reexecute bit should not change");
 858 
 859   // If we are guaranteed to throw, we can prune everything but the
 860   // input to the current bytecode.
 861   bool can_prune_locals = false;
 862   uint stack_slots_not_pruned = 0;
 863   int inputs = 0, depth = 0;
 864   if (must_throw) {
 865     assert(method() == youngest_jvms->method(), "sanity");
 866     if (compute_stack_effects(inputs, depth)) {
 867       can_prune_locals = true;
 868       stack_slots_not_pruned = inputs;
 869     }
 870   }
 871 
 872   if (env()->should_retain_local_variables()) {
 873     // At any safepoint, this method can get breakpointed, which would
 874     // then require an immediate deoptimization.
 875     can_prune_locals = false;  // do not prune locals
 876     stack_slots_not_pruned = 0;
 877   }
 878 
 879   // do not scribble on the input jvms
 880   JVMState* out_jvms = youngest_jvms->clone_deep(C);
 881   call->set_jvms(out_jvms); // Start jvms list for call node
 882 
 883   // For a known set of bytecodes, the interpreter should reexecute them if
 884   // deoptimization happens. We set the reexecute state for them here
 885   if (out_jvms->is_reexecute_undefined() && //don't change if already specified
 886       should_reexecute_implied_by_bytecode(out_jvms, call->is_AllocateArray())) {
 887     out_jvms->set_should_reexecute(true); //NOTE: youngest_jvms not changed
 888   }
 889 
 890   // Presize the call:
 891   DEBUG_ONLY(uint non_debug_edges = call->req());
 892   call->add_req_batch(top(), youngest_jvms->debug_depth());
 893   assert(call->req() == non_debug_edges + youngest_jvms->debug_depth(), "");
 894 
 895   // Set up edges so that the call looks like this:
 896   //  Call [state:] ctl io mem fptr retadr
 897   //       [parms:] parm0 ... parmN
 898   //       [root:]  loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 899   //    [...mid:]   loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN [...]
 900   //       [young:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 901   // Note that caller debug info precedes callee debug info.
 902 
 903   // Fill pointer walks backwards from "young:" to "root:" in the diagram above:
 904   uint debug_ptr = call->req();
 905 
 906   // Loop over the map input edges associated with jvms, add them
 907   // to the call node, & reset all offsets to match call node array.
 908   for (JVMState* in_jvms = youngest_jvms; in_jvms != NULL; ) {
 909     uint debug_end   = debug_ptr;
 910     uint debug_start = debug_ptr - in_jvms->debug_size();
 911     debug_ptr = debug_start;  // back up the ptr
 912 
 913     uint p = debug_start;  // walks forward in [debug_start, debug_end)
 914     uint j, k, l;
 915     SafePointNode* in_map = in_jvms->map();
 916     out_jvms->set_map(call);
 917 
 918     if (can_prune_locals) {
 919       assert(in_jvms->method() == out_jvms->method(), "sanity");
 920       // If the current throw can reach an exception handler in this JVMS,
 921       // then we must keep everything live that can reach that handler.
 922       // As a quick and dirty approximation, we look for any handlers at all.
 923       if (in_jvms->method()->has_exception_handlers()) {
 924         can_prune_locals = false;
 925       }
 926     }
 927 
 928     // Add the Locals
 929     k = in_jvms->locoff();
 930     l = in_jvms->loc_size();
 931     out_jvms->set_locoff(p);
 932     if (!can_prune_locals) {
 933       for (j = 0; j < l; j++)
 934         call->set_req(p++, in_map->in(k+j));
 935     } else {
 936       p += l;  // already set to top above by add_req_batch
 937     }
 938 
 939     // Add the Expression Stack
 940     k = in_jvms->stkoff();
 941     l = in_jvms->sp();
 942     out_jvms->set_stkoff(p);
 943     if (!can_prune_locals) {
 944       for (j = 0; j < l; j++)
 945         call->set_req(p++, in_map->in(k+j));
 946     } else if (can_prune_locals && stack_slots_not_pruned != 0) {
 947       // Divide stack into {S0,...,S1}, where S0 is set to top.
 948       uint s1 = stack_slots_not_pruned;
 949       stack_slots_not_pruned = 0;  // for next iteration
 950       if (s1 > l)  s1 = l;
 951       uint s0 = l - s1;
 952       p += s0;  // skip the tops preinstalled by add_req_batch
 953       for (j = s0; j < l; j++)
 954         call->set_req(p++, in_map->in(k+j));
 955     } else {
 956       p += l;  // already set to top above by add_req_batch
 957     }
 958 
 959     // Add the Monitors
 960     k = in_jvms->monoff();
 961     l = in_jvms->mon_size();
 962     out_jvms->set_monoff(p);
 963     for (j = 0; j < l; j++)
 964       call->set_req(p++, in_map->in(k+j));
 965 
 966     // Copy any scalar object fields.
 967     k = in_jvms->scloff();
 968     l = in_jvms->scl_size();
 969     out_jvms->set_scloff(p);
 970     for (j = 0; j < l; j++)
 971       call->set_req(p++, in_map->in(k+j));
 972 
 973     // Finish the new jvms.
 974     out_jvms->set_endoff(p);
 975 
 976     assert(out_jvms->endoff()     == debug_end,             "fill ptr must match");
 977     assert(out_jvms->depth()      == in_jvms->depth(),      "depth must match");
 978     assert(out_jvms->loc_size()   == in_jvms->loc_size(),   "size must match");
 979     assert(out_jvms->mon_size()   == in_jvms->mon_size(),   "size must match");
 980     assert(out_jvms->scl_size()   == in_jvms->scl_size(),   "size must match");
 981     assert(out_jvms->debug_size() == in_jvms->debug_size(), "size must match");
 982 
 983     // Update the two tail pointers in parallel.
 984     out_jvms = out_jvms->caller();
 985     in_jvms  = in_jvms->caller();
 986   }
 987 
 988   assert(debug_ptr == non_debug_edges, "debug info must fit exactly");
 989 
 990   // Test the correctness of JVMState::debug_xxx accessors:
 991   assert(call->jvms()->debug_start() == non_debug_edges, "");
 992   assert(call->jvms()->debug_end()   == call->req(), "");
 993   assert(call->jvms()->debug_depth() == call->req() - non_debug_edges, "");
 994 }
 995 
 996 bool GraphKit::compute_stack_effects(int& inputs, int& depth) {
 997   Bytecodes::Code code = java_bc();
 998   if (code == Bytecodes::_wide) {
 999     code = method()->java_code_at_bci(bci() + 1);
1000   }
1001 
1002   BasicType rtype = T_ILLEGAL;
1003   int       rsize = 0;
1004 
1005   if (code != Bytecodes::_illegal) {
1006     depth = Bytecodes::depth(code); // checkcast=0, athrow=-1
1007     rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V
1008     if (rtype < T_CONFLICT)
1009       rsize = type2size[rtype];
1010   }
1011 
1012   switch (code) {
1013   case Bytecodes::_illegal:
1014     return false;
1015 
1016   case Bytecodes::_ldc:
1017   case Bytecodes::_ldc_w:
1018   case Bytecodes::_ldc2_w:
1019     inputs = 0;
1020     break;
1021 
1022   case Bytecodes::_dup:         inputs = 1;  break;
1023   case Bytecodes::_dup_x1:      inputs = 2;  break;
1024   case Bytecodes::_dup_x2:      inputs = 3;  break;
1025   case Bytecodes::_dup2:        inputs = 2;  break;
1026   case Bytecodes::_dup2_x1:     inputs = 3;  break;
1027   case Bytecodes::_dup2_x2:     inputs = 4;  break;
1028   case Bytecodes::_swap:        inputs = 2;  break;
1029   case Bytecodes::_arraylength: inputs = 1;  break;
1030 
1031   case Bytecodes::_getstatic:
1032   case Bytecodes::_putstatic:
1033   case Bytecodes::_getfield:
1034   case Bytecodes::_putfield:
1035     {
1036       bool ignored_will_link;
1037       ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
1038       int      size  = field->type()->size();
1039       bool is_get = (depth >= 0), is_static = (depth & 1);
1040       inputs = (is_static ? 0 : 1);
1041       if (is_get) {
1042         depth = size - inputs;
1043       } else {
1044         inputs += size;        // putxxx pops the value from the stack
1045         depth = - inputs;
1046       }
1047     }
1048     break;
1049 
1050   case Bytecodes::_invokevirtual:
1051   case Bytecodes::_invokespecial:
1052   case Bytecodes::_invokestatic:
1053   case Bytecodes::_invokedynamic:
1054   case Bytecodes::_invokeinterface:
1055     {
1056       bool ignored_will_link;
1057       ciSignature* declared_signature = NULL;
1058       ciMethod* ignored_callee = method()->get_method_at_bci(bci(), ignored_will_link, &declared_signature);
1059       assert(declared_signature != NULL, "cannot be null");
1060       inputs   = declared_signature->arg_size_for_bc(code);
1061       int size = declared_signature->return_type()->size();
1062       depth = size - inputs;
1063     }
1064     break;
1065 
1066   case Bytecodes::_multianewarray:
1067     {
1068       ciBytecodeStream iter(method());
1069       iter.reset_to_bci(bci());
1070       iter.next();
1071       inputs = iter.get_dimensions();
1072       assert(rsize == 1, "");
1073       depth = rsize - inputs;
1074     }
1075     break;
1076 
1077   case Bytecodes::_ireturn:
1078   case Bytecodes::_lreturn:
1079   case Bytecodes::_freturn:
1080   case Bytecodes::_dreturn:
1081   case Bytecodes::_areturn:
1082     assert(rsize = -depth, "");
1083     inputs = rsize;
1084     break;
1085 
1086   case Bytecodes::_jsr:
1087   case Bytecodes::_jsr_w:
1088     inputs = 0;
1089     depth  = 1;                  // S.B. depth=1, not zero
1090     break;
1091 
1092   default:
1093     // bytecode produces a typed result
1094     inputs = rsize - depth;
1095     assert(inputs >= 0, "");
1096     break;
1097   }
1098 
1099 #ifdef ASSERT
1100   // spot check
1101   int outputs = depth + inputs;
1102   assert(outputs >= 0, "sanity");
1103   switch (code) {
1104   case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break;
1105   case Bytecodes::_athrow:    assert(inputs == 1 && outputs == 0, ""); break;
1106   case Bytecodes::_aload_0:   assert(inputs == 0 && outputs == 1, ""); break;
1107   case Bytecodes::_return:    assert(inputs == 0 && outputs == 0, ""); break;
1108   case Bytecodes::_drem:      assert(inputs == 4 && outputs == 2, ""); break;
1109   }
1110 #endif //ASSERT
1111 
1112   return true;
1113 }
1114 
1115 
1116 
1117 //------------------------------basic_plus_adr---------------------------------
1118 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) {
1119   // short-circuit a common case
1120   if (offset == intcon(0))  return ptr;
1121   return _gvn.transform( new (C) AddPNode(base, ptr, offset) );
1122 }
1123 
1124 Node* GraphKit::ConvI2L(Node* offset) {
1125   // short-circuit a common case
1126   jint offset_con = find_int_con(offset, Type::OffsetBot);
1127   if (offset_con != Type::OffsetBot) {
1128     return longcon((jlong) offset_con);
1129   }
1130   return _gvn.transform( new (C) ConvI2LNode(offset));
1131 }
1132 
1133 Node* GraphKit::ConvI2UL(Node* offset) {
1134   juint offset_con = (juint) find_int_con(offset, Type::OffsetBot);
1135   if (offset_con != (juint) Type::OffsetBot) {
1136     return longcon((julong) offset_con);
1137   }
1138   Node* conv = _gvn.transform( new (C) ConvI2LNode(offset));
1139   Node* mask = _gvn.transform( ConLNode::make(C, (julong) max_juint) );
1140   return _gvn.transform( new (C) AndLNode(conv, mask) );
1141 }
1142 
1143 Node* GraphKit::ConvL2I(Node* offset) {
1144   // short-circuit a common case
1145   jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot);
1146   if (offset_con != (jlong)Type::OffsetBot) {
1147     return intcon((int) offset_con);
1148   }
1149   return _gvn.transform( new (C) ConvL2INode(offset));
1150 }
1151 
1152 //-------------------------load_object_klass-----------------------------------
1153 Node* GraphKit::load_object_klass(Node* obj) {
1154   // Special-case a fresh allocation to avoid building nodes:
1155   Node* akls = AllocateNode::Ideal_klass(obj, &_gvn);
1156   if (akls != NULL)  return akls;
1157   Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1158   return _gvn.transform( LoadKlassNode::make(_gvn, immutable_memory(), k_adr, TypeInstPtr::KLASS) );
1159 }
1160 
1161 //-------------------------load_array_length-----------------------------------
1162 Node* GraphKit::load_array_length(Node* array) {
1163   // Special-case a fresh allocation to avoid building nodes:
1164   AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array, &_gvn);
1165   Node *alen;
1166   if (alloc == NULL) {
1167     Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes());
1168     alen = _gvn.transform( new (C) LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS));
1169   } else {
1170     alen = alloc->Ideal_length();
1171     Node* ccast = alloc->make_ideal_length(_gvn.type(array)->is_oopptr(), &_gvn);
1172     if (ccast != alen) {
1173       alen = _gvn.transform(ccast);
1174     }
1175   }
1176   return alen;
1177 }
1178 
1179 //------------------------------do_null_check----------------------------------
1180 // Helper function to do a NULL pointer check.  Returned value is
1181 // the incoming address with NULL casted away.  You are allowed to use the
1182 // not-null value only if you are control dependent on the test.
1183 extern int explicit_null_checks_inserted,
1184            explicit_null_checks_elided;
1185 Node* GraphKit::null_check_common(Node* value, BasicType type,
1186                                   // optional arguments for variations:
1187                                   bool assert_null,
1188                                   Node* *null_control,
1189                                   bool speculative) {
1190   assert(!assert_null || null_control == NULL, "not both at once");
1191   if (stopped())  return top();
1192   if (!GenerateCompilerNullChecks && !assert_null && null_control == NULL) {
1193     // For some performance testing, we may wish to suppress null checking.
1194     value = cast_not_null(value);   // Make it appear to be non-null (4962416).
1195     return value;
1196   }
1197   explicit_null_checks_inserted++;
1198 
1199   // Construct NULL check
1200   Node *chk = NULL;
1201   switch(type) {
1202     case T_LONG   : chk = new (C) CmpLNode(value, _gvn.zerocon(T_LONG)); break;
1203     case T_INT    : chk = new (C) CmpINode(value, _gvn.intcon(0)); break;
1204     case T_ARRAY  : // fall through
1205       type = T_OBJECT;  // simplify further tests
1206     case T_OBJECT : {
1207       const Type *t = _gvn.type( value );
1208 
1209       const TypeOopPtr* tp = t->isa_oopptr();
1210       if (tp != NULL && tp->klass() != NULL && !tp->klass()->is_loaded()
1211           // Only for do_null_check, not any of its siblings:
1212           && !assert_null && null_control == NULL) {
1213         // Usually, any field access or invocation on an unloaded oop type
1214         // will simply fail to link, since the statically linked class is
1215         // likely also to be unloaded.  However, in -Xcomp mode, sometimes
1216         // the static class is loaded but the sharper oop type is not.
1217         // Rather than checking for this obscure case in lots of places,
1218         // we simply observe that a null check on an unloaded class
1219         // will always be followed by a nonsense operation, so we
1220         // can just issue the uncommon trap here.
1221         // Our access to the unloaded class will only be correct
1222         // after it has been loaded and initialized, which requires
1223         // a trip through the interpreter.
1224 #ifndef PRODUCT
1225         if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); }
1226 #endif
1227         uncommon_trap(Deoptimization::Reason_unloaded,
1228                       Deoptimization::Action_reinterpret,
1229                       tp->klass(), "!loaded");
1230         return top();
1231       }
1232 
1233       if (assert_null) {
1234         // See if the type is contained in NULL_PTR.
1235         // If so, then the value is already null.
1236         if (t->higher_equal(TypePtr::NULL_PTR)) {
1237           explicit_null_checks_elided++;
1238           return value;           // Elided null assert quickly!
1239         }
1240       } else {
1241         // See if mixing in the NULL pointer changes type.
1242         // If so, then the NULL pointer was not allowed in the original
1243         // type.  In other words, "value" was not-null.
1244         if (t->meet(TypePtr::NULL_PTR) != t->remove_speculative()) {
1245           // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
1246           explicit_null_checks_elided++;
1247           return value;           // Elided null check quickly!
1248         }
1249       }
1250       chk = new (C) CmpPNode( value, null() );
1251       break;
1252     }
1253 
1254     default:
1255       fatal(err_msg_res("unexpected type: %s", type2name(type)));
1256   }
1257   assert(chk != NULL, "sanity check");
1258   chk = _gvn.transform(chk);
1259 
1260   BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
1261   BoolNode *btst = new (C) BoolNode( chk, btest);
1262   Node   *tst = _gvn.transform( btst );
1263 
1264   //-----------
1265   // if peephole optimizations occurred, a prior test existed.
1266   // If a prior test existed, maybe it dominates as we can avoid this test.
1267   if (tst != btst && type == T_OBJECT) {
1268     // At this point we want to scan up the CFG to see if we can
1269     // find an identical test (and so avoid this test altogether).
1270     Node *cfg = control();
1271     int depth = 0;
1272     while( depth < 16 ) {       // Limit search depth for speed
1273       if( cfg->Opcode() == Op_IfTrue &&
1274           cfg->in(0)->in(1) == tst ) {
1275         // Found prior test.  Use "cast_not_null" to construct an identical
1276         // CastPP (and hence hash to) as already exists for the prior test.
1277         // Return that casted value.
1278         if (assert_null) {
1279           replace_in_map(value, null());
1280           return null();  // do not issue the redundant test
1281         }
1282         Node *oldcontrol = control();
1283         set_control(cfg);
1284         Node *res = cast_not_null(value);
1285         set_control(oldcontrol);
1286         explicit_null_checks_elided++;
1287         return res;
1288       }
1289       cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true);
1290       if (cfg == NULL)  break;  // Quit at region nodes
1291       depth++;
1292     }
1293   }
1294 
1295   //-----------
1296   // Branch to failure if null
1297   float ok_prob = PROB_MAX;  // a priori estimate:  nulls never happen
1298   Deoptimization::DeoptReason reason;
1299   if (assert_null) {
1300     reason = Deoptimization::Reason_null_assert;
1301   } else if (type == T_OBJECT) {
1302     reason = Deoptimization::reason_null_check(speculative);
1303   } else {
1304     reason = Deoptimization::Reason_div0_check;
1305   }
1306   // %%% Since Reason_unhandled is not recorded on a per-bytecode basis,
1307   // ciMethodData::has_trap_at will return a conservative -1 if any
1308   // must-be-null assertion has failed.  This could cause performance
1309   // problems for a method after its first do_null_assert failure.
1310   // Consider using 'Reason_class_check' instead?
1311 
1312   // To cause an implicit null check, we set the not-null probability
1313   // to the maximum (PROB_MAX).  For an explicit check the probability
1314   // is set to a smaller value.
1315   if (null_control != NULL || too_many_traps(reason)) {
1316     // probability is less likely
1317     ok_prob =  PROB_LIKELY_MAG(3);
1318   } else if (!assert_null &&
1319              (ImplicitNullCheckThreshold > 0) &&
1320              method() != NULL &&
1321              (method()->method_data()->trap_count(reason)
1322               >= (uint)ImplicitNullCheckThreshold)) {
1323     ok_prob =  PROB_LIKELY_MAG(3);
1324   }
1325 
1326   if (null_control != NULL) {
1327     IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN);
1328     Node* null_true = _gvn.transform( new (C) IfFalseNode(iff));
1329     set_control(      _gvn.transform( new (C) IfTrueNode(iff)));
1330     if (null_true == top())
1331       explicit_null_checks_elided++;
1332     (*null_control) = null_true;
1333   } else {
1334     BuildCutout unless(this, tst, ok_prob);
1335     // Check for optimizer eliding test at parse time
1336     if (stopped()) {
1337       // Failure not possible; do not bother making uncommon trap.
1338       explicit_null_checks_elided++;
1339     } else if (assert_null) {
1340       uncommon_trap(reason,
1341                     Deoptimization::Action_make_not_entrant,
1342                     NULL, "assert_null");
1343     } else {
1344       replace_in_map(value, zerocon(type));
1345       builtin_throw(reason);
1346     }
1347   }
1348 
1349   // Must throw exception, fall-thru not possible?
1350   if (stopped()) {
1351     return top();               // No result
1352   }
1353 
1354   if (assert_null) {
1355     // Cast obj to null on this path.
1356     replace_in_map(value, zerocon(type));
1357     return zerocon(type);
1358   }
1359 
1360   // Cast obj to not-null on this path, if there is no null_control.
1361   // (If there is a null_control, a non-null value may come back to haunt us.)
1362   if (type == T_OBJECT) {
1363     Node* cast = cast_not_null(value, false);
1364     if (null_control == NULL || (*null_control) == top())
1365       replace_in_map(value, cast);
1366     value = cast;
1367   }
1368 
1369   return value;
1370 }
1371 
1372 
1373 //------------------------------cast_not_null----------------------------------
1374 // Cast obj to not-null on this path
1375 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) {
1376   const Type *t = _gvn.type(obj);
1377   const Type *t_not_null = t->join_speculative(TypePtr::NOTNULL);
1378   // Object is already not-null?
1379   if( t == t_not_null ) return obj;
1380 
1381   Node *cast = new (C) CastPPNode(obj,t_not_null);
1382   cast->init_req(0, control());
1383   cast = _gvn.transform( cast );
1384 
1385   // Scan for instances of 'obj' in the current JVM mapping.
1386   // These instances are known to be not-null after the test.
1387   if (do_replace_in_map)
1388     replace_in_map(obj, cast);
1389 
1390   return cast;                  // Return casted value
1391 }
1392 
1393 
1394 //--------------------------replace_in_map-------------------------------------
1395 void GraphKit::replace_in_map(Node* old, Node* neww) {
1396   if (old == neww) {
1397     return;
1398   }
1399 
1400   map()->replace_edge(old, neww);
1401 
1402   // Note: This operation potentially replaces any edge
1403   // on the map.  This includes locals, stack, and monitors
1404   // of the current (innermost) JVM state.
1405 
1406   if (!ReplaceInParentMaps) {
1407     return;
1408   }
1409 
1410   // PreserveJVMState doesn't do a deep copy so we can't modify
1411   // parents
1412   if (Compile::current()->has_preserve_jvm_state()) {
1413     return;
1414   }
1415 
1416   Parse* parser = is_Parse();
1417   bool progress = true;
1418   Node* ctrl = map()->in(0);
1419   // Follow the chain of parsers and see whether the update can be
1420   // done in the map of callers. We can do the replace for a caller if
1421   // the current control post dominates the control of a caller.
1422   while (parser != NULL && parser->caller() != NULL && progress) {
1423     progress = false;
1424     Node* parent_map = parser->caller()->map();
1425     assert(parser->exits().map()->jvms()->depth() == parser->caller()->depth(), "map mismatch");
1426 
1427     Node* parent_ctrl = parent_map->in(0);
1428 
1429     while (parent_ctrl->is_Region()) {
1430       Node* n = parent_ctrl->as_Region()->is_copy();
1431       if (n == NULL) {
1432         break;
1433       }
1434       parent_ctrl = n;
1435     }
1436 
1437     for (;;) {
1438       if (ctrl == parent_ctrl) {
1439         // update the map of the exits which is the one that will be
1440         // used when compilation resume after inlining
1441         parser->exits().map()->replace_edge(old, neww);
1442         progress = true;
1443         break;
1444       }
1445       if (ctrl->is_Proj() && ctrl->as_Proj()->is_uncommon_trap_if_pattern(Deoptimization::Reason_none)) {
1446         ctrl = ctrl->in(0)->in(0);
1447       } else if (ctrl->is_Region()) {
1448         Node* n = ctrl->as_Region()->is_copy();
1449         if (n == NULL) {
1450           break;
1451         }
1452         ctrl = n;
1453       } else {
1454         break;
1455       }
1456     }
1457 
1458     parser = parser->parent_parser();
1459   }
1460 }
1461 
1462 
1463 //=============================================================================
1464 //--------------------------------memory---------------------------------------
1465 Node* GraphKit::memory(uint alias_idx) {
1466   MergeMemNode* mem = merged_memory();
1467   Node* p = mem->memory_at(alias_idx);
1468   _gvn.set_type(p, Type::MEMORY);  // must be mapped
1469   return p;
1470 }
1471 
1472 //-----------------------------reset_memory------------------------------------
1473 Node* GraphKit::reset_memory() {
1474   Node* mem = map()->memory();
1475   // do not use this node for any more parsing!
1476   debug_only( map()->set_memory((Node*)NULL) );
1477   return _gvn.transform( mem );
1478 }
1479 
1480 //------------------------------set_all_memory---------------------------------
1481 void GraphKit::set_all_memory(Node* newmem) {
1482   Node* mergemem = MergeMemNode::make(C, newmem);
1483   gvn().set_type_bottom(mergemem);
1484   map()->set_memory(mergemem);
1485 }
1486 
1487 //------------------------------set_all_memory_call----------------------------
1488 void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) {
1489   Node* newmem = _gvn.transform( new (C) ProjNode(call, TypeFunc::Memory, separate_io_proj) );
1490   set_all_memory(newmem);
1491 }
1492 
1493 //=============================================================================
1494 //
1495 // parser factory methods for MemNodes
1496 //
1497 // These are layered on top of the factory methods in LoadNode and StoreNode,
1498 // and integrate with the parser's memory state and _gvn engine.
1499 //
1500 
1501 // factory methods in "int adr_idx"
1502 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
1503                           int adr_idx,
1504                           MemNode::MemOrd mo, bool require_atomic_access) {
1505   assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
1506   const TypePtr* adr_type = NULL; // debug-mode-only argument
1507   debug_only(adr_type = C->get_adr_type(adr_idx));
1508   Node* mem = memory(adr_idx);
1509   Node* ld;
1510   if (require_atomic_access && bt == T_LONG) {
1511     ld = LoadLNode::make_atomic(C, ctl, mem, adr, adr_type, t, mo);
1512   } else if (require_atomic_access && bt == T_DOUBLE) {
1513     ld = LoadDNode::make_atomic(C, ctl, mem, adr, adr_type, t, mo);
1514   } else {
1515     ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, mo);
1516   }
1517   ld = _gvn.transform(ld);
1518   if ((bt == T_OBJECT) && C->do_escape_analysis() || C->eliminate_boxing()) {
1519     // Improve graph before escape analysis and boxing elimination.
1520     record_for_igvn(ld);
1521   }
1522   return ld;
1523 }
1524 
1525 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
1526                                 int adr_idx,
1527                                 MemNode::MemOrd mo,
1528                                 bool require_atomic_access) {
1529   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1530   const TypePtr* adr_type = NULL;
1531   debug_only(adr_type = C->get_adr_type(adr_idx));
1532   Node *mem = memory(adr_idx);
1533   Node* st;
1534   if (require_atomic_access && bt == T_LONG) {
1535     st = StoreLNode::make_atomic(C, ctl, mem, adr, adr_type, val, mo);
1536   } else if (require_atomic_access && bt == T_DOUBLE) {
1537     st = StoreDNode::make_atomic(C, ctl, mem, adr, adr_type, val, mo);
1538   } else {
1539     st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt, mo);
1540   }
1541   st = _gvn.transform(st);
1542   set_memory(st, adr_idx);
1543   // Back-to-back stores can only remove intermediate store with DU info
1544   // so push on worklist for optimizer.
1545   if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
1546     record_for_igvn(st);
1547 
1548   return st;
1549 }
1550 
1551 
1552 void GraphKit::pre_barrier(bool do_load,
1553                            Node* ctl,
1554                            Node* obj,
1555                            Node* adr,
1556                            uint  adr_idx,
1557                            Node* val,
1558                            const TypeOopPtr* val_type,
1559                            Node* pre_val,
1560                            BasicType bt) {
1561 
1562   BarrierSet* bs = Universe::heap()->barrier_set();
1563   set_control(ctl);
1564   switch (bs->kind()) {
1565     case BarrierSet::G1SATBCT:
1566     case BarrierSet::G1SATBCTLogging:
1567       g1_write_barrier_pre(do_load, obj, adr, adr_idx, val, val_type, pre_val, bt);
1568       break;
1569 
1570     case BarrierSet::CardTableModRef:
1571     case BarrierSet::CardTableExtension:
1572     case BarrierSet::ModRef:
1573       break;
1574 
1575     case BarrierSet::Other:
1576     default      :
1577       ShouldNotReachHere();
1578 
1579   }
1580 }
1581 
1582 bool GraphKit::can_move_pre_barrier() const {
1583   BarrierSet* bs = Universe::heap()->barrier_set();
1584   switch (bs->kind()) {
1585     case BarrierSet::G1SATBCT:
1586     case BarrierSet::G1SATBCTLogging:
1587       return true; // Can move it if no safepoint
1588 
1589     case BarrierSet::CardTableModRef:
1590     case BarrierSet::CardTableExtension:
1591     case BarrierSet::ModRef:
1592       return true; // There is no pre-barrier
1593 
1594     case BarrierSet::Other:
1595     default      :
1596       ShouldNotReachHere();
1597   }
1598   return false;
1599 }
1600 
1601 void GraphKit::post_barrier(Node* ctl,
1602                             Node* store,
1603                             Node* obj,
1604                             Node* adr,
1605                             uint  adr_idx,
1606                             Node* val,
1607                             BasicType bt,
1608                             bool use_precise) {
1609   BarrierSet* bs = Universe::heap()->barrier_set();
1610   set_control(ctl);
1611   switch (bs->kind()) {
1612     case BarrierSet::G1SATBCT:
1613     case BarrierSet::G1SATBCTLogging:
1614       g1_write_barrier_post(store, obj, adr, adr_idx, val, bt, use_precise);
1615       break;
1616 
1617     case BarrierSet::CardTableModRef:
1618     case BarrierSet::CardTableExtension:
1619       write_barrier_post(store, obj, adr, adr_idx, val, use_precise);
1620       break;
1621 
1622     case BarrierSet::ModRef:
1623       break;
1624 
1625     case BarrierSet::Other:
1626     default      :
1627       ShouldNotReachHere();
1628 
1629   }
1630 }
1631 
1632 Node* GraphKit::store_oop(Node* ctl,
1633                           Node* obj,
1634                           Node* adr,
1635                           const TypePtr* adr_type,
1636                           Node* val,
1637                           const TypeOopPtr* val_type,
1638                           BasicType bt,
1639                           bool use_precise,
1640                           MemNode::MemOrd mo) {
1641   // Transformation of a value which could be NULL pointer (CastPP #NULL)
1642   // could be delayed during Parse (for example, in adjust_map_after_if()).
1643   // Execute transformation here to avoid barrier generation in such case.
1644   if (_gvn.type(val) == TypePtr::NULL_PTR)
1645     val = _gvn.makecon(TypePtr::NULL_PTR);
1646 
1647   set_control(ctl);
1648   if (stopped()) return top(); // Dead path ?
1649 
1650   assert(bt == T_OBJECT, "sanity");
1651   assert(val != NULL, "not dead path");
1652   uint adr_idx = C->get_alias_index(adr_type);
1653   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1654 
1655   pre_barrier(true /* do_load */,
1656               control(), obj, adr, adr_idx, val, val_type,
1657               NULL /* pre_val */,
1658               bt);
1659 
1660   Node* store = store_to_memory(control(), adr, val, bt, adr_idx, mo);
1661   post_barrier(control(), store, obj, adr, adr_idx, val, bt, use_precise);
1662   return store;
1663 }
1664 
1665 // Could be an array or object we don't know at compile time (unsafe ref.)
1666 Node* GraphKit::store_oop_to_unknown(Node* ctl,
1667                              Node* obj,   // containing obj
1668                              Node* adr,  // actual adress to store val at
1669                              const TypePtr* adr_type,
1670                              Node* val,
1671                              BasicType bt,
1672                              MemNode::MemOrd mo) {
1673   Compile::AliasType* at = C->alias_type(adr_type);
1674   const TypeOopPtr* val_type = NULL;
1675   if (adr_type->isa_instptr()) {
1676     if (at->field() != NULL) {
1677       // known field.  This code is a copy of the do_put_xxx logic.
1678       ciField* field = at->field();
1679       if (!field->type()->is_loaded()) {
1680         val_type = TypeInstPtr::BOTTOM;
1681       } else {
1682         val_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
1683       }
1684     }
1685   } else if (adr_type->isa_aryptr()) {
1686     val_type = adr_type->is_aryptr()->elem()->make_oopptr();
1687   }
1688   if (val_type == NULL) {
1689     val_type = TypeInstPtr::BOTTOM;
1690   }
1691   return store_oop(ctl, obj, adr, adr_type, val, val_type, bt, true, mo);
1692 }
1693 
1694 
1695 //-------------------------array_element_address-------------------------
1696 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1697                                       const TypeInt* sizetype) {
1698   uint shift  = exact_log2(type2aelembytes(elembt));
1699   uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1700 
1701   // short-circuit a common case (saves lots of confusing waste motion)
1702   jint idx_con = find_int_con(idx, -1);
1703   if (idx_con >= 0) {
1704     intptr_t offset = header + ((intptr_t)idx_con << shift);
1705     return basic_plus_adr(ary, offset);
1706   }
1707 
1708   // must be correct type for alignment purposes
1709   Node* base  = basic_plus_adr(ary, header);
1710 #ifdef _LP64
1711   // The scaled index operand to AddP must be a clean 64-bit value.
1712   // Java allows a 32-bit int to be incremented to a negative
1713   // value, which appears in a 64-bit register as a large
1714   // positive number.  Using that large positive number as an
1715   // operand in pointer arithmetic has bad consequences.
1716   // On the other hand, 32-bit overflow is rare, and the possibility
1717   // can often be excluded, if we annotate the ConvI2L node with
1718   // a type assertion that its value is known to be a small positive
1719   // number.  (The prior range check has ensured this.)
1720   // This assertion is used by ConvI2LNode::Ideal.
1721   int index_max = max_jint - 1;  // array size is max_jint, index is one less
1722   if (sizetype != NULL)  index_max = sizetype->_hi - 1;
1723   const TypeLong* lidxtype = TypeLong::make(CONST64(0), index_max, Type::WidenMax);
1724   idx = _gvn.transform( new (C) ConvI2LNode(idx, lidxtype) );
1725 #endif
1726   Node* scale = _gvn.transform( new (C) LShiftXNode(idx, intcon(shift)) );
1727   return basic_plus_adr(ary, base, scale);
1728 }
1729 
1730 //-------------------------load_array_element-------------------------
1731 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) {
1732   const Type* elemtype = arytype->elem();
1733   BasicType elembt = elemtype->array_element_basic_type();
1734   Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1735   Node* ld = make_load(ctl, adr, elemtype, elembt, arytype, MemNode::unordered);
1736   return ld;
1737 }
1738 
1739 //-------------------------set_arguments_for_java_call-------------------------
1740 // Arguments (pre-popped from the stack) are taken from the JVMS.
1741 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1742   // Add the call arguments:
1743   uint nargs = call->method()->arg_size();
1744   for (uint i = 0; i < nargs; i++) {
1745     Node* arg = argument(i);
1746     call->init_req(i + TypeFunc::Parms, arg);
1747   }
1748 }
1749 
1750 //---------------------------set_edges_for_java_call---------------------------
1751 // Connect a newly created call into the current JVMS.
1752 // A return value node (if any) is returned from set_edges_for_java_call.
1753 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {
1754 
1755   // Add the predefined inputs:
1756   call->init_req( TypeFunc::Control, control() );
1757   call->init_req( TypeFunc::I_O    , i_o() );
1758   call->init_req( TypeFunc::Memory , reset_memory() );
1759   call->init_req( TypeFunc::FramePtr, frameptr() );
1760   call->init_req( TypeFunc::ReturnAdr, top() );
1761 
1762   add_safepoint_edges(call, must_throw);
1763 
1764   Node* xcall = _gvn.transform(call);
1765 
1766   if (xcall == top()) {
1767     set_control(top());
1768     return;
1769   }
1770   assert(xcall == call, "call identity is stable");
1771 
1772   // Re-use the current map to produce the result.
1773 
1774   set_control(_gvn.transform(new (C) ProjNode(call, TypeFunc::Control)));
1775   set_i_o(    _gvn.transform(new (C) ProjNode(call, TypeFunc::I_O    , separate_io_proj)));
1776   set_all_memory_call(xcall, separate_io_proj);
1777 
1778   //return xcall;   // no need, caller already has it
1779 }
1780 
1781 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj) {
1782   if (stopped())  return top();  // maybe the call folded up?
1783 
1784   // Capture the return value, if any.
1785   Node* ret;
1786   if (call->method() == NULL ||
1787       call->method()->return_type()->basic_type() == T_VOID)
1788         ret = top();
1789   else  ret = _gvn.transform(new (C) ProjNode(call, TypeFunc::Parms));
1790 
1791   // Note:  Since any out-of-line call can produce an exception,
1792   // we always insert an I_O projection from the call into the result.
1793 
1794   make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj);
1795 
1796   if (separate_io_proj) {
1797     // The caller requested separate projections be used by the fall
1798     // through and exceptional paths, so replace the projections for
1799     // the fall through path.
1800     set_i_o(_gvn.transform( new (C) ProjNode(call, TypeFunc::I_O) ));
1801     set_all_memory(_gvn.transform( new (C) ProjNode(call, TypeFunc::Memory) ));
1802   }
1803   return ret;
1804 }
1805 
1806 //--------------------set_predefined_input_for_runtime_call--------------------
1807 // Reading and setting the memory state is way conservative here.
1808 // The real problem is that I am not doing real Type analysis on memory,
1809 // so I cannot distinguish card mark stores from other stores.  Across a GC
1810 // point the Store Barrier and the card mark memory has to agree.  I cannot
1811 // have a card mark store and its barrier split across the GC point from
1812 // either above or below.  Here I get that to happen by reading ALL of memory.
1813 // A better answer would be to separate out card marks from other memory.
1814 // For now, return the input memory state, so that it can be reused
1815 // after the call, if this call has restricted memory effects.
1816 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) {
1817   // Set fixed predefined input arguments
1818   Node* memory = reset_memory();
1819   call->init_req( TypeFunc::Control,   control()  );
1820   call->init_req( TypeFunc::I_O,       top()      ); // does no i/o
1821   call->init_req( TypeFunc::Memory,    memory     ); // may gc ptrs
1822   call->init_req( TypeFunc::FramePtr,  frameptr() );
1823   call->init_req( TypeFunc::ReturnAdr, top()      );
1824   return memory;
1825 }
1826 
1827 //-------------------set_predefined_output_for_runtime_call--------------------
1828 // Set control and memory (not i_o) from the call.
1829 // If keep_mem is not NULL, use it for the output state,
1830 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1831 // If hook_mem is NULL, this call produces no memory effects at all.
1832 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1833 // then only that memory slice is taken from the call.
1834 // In the last case, we must put an appropriate memory barrier before
1835 // the call, so as to create the correct anti-dependencies on loads
1836 // preceding the call.
1837 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1838                                                       Node* keep_mem,
1839                                                       const TypePtr* hook_mem) {
1840   // no i/o
1841   set_control(_gvn.transform( new (C) ProjNode(call,TypeFunc::Control) ));
1842   if (keep_mem) {
1843     // First clone the existing memory state
1844     set_all_memory(keep_mem);
1845     if (hook_mem != NULL) {
1846       // Make memory for the call
1847       Node* mem = _gvn.transform( new (C) ProjNode(call, TypeFunc::Memory) );
1848       // Set the RawPtr memory state only.  This covers all the heap top/GC stuff
1849       // We also use hook_mem to extract specific effects from arraycopy stubs.
1850       set_memory(mem, hook_mem);
1851     }
1852     // ...else the call has NO memory effects.
1853 
1854     // Make sure the call advertises its memory effects precisely.
1855     // This lets us build accurate anti-dependences in gcm.cpp.
1856     assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
1857            "call node must be constructed correctly");
1858   } else {
1859     assert(hook_mem == NULL, "");
1860     // This is not a "slow path" call; all memory comes from the call.
1861     set_all_memory_call(call);
1862   }
1863 }
1864 
1865 
1866 // Replace the call with the current state of the kit.
1867 void GraphKit::replace_call(CallNode* call, Node* result) {
1868   JVMState* ejvms = NULL;
1869   if (has_exceptions()) {
1870     ejvms = transfer_exceptions_into_jvms();
1871   }
1872 
1873   SafePointNode* final_state = stop();
1874 
1875   // Find all the needed outputs of this call
1876   CallProjections callprojs;
1877   call->extract_projections(&callprojs, true);
1878 
1879   Node* init_mem = call->in(TypeFunc::Memory);
1880   Node* final_mem = final_state->in(TypeFunc::Memory);
1881   Node* final_ctl = final_state->in(TypeFunc::Control);
1882   Node* final_io = final_state->in(TypeFunc::I_O);
1883 
1884   // Replace all the old call edges with the edges from the inlining result
1885   if (callprojs.fallthrough_catchproj != NULL) {
1886     C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl);
1887   }
1888   if (callprojs.fallthrough_memproj != NULL) {
1889     C->gvn_replace_by(callprojs.fallthrough_memproj,   final_mem);
1890   }
1891   if (callprojs.fallthrough_ioproj != NULL) {
1892     C->gvn_replace_by(callprojs.fallthrough_ioproj,    final_io);
1893   }
1894 
1895   // Replace the result with the new result if it exists and is used
1896   if (callprojs.resproj != NULL && result != NULL) {
1897     C->gvn_replace_by(callprojs.resproj, result);
1898   }
1899 
1900   if (ejvms == NULL) {
1901     // No exception edges to simply kill off those paths
1902     if (callprojs.catchall_catchproj != NULL) {
1903       C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
1904     }
1905     if (callprojs.catchall_memproj != NULL) {
1906       C->gvn_replace_by(callprojs.catchall_memproj,   C->top());
1907     }
1908     if (callprojs.catchall_ioproj != NULL) {
1909       C->gvn_replace_by(callprojs.catchall_ioproj,    C->top());
1910     }
1911     // Replace the old exception object with top
1912     if (callprojs.exobj != NULL) {
1913       C->gvn_replace_by(callprojs.exobj, C->top());
1914     }
1915   } else {
1916     GraphKit ekit(ejvms);
1917 
1918     // Load my combined exception state into the kit, with all phis transformed:
1919     SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();
1920 
1921     Node* ex_oop = ekit.use_exception_state(ex_map);
1922     if (callprojs.catchall_catchproj != NULL) {
1923       C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
1924     }
1925     if (callprojs.catchall_memproj != NULL) {
1926       C->gvn_replace_by(callprojs.catchall_memproj,   ekit.reset_memory());
1927     }
1928     if (callprojs.catchall_ioproj != NULL) {
1929       C->gvn_replace_by(callprojs.catchall_ioproj,    ekit.i_o());
1930     }
1931 
1932     // Replace the old exception object with the newly created one
1933     if (callprojs.exobj != NULL) {
1934       C->gvn_replace_by(callprojs.exobj, ex_oop);
1935     }
1936   }
1937 
1938   // Disconnect the call from the graph
1939   call->disconnect_inputs(NULL, C);
1940   C->gvn_replace_by(call, C->top());
1941 
1942   // Clean up any MergeMems that feed other MergeMems since the
1943   // optimizer doesn't like that.
1944   if (final_mem->is_MergeMem()) {
1945     Node_List wl;
1946     for (SimpleDUIterator i(final_mem); i.has_next(); i.next()) {
1947       Node* m = i.get();
1948       if (m->is_MergeMem() && !wl.contains(m)) {
1949         wl.push(m);
1950       }
1951     }
1952     while (wl.size()  > 0) {
1953       _gvn.transform(wl.pop());
1954     }
1955   }
1956 }
1957 
1958 
1959 //------------------------------increment_counter------------------------------
1960 // for statistics: increment a VM counter by 1
1961 
1962 void GraphKit::increment_counter(address counter_addr) {
1963   Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
1964   increment_counter(adr1);
1965 }
1966 
1967 void GraphKit::increment_counter(Node* counter_addr) {
1968   int adr_type = Compile::AliasIdxRaw;
1969   Node* ctrl = control();
1970   Node* cnt  = make_load(ctrl, counter_addr, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
1971   Node* incr = _gvn.transform(new (C) AddINode(cnt, _gvn.intcon(1)));
1972   store_to_memory(ctrl, counter_addr, incr, T_INT, adr_type, MemNode::unordered);
1973 }
1974 
1975 
1976 //------------------------------uncommon_trap----------------------------------
1977 // Bail out to the interpreter in mid-method.  Implemented by calling the
1978 // uncommon_trap blob.  This helper function inserts a runtime call with the
1979 // right debug info.
1980 void GraphKit::uncommon_trap(int trap_request,
1981                              ciKlass* klass, const char* comment,
1982                              bool must_throw,
1983                              bool keep_exact_action) {
1984   if (failing())  stop();
1985   if (stopped())  return; // trap reachable?
1986 
1987   // Note:  If ProfileTraps is true, and if a deopt. actually
1988   // occurs here, the runtime will make sure an MDO exists.  There is
1989   // no need to call method()->ensure_method_data() at this point.
1990 
1991   // Set the stack pointer to the right value for reexecution:
1992   set_sp(reexecute_sp());
1993 
1994 #ifdef ASSERT
1995   if (!must_throw) {
1996     // Make sure the stack has at least enough depth to execute
1997     // the current bytecode.
1998     int inputs, ignored_depth;
1999     if (compute_stack_effects(inputs, ignored_depth)) {
2000       assert(sp() >= inputs, err_msg_res("must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
2001              Bytecodes::name(java_bc()), sp(), inputs));
2002     }
2003   }
2004 #endif
2005 
2006   Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
2007   Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
2008 
2009   switch (action) {
2010   case Deoptimization::Action_maybe_recompile:
2011   case Deoptimization::Action_reinterpret:
2012     // Temporary fix for 6529811 to allow virtual calls to be sure they
2013     // get the chance to go from mono->bi->mega
2014     if (!keep_exact_action &&
2015         Deoptimization::trap_request_index(trap_request) < 0 &&
2016         too_many_recompiles(reason)) {
2017       // This BCI is causing too many recompilations.
2018       action = Deoptimization::Action_none;
2019       trap_request = Deoptimization::make_trap_request(reason, action);
2020     } else {
2021       C->set_trap_can_recompile(true);
2022     }
2023     break;
2024   case Deoptimization::Action_make_not_entrant:
2025     C->set_trap_can_recompile(true);
2026     break;
2027 #ifdef ASSERT
2028   case Deoptimization::Action_none:
2029   case Deoptimization::Action_make_not_compilable:
2030     break;
2031   default:
2032     fatal(err_msg_res("unknown action %d: %s", action, Deoptimization::trap_action_name(action)));
2033     break;
2034 #endif
2035   }
2036 
2037   if (TraceOptoParse) {
2038     char buf[100];
2039     tty->print_cr("Uncommon trap %s at bci:%d",
2040                   Deoptimization::format_trap_request(buf, sizeof(buf),
2041                                                       trap_request), bci());
2042   }
2043 
2044   CompileLog* log = C->log();
2045   if (log != NULL) {
2046     int kid = (klass == NULL)? -1: log->identify(klass);
2047     log->begin_elem("uncommon_trap bci='%d'", bci());
2048     char buf[100];
2049     log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
2050                                                           trap_request));
2051     if (kid >= 0)         log->print(" klass='%d'", kid);
2052     if (comment != NULL)  log->print(" comment='%s'", comment);
2053     log->end_elem();
2054   }
2055 
2056   // Make sure any guarding test views this path as very unlikely
2057   Node *i0 = control()->in(0);
2058   if (i0 != NULL && i0->is_If()) {        // Found a guarding if test?
2059     IfNode *iff = i0->as_If();
2060     float f = iff->_prob;   // Get prob
2061     if (control()->Opcode() == Op_IfTrue) {
2062       if (f > PROB_UNLIKELY_MAG(4))
2063         iff->_prob = PROB_MIN;
2064     } else {
2065       if (f < PROB_LIKELY_MAG(4))
2066         iff->_prob = PROB_MAX;
2067     }
2068   }
2069 
2070   // Clear out dead values from the debug info.
2071   kill_dead_locals();
2072 
2073   // Now insert the uncommon trap subroutine call
2074   address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
2075   const TypePtr* no_memory_effects = NULL;
2076   // Pass the index of the class to be loaded
2077   Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
2078                                  (must_throw ? RC_MUST_THROW : 0),
2079                                  OptoRuntime::uncommon_trap_Type(),
2080                                  call_addr, "uncommon_trap", no_memory_effects,
2081                                  intcon(trap_request));
2082   assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
2083          "must extract request correctly from the graph");
2084   assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
2085 
2086   call->set_req(TypeFunc::ReturnAdr, returnadr());
2087   // The debug info is the only real input to this call.
2088 
2089   // Halt-and-catch fire here.  The above call should never return!
2090   HaltNode* halt = new(C) HaltNode(control(), frameptr());
2091   _gvn.set_type_bottom(halt);
2092   root()->add_req(halt);
2093 
2094   stop_and_kill_map();
2095 }
2096 
2097 
2098 //--------------------------just_allocated_object------------------------------
2099 // Report the object that was just allocated.
2100 // It must be the case that there are no intervening safepoints.
2101 // We use this to determine if an object is so "fresh" that
2102 // it does not require card marks.
2103 Node* GraphKit::just_allocated_object(Node* current_control) {
2104   if (C->recent_alloc_ctl() == current_control)
2105     return C->recent_alloc_obj();
2106   return NULL;
2107 }
2108 
2109 
2110 void GraphKit::round_double_arguments(ciMethod* dest_method) {
2111   // (Note:  TypeFunc::make has a cache that makes this fast.)
2112   const TypeFunc* tf    = TypeFunc::make(dest_method);
2113   int             nargs = tf->_domain->_cnt - TypeFunc::Parms;
2114   for (int j = 0; j < nargs; j++) {
2115     const Type *targ = tf->_domain->field_at(j + TypeFunc::Parms);
2116     if( targ->basic_type() == T_DOUBLE ) {
2117       // If any parameters are doubles, they must be rounded before
2118       // the call, dstore_rounding does gvn.transform
2119       Node *arg = argument(j);
2120       arg = dstore_rounding(arg);
2121       set_argument(j, arg);
2122     }
2123   }
2124 }
2125 
2126 /**
2127  * Record profiling data exact_kls for Node n with the type system so
2128  * that it can propagate it (speculation)
2129  *
2130  * @param n          node that the type applies to
2131  * @param exact_kls  type from profiling
2132  * @param maybe_null did profiling see null?
2133  *
2134  * @return           node with improved type
2135  */
2136 Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls, bool maybe_null) {
2137   const Type* current_type = _gvn.type(n);
2138   assert(UseTypeSpeculation, "type speculation must be on");
2139 
2140   const TypePtr* speculative = current_type->speculative();
2141 
2142   // Should the klass from the profile be recorded in the speculative type?
2143   if (current_type->would_improve_type(exact_kls, jvms()->depth())) {
2144     const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls);
2145     const TypeOopPtr* xtype = tklass->as_instance_type();
2146     assert(xtype->klass_is_exact(), "Should be exact");
2147     // Any reason to believe n is not null (from this profiling or a previous one)?
2148     const TypePtr* ptr = (maybe_null && current_type->speculative_maybe_null()) ? TypePtr::BOTTOM : TypePtr::NOTNULL;
2149     // record the new speculative type's depth
2150     speculative = xtype->cast_to_ptr_type(ptr->ptr())->is_ptr();
2151     speculative = speculative->with_inline_depth(jvms()->depth());
2152   } else if (current_type->would_improve_ptr(maybe_null)) {
2153     // Profiling report that null was never seen so we can change the
2154     // speculative type to non null ptr.
2155     assert(!maybe_null, "nothing to improve");
2156     if (speculative == NULL) {
2157       speculative = TypePtr::NOTNULL;
2158     } else {
2159       const TypePtr* ptr = TypePtr::NOTNULL;
2160       speculative = speculative->cast_to_ptr_type(ptr->ptr())->is_ptr();
2161     }
2162   }
2163 
2164   if (speculative != current_type->speculative()) {
2165     // Build a type with a speculative type (what we think we know
2166     // about the type but will need a guard when we use it)
2167     const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::OffsetBot, TypeOopPtr::InstanceBot, speculative);
2168     // We're changing the type, we need a new CheckCast node to carry
2169     // the new type. The new type depends on the control: what
2170     // profiling tells us is only valid from here as far as we can
2171     // tell.
2172     Node* cast = new(C) CheckCastPPNode(control(), n, current_type->remove_speculative()->join_speculative(spec_type));
2173     cast = _gvn.transform(cast);
2174     replace_in_map(n, cast);
2175     n = cast;
2176   }
2177 
2178   return n;
2179 }
2180 
2181 /**
2182  * Record profiling data from receiver profiling at an invoke with the
2183  * type system so that it can propagate it (speculation)
2184  *
2185  * @param n  receiver node
2186  *
2187  * @return   node with improved type
2188  */
2189 Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) {
2190   if (!UseTypeSpeculation) {
2191     return n;
2192   }
2193   ciKlass* exact_kls = profile_has_unique_klass();
2194   bool maybe_null = true;
2195   if (java_bc() == Bytecodes::_checkcast ||
2196       java_bc() == Bytecodes::_instanceof ||
2197       java_bc() == Bytecodes::_aastore) {
2198     ciProfileData* data = method()->method_data()->bci_to_data(bci());
2199     bool maybe_null = data == NULL ? true : data->as_BitData()->null_seen();
2200   }
2201   return record_profile_for_speculation(n, exact_kls, maybe_null);
2202   return n;
2203 }
2204 
2205 /**
2206  * Record profiling data from argument profiling at an invoke with the
2207  * type system so that it can propagate it (speculation)
2208  *
2209  * @param dest_method  target method for the call
2210  * @param bc           what invoke bytecode is this?
2211  */
2212 void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) {
2213   if (!UseTypeSpeculation) {
2214     return;
2215   }
2216   const TypeFunc* tf    = TypeFunc::make(dest_method);
2217   int             nargs = tf->_domain->_cnt - TypeFunc::Parms;
2218   int skip = Bytecodes::has_receiver(bc) ? 1 : 0;
2219   for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) {
2220     const Type *targ = tf->_domain->field_at(j + TypeFunc::Parms);
2221     if (targ->basic_type() == T_OBJECT || targ->basic_type() == T_ARRAY) {
2222       bool maybe_null = true;
2223       ciKlass* better_type = NULL;
2224       if (method()->argument_profiled_type(bci(), i, better_type, maybe_null)) {
2225         record_profile_for_speculation(argument(j), better_type, maybe_null);
2226       }
2227       i++;
2228     }
2229   }
2230 }
2231 
2232 /**
2233  * Record profiling data from parameter profiling at an invoke with
2234  * the type system so that it can propagate it (speculation)
2235  */
2236 void GraphKit::record_profiled_parameters_for_speculation() {
2237   if (!UseTypeSpeculation) {
2238     return;
2239   }
2240   for (int i = 0, j = 0; i < method()->arg_size() ; i++) {
2241     if (_gvn.type(local(i))->isa_oopptr()) {
2242       bool maybe_null = true;
2243       ciKlass* better_type = NULL;
2244       if (method()->parameter_profiled_type(j, better_type, maybe_null)) {
2245         record_profile_for_speculation(local(i), better_type, maybe_null);
2246       }
2247       j++;
2248     }
2249   }
2250 }
2251 
2252 /**
2253  * Record profiling data from return value profiling at an invoke with
2254  * the type system so that it can propagate it (speculation)
2255  */
2256 void GraphKit::record_profiled_return_for_speculation() {
2257   if (!UseTypeSpeculation) {
2258     return;
2259   }
2260   bool maybe_null = true;
2261   ciKlass* better_type = NULL;
2262   if (method()->return_profiled_type(bci(), better_type, maybe_null)) {
2263     // If profiling reports a single type for the return value,
2264     // feed it to the type system so it can propagate it as a
2265     // speculative type
2266     record_profile_for_speculation(stack(sp()-1), better_type, maybe_null);
2267   }
2268 }
2269 
2270 void GraphKit::round_double_result(ciMethod* dest_method) {
2271   // A non-strict method may return a double value which has an extended
2272   // exponent, but this must not be visible in a caller which is 'strict'
2273   // If a strict caller invokes a non-strict callee, round a double result
2274 
2275   BasicType result_type = dest_method->return_type()->basic_type();
2276   assert( method() != NULL, "must have caller context");
2277   if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) {
2278     // Destination method's return value is on top of stack
2279     // dstore_rounding() does gvn.transform
2280     Node *result = pop_pair();
2281     result = dstore_rounding(result);
2282     push_pair(result);
2283   }
2284 }
2285 
2286 // rounding for strict float precision conformance
2287 Node* GraphKit::precision_rounding(Node* n) {
2288   return UseStrictFP && _method->flags().is_strict()
2289     && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding
2290     ? _gvn.transform( new (C) RoundFloatNode(0, n) )
2291     : n;
2292 }
2293 
2294 // rounding for strict double precision conformance
2295 Node* GraphKit::dprecision_rounding(Node *n) {
2296   return UseStrictFP && _method->flags().is_strict()
2297     && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding
2298     ? _gvn.transform( new (C) RoundDoubleNode(0, n) )
2299     : n;
2300 }
2301 
2302 // rounding for non-strict double stores
2303 Node* GraphKit::dstore_rounding(Node* n) {
2304   return Matcher::strict_fp_requires_explicit_rounding
2305     && UseSSE <= 1
2306     ? _gvn.transform( new (C) RoundDoubleNode(0, n) )
2307     : n;
2308 }
2309 
2310 //=============================================================================
2311 // Generate a fast path/slow path idiom.  Graph looks like:
2312 // [foo] indicates that 'foo' is a parameter
2313 //
2314 //              [in]     NULL
2315 //                 \    /
2316 //                  CmpP
2317 //                  Bool ne
2318 //                   If
2319 //                  /  \
2320 //              True    False-<2>
2321 //              / |
2322 //             /  cast_not_null
2323 //           Load  |    |   ^
2324 //        [fast_test]   |   |
2325 // gvn to   opt_test    |   |
2326 //          /    \      |  <1>
2327 //      True     False  |
2328 //        |         \\  |
2329 //   [slow_call]     \[fast_result]
2330 //    Ctl   Val       \      \
2331 //     |               \      \
2332 //    Catch       <1>   \      \
2333 //   /    \        ^     \      \
2334 //  Ex    No_Ex    |      \      \
2335 //  |       \   \  |       \ <2>  \
2336 //  ...      \  [slow_res] |  |    \   [null_result]
2337 //            \         \--+--+---  |  |
2338 //             \           | /    \ | /
2339 //              --------Region     Phi
2340 //
2341 //=============================================================================
2342 // Code is structured as a series of driver functions all called 'do_XXX' that
2343 // call a set of helper functions.  Helper functions first, then drivers.
2344 
2345 //------------------------------null_check_oop---------------------------------
2346 // Null check oop.  Set null-path control into Region in slot 3.
2347 // Make a cast-not-nullness use the other not-null control.  Return cast.
2348 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2349                                bool never_see_null,
2350                                bool safe_for_replace,
2351                                bool speculative) {
2352   // Initial NULL check taken path
2353   (*null_control) = top();
2354   Node* cast = null_check_common(value, T_OBJECT, false, null_control, speculative);
2355 
2356   // Generate uncommon_trap:
2357   if (never_see_null && (*null_control) != top()) {
2358     // If we see an unexpected null at a check-cast we record it and force a
2359     // recompile; the offending check-cast will be compiled to handle NULLs.
2360     // If we see more than one offending BCI, then all checkcasts in the
2361     // method will be compiled to handle NULLs.
2362     PreserveJVMState pjvms(this);
2363     set_control(*null_control);
2364     replace_in_map(value, null());
2365     Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculative);
2366     uncommon_trap(reason,
2367                   Deoptimization::Action_make_not_entrant);
2368     (*null_control) = top();    // NULL path is dead
2369   }
2370   if ((*null_control) == top() && safe_for_replace) {
2371     replace_in_map(value, cast);
2372   }
2373 
2374   // Cast away null-ness on the result
2375   return cast;
2376 }
2377 
2378 //------------------------------opt_iff----------------------------------------
2379 // Optimize the fast-check IfNode.  Set the fast-path region slot 2.
2380 // Return slow-path control.
2381 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2382   IfNode *opt_iff = _gvn.transform(iff)->as_If();
2383 
2384   // Fast path taken; set region slot 2
2385   Node *fast_taken = _gvn.transform( new (C) IfFalseNode(opt_iff) );
2386   region->init_req(2,fast_taken); // Capture fast-control
2387 
2388   // Fast path not-taken, i.e. slow path
2389   Node *slow_taken = _gvn.transform( new (C) IfTrueNode(opt_iff) );
2390   return slow_taken;
2391 }
2392 
2393 //-----------------------------make_runtime_call-------------------------------
2394 Node* GraphKit::make_runtime_call(int flags,
2395                                   const TypeFunc* call_type, address call_addr,
2396                                   const char* call_name,
2397                                   const TypePtr* adr_type,
2398                                   // The following parms are all optional.
2399                                   // The first NULL ends the list.
2400                                   Node* parm0, Node* parm1,
2401                                   Node* parm2, Node* parm3,
2402                                   Node* parm4, Node* parm5,
2403                                   Node* parm6, Node* parm7) {
2404   // Slow-path call
2405   bool is_leaf = !(flags & RC_NO_LEAF);
2406   bool has_io  = (!is_leaf && !(flags & RC_NO_IO));
2407   if (call_name == NULL) {
2408     assert(!is_leaf, "must supply name for leaf");
2409     call_name = OptoRuntime::stub_name(call_addr);
2410   }
2411   CallNode* call;
2412   if (!is_leaf) {
2413     call = new(C) CallStaticJavaNode(call_type, call_addr, call_name,
2414                                            bci(), adr_type);
2415   } else if (flags & RC_NO_FP) {
2416     call = new(C) CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2417   } else {
2418     call = new(C) CallLeafNode(call_type, call_addr, call_name, adr_type);
2419   }
2420 
2421   // The following is similar to set_edges_for_java_call,
2422   // except that the memory effects of the call are restricted to AliasIdxRaw.
2423 
2424   // Slow path call has no side-effects, uses few values
2425   bool wide_in  = !(flags & RC_NARROW_MEM);
2426   bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2427 
2428   Node* prev_mem = NULL;
2429   if (wide_in) {
2430     prev_mem = set_predefined_input_for_runtime_call(call);
2431   } else {
2432     assert(!wide_out, "narrow in => narrow out");
2433     Node* narrow_mem = memory(adr_type);
2434     prev_mem = reset_memory();
2435     map()->set_memory(narrow_mem);
2436     set_predefined_input_for_runtime_call(call);
2437   }
2438 
2439   // Hook each parm in order.  Stop looking at the first NULL.
2440   if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
2441   if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
2442   if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
2443   if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
2444   if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
2445   if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
2446   if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
2447   if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
2448     /* close each nested if ===> */  } } } } } } } }
2449   assert(call->in(call->req()-1) != NULL, "must initialize all parms");
2450 
2451   if (!is_leaf) {
2452     // Non-leaves can block and take safepoints:
2453     add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2454   }
2455   // Non-leaves can throw exceptions:
2456   if (has_io) {
2457     call->set_req(TypeFunc::I_O, i_o());
2458   }
2459 
2460   if (flags & RC_UNCOMMON) {
2461     // Set the count to a tiny probability.  Cf. Estimate_Block_Frequency.
2462     // (An "if" probability corresponds roughly to an unconditional count.
2463     // Sort of.)
2464     call->set_cnt(PROB_UNLIKELY_MAG(4));
2465   }
2466 
2467   Node* c = _gvn.transform(call);
2468   assert(c == call, "cannot disappear");
2469 
2470   if (wide_out) {
2471     // Slow path call has full side-effects.
2472     set_predefined_output_for_runtime_call(call);
2473   } else {
2474     // Slow path call has few side-effects, and/or sets few values.
2475     set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2476   }
2477 
2478   if (has_io) {
2479     set_i_o(_gvn.transform(new (C) ProjNode(call, TypeFunc::I_O)));
2480   }
2481   return call;
2482 
2483 }
2484 
2485 //------------------------------merge_memory-----------------------------------
2486 // Merge memory from one path into the current memory state.
2487 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2488   for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2489     Node* old_slice = mms.force_memory();
2490     Node* new_slice = mms.memory2();
2491     if (old_slice != new_slice) {
2492       PhiNode* phi;
2493       if (new_slice->is_Phi() && new_slice->as_Phi()->region() == region) {
2494         phi = new_slice->as_Phi();
2495         #ifdef ASSERT
2496         if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region)
2497           old_slice = old_slice->in(new_path);
2498         // Caller is responsible for ensuring that any pre-existing
2499         // phis are already aware of old memory.
2500         int old_path = (new_path > 1) ? 1 : 2;  // choose old_path != new_path
2501         assert(phi->in(old_path) == old_slice, "pre-existing phis OK");
2502         #endif
2503         mms.set_memory(phi);
2504       } else {
2505         phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2506         _gvn.set_type(phi, Type::MEMORY);
2507         phi->set_req(new_path, new_slice);
2508         mms.set_memory(_gvn.transform(phi));  // assume it is complete
2509       }
2510     }
2511   }
2512 }
2513 
2514 //------------------------------make_slow_call_ex------------------------------
2515 // Make the exception handler hookups for the slow call
2516 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj) {
2517   if (stopped())  return;
2518 
2519   // Make a catch node with just two handlers:  fall-through and catch-all
2520   Node* i_o  = _gvn.transform( new (C) ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2521   Node* catc = _gvn.transform( new (C) CatchNode(control(), i_o, 2) );
2522   Node* norm = _gvn.transform( new (C) CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
2523   Node* excp = _gvn.transform( new (C) CatchProjNode(catc, CatchProjNode::catch_all_index,    CatchProjNode::no_handler_bci) );
2524 
2525   { PreserveJVMState pjvms(this);
2526     set_control(excp);
2527     set_i_o(i_o);
2528 
2529     if (excp != top()) {
2530       // Create an exception state also.
2531       // Use an exact type if the caller has specified a specific exception.
2532       const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2533       Node*       ex_oop  = new (C) CreateExNode(ex_type, control(), i_o);
2534       add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2535     }
2536   }
2537 
2538   // Get the no-exception control from the CatchNode.
2539   set_control(norm);
2540 }
2541 
2542 
2543 //-------------------------------gen_subtype_check-----------------------------
2544 // Generate a subtyping check.  Takes as input the subtype and supertype.
2545 // Returns 2 values: sets the default control() to the true path and returns
2546 // the false path.  Only reads invariant memory; sets no (visible) memory.
2547 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2548 // but that's not exposed to the optimizer.  This call also doesn't take in an
2549 // Object; if you wish to check an Object you need to load the Object's class
2550 // prior to coming here.
2551 Node* GraphKit::gen_subtype_check(Node* subklass, Node* superklass) {
2552   // Fast check for identical types, perhaps identical constants.
2553   // The types can even be identical non-constants, in cases
2554   // involving Array.newInstance, Object.clone, etc.
2555   if (subklass == superklass)
2556     return top();             // false path is dead; no test needed.
2557 
2558   if (_gvn.type(superklass)->singleton()) {
2559     ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
2560     ciKlass* subk   = _gvn.type(subklass)->is_klassptr()->klass();
2561 
2562     // In the common case of an exact superklass, try to fold up the
2563     // test before generating code.  You may ask, why not just generate
2564     // the code and then let it fold up?  The answer is that the generated
2565     // code will necessarily include null checks, which do not always
2566     // completely fold away.  If they are also needless, then they turn
2567     // into a performance loss.  Example:
2568     //    Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2569     // Here, the type of 'fa' is often exact, so the store check
2570     // of fa[1]=x will fold up, without testing the nullness of x.
2571     switch (static_subtype_check(superk, subk)) {
2572     case SSC_always_false:
2573       {
2574         Node* always_fail = control();
2575         set_control(top());
2576         return always_fail;
2577       }
2578     case SSC_always_true:
2579       return top();
2580     case SSC_easy_test:
2581       {
2582         // Just do a direct pointer compare and be done.
2583         Node* cmp = _gvn.transform( new(C) CmpPNode(subklass, superklass) );
2584         Node* bol = _gvn.transform( new(C) BoolNode(cmp, BoolTest::eq) );
2585         IfNode* iff = create_and_xform_if(control(), bol, PROB_STATIC_FREQUENT, COUNT_UNKNOWN);
2586         set_control( _gvn.transform( new(C) IfTrueNode (iff) ) );
2587         return       _gvn.transform( new(C) IfFalseNode(iff) );
2588       }
2589     case SSC_full_test:
2590       break;
2591     default:
2592       ShouldNotReachHere();
2593     }
2594   }
2595 
2596   // %%% Possible further optimization:  Even if the superklass is not exact,
2597   // if the subklass is the unique subtype of the superklass, the check
2598   // will always succeed.  We could leave a dependency behind to ensure this.
2599 
2600   // First load the super-klass's check-offset
2601   Node *p1 = basic_plus_adr( superklass, superklass, in_bytes(Klass::super_check_offset_offset()) );
2602   Node *chk_off = _gvn.transform(new (C) LoadINode(NULL, memory(p1), p1, _gvn.type(p1)->is_ptr(),
2603                                                    TypeInt::INT, MemNode::unordered));
2604   int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
2605   bool might_be_cache = (find_int_con(chk_off, cacheoff_con) == cacheoff_con);
2606 
2607   // Load from the sub-klass's super-class display list, or a 1-word cache of
2608   // the secondary superclass list, or a failing value with a sentinel offset
2609   // if the super-klass is an interface or exceptionally deep in the Java
2610   // hierarchy and we have to scan the secondary superclass list the hard way.
2611   // Worst-case type is a little odd: NULL is allowed as a result (usually
2612   // klass loads can never produce a NULL).
2613   Node *chk_off_X = ConvI2X(chk_off);
2614   Node *p2 = _gvn.transform( new (C) AddPNode(subklass,subklass,chk_off_X) );
2615   // For some types like interfaces the following loadKlass is from a 1-word
2616   // cache which is mutable so can't use immutable memory.  Other
2617   // types load from the super-class display table which is immutable.
2618   Node *kmem = might_be_cache ? memory(p2) : immutable_memory();
2619   Node *nkls = _gvn.transform( LoadKlassNode::make( _gvn, kmem, p2, _gvn.type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL ) );
2620 
2621   // Compile speed common case: ARE a subtype and we canNOT fail
2622   if( superklass == nkls )
2623     return top();             // false path is dead; no test needed.
2624 
2625   // See if we get an immediate positive hit.  Happens roughly 83% of the
2626   // time.  Test to see if the value loaded just previously from the subklass
2627   // is exactly the superklass.
2628   Node *cmp1 = _gvn.transform( new (C) CmpPNode( superklass, nkls ) );
2629   Node *bol1 = _gvn.transform( new (C) BoolNode( cmp1, BoolTest::eq ) );
2630   IfNode *iff1 = create_and_xform_if( control(), bol1, PROB_LIKELY(0.83f), COUNT_UNKNOWN );
2631   Node *iftrue1 = _gvn.transform( new (C) IfTrueNode ( iff1 ) );
2632   set_control(    _gvn.transform( new (C) IfFalseNode( iff1 ) ) );
2633 
2634   // Compile speed common case: Check for being deterministic right now.  If
2635   // chk_off is a constant and not equal to cacheoff then we are NOT a
2636   // subklass.  In this case we need exactly the 1 test above and we can
2637   // return those results immediately.
2638   if (!might_be_cache) {
2639     Node* not_subtype_ctrl = control();
2640     set_control(iftrue1); // We need exactly the 1 test above
2641     return not_subtype_ctrl;
2642   }
2643 
2644   // Gather the various success & failures here
2645   RegionNode *r_ok_subtype = new (C) RegionNode(4);
2646   record_for_igvn(r_ok_subtype);
2647   RegionNode *r_not_subtype = new (C) RegionNode(3);
2648   record_for_igvn(r_not_subtype);
2649 
2650   r_ok_subtype->init_req(1, iftrue1);
2651 
2652   // Check for immediate negative hit.  Happens roughly 11% of the time (which
2653   // is roughly 63% of the remaining cases).  Test to see if the loaded
2654   // check-offset points into the subklass display list or the 1-element
2655   // cache.  If it points to the display (and NOT the cache) and the display
2656   // missed then it's not a subtype.
2657   Node *cacheoff = _gvn.intcon(cacheoff_con);
2658   Node *cmp2 = _gvn.transform( new (C) CmpINode( chk_off, cacheoff ) );
2659   Node *bol2 = _gvn.transform( new (C) BoolNode( cmp2, BoolTest::ne ) );
2660   IfNode *iff2 = create_and_xform_if( control(), bol2, PROB_LIKELY(0.63f), COUNT_UNKNOWN );
2661   r_not_subtype->init_req(1, _gvn.transform( new (C) IfTrueNode (iff2) ) );
2662   set_control(                _gvn.transform( new (C) IfFalseNode(iff2) ) );
2663 
2664   // Check for self.  Very rare to get here, but it is taken 1/3 the time.
2665   // No performance impact (too rare) but allows sharing of secondary arrays
2666   // which has some footprint reduction.
2667   Node *cmp3 = _gvn.transform( new (C) CmpPNode( subklass, superklass ) );
2668   Node *bol3 = _gvn.transform( new (C) BoolNode( cmp3, BoolTest::eq ) );
2669   IfNode *iff3 = create_and_xform_if( control(), bol3, PROB_LIKELY(0.36f), COUNT_UNKNOWN );
2670   r_ok_subtype->init_req(2, _gvn.transform( new (C) IfTrueNode ( iff3 ) ) );
2671   set_control(               _gvn.transform( new (C) IfFalseNode( iff3 ) ) );
2672 
2673   // -- Roads not taken here: --
2674   // We could also have chosen to perform the self-check at the beginning
2675   // of this code sequence, as the assembler does.  This would not pay off
2676   // the same way, since the optimizer, unlike the assembler, can perform
2677   // static type analysis to fold away many successful self-checks.
2678   // Non-foldable self checks work better here in second position, because
2679   // the initial primary superclass check subsumes a self-check for most
2680   // types.  An exception would be a secondary type like array-of-interface,
2681   // which does not appear in its own primary supertype display.
2682   // Finally, we could have chosen to move the self-check into the
2683   // PartialSubtypeCheckNode, and from there out-of-line in a platform
2684   // dependent manner.  But it is worthwhile to have the check here,
2685   // where it can be perhaps be optimized.  The cost in code space is
2686   // small (register compare, branch).
2687 
2688   // Now do a linear scan of the secondary super-klass array.  Again, no real
2689   // performance impact (too rare) but it's gotta be done.
2690   // Since the code is rarely used, there is no penalty for moving it
2691   // out of line, and it can only improve I-cache density.
2692   // The decision to inline or out-of-line this final check is platform
2693   // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2694   Node* psc = _gvn.transform(
2695     new (C) PartialSubtypeCheckNode(control(), subklass, superklass) );
2696 
2697   Node *cmp4 = _gvn.transform( new (C) CmpPNode( psc, null() ) );
2698   Node *bol4 = _gvn.transform( new (C) BoolNode( cmp4, BoolTest::ne ) );
2699   IfNode *iff4 = create_and_xform_if( control(), bol4, PROB_FAIR, COUNT_UNKNOWN );
2700   r_not_subtype->init_req(2, _gvn.transform( new (C) IfTrueNode (iff4) ) );
2701   r_ok_subtype ->init_req(3, _gvn.transform( new (C) IfFalseNode(iff4) ) );
2702 
2703   // Return false path; set default control to true path.
2704   set_control( _gvn.transform(r_ok_subtype) );
2705   return _gvn.transform(r_not_subtype);
2706 }
2707 
2708 //----------------------------static_subtype_check-----------------------------
2709 // Shortcut important common cases when superklass is exact:
2710 // (0) superklass is java.lang.Object (can occur in reflective code)
2711 // (1) subklass is already limited to a subtype of superklass => always ok
2712 // (2) subklass does not overlap with superklass => always fail
2713 // (3) superklass has NO subtypes and we can check with a simple compare.
2714 int GraphKit::static_subtype_check(ciKlass* superk, ciKlass* subk) {
2715   if (StressReflectiveCode) {
2716     return SSC_full_test;       // Let caller generate the general case.
2717   }
2718 
2719   if (superk == env()->Object_klass()) {
2720     return SSC_always_true;     // (0) this test cannot fail
2721   }
2722 
2723   ciType* superelem = superk;
2724   if (superelem->is_array_klass())
2725     superelem = superelem->as_array_klass()->base_element_type();
2726 
2727   if (!subk->is_interface()) {  // cannot trust static interface types yet
2728     if (subk->is_subtype_of(superk)) {
2729       return SSC_always_true;   // (1) false path dead; no dynamic test needed
2730     }
2731     if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
2732         !superk->is_subtype_of(subk)) {
2733       return SSC_always_false;
2734     }
2735   }
2736 
2737   // If casting to an instance klass, it must have no subtypes
2738   if (superk->is_interface()) {
2739     // Cannot trust interfaces yet.
2740     // %%% S.B. superk->nof_implementors() == 1
2741   } else if (superelem->is_instance_klass()) {
2742     ciInstanceKlass* ik = superelem->as_instance_klass();
2743     if (!ik->has_subklass() && !ik->is_interface()) {
2744       if (!ik->is_final()) {
2745         // Add a dependency if there is a chance of a later subclass.
2746         C->dependencies()->assert_leaf_type(ik);
2747       }
2748       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
2749     }
2750   } else {
2751     // A primitive array type has no subtypes.
2752     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
2753   }
2754 
2755   return SSC_full_test;
2756 }
2757 
2758 // Profile-driven exact type check:
2759 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
2760                                     float prob,
2761                                     Node* *casted_receiver) {
2762   const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2763   Node* recv_klass = load_object_klass(receiver);
2764   Node* want_klass = makecon(tklass);
2765   Node* cmp = _gvn.transform( new(C) CmpPNode(recv_klass, want_klass) );
2766   Node* bol = _gvn.transform( new(C) BoolNode(cmp, BoolTest::eq) );
2767   IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
2768   set_control( _gvn.transform( new(C) IfTrueNode (iff) ));
2769   Node* fail = _gvn.transform( new(C) IfFalseNode(iff) );
2770 
2771   const TypeOopPtr* recv_xtype = tklass->as_instance_type();
2772   assert(recv_xtype->klass_is_exact(), "");
2773 
2774   // Subsume downstream occurrences of receiver with a cast to
2775   // recv_xtype, since now we know what the type will be.
2776   Node* cast = new(C) CheckCastPPNode(control(), receiver, recv_xtype);
2777   (*casted_receiver) = _gvn.transform(cast);
2778   // (User must make the replace_in_map call.)
2779 
2780   return fail;
2781 }
2782 
2783 
2784 //------------------------------seems_never_null-------------------------------
2785 // Use null_seen information if it is available from the profile.
2786 // If we see an unexpected null at a type check we record it and force a
2787 // recompile; the offending check will be recompiled to handle NULLs.
2788 // If we see several offending BCIs, then all checks in the
2789 // method will be recompiled.
2790 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data, bool& speculating) {
2791   speculating = !_gvn.type(obj)->speculative_maybe_null();
2792   Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculating);
2793   if (UncommonNullCast               // Cutout for this technique
2794       && obj != null()               // And not the -Xcomp stupid case?
2795       && !too_many_traps(reason)
2796       ) {
2797     if (speculating) {
2798       return true;
2799     }
2800     if (data == NULL)
2801       // Edge case:  no mature data.  Be optimistic here.
2802       return true;
2803     // If the profile has not seen a null, assume it won't happen.
2804     assert(java_bc() == Bytecodes::_checkcast ||
2805            java_bc() == Bytecodes::_instanceof ||
2806            java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
2807     return !data->as_BitData()->null_seen();
2808   }
2809   speculating = false;
2810   return false;
2811 }
2812 
2813 //------------------------maybe_cast_profiled_receiver-------------------------
2814 // If the profile has seen exactly one type, narrow to exactly that type.
2815 // Subsequent type checks will always fold up.
2816 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
2817                                              ciKlass* require_klass,
2818                                              ciKlass* spec_klass,
2819                                              bool safe_for_replace) {
2820   if (!UseTypeProfile || !TypeProfileCasts) return NULL;
2821 
2822   Deoptimization::DeoptReason reason = Deoptimization::reason_class_check(spec_klass != NULL);
2823 
2824   // Make sure we haven't already deoptimized from this tactic.
2825   if (too_many_traps(reason))
2826     return NULL;
2827 
2828   // (No, this isn't a call, but it's enough like a virtual call
2829   // to use the same ciMethod accessor to get the profile info...)
2830   // If we have a speculative type use it instead of profiling (which
2831   // may not help us)
2832   ciKlass* exact_kls = spec_klass == NULL ? profile_has_unique_klass() : spec_klass;
2833   if (exact_kls != NULL) {// no cast failures here
2834     if (require_klass == NULL ||
2835         static_subtype_check(require_klass, exact_kls) == SSC_always_true) {
2836       // If we narrow the type to match what the type profile sees or
2837       // the speculative type, we can then remove the rest of the
2838       // cast.
2839       // This is a win, even if the exact_kls is very specific,
2840       // because downstream operations, such as method calls,
2841       // will often benefit from the sharper type.
2842       Node* exact_obj = not_null_obj; // will get updated in place...
2843       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2844                                             &exact_obj);
2845       { PreserveJVMState pjvms(this);
2846         set_control(slow_ctl);
2847         uncommon_trap(reason,
2848                       Deoptimization::Action_maybe_recompile);
2849       }
2850       if (safe_for_replace) {
2851         replace_in_map(not_null_obj, exact_obj);
2852       }
2853       return exact_obj;
2854     }
2855     // assert(ssc == SSC_always_true)... except maybe the profile lied to us.
2856   }
2857 
2858   return NULL;
2859 }
2860 
2861 /**
2862  * Cast obj to type and emit guard unless we had too many traps here
2863  * already
2864  *
2865  * @param obj       node being casted
2866  * @param type      type to cast the node to
2867  * @param not_null  true if we know node cannot be null
2868  */
2869 Node* GraphKit::maybe_cast_profiled_obj(Node* obj,
2870                                         ciKlass* type,
2871                                         bool not_null) {
2872   // type == NULL if profiling tells us this object is always null
2873   if (type != NULL) {
2874     Deoptimization::DeoptReason class_reason = Deoptimization::Reason_speculate_class_check;
2875     Deoptimization::DeoptReason null_reason = Deoptimization::Reason_speculate_null_check;
2876     if (!too_many_traps(null_reason) &&
2877         !too_many_traps(class_reason)) {
2878       Node* not_null_obj = NULL;
2879       // not_null is true if we know the object is not null and
2880       // there's no need for a null check
2881       if (!not_null) {
2882         Node* null_ctl = top();
2883         not_null_obj = null_check_oop(obj, &null_ctl, true, true, true);
2884         assert(null_ctl->is_top(), "no null control here");
2885       } else {
2886         not_null_obj = obj;
2887       }
2888 
2889       Node* exact_obj = not_null_obj;
2890       ciKlass* exact_kls = type;
2891       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2892                                             &exact_obj);
2893       {
2894         PreserveJVMState pjvms(this);
2895         set_control(slow_ctl);
2896         uncommon_trap(class_reason,
2897                       Deoptimization::Action_maybe_recompile);
2898       }
2899       replace_in_map(not_null_obj, exact_obj);
2900       obj = exact_obj;
2901     }
2902   } else {
2903     if (!too_many_traps(Deoptimization::Reason_null_assert)) {
2904       Node* exact_obj = null_assert(obj);
2905       replace_in_map(obj, exact_obj);
2906       obj = exact_obj;
2907     }
2908   }
2909   return obj;
2910 }
2911 
2912 //-------------------------------gen_instanceof--------------------------------
2913 // Generate an instance-of idiom.  Used by both the instance-of bytecode
2914 // and the reflective instance-of call.
2915 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replace) {
2916   kill_dead_locals();           // Benefit all the uncommon traps
2917   assert( !stopped(), "dead parse path should be checked in callers" );
2918   assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
2919          "must check for not-null not-dead klass in callers");
2920 
2921   // Make the merge point
2922   enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
2923   RegionNode* region = new(C) RegionNode(PATH_LIMIT);
2924   Node*       phi    = new(C) PhiNode(region, TypeInt::BOOL);
2925   C->set_has_split_ifs(true); // Has chance for split-if optimization
2926 
2927   ciProfileData* data = NULL;
2928   if (java_bc() == Bytecodes::_instanceof) {  // Only for the bytecode
2929     data = method()->method_data()->bci_to_data(bci());
2930   }
2931   bool speculative_not_null = false;
2932   bool never_see_null = (ProfileDynamicTypes  // aggressive use of profile
2933                          && seems_never_null(obj, data, speculative_not_null));
2934 
2935   // Null check; get casted pointer; set region slot 3
2936   Node* null_ctl = top();
2937   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
2938 
2939   // If not_null_obj is dead, only null-path is taken
2940   if (stopped()) {              // Doing instance-of on a NULL?
2941     set_control(null_ctl);
2942     return intcon(0);
2943   }
2944   region->init_req(_null_path, null_ctl);
2945   phi   ->init_req(_null_path, intcon(0)); // Set null path value
2946   if (null_ctl == top()) {
2947     // Do this eagerly, so that pattern matches like is_diamond_phi
2948     // will work even during parsing.
2949     assert(_null_path == PATH_LIMIT-1, "delete last");
2950     region->del_req(_null_path);
2951     phi   ->del_req(_null_path);
2952   }
2953 
2954   // Do we know the type check always succeed?
2955   bool known_statically = false;
2956   if (_gvn.type(superklass)->singleton()) {
2957     ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
2958     ciKlass* subk = _gvn.type(obj)->is_oopptr()->klass();
2959     if (subk != NULL && subk->is_loaded()) {
2960       int static_res = static_subtype_check(superk, subk);
2961       known_statically = (static_res == SSC_always_true || static_res == SSC_always_false);
2962     }
2963   }
2964 
2965   if (known_statically && UseTypeSpeculation) {
2966     // If we know the type check always succeeds then we don't use the
2967     // profiling data at this bytecode. Don't lose it, feed it to the
2968     // type system as a speculative type.
2969     not_null_obj = record_profiled_receiver_for_speculation(not_null_obj);
2970   } else {
2971     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
2972     // We may not have profiling here or it may not help us. If we
2973     // have a speculative type use it to perform an exact cast.
2974     ciKlass* spec_obj_type = obj_type->speculative_type();
2975     if (spec_obj_type != NULL || (ProfileDynamicTypes && data != NULL)) {
2976       Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, NULL, spec_obj_type, safe_for_replace);
2977       if (stopped()) {            // Profile disagrees with this path.
2978         set_control(null_ctl);    // Null is the only remaining possibility.
2979         return intcon(0);
2980       }
2981       if (cast_obj != NULL) {
2982         not_null_obj = cast_obj;
2983       }
2984     }
2985   }
2986 
2987   // Load the object's klass
2988   Node* obj_klass = load_object_klass(not_null_obj);
2989 
2990   // Generate the subtype check
2991   Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);
2992 
2993   // Plug in the success path to the general merge in slot 1.
2994   region->init_req(_obj_path, control());
2995   phi   ->init_req(_obj_path, intcon(1));
2996 
2997   // Plug in the failing path to the general merge in slot 2.
2998   region->init_req(_fail_path, not_subtype_ctrl);
2999   phi   ->init_req(_fail_path, intcon(0));
3000 
3001   // Return final merged results
3002   set_control( _gvn.transform(region) );
3003   record_for_igvn(region);
3004   return _gvn.transform(phi);
3005 }
3006 
3007 //-------------------------------gen_checkcast---------------------------------
3008 // Generate a checkcast idiom.  Used by both the checkcast bytecode and the
3009 // array store bytecode.  Stack must be as-if BEFORE doing the bytecode so the
3010 // uncommon-trap paths work.  Adjust stack after this call.
3011 // If failure_control is supplied and not null, it is filled in with
3012 // the control edge for the cast failure.  Otherwise, an appropriate
3013 // uncommon trap or exception is thrown.
3014 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
3015                               Node* *failure_control) {
3016   kill_dead_locals();           // Benefit all the uncommon traps
3017   const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr();
3018   const Type *toop = TypeOopPtr::make_from_klass(tk->klass());
3019 
3020   // Fast cutout:  Check the case that the cast is vacuously true.
3021   // This detects the common cases where the test will short-circuit
3022   // away completely.  We do this before we perform the null check,
3023   // because if the test is going to turn into zero code, we don't
3024   // want a residual null check left around.  (Causes a slowdown,
3025   // for example, in some objArray manipulations, such as a[i]=a[j].)
3026   if (tk->singleton()) {
3027     const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
3028     if (objtp != NULL && objtp->klass() != NULL) {
3029       switch (static_subtype_check(tk->klass(), objtp->klass())) {
3030       case SSC_always_true:
3031         // If we know the type check always succeed then we don't use
3032         // the profiling data at this bytecode. Don't lose it, feed it
3033         // to the type system as a speculative type.
3034         return record_profiled_receiver_for_speculation(obj);
3035       case SSC_always_false:
3036         // It needs a null check because a null will *pass* the cast check.
3037         // A non-null value will always produce an exception.
3038         return null_assert(obj);
3039       }
3040     }
3041   }
3042 
3043   ciProfileData* data = NULL;
3044   bool safe_for_replace = false;
3045   if (failure_control == NULL) {        // use MDO in regular case only
3046     assert(java_bc() == Bytecodes::_aastore ||
3047            java_bc() == Bytecodes::_checkcast,
3048            "interpreter profiles type checks only for these BCs");
3049     data = method()->method_data()->bci_to_data(bci());
3050     safe_for_replace = true;
3051   }
3052 
3053   // Make the merge point
3054   enum { _obj_path = 1, _null_path, PATH_LIMIT };
3055   RegionNode* region = new (C) RegionNode(PATH_LIMIT);
3056   Node*       phi    = new (C) PhiNode(region, toop);
3057   C->set_has_split_ifs(true); // Has chance for split-if optimization
3058 
3059   // Use null-cast information if it is available
3060   bool speculative_not_null = false;
3061   bool never_see_null = ((failure_control == NULL)  // regular case only
3062                          && seems_never_null(obj, data, speculative_not_null));
3063 
3064   // Null check; get casted pointer; set region slot 3
3065   Node* null_ctl = top();
3066   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
3067 
3068   // If not_null_obj is dead, only null-path is taken
3069   if (stopped()) {              // Doing instance-of on a NULL?
3070     set_control(null_ctl);
3071     return null();
3072   }
3073   region->init_req(_null_path, null_ctl);
3074   phi   ->init_req(_null_path, null());  // Set null path value
3075   if (null_ctl == top()) {
3076     // Do this eagerly, so that pattern matches like is_diamond_phi
3077     // will work even during parsing.
3078     assert(_null_path == PATH_LIMIT-1, "delete last");
3079     region->del_req(_null_path);
3080     phi   ->del_req(_null_path);
3081   }
3082 
3083   Node* cast_obj = NULL;
3084   if (tk->klass_is_exact()) {
3085     // The following optimization tries to statically cast the speculative type of the object
3086     // (for example obtained during profiling) to the type of the superklass and then do a
3087     // dynamic check that the type of the object is what we expect. To work correctly
3088     // for checkcast and aastore the type of superklass should be exact.
3089     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
3090     // We may not have profiling here or it may not help us. If we have
3091     // a speculative type use it to perform an exact cast.
3092     ciKlass* spec_obj_type = obj_type->speculative_type();
3093     if (spec_obj_type != NULL ||
3094         (data != NULL &&
3095          // Counter has never been decremented (due to cast failure).
3096          // ...This is a reasonable thing to expect.  It is true of
3097          // all casts inserted by javac to implement generic types.
3098          data->as_CounterData()->count() >= 0)) {
3099       cast_obj = maybe_cast_profiled_receiver(not_null_obj, tk->klass(), spec_obj_type, safe_for_replace);
3100       if (cast_obj != NULL) {
3101         if (failure_control != NULL) // failure is now impossible
3102           (*failure_control) = top();
3103         // adjust the type of the phi to the exact klass:
3104         phi->raise_bottom_type(_gvn.type(cast_obj)->meet_speculative(TypePtr::NULL_PTR));
3105       }
3106     }
3107   }
3108 
3109   if (cast_obj == NULL) {
3110     // Load the object's klass
3111     Node* obj_klass = load_object_klass(not_null_obj);
3112 
3113     // Generate the subtype check
3114     Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );
3115 
3116     // Plug in success path into the merge
3117     cast_obj = _gvn.transform(new (C) CheckCastPPNode(control(),
3118                                                          not_null_obj, toop));
3119     // Failure path ends in uncommon trap (or may be dead - failure impossible)
3120     if (failure_control == NULL) {
3121       if (not_subtype_ctrl != top()) { // If failure is possible
3122         PreserveJVMState pjvms(this);
3123         set_control(not_subtype_ctrl);
3124         builtin_throw(Deoptimization::Reason_class_check, obj_klass);
3125       }
3126     } else {
3127       (*failure_control) = not_subtype_ctrl;
3128     }
3129   }
3130 
3131   region->init_req(_obj_path, control());
3132   phi   ->init_req(_obj_path, cast_obj);
3133 
3134   // A merge of NULL or Casted-NotNull obj
3135   Node* res = _gvn.transform(phi);
3136 
3137   // Note I do NOT always 'replace_in_map(obj,result)' here.
3138   //  if( tk->klass()->can_be_primary_super()  )
3139     // This means that if I successfully store an Object into an array-of-String
3140     // I 'forget' that the Object is really now known to be a String.  I have to
3141     // do this because we don't have true union types for interfaces - if I store
3142     // a Baz into an array-of-Interface and then tell the optimizer it's an
3143     // Interface, I forget that it's also a Baz and cannot do Baz-like field
3144     // references to it.  FIX THIS WHEN UNION TYPES APPEAR!
3145   //  replace_in_map( obj, res );
3146 
3147   // Return final merged results
3148   set_control( _gvn.transform(region) );
3149   record_for_igvn(region);
3150   return res;
3151 }
3152 
3153 //------------------------------next_monitor-----------------------------------
3154 // What number should be given to the next monitor?
3155 int GraphKit::next_monitor() {
3156   int current = jvms()->monitor_depth()* C->sync_stack_slots();
3157   int next = current + C->sync_stack_slots();
3158   // Keep the toplevel high water mark current:
3159   if (C->fixed_slots() < next)  C->set_fixed_slots(next);
3160   return current;
3161 }
3162 
3163 //------------------------------insert_mem_bar---------------------------------
3164 // Memory barrier to avoid floating things around
3165 // The membar serves as a pinch point between both control and all memory slices.
3166 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
3167   MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
3168   mb->init_req(TypeFunc::Control, control());
3169   mb->init_req(TypeFunc::Memory,  reset_memory());
3170   Node* membar = _gvn.transform(mb);
3171   set_control(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Control)));
3172   set_all_memory_call(membar);
3173   return membar;
3174 }
3175 
3176 //-------------------------insert_mem_bar_volatile----------------------------
3177 // Memory barrier to avoid floating things around
3178 // The membar serves as a pinch point between both control and memory(alias_idx).
3179 // If you want to make a pinch point on all memory slices, do not use this
3180 // function (even with AliasIdxBot); use insert_mem_bar() instead.
3181 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
3182   // When Parse::do_put_xxx updates a volatile field, it appends a series
3183   // of MemBarVolatile nodes, one for *each* volatile field alias category.
3184   // The first membar is on the same memory slice as the field store opcode.
3185   // This forces the membar to follow the store.  (Bug 6500685 broke this.)
3186   // All the other membars (for other volatile slices, including AliasIdxBot,
3187   // which stands for all unknown volatile slices) are control-dependent
3188   // on the first membar.  This prevents later volatile loads or stores
3189   // from sliding up past the just-emitted store.
3190 
3191   MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
3192   mb->set_req(TypeFunc::Control,control());
3193   if (alias_idx == Compile::AliasIdxBot) {
3194     mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
3195   } else {
3196     assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
3197     mb->set_req(TypeFunc::Memory, memory(alias_idx));
3198   }
3199   Node* membar = _gvn.transform(mb);
3200   set_control(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Control)));
3201   if (alias_idx == Compile::AliasIdxBot) {
3202     merged_memory()->set_base_memory(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Memory)));
3203   } else {
3204     set_memory(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Memory)),alias_idx);
3205   }
3206   return membar;
3207 }
3208 
3209 //------------------------------shared_lock------------------------------------
3210 // Emit locking code.
3211 FastLockNode* GraphKit::shared_lock(Node* obj) {
3212   // bci is either a monitorenter bc or InvocationEntryBci
3213   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3214   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3215 
3216   if( !GenerateSynchronizationCode )
3217     return NULL;                // Not locking things?
3218   if (stopped())                // Dead monitor?
3219     return NULL;
3220 
3221   assert(dead_locals_are_killed(), "should kill locals before sync. point");
3222 
3223   // Box the stack location
3224   Node* box = _gvn.transform(new (C) BoxLockNode(next_monitor()));
3225   Node* mem = reset_memory();
3226 
3227   FastLockNode * flock = _gvn.transform(new (C) FastLockNode(0, obj, box) )->as_FastLock();
3228   if (UseBiasedLocking && PrintPreciseBiasedLockingStatistics) {
3229     // Create the counters for this fast lock.
3230     flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3231   }
3232 
3233   // Create the rtm counters for this fast lock if needed.
3234   flock->create_rtm_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3235 
3236   // Add monitor to debug info for the slow path.  If we block inside the
3237   // slow path and de-opt, we need the monitor hanging around
3238   map()->push_monitor( flock );
3239 
3240   const TypeFunc *tf = LockNode::lock_type();
3241   LockNode *lock = new (C) LockNode(C, tf);
3242 
3243   lock->init_req( TypeFunc::Control, control() );
3244   lock->init_req( TypeFunc::Memory , mem );
3245   lock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3246   lock->init_req( TypeFunc::FramePtr, frameptr() );
3247   lock->init_req( TypeFunc::ReturnAdr, top() );
3248 
3249   lock->init_req(TypeFunc::Parms + 0, obj);
3250   lock->init_req(TypeFunc::Parms + 1, box);
3251   lock->init_req(TypeFunc::Parms + 2, flock);
3252   add_safepoint_edges(lock);
3253 
3254   lock = _gvn.transform( lock )->as_Lock();
3255 
3256   // lock has no side-effects, sets few values
3257   set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
3258 
3259   insert_mem_bar(Op_MemBarAcquireLock);
3260 
3261   // Add this to the worklist so that the lock can be eliminated
3262   record_for_igvn(lock);
3263 
3264 #ifndef PRODUCT
3265   if (PrintLockStatistics) {
3266     // Update the counter for this lock.  Don't bother using an atomic
3267     // operation since we don't require absolute accuracy.
3268     lock->create_lock_counter(map()->jvms());
3269     increment_counter(lock->counter()->addr());
3270   }
3271 #endif
3272 
3273   return flock;
3274 }
3275 
3276 
3277 //------------------------------shared_unlock----------------------------------
3278 // Emit unlocking code.
3279 void GraphKit::shared_unlock(Node* box, Node* obj) {
3280   // bci is either a monitorenter bc or InvocationEntryBci
3281   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3282   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3283 
3284   if( !GenerateSynchronizationCode )
3285     return;
3286   if (stopped()) {               // Dead monitor?
3287     map()->pop_monitor();        // Kill monitor from debug info
3288     return;
3289   }
3290 
3291   // Memory barrier to avoid floating things down past the locked region
3292   insert_mem_bar(Op_MemBarReleaseLock);
3293 
3294   const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
3295   UnlockNode *unlock = new (C) UnlockNode(C, tf);
3296   uint raw_idx = Compile::AliasIdxRaw;
3297   unlock->init_req( TypeFunc::Control, control() );
3298   unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
3299   unlock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3300   unlock->init_req( TypeFunc::FramePtr, frameptr() );
3301   unlock->init_req( TypeFunc::ReturnAdr, top() );
3302 
3303   unlock->init_req(TypeFunc::Parms + 0, obj);
3304   unlock->init_req(TypeFunc::Parms + 1, box);
3305   unlock = _gvn.transform(unlock)->as_Unlock();
3306 
3307   Node* mem = reset_memory();
3308 
3309   // unlock has no side-effects, sets few values
3310   set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
3311 
3312   // Kill monitor from debug info
3313   map()->pop_monitor( );
3314 }
3315 
3316 //-------------------------------get_layout_helper-----------------------------
3317 // If the given klass is a constant or known to be an array,
3318 // fetch the constant layout helper value into constant_value
3319 // and return (Node*)NULL.  Otherwise, load the non-constant
3320 // layout helper value, and return the node which represents it.
3321 // This two-faced routine is useful because allocation sites
3322 // almost always feature constant types.
3323 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
3324   const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr();
3325   if (!StressReflectiveCode && inst_klass != NULL) {
3326     ciKlass* klass = inst_klass->klass();
3327     bool    xklass = inst_klass->klass_is_exact();
3328     if (xklass || klass->is_array_klass()) {
3329       jint lhelper = klass->layout_helper();
3330       if (lhelper != Klass::_lh_neutral_value) {
3331         constant_value = lhelper;
3332         return (Node*) NULL;
3333       }
3334     }
3335   }
3336   constant_value = Klass::_lh_neutral_value;  // put in a known value
3337   Node* lhp = basic_plus_adr(klass_node, klass_node, in_bytes(Klass::layout_helper_offset()));
3338   return make_load(NULL, lhp, TypeInt::INT, T_INT, MemNode::unordered);
3339 }
3340 
3341 // We just put in an allocate/initialize with a big raw-memory effect.
3342 // Hook selected additional alias categories on the initialization.
3343 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
3344                                 MergeMemNode* init_in_merge,
3345                                 Node* init_out_raw) {
3346   DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
3347   assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
3348 
3349   Node* prevmem = kit.memory(alias_idx);
3350   init_in_merge->set_memory_at(alias_idx, prevmem);
3351   kit.set_memory(init_out_raw, alias_idx);
3352 }
3353 
3354 //---------------------------set_output_for_allocation-------------------------
3355 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
3356                                           const TypeOopPtr* oop_type) {
3357   int rawidx = Compile::AliasIdxRaw;
3358   alloc->set_req( TypeFunc::FramePtr, frameptr() );
3359   add_safepoint_edges(alloc);
3360   Node* allocx = _gvn.transform(alloc);
3361   set_control( _gvn.transform(new (C) ProjNode(allocx, TypeFunc::Control) ) );
3362   // create memory projection for i_o
3363   set_memory ( _gvn.transform( new (C) ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
3364   make_slow_call_ex(allocx, env()->Throwable_klass(), true);
3365 
3366   // create a memory projection as for the normal control path
3367   Node* malloc = _gvn.transform(new (C) ProjNode(allocx, TypeFunc::Memory));
3368   set_memory(malloc, rawidx);
3369 
3370   // a normal slow-call doesn't change i_o, but an allocation does
3371   // we create a separate i_o projection for the normal control path
3372   set_i_o(_gvn.transform( new (C) ProjNode(allocx, TypeFunc::I_O, false) ) );
3373   Node* rawoop = _gvn.transform( new (C) ProjNode(allocx, TypeFunc::Parms) );
3374 
3375   // put in an initialization barrier
3376   InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
3377                                                  rawoop)->as_Initialize();
3378   assert(alloc->initialization() == init,  "2-way macro link must work");
3379   assert(init ->allocation()     == alloc, "2-way macro link must work");
3380   {
3381     // Extract memory strands which may participate in the new object's
3382     // initialization, and source them from the new InitializeNode.
3383     // This will allow us to observe initializations when they occur,
3384     // and link them properly (as a group) to the InitializeNode.
3385     assert(init->in(InitializeNode::Memory) == malloc, "");
3386     MergeMemNode* minit_in = MergeMemNode::make(C, malloc);
3387     init->set_req(InitializeNode::Memory, minit_in);
3388     record_for_igvn(minit_in); // fold it up later, if possible
3389     Node* minit_out = memory(rawidx);
3390     assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
3391     if (oop_type->isa_aryptr()) {
3392       const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
3393       int            elemidx  = C->get_alias_index(telemref);
3394       hook_memory_on_init(*this, elemidx, minit_in, minit_out);
3395     } else if (oop_type->isa_instptr()) {
3396       ciInstanceKlass* ik = oop_type->klass()->as_instance_klass();
3397       for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
3398         ciField* field = ik->nonstatic_field_at(i);
3399         if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
3400           continue;  // do not bother to track really large numbers of fields
3401         // Find (or create) the alias category for this field:
3402         int fieldidx = C->alias_type(field)->index();
3403         hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
3404       }
3405     }
3406   }
3407 
3408   // Cast raw oop to the real thing...
3409   Node* javaoop = new (C) CheckCastPPNode(control(), rawoop, oop_type);
3410   javaoop = _gvn.transform(javaoop);
3411   C->set_recent_alloc(control(), javaoop);
3412   assert(just_allocated_object(control()) == javaoop, "just allocated");
3413 
3414 #ifdef ASSERT
3415   { // Verify that the AllocateNode::Ideal_allocation recognizers work:
3416     assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc,
3417            "Ideal_allocation works");
3418     assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc,
3419            "Ideal_allocation works");
3420     if (alloc->is_AllocateArray()) {
3421       assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(),
3422              "Ideal_allocation works");
3423       assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(),
3424              "Ideal_allocation works");
3425     } else {
3426       assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
3427     }
3428   }
3429 #endif //ASSERT
3430 
3431   return javaoop;
3432 }
3433 
3434 //---------------------------new_instance--------------------------------------
3435 // This routine takes a klass_node which may be constant (for a static type)
3436 // or may be non-constant (for reflective code).  It will work equally well
3437 // for either, and the graph will fold nicely if the optimizer later reduces
3438 // the type to a constant.
3439 // The optional arguments are for specialized use by intrinsics:
3440 //  - If 'extra_slow_test' if not null is an extra condition for the slow-path.
3441 //  - If 'return_size_val', report the the total object size to the caller.
3442 Node* GraphKit::new_instance(Node* klass_node,
3443                              Node* extra_slow_test,
3444                              Node* *return_size_val) {
3445   // Compute size in doublewords
3446   // The size is always an integral number of doublewords, represented
3447   // as a positive bytewise size stored in the klass's layout_helper.
3448   // The layout_helper also encodes (in a low bit) the need for a slow path.
3449   jint  layout_con = Klass::_lh_neutral_value;
3450   Node* layout_val = get_layout_helper(klass_node, layout_con);
3451   int   layout_is_con = (layout_val == NULL);
3452 
3453   if (extra_slow_test == NULL)  extra_slow_test = intcon(0);
3454   // Generate the initial go-slow test.  It's either ALWAYS (return a
3455   // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective
3456   // case) a computed value derived from the layout_helper.
3457   Node* initial_slow_test = NULL;
3458   if (layout_is_con) {
3459     assert(!StressReflectiveCode, "stress mode does not use these paths");
3460     bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
3461     initial_slow_test = must_go_slow? intcon(1): extra_slow_test;
3462 
3463   } else {   // reflective case
3464     // This reflective path is used by Unsafe.allocateInstance.
3465     // (It may be stress-tested by specifying StressReflectiveCode.)
3466     // Basically, we want to get into the VM is there's an illegal argument.
3467     Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
3468     initial_slow_test = _gvn.transform( new (C) AndINode(layout_val, bit) );
3469     if (extra_slow_test != intcon(0)) {
3470       initial_slow_test = _gvn.transform( new (C) OrINode(initial_slow_test, extra_slow_test) );
3471     }
3472     // (Macro-expander will further convert this to a Bool, if necessary.)
3473   }
3474 
3475   // Find the size in bytes.  This is easy; it's the layout_helper.
3476   // The size value must be valid even if the slow path is taken.
3477   Node* size = NULL;
3478   if (layout_is_con) {
3479     size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
3480   } else {   // reflective case
3481     // This reflective path is used by clone and Unsafe.allocateInstance.
3482     size = ConvI2X(layout_val);
3483 
3484     // Clear the low bits to extract layout_helper_size_in_bytes:
3485     assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
3486     Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
3487     size = _gvn.transform( new (C) AndXNode(size, mask) );
3488   }
3489   if (return_size_val != NULL) {
3490     (*return_size_val) = size;
3491   }
3492 
3493   // This is a precise notnull oop of the klass.
3494   // (Actually, it need not be precise if this is a reflective allocation.)
3495   // It's what we cast the result to.
3496   const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3497   if (!tklass)  tklass = TypeKlassPtr::OBJECT;
3498   const TypeOopPtr* oop_type = tklass->as_instance_type();
3499 
3500   // Now generate allocation code
3501 
3502   // The entire memory state is needed for slow path of the allocation
3503   // since GC and deoptimization can happened.
3504   Node *mem = reset_memory();
3505   set_all_memory(mem); // Create new memory state
3506 
3507   AllocateNode* alloc
3508     = new (C) AllocateNode(C, AllocateNode::alloc_type(Type::TOP),
3509                            control(), mem, i_o(),
3510                            size, klass_node,
3511                            initial_slow_test);
3512 
3513   return set_output_for_allocation(alloc, oop_type);
3514 }
3515 
3516 //-------------------------------new_array-------------------------------------
3517 // helper for both newarray and anewarray
3518 // The 'length' parameter is (obviously) the length of the array.
3519 // See comments on new_instance for the meaning of the other arguments.
3520 Node* GraphKit::new_array(Node* klass_node,     // array klass (maybe variable)
3521                           Node* length,         // number of array elements
3522                           int   nargs,          // number of arguments to push back for uncommon trap
3523                           Node* *return_size_val) {
3524   jint  layout_con = Klass::_lh_neutral_value;
3525   Node* layout_val = get_layout_helper(klass_node, layout_con);
3526   int   layout_is_con = (layout_val == NULL);
3527 
3528   if (!layout_is_con && !StressReflectiveCode &&
3529       !too_many_traps(Deoptimization::Reason_class_check)) {
3530     // This is a reflective array creation site.
3531     // Optimistically assume that it is a subtype of Object[],
3532     // so that we can fold up all the address arithmetic.
3533     layout_con = Klass::array_layout_helper(T_OBJECT);
3534     Node* cmp_lh = _gvn.transform( new(C) CmpINode(layout_val, intcon(layout_con)) );
3535     Node* bol_lh = _gvn.transform( new(C) BoolNode(cmp_lh, BoolTest::eq) );
3536     { BuildCutout unless(this, bol_lh, PROB_MAX);
3537       inc_sp(nargs);
3538       uncommon_trap(Deoptimization::Reason_class_check,
3539                     Deoptimization::Action_maybe_recompile);
3540     }
3541     layout_val = NULL;
3542     layout_is_con = true;
3543   }
3544 
3545   // Generate the initial go-slow test.  Make sure we do not overflow
3546   // if length is huge (near 2Gig) or negative!  We do not need
3547   // exact double-words here, just a close approximation of needed
3548   // double-words.  We can't add any offset or rounding bits, lest we
3549   // take a size -1 of bytes and make it positive.  Use an unsigned
3550   // compare, so negative sizes look hugely positive.
3551   int fast_size_limit = FastAllocateSizeLimit;
3552   if (layout_is_con) {
3553     assert(!StressReflectiveCode, "stress mode does not use these paths");
3554     // Increase the size limit if we have exact knowledge of array type.
3555     int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3556     fast_size_limit <<= (LogBytesPerLong - log2_esize);
3557   }
3558 
3559   Node* initial_slow_cmp  = _gvn.transform( new (C) CmpUNode( length, intcon( fast_size_limit ) ) );
3560   Node* initial_slow_test = _gvn.transform( new (C) BoolNode( initial_slow_cmp, BoolTest::gt ) );
3561   if (initial_slow_test->is_Bool()) {
3562     // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
3563     initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
3564   }
3565 
3566   // --- Size Computation ---
3567   // array_size = round_to_heap(array_header + (length << elem_shift));
3568   // where round_to_heap(x) == round_to(x, MinObjAlignmentInBytes)
3569   // and round_to(x, y) == ((x + y-1) & ~(y-1))
3570   // The rounding mask is strength-reduced, if possible.
3571   int round_mask = MinObjAlignmentInBytes - 1;
3572   Node* header_size = NULL;
3573   int   header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3574   // (T_BYTE has the weakest alignment and size restrictions...)
3575   if (layout_is_con) {
3576     int       hsize  = Klass::layout_helper_header_size(layout_con);
3577     int       eshift = Klass::layout_helper_log2_element_size(layout_con);
3578     BasicType etype  = Klass::layout_helper_element_type(layout_con);
3579     if ((round_mask & ~right_n_bits(eshift)) == 0)
3580       round_mask = 0;  // strength-reduce it if it goes away completely
3581     assert((hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3582     assert(header_size_min <= hsize, "generic minimum is smallest");
3583     header_size_min = hsize;
3584     header_size = intcon(hsize + round_mask);
3585   } else {
3586     Node* hss   = intcon(Klass::_lh_header_size_shift);
3587     Node* hsm   = intcon(Klass::_lh_header_size_mask);
3588     Node* hsize = _gvn.transform( new(C) URShiftINode(layout_val, hss) );
3589     hsize       = _gvn.transform( new(C) AndINode(hsize, hsm) );
3590     Node* mask  = intcon(round_mask);
3591     header_size = _gvn.transform( new(C) AddINode(hsize, mask) );
3592   }
3593 
3594   Node* elem_shift = NULL;
3595   if (layout_is_con) {
3596     int eshift = Klass::layout_helper_log2_element_size(layout_con);
3597     if (eshift != 0)
3598       elem_shift = intcon(eshift);
3599   } else {
3600     // There is no need to mask or shift this value.
3601     // The semantics of LShiftINode include an implicit mask to 0x1F.
3602     assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3603     elem_shift = layout_val;
3604   }
3605 
3606   // Transition to native address size for all offset calculations:
3607   Node* lengthx = ConvI2X(length);
3608   Node* headerx = ConvI2X(header_size);
3609 #ifdef _LP64
3610   { const TypeLong* tllen = _gvn.find_long_type(lengthx);
3611     if (tllen != NULL && tllen->_lo < 0) {
3612       // Add a manual constraint to a positive range.  Cf. array_element_address.
3613       jlong size_max = arrayOopDesc::max_array_length(T_BYTE);
3614       if (size_max > tllen->_hi)  size_max = tllen->_hi;
3615       const TypeLong* tlcon = TypeLong::make(CONST64(0), size_max, Type::WidenMin);
3616       lengthx = _gvn.transform( new (C) ConvI2LNode(length, tlcon));
3617     }
3618   }
3619 #endif
3620 
3621   // Combine header size (plus rounding) and body size.  Then round down.
3622   // This computation cannot overflow, because it is used only in two
3623   // places, one where the length is sharply limited, and the other
3624   // after a successful allocation.
3625   Node* abody = lengthx;
3626   if (elem_shift != NULL)
3627     abody     = _gvn.transform( new(C) LShiftXNode(lengthx, elem_shift) );
3628   Node* size  = _gvn.transform( new(C) AddXNode(headerx, abody) );
3629   if (round_mask != 0) {
3630     Node* mask = MakeConX(~round_mask);
3631     size       = _gvn.transform( new(C) AndXNode(size, mask) );
3632   }
3633   // else if round_mask == 0, the size computation is self-rounding
3634 
3635   if (return_size_val != NULL) {
3636     // This is the size
3637     (*return_size_val) = size;
3638   }
3639 
3640   // Now generate allocation code
3641 
3642   // The entire memory state is needed for slow path of the allocation
3643   // since GC and deoptimization can happened.
3644   Node *mem = reset_memory();
3645   set_all_memory(mem); // Create new memory state
3646 
3647   // Create the AllocateArrayNode and its result projections
3648   AllocateArrayNode* alloc
3649     = new (C) AllocateArrayNode(C, AllocateArrayNode::alloc_type(TypeInt::INT),
3650                                 control(), mem, i_o(),
3651                                 size, klass_node,
3652                                 initial_slow_test,
3653                                 length);
3654 
3655   // Cast to correct type.  Note that the klass_node may be constant or not,
3656   // and in the latter case the actual array type will be inexact also.
3657   // (This happens via a non-constant argument to inline_native_newArray.)
3658   // In any case, the value of klass_node provides the desired array type.
3659   const TypeInt* length_type = _gvn.find_int_type(length);
3660   const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
3661   if (ary_type->isa_aryptr() && length_type != NULL) {
3662     // Try to get a better type than POS for the size
3663     ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
3664   }
3665 
3666   Node* javaoop = set_output_for_allocation(alloc, ary_type);
3667 
3668   // Cast length on remaining path to be as narrow as possible
3669   if (map()->find_edge(length) >= 0) {
3670     Node* ccast = alloc->make_ideal_length(ary_type, &_gvn);
3671     if (ccast != length) {
3672       _gvn.set_type_bottom(ccast);
3673       record_for_igvn(ccast);
3674       replace_in_map(length, ccast);
3675     }
3676   }
3677 
3678   return javaoop;
3679 }
3680 
3681 // The following "Ideal_foo" functions are placed here because they recognize
3682 // the graph shapes created by the functions immediately above.
3683 
3684 //---------------------------Ideal_allocation----------------------------------
3685 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
3686 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) {
3687   if (ptr == NULL) {     // reduce dumb test in callers
3688     return NULL;
3689   }
3690   if (ptr->is_CheckCastPP()) { // strip only one raw-to-oop cast
3691     ptr = ptr->in(1);
3692     if (ptr == NULL) return NULL;
3693   }
3694   // Return NULL for allocations with several casts:
3695   //   j.l.reflect.Array.newInstance(jobject, jint)
3696   //   Object.clone()
3697   // to keep more precise type from last cast.
3698   if (ptr->is_Proj()) {
3699     Node* allo = ptr->in(0);
3700     if (allo != NULL && allo->is_Allocate()) {
3701       return allo->as_Allocate();
3702     }
3703   }
3704   // Report failure to match.
3705   return NULL;
3706 }
3707 
3708 // Fancy version which also strips off an offset (and reports it to caller).
3709 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase,
3710                                              intptr_t& offset) {
3711   Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
3712   if (base == NULL)  return NULL;
3713   return Ideal_allocation(base, phase);
3714 }
3715 
3716 // Trace Initialize <- Proj[Parm] <- Allocate
3717 AllocateNode* InitializeNode::allocation() {
3718   Node* rawoop = in(InitializeNode::RawAddress);
3719   if (rawoop->is_Proj()) {
3720     Node* alloc = rawoop->in(0);
3721     if (alloc->is_Allocate()) {
3722       return alloc->as_Allocate();
3723     }
3724   }
3725   return NULL;
3726 }
3727 
3728 // Trace Allocate -> Proj[Parm] -> Initialize
3729 InitializeNode* AllocateNode::initialization() {
3730   ProjNode* rawoop = proj_out(AllocateNode::RawAddress);
3731   if (rawoop == NULL)  return NULL;
3732   for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
3733     Node* init = rawoop->fast_out(i);
3734     if (init->is_Initialize()) {
3735       assert(init->as_Initialize()->allocation() == this, "2-way link");
3736       return init->as_Initialize();
3737     }
3738   }
3739   return NULL;
3740 }
3741 
3742 //----------------------------- loop predicates ---------------------------
3743 
3744 //------------------------------add_predicate_impl----------------------------
3745 void GraphKit::add_predicate_impl(Deoptimization::DeoptReason reason, int nargs) {
3746   // Too many traps seen?
3747   if (too_many_traps(reason)) {
3748 #ifdef ASSERT
3749     if (TraceLoopPredicate) {
3750       int tc = C->trap_count(reason);
3751       tty->print("too many traps=%s tcount=%d in ",
3752                     Deoptimization::trap_reason_name(reason), tc);
3753       method()->print(); // which method has too many predicate traps
3754       tty->cr();
3755     }
3756 #endif
3757     // We cannot afford to take more traps here,
3758     // do not generate predicate.
3759     return;
3760   }
3761 
3762   Node *cont    = _gvn.intcon(1);
3763   Node* opq     = _gvn.transform(new (C) Opaque1Node(C, cont));
3764   Node *bol     = _gvn.transform(new (C) Conv2BNode(opq));
3765   IfNode* iff   = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
3766   Node* iffalse = _gvn.transform(new (C) IfFalseNode(iff));
3767   C->add_predicate_opaq(opq);
3768   {
3769     PreserveJVMState pjvms(this);
3770     set_control(iffalse);
3771     inc_sp(nargs);
3772     uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
3773   }
3774   Node* iftrue = _gvn.transform(new (C) IfTrueNode(iff));
3775   set_control(iftrue);
3776 }
3777 
3778 //------------------------------add_predicate---------------------------------
3779 void GraphKit::add_predicate(int nargs) {
3780   if (UseLoopPredicate) {
3781     add_predicate_impl(Deoptimization::Reason_predicate, nargs);
3782   }
3783   // loop's limit check predicate should be near the loop.
3784   if (LoopLimitCheck) {
3785     add_predicate_impl(Deoptimization::Reason_loop_limit_check, nargs);
3786   }
3787 }
3788 
3789 //----------------------------- store barriers ----------------------------
3790 #define __ ideal.
3791 
3792 void GraphKit::sync_kit(IdealKit& ideal) {
3793   set_all_memory(__ merged_memory());
3794   set_i_o(__ i_o());
3795   set_control(__ ctrl());
3796 }
3797 
3798 void GraphKit::final_sync(IdealKit& ideal) {
3799   // Final sync IdealKit and graphKit.
3800   sync_kit(ideal);
3801 }
3802 
3803 // vanilla/CMS post barrier
3804 // Insert a write-barrier store.  This is to let generational GC work; we have
3805 // to flag all oop-stores before the next GC point.
3806 void GraphKit::write_barrier_post(Node* oop_store,
3807                                   Node* obj,
3808                                   Node* adr,
3809                                   uint  adr_idx,
3810                                   Node* val,
3811                                   bool use_precise) {
3812   // No store check needed if we're storing a NULL or an old object
3813   // (latter case is probably a string constant). The concurrent
3814   // mark sweep garbage collector, however, needs to have all nonNull
3815   // oop updates flagged via card-marks.
3816   if (val != NULL && val->is_Con()) {
3817     // must be either an oop or NULL
3818     const Type* t = val->bottom_type();
3819     if (t == TypePtr::NULL_PTR || t == Type::TOP)
3820       // stores of null never (?) need barriers
3821       return;
3822   }
3823 
3824   if (use_ReduceInitialCardMarks()
3825       && obj == just_allocated_object(control())) {
3826     // We can skip marks on a freshly-allocated object in Eden.
3827     // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
3828     // That routine informs GC to take appropriate compensating steps,
3829     // upon a slow-path allocation, so as to make this card-mark
3830     // elision safe.
3831     return;
3832   }
3833 
3834   if (!use_precise) {
3835     // All card marks for a (non-array) instance are in one place:
3836     adr = obj;
3837   }
3838   // (Else it's an array (or unknown), and we want more precise card marks.)
3839   assert(adr != NULL, "");
3840 
3841   IdealKit ideal(this, true);
3842 
3843   // Convert the pointer to an int prior to doing math on it
3844   Node* cast = __ CastPX(__ ctrl(), adr);
3845 
3846   // Divide by card size
3847   assert(Universe::heap()->barrier_set()->kind() == BarrierSet::CardTableModRef,
3848          "Only one we handle so far.");
3849   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
3850 
3851   // Combine card table base and card offset
3852   Node* card_adr = __ AddP(__ top(), byte_map_base_node(), card_offset );
3853 
3854   // Get the alias_index for raw card-mark memory
3855   int adr_type = Compile::AliasIdxRaw;
3856   Node*   zero = __ ConI(0); // Dirty card value
3857   BasicType bt = T_BYTE;
3858 
3859   if (UseCondCardMark) {
3860     // The classic GC reference write barrier is typically implemented
3861     // as a store into the global card mark table.  Unfortunately
3862     // unconditional stores can result in false sharing and excessive
3863     // coherence traffic as well as false transactional aborts.
3864     // UseCondCardMark enables MP "polite" conditional card mark
3865     // stores.  In theory we could relax the load from ctrl() to
3866     // no_ctrl, but that doesn't buy much latitude.
3867     Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, bt, adr_type);
3868     __ if_then(card_val, BoolTest::ne, zero);
3869   }
3870 
3871   // Smash zero into card
3872   if( !UseConcMarkSweepGC ) {
3873     __ store(__ ctrl(), card_adr, zero, bt, adr_type, MemNode::release);
3874   } else {
3875     // Specialized path for CM store barrier
3876     __ storeCM(__ ctrl(), card_adr, zero, oop_store, adr_idx, bt, adr_type);
3877   }
3878 
3879   if (UseCondCardMark) {
3880     __ end_if();
3881   }
3882 
3883   // Final sync IdealKit and GraphKit.
3884   final_sync(ideal);
3885 }
3886 
3887 // G1 pre/post barriers
3888 void GraphKit::g1_write_barrier_pre(bool do_load,
3889                                     Node* obj,
3890                                     Node* adr,
3891                                     uint alias_idx,
3892                                     Node* val,
3893                                     const TypeOopPtr* val_type,
3894                                     Node* pre_val,
3895                                     BasicType bt) {
3896 
3897   // Some sanity checks
3898   // Note: val is unused in this routine.
3899 
3900   if (do_load) {
3901     // We need to generate the load of the previous value
3902     assert(obj != NULL, "must have a base");
3903     assert(adr != NULL, "where are loading from?");
3904     assert(pre_val == NULL, "loaded already?");
3905     assert(val_type != NULL, "need a type");
3906   } else {
3907     // In this case both val_type and alias_idx are unused.
3908     assert(pre_val != NULL, "must be loaded already");
3909     // Nothing to be done if pre_val is null.
3910     if (pre_val->bottom_type() == TypePtr::NULL_PTR) return;
3911     assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here");
3912   }
3913   assert(bt == T_OBJECT, "or we shouldn't be here");
3914 
3915   IdealKit ideal(this, true);
3916 
3917   Node* tls = __ thread(); // ThreadLocalStorage
3918 
3919   Node* no_ctrl = NULL;
3920   Node* no_base = __ top();
3921   Node* zero  = __ ConI(0);
3922   Node* zeroX = __ ConX(0);
3923 
3924   float likely  = PROB_LIKELY(0.999);
3925   float unlikely  = PROB_UNLIKELY(0.999);
3926 
3927   BasicType active_type = in_bytes(PtrQueue::byte_width_of_active()) == 4 ? T_INT : T_BYTE;
3928   assert(in_bytes(PtrQueue::byte_width_of_active()) == 4 || in_bytes(PtrQueue::byte_width_of_active()) == 1, "flag width");
3929 
3930   // Offsets into the thread
3931   const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +  // 648
3932                                           PtrQueue::byte_offset_of_active());
3933   const int index_offset   = in_bytes(JavaThread::satb_mark_queue_offset() +  // 656
3934                                           PtrQueue::byte_offset_of_index());
3935   const int buffer_offset  = in_bytes(JavaThread::satb_mark_queue_offset() +  // 652
3936                                           PtrQueue::byte_offset_of_buf());
3937 
3938   // Now the actual pointers into the thread
3939   Node* marking_adr = __ AddP(no_base, tls, __ ConX(marking_offset));
3940   Node* buffer_adr  = __ AddP(no_base, tls, __ ConX(buffer_offset));
3941   Node* index_adr   = __ AddP(no_base, tls, __ ConX(index_offset));
3942 
3943   // Now some of the values
3944   Node* marking = __ load(__ ctrl(), marking_adr, TypeInt::INT, active_type, Compile::AliasIdxRaw);
3945 
3946   // if (!marking)
3947   __ if_then(marking, BoolTest::ne, zero, unlikely); {
3948     BasicType index_bt = TypeX_X->basic_type();
3949     assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 PtrQueue::_index with wrong size.");
3950     Node* index   = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
3951 
3952     if (do_load) {
3953       // load original value
3954       // alias_idx correct??
3955       pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx);
3956     }
3957 
3958     // if (pre_val != NULL)
3959     __ if_then(pre_val, BoolTest::ne, null()); {
3960       Node* buffer  = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
3961 
3962       // is the queue for this thread full?
3963       __ if_then(index, BoolTest::ne, zeroX, likely); {
3964 
3965         // decrement the index
3966         Node* next_index = _gvn.transform(new (C) SubXNode(index, __ ConX(sizeof(intptr_t))));
3967 
3968         // Now get the buffer location we will log the previous value into and store it
3969         Node *log_addr = __ AddP(no_base, buffer, next_index);
3970         __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered);
3971         // update the index
3972         __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered);
3973 
3974       } __ else_(); {
3975 
3976         // logging buffer is full, call the runtime
3977         const TypeFunc *tf = OptoRuntime::g1_wb_pre_Type();
3978         __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), "g1_wb_pre", pre_val, tls);
3979       } __ end_if();  // (!index)
3980     } __ end_if();  // (pre_val != NULL)
3981   } __ end_if();  // (!marking)
3982 
3983   // Final sync IdealKit and GraphKit.
3984   final_sync(ideal);
3985 }
3986 
3987 //
3988 // Update the card table and add card address to the queue
3989 //
3990 void GraphKit::g1_mark_card(IdealKit& ideal,
3991                             Node* card_adr,
3992                             Node* oop_store,
3993                             uint oop_alias_idx,
3994                             Node* index,
3995                             Node* index_adr,
3996                             Node* buffer,
3997                             const TypeFunc* tf) {
3998 
3999   Node* zero  = __ ConI(0);
4000   Node* zeroX = __ ConX(0);
4001   Node* no_base = __ top();
4002   BasicType card_bt = T_BYTE;
4003   // Smash zero into card. MUST BE ORDERED WRT TO STORE
4004   __ storeCM(__ ctrl(), card_adr, zero, oop_store, oop_alias_idx, card_bt, Compile::AliasIdxRaw);
4005 
4006   //  Now do the queue work
4007   __ if_then(index, BoolTest::ne, zeroX); {
4008 
4009     Node* next_index = _gvn.transform(new (C) SubXNode(index, __ ConX(sizeof(intptr_t))));
4010     Node* log_addr = __ AddP(no_base, buffer, next_index);
4011 
4012     // Order, see storeCM.
4013     __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw, MemNode::unordered);
4014     __ store(__ ctrl(), index_adr, next_index, TypeX_X->basic_type(), Compile::AliasIdxRaw, MemNode::unordered);
4015 
4016   } __ else_(); {
4017     __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), "g1_wb_post", card_adr, __ thread());
4018   } __ end_if();
4019 
4020 }
4021 
4022 void GraphKit::g1_write_barrier_post(Node* oop_store,
4023                                      Node* obj,
4024                                      Node* adr,
4025                                      uint alias_idx,
4026                                      Node* val,
4027                                      BasicType bt,
4028                                      bool use_precise) {
4029   // If we are writing a NULL then we need no post barrier
4030 
4031   if (val != NULL && val->is_Con() && val->bottom_type() == TypePtr::NULL_PTR) {
4032     // Must be NULL
4033     const Type* t = val->bottom_type();
4034     assert(t == Type::TOP || t == TypePtr::NULL_PTR, "must be NULL");
4035     // No post barrier if writing NULLx
4036     return;
4037   }
4038 
4039   if (!use_precise) {
4040     // All card marks for a (non-array) instance are in one place:
4041     adr = obj;
4042   }
4043   // (Else it's an array (or unknown), and we want more precise card marks.)
4044   assert(adr != NULL, "");
4045 
4046   IdealKit ideal(this, true);
4047 
4048   Node* tls = __ thread(); // ThreadLocalStorage
4049 
4050   Node* no_base = __ top();
4051   float likely  = PROB_LIKELY(0.999);
4052   float unlikely  = PROB_UNLIKELY(0.999);
4053   Node* young_card = __ ConI((jint)G1SATBCardTableModRefBS::g1_young_card_val());
4054   Node* dirty_card = __ ConI((jint)CardTableModRefBS::dirty_card_val());
4055   Node* zeroX = __ ConX(0);
4056 
4057   // Get the alias_index for raw card-mark memory
4058   const TypePtr* card_type = TypeRawPtr::BOTTOM;
4059 
4060   const TypeFunc *tf = OptoRuntime::g1_wb_post_Type();
4061 
4062   // Offsets into the thread
4063   const int index_offset  = in_bytes(JavaThread::dirty_card_queue_offset() +
4064                                      PtrQueue::byte_offset_of_index());
4065   const int buffer_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
4066                                      PtrQueue::byte_offset_of_buf());
4067 
4068   // Pointers into the thread
4069 
4070   Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
4071   Node* index_adr =  __ AddP(no_base, tls, __ ConX(index_offset));
4072 
4073   // Now some values
4074   // Use ctrl to avoid hoisting these values past a safepoint, which could
4075   // potentially reset these fields in the JavaThread.
4076   Node* index  = __ load(__ ctrl(), index_adr, TypeX_X, TypeX_X->basic_type(), Compile::AliasIdxRaw);
4077   Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4078 
4079   // Convert the store obj pointer to an int prior to doing math on it
4080   // Must use ctrl to prevent "integerized oop" existing across safepoint
4081   Node* cast =  __ CastPX(__ ctrl(), adr);
4082 
4083   // Divide pointer by card size
4084   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
4085 
4086   // Combine card table base and card offset
4087   Node* card_adr = __ AddP(no_base, byte_map_base_node(), card_offset );
4088 
4089   // If we know the value being stored does it cross regions?
4090 
4091   if (val != NULL) {
4092     // Does the store cause us to cross regions?
4093 
4094     // Should be able to do an unsigned compare of region_size instead of
4095     // and extra shift. Do we have an unsigned compare??
4096     // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes);
4097     Node* xor_res =  __ URShiftX ( __ XorX( cast,  __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes));
4098 
4099     // if (xor_res == 0) same region so skip
4100     __ if_then(xor_res, BoolTest::ne, zeroX); {
4101 
4102       // No barrier if we are storing a NULL
4103       __ if_then(val, BoolTest::ne, null(), unlikely); {
4104 
4105         // Ok must mark the card if not already dirty
4106 
4107         // load the original value of the card
4108         Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4109 
4110         __ if_then(card_val, BoolTest::ne, young_card); {
4111           sync_kit(ideal);
4112           // Use Op_MemBarVolatile to achieve the effect of a StoreLoad barrier.
4113           insert_mem_bar(Op_MemBarVolatile, oop_store);
4114           __ sync_kit(this);
4115 
4116           Node* card_val_reload = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4117           __ if_then(card_val_reload, BoolTest::ne, dirty_card); {
4118             g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4119           } __ end_if();
4120         } __ end_if();
4121       } __ end_if();
4122     } __ end_if();
4123   } else {
4124     // Object.clone() instrinsic uses this path.
4125     g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4126   }
4127 
4128   // Final sync IdealKit and GraphKit.
4129   final_sync(ideal);
4130 }
4131 #undef __
4132 
4133 
4134 
4135 Node* GraphKit::load_String_offset(Node* ctrl, Node* str) {
4136   if (java_lang_String::has_offset_field()) {
4137     int offset_offset = java_lang_String::offset_offset_in_bytes();
4138     const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4139                                                        false, NULL, 0);
4140     const TypePtr* offset_field_type = string_type->add_offset(offset_offset);
4141     int offset_field_idx = C->get_alias_index(offset_field_type);
4142     return make_load(ctrl,
4143                      basic_plus_adr(str, str, offset_offset),
4144                      TypeInt::INT, T_INT, offset_field_idx, MemNode::unordered);
4145   } else {
4146     return intcon(0);
4147   }
4148 }
4149 
4150 Node* GraphKit::load_String_length(Node* ctrl, Node* str) {
4151   if (java_lang_String::has_count_field()) {
4152     int count_offset = java_lang_String::count_offset_in_bytes();
4153     const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4154                                                        false, NULL, 0);
4155     const TypePtr* count_field_type = string_type->add_offset(count_offset);
4156     int count_field_idx = C->get_alias_index(count_field_type);
4157     return make_load(ctrl,
4158                      basic_plus_adr(str, str, count_offset),
4159                      TypeInt::INT, T_INT, count_field_idx, MemNode::unordered);
4160   } else {
4161     return load_array_length(load_String_value(ctrl, str));
4162   }
4163 }
4164 
4165 Node* GraphKit::load_String_value(Node* ctrl, Node* str) {
4166   int value_offset = java_lang_String::value_offset_in_bytes();
4167   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4168                                                      false, NULL, 0);
4169   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4170   const TypeAryPtr*  value_type = TypeAryPtr::make(TypePtr::NotNull,
4171                                                    TypeAry::make(TypeInt::CHAR,TypeInt::POS),
4172                                                    ciTypeArrayKlass::make(T_CHAR), true, 0);
4173   int value_field_idx = C->get_alias_index(value_field_type);
4174   Node* load = make_load(ctrl, basic_plus_adr(str, str, value_offset),
4175                          value_type, T_OBJECT, value_field_idx, MemNode::unordered);
4176   // String.value field is known to be @Stable.
4177   if (UseImplicitStableValues) {
4178     load = cast_array_to_stable(load, value_type);
4179   }
4180   return load;
4181 }
4182 
4183 void GraphKit::store_String_offset(Node* ctrl, Node* str, Node* value) {
4184   int offset_offset = java_lang_String::offset_offset_in_bytes();
4185   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4186                                                      false, NULL, 0);
4187   const TypePtr* offset_field_type = string_type->add_offset(offset_offset);
4188   int offset_field_idx = C->get_alias_index(offset_field_type);
4189   store_to_memory(ctrl, basic_plus_adr(str, offset_offset),
4190                   value, T_INT, offset_field_idx, MemNode::unordered);
4191 }
4192 
4193 void GraphKit::store_String_value(Node* ctrl, Node* str, Node* value) {
4194   int value_offset = java_lang_String::value_offset_in_bytes();
4195   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4196                                                      false, NULL, 0);
4197   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4198 
4199   store_oop_to_object(ctrl, str,  basic_plus_adr(str, value_offset), value_field_type,
4200       value, TypeAryPtr::CHARS, T_OBJECT, MemNode::unordered);
4201 }
4202 
4203 void GraphKit::store_String_length(Node* ctrl, Node* str, Node* value) {
4204   int count_offset = java_lang_String::count_offset_in_bytes();
4205   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4206                                                      false, NULL, 0);
4207   const TypePtr* count_field_type = string_type->add_offset(count_offset);
4208   int count_field_idx = C->get_alias_index(count_field_type);
4209   store_to_memory(ctrl, basic_plus_adr(str, count_offset),
4210                   value, T_INT, count_field_idx, MemNode::unordered);
4211 }
4212 
4213 Node* GraphKit::cast_array_to_stable(Node* ary, const TypeAryPtr* ary_type) {
4214   // Reify the property as a CastPP node in Ideal graph to comply with monotonicity
4215   // assumption of CCP analysis.
4216   return _gvn.transform(new(C) CastPPNode(ary, ary_type->cast_to_stable(true)));
4217 }