1 /*
   2  * Copyright (c) 2001, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "ci/ciUtilities.hpp"
  27 #include "compiler/compileLog.hpp"
  28 #include "gc/g1/g1CardTable.hpp"
  29 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
  30 #include "gc/g1/heapRegion.hpp"
  31 #include "gc/shared/barrierSet.hpp"
  32 #include "gc/shared/cardTable.hpp"
  33 #include "gc/shared/cardTableModRefBS.hpp"
  34 #include "gc/shared/collectedHeap.hpp"
  35 #include "memory/resourceArea.hpp"
  36 #include "opto/addnode.hpp"
  37 #include "opto/castnode.hpp"
  38 #include "opto/convertnode.hpp"
  39 #include "opto/graphKit.hpp"
  40 #include "opto/idealKit.hpp"
  41 #include "opto/intrinsicnode.hpp"
  42 #include "opto/locknode.hpp"
  43 #include "opto/machnode.hpp"
  44 #include "opto/opaquenode.hpp"
  45 #include "opto/parse.hpp"
  46 #include "opto/rootnode.hpp"
  47 #include "opto/runtime.hpp"
  48 #include "runtime/deoptimization.hpp"
  49 #include "runtime/sharedRuntime.hpp"
  50 
  51 //----------------------------GraphKit-----------------------------------------
  52 // Main utility constructor.
  53 GraphKit::GraphKit(JVMState* jvms)
  54   : Phase(Phase::Parser),
  55     _env(C->env()),
  56     _gvn(*C->initial_gvn())
  57 {
  58   _exceptions = jvms->map()->next_exception();
  59   if (_exceptions != NULL)  jvms->map()->set_next_exception(NULL);
  60   set_jvms(jvms);
  61 }
  62 
  63 // Private constructor for parser.
  64 GraphKit::GraphKit()
  65   : Phase(Phase::Parser),
  66     _env(C->env()),
  67     _gvn(*C->initial_gvn())
  68 {
  69   _exceptions = NULL;
  70   set_map(NULL);
  71   debug_only(_sp = -99);
  72   debug_only(set_bci(-99));
  73 }
  74 
  75 
  76 
  77 //---------------------------clean_stack---------------------------------------
  78 // Clear away rubbish from the stack area of the JVM state.
  79 // This destroys any arguments that may be waiting on the stack.
  80 void GraphKit::clean_stack(int from_sp) {
  81   SafePointNode* map      = this->map();
  82   JVMState*      jvms     = this->jvms();
  83   int            stk_size = jvms->stk_size();
  84   int            stkoff   = jvms->stkoff();
  85   Node*          top      = this->top();
  86   for (int i = from_sp; i < stk_size; i++) {
  87     if (map->in(stkoff + i) != top) {
  88       map->set_req(stkoff + i, top);
  89     }
  90   }
  91 }
  92 
  93 
  94 //--------------------------------sync_jvms-----------------------------------
  95 // Make sure our current jvms agrees with our parse state.
  96 JVMState* GraphKit::sync_jvms() const {
  97   JVMState* jvms = this->jvms();
  98   jvms->set_bci(bci());       // Record the new bci in the JVMState
  99   jvms->set_sp(sp());         // Record the new sp in the JVMState
 100   assert(jvms_in_sync(), "jvms is now in sync");
 101   return jvms;
 102 }
 103 
 104 //--------------------------------sync_jvms_for_reexecute---------------------
 105 // Make sure our current jvms agrees with our parse state.  This version
 106 // uses the reexecute_sp for reexecuting bytecodes.
 107 JVMState* GraphKit::sync_jvms_for_reexecute() {
 108   JVMState* jvms = this->jvms();
 109   jvms->set_bci(bci());          // Record the new bci in the JVMState
 110   jvms->set_sp(reexecute_sp());  // Record the new sp in the JVMState
 111   return jvms;
 112 }
 113 
 114 #ifdef ASSERT
 115 bool GraphKit::jvms_in_sync() const {
 116   Parse* parse = is_Parse();
 117   if (parse == NULL) {
 118     if (bci() !=      jvms()->bci())          return false;
 119     if (sp()  != (int)jvms()->sp())           return false;
 120     return true;
 121   }
 122   if (jvms()->method() != parse->method())    return false;
 123   if (jvms()->bci()    != parse->bci())       return false;
 124   int jvms_sp = jvms()->sp();
 125   if (jvms_sp          != parse->sp())        return false;
 126   int jvms_depth = jvms()->depth();
 127   if (jvms_depth       != parse->depth())     return false;
 128   return true;
 129 }
 130 
 131 // Local helper checks for special internal merge points
 132 // used to accumulate and merge exception states.
 133 // They are marked by the region's in(0) edge being the map itself.
 134 // Such merge points must never "escape" into the parser at large,
 135 // until they have been handed to gvn.transform.
 136 static bool is_hidden_merge(Node* reg) {
 137   if (reg == NULL)  return false;
 138   if (reg->is_Phi()) {
 139     reg = reg->in(0);
 140     if (reg == NULL)  return false;
 141   }
 142   return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root();
 143 }
 144 
 145 void GraphKit::verify_map() const {
 146   if (map() == NULL)  return;  // null map is OK
 147   assert(map()->req() <= jvms()->endoff(), "no extra garbage on map");
 148   assert(!map()->has_exceptions(),    "call add_exception_states_from 1st");
 149   assert(!is_hidden_merge(control()), "call use_exception_state, not set_map");
 150 }
 151 
 152 void GraphKit::verify_exception_state(SafePointNode* ex_map) {
 153   assert(ex_map->next_exception() == NULL, "not already part of a chain");
 154   assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop");
 155 }
 156 #endif
 157 
 158 //---------------------------stop_and_kill_map---------------------------------
 159 // Set _map to NULL, signalling a stop to further bytecode execution.
 160 // First smash the current map's control to a constant, to mark it dead.
 161 void GraphKit::stop_and_kill_map() {
 162   SafePointNode* dead_map = stop();
 163   if (dead_map != NULL) {
 164     dead_map->disconnect_inputs(NULL, C); // Mark the map as killed.
 165     assert(dead_map->is_killed(), "must be so marked");
 166   }
 167 }
 168 
 169 
 170 //--------------------------------stopped--------------------------------------
 171 // Tell if _map is NULL, or control is top.
 172 bool GraphKit::stopped() {
 173   if (map() == NULL)           return true;
 174   else if (control() == top()) return true;
 175   else                         return false;
 176 }
 177 
 178 
 179 //-----------------------------has_ex_handler----------------------------------
 180 // Tell if this method or any caller method has exception handlers.
 181 bool GraphKit::has_ex_handler() {
 182   for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) {
 183     if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) {
 184       return true;
 185     }
 186   }
 187   return false;
 188 }
 189 
 190 //------------------------------save_ex_oop------------------------------------
 191 // Save an exception without blowing stack contents or other JVM state.
 192 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) {
 193   assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again");
 194   ex_map->add_req(ex_oop);
 195   debug_only(verify_exception_state(ex_map));
 196 }
 197 
 198 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) {
 199   assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there");
 200   Node* ex_oop = ex_map->in(ex_map->req()-1);
 201   if (clear_it)  ex_map->del_req(ex_map->req()-1);
 202   return ex_oop;
 203 }
 204 
 205 //-----------------------------saved_ex_oop------------------------------------
 206 // Recover a saved exception from its map.
 207 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) {
 208   return common_saved_ex_oop(ex_map, false);
 209 }
 210 
 211 //--------------------------clear_saved_ex_oop---------------------------------
 212 // Erase a previously saved exception from its map.
 213 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) {
 214   return common_saved_ex_oop(ex_map, true);
 215 }
 216 
 217 #ifdef ASSERT
 218 //---------------------------has_saved_ex_oop----------------------------------
 219 // Erase a previously saved exception from its map.
 220 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) {
 221   return ex_map->req() == ex_map->jvms()->endoff()+1;
 222 }
 223 #endif
 224 
 225 //-------------------------make_exception_state--------------------------------
 226 // Turn the current JVM state into an exception state, appending the ex_oop.
 227 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) {
 228   sync_jvms();
 229   SafePointNode* ex_map = stop();  // do not manipulate this map any more
 230   set_saved_ex_oop(ex_map, ex_oop);
 231   return ex_map;
 232 }
 233 
 234 
 235 //--------------------------add_exception_state--------------------------------
 236 // Add an exception to my list of exceptions.
 237 void GraphKit::add_exception_state(SafePointNode* ex_map) {
 238   if (ex_map == NULL || ex_map->control() == top()) {
 239     return;
 240   }
 241 #ifdef ASSERT
 242   verify_exception_state(ex_map);
 243   if (has_exceptions()) {
 244     assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place");
 245   }
 246 #endif
 247 
 248   // If there is already an exception of exactly this type, merge with it.
 249   // In particular, null-checks and other low-level exceptions common up here.
 250   Node*       ex_oop  = saved_ex_oop(ex_map);
 251   const Type* ex_type = _gvn.type(ex_oop);
 252   if (ex_oop == top()) {
 253     // No action needed.
 254     return;
 255   }
 256   assert(ex_type->isa_instptr(), "exception must be an instance");
 257   for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) {
 258     const Type* ex_type2 = _gvn.type(saved_ex_oop(e2));
 259     // We check sp also because call bytecodes can generate exceptions
 260     // both before and after arguments are popped!
 261     if (ex_type2 == ex_type
 262         && e2->_jvms->sp() == ex_map->_jvms->sp()) {
 263       combine_exception_states(ex_map, e2);
 264       return;
 265     }
 266   }
 267 
 268   // No pre-existing exception of the same type.  Chain it on the list.
 269   push_exception_state(ex_map);
 270 }
 271 
 272 //-----------------------add_exception_states_from-----------------------------
 273 void GraphKit::add_exception_states_from(JVMState* jvms) {
 274   SafePointNode* ex_map = jvms->map()->next_exception();
 275   if (ex_map != NULL) {
 276     jvms->map()->set_next_exception(NULL);
 277     for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) {
 278       next_map = ex_map->next_exception();
 279       ex_map->set_next_exception(NULL);
 280       add_exception_state(ex_map);
 281     }
 282   }
 283 }
 284 
 285 //-----------------------transfer_exceptions_into_jvms-------------------------
 286 JVMState* GraphKit::transfer_exceptions_into_jvms() {
 287   if (map() == NULL) {
 288     // We need a JVMS to carry the exceptions, but the map has gone away.
 289     // Create a scratch JVMS, cloned from any of the exception states...
 290     if (has_exceptions()) {
 291       _map = _exceptions;
 292       _map = clone_map();
 293       _map->set_next_exception(NULL);
 294       clear_saved_ex_oop(_map);
 295       debug_only(verify_map());
 296     } else {
 297       // ...or created from scratch
 298       JVMState* jvms = new (C) JVMState(_method, NULL);
 299       jvms->set_bci(_bci);
 300       jvms->set_sp(_sp);
 301       jvms->set_map(new SafePointNode(TypeFunc::Parms, jvms));
 302       set_jvms(jvms);
 303       for (uint i = 0; i < map()->req(); i++)  map()->init_req(i, top());
 304       set_all_memory(top());
 305       while (map()->req() < jvms->endoff())  map()->add_req(top());
 306     }
 307     // (This is a kludge, in case you didn't notice.)
 308     set_control(top());
 309   }
 310   JVMState* jvms = sync_jvms();
 311   assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet");
 312   jvms->map()->set_next_exception(_exceptions);
 313   _exceptions = NULL;   // done with this set of exceptions
 314   return jvms;
 315 }
 316 
 317 static inline void add_n_reqs(Node* dstphi, Node* srcphi) {
 318   assert(is_hidden_merge(dstphi), "must be a special merge node");
 319   assert(is_hidden_merge(srcphi), "must be a special merge node");
 320   uint limit = srcphi->req();
 321   for (uint i = PhiNode::Input; i < limit; i++) {
 322     dstphi->add_req(srcphi->in(i));
 323   }
 324 }
 325 static inline void add_one_req(Node* dstphi, Node* src) {
 326   assert(is_hidden_merge(dstphi), "must be a special merge node");
 327   assert(!is_hidden_merge(src), "must not be a special merge node");
 328   dstphi->add_req(src);
 329 }
 330 
 331 //-----------------------combine_exception_states------------------------------
 332 // This helper function combines exception states by building phis on a
 333 // specially marked state-merging region.  These regions and phis are
 334 // untransformed, and can build up gradually.  The region is marked by
 335 // having a control input of its exception map, rather than NULL.  Such
 336 // regions do not appear except in this function, and in use_exception_state.
 337 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) {
 338   if (failing())  return;  // dying anyway...
 339   JVMState* ex_jvms = ex_map->_jvms;
 340   assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains");
 341   assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals");
 342   assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes");
 343   assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS");
 344   assert(ex_jvms->scloff() == phi_map->_jvms->scloff(), "matching scalar replaced objects");
 345   assert(ex_map->req() == phi_map->req(), "matching maps");
 346   uint tos = ex_jvms->stkoff() + ex_jvms->sp();
 347   Node*         hidden_merge_mark = root();
 348   Node*         region  = phi_map->control();
 349   MergeMemNode* phi_mem = phi_map->merged_memory();
 350   MergeMemNode* ex_mem  = ex_map->merged_memory();
 351   if (region->in(0) != hidden_merge_mark) {
 352     // The control input is not (yet) a specially-marked region in phi_map.
 353     // Make it so, and build some phis.
 354     region = new RegionNode(2);
 355     _gvn.set_type(region, Type::CONTROL);
 356     region->set_req(0, hidden_merge_mark);  // marks an internal ex-state
 357     region->init_req(1, phi_map->control());
 358     phi_map->set_control(region);
 359     Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO);
 360     record_for_igvn(io_phi);
 361     _gvn.set_type(io_phi, Type::ABIO);
 362     phi_map->set_i_o(io_phi);
 363     for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) {
 364       Node* m = mms.memory();
 365       Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C));
 366       record_for_igvn(m_phi);
 367       _gvn.set_type(m_phi, Type::MEMORY);
 368       mms.set_memory(m_phi);
 369     }
 370   }
 371 
 372   // Either or both of phi_map and ex_map might already be converted into phis.
 373   Node* ex_control = ex_map->control();
 374   // if there is special marking on ex_map also, we add multiple edges from src
 375   bool add_multiple = (ex_control->in(0) == hidden_merge_mark);
 376   // how wide was the destination phi_map, originally?
 377   uint orig_width = region->req();
 378 
 379   if (add_multiple) {
 380     add_n_reqs(region, ex_control);
 381     add_n_reqs(phi_map->i_o(), ex_map->i_o());
 382   } else {
 383     // ex_map has no merges, so we just add single edges everywhere
 384     add_one_req(region, ex_control);
 385     add_one_req(phi_map->i_o(), ex_map->i_o());
 386   }
 387   for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) {
 388     if (mms.is_empty()) {
 389       // get a copy of the base memory, and patch some inputs into it
 390       const TypePtr* adr_type = mms.adr_type(C);
 391       Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
 392       assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
 393       mms.set_memory(phi);
 394       // Prepare to append interesting stuff onto the newly sliced phi:
 395       while (phi->req() > orig_width)  phi->del_req(phi->req()-1);
 396     }
 397     // Append stuff from ex_map:
 398     if (add_multiple) {
 399       add_n_reqs(mms.memory(), mms.memory2());
 400     } else {
 401       add_one_req(mms.memory(), mms.memory2());
 402     }
 403   }
 404   uint limit = ex_map->req();
 405   for (uint i = TypeFunc::Parms; i < limit; i++) {
 406     // Skip everything in the JVMS after tos.  (The ex_oop follows.)
 407     if (i == tos)  i = ex_jvms->monoff();
 408     Node* src = ex_map->in(i);
 409     Node* dst = phi_map->in(i);
 410     if (src != dst) {
 411       PhiNode* phi;
 412       if (dst->in(0) != region) {
 413         dst = phi = PhiNode::make(region, dst, _gvn.type(dst));
 414         record_for_igvn(phi);
 415         _gvn.set_type(phi, phi->type());
 416         phi_map->set_req(i, dst);
 417         // Prepare to append interesting stuff onto the new phi:
 418         while (dst->req() > orig_width)  dst->del_req(dst->req()-1);
 419       } else {
 420         assert(dst->is_Phi(), "nobody else uses a hidden region");
 421         phi = dst->as_Phi();
 422       }
 423       if (add_multiple && src->in(0) == ex_control) {
 424         // Both are phis.
 425         add_n_reqs(dst, src);
 426       } else {
 427         while (dst->req() < region->req())  add_one_req(dst, src);
 428       }
 429       const Type* srctype = _gvn.type(src);
 430       if (phi->type() != srctype) {
 431         const Type* dsttype = phi->type()->meet_speculative(srctype);
 432         if (phi->type() != dsttype) {
 433           phi->set_type(dsttype);
 434           _gvn.set_type(phi, dsttype);
 435         }
 436       }
 437     }
 438   }
 439   phi_map->merge_replaced_nodes_with(ex_map);
 440 }
 441 
 442 //--------------------------use_exception_state--------------------------------
 443 Node* GraphKit::use_exception_state(SafePointNode* phi_map) {
 444   if (failing()) { stop(); return top(); }
 445   Node* region = phi_map->control();
 446   Node* hidden_merge_mark = root();
 447   assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation");
 448   Node* ex_oop = clear_saved_ex_oop(phi_map);
 449   if (region->in(0) == hidden_merge_mark) {
 450     // Special marking for internal ex-states.  Process the phis now.
 451     region->set_req(0, region);  // now it's an ordinary region
 452     set_jvms(phi_map->jvms());   // ...so now we can use it as a map
 453     // Note: Setting the jvms also sets the bci and sp.
 454     set_control(_gvn.transform(region));
 455     uint tos = jvms()->stkoff() + sp();
 456     for (uint i = 1; i < tos; i++) {
 457       Node* x = phi_map->in(i);
 458       if (x->in(0) == region) {
 459         assert(x->is_Phi(), "expected a special phi");
 460         phi_map->set_req(i, _gvn.transform(x));
 461       }
 462     }
 463     for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
 464       Node* x = mms.memory();
 465       if (x->in(0) == region) {
 466         assert(x->is_Phi(), "nobody else uses a hidden region");
 467         mms.set_memory(_gvn.transform(x));
 468       }
 469     }
 470     if (ex_oop->in(0) == region) {
 471       assert(ex_oop->is_Phi(), "expected a special phi");
 472       ex_oop = _gvn.transform(ex_oop);
 473     }
 474   } else {
 475     set_jvms(phi_map->jvms());
 476   }
 477 
 478   assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared");
 479   assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared");
 480   return ex_oop;
 481 }
 482 
 483 //---------------------------------java_bc-------------------------------------
 484 Bytecodes::Code GraphKit::java_bc() const {
 485   ciMethod* method = this->method();
 486   int       bci    = this->bci();
 487   if (method != NULL && bci != InvocationEntryBci)
 488     return method->java_code_at_bci(bci);
 489   else
 490     return Bytecodes::_illegal;
 491 }
 492 
 493 void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
 494                                                           bool must_throw) {
 495     // if the exception capability is set, then we will generate code
 496     // to check the JavaThread.should_post_on_exceptions flag to see
 497     // if we actually need to report exception events (for this
 498     // thread).  If we don't need to report exception events, we will
 499     // take the normal fast path provided by add_exception_events.  If
 500     // exception event reporting is enabled for this thread, we will
 501     // take the uncommon_trap in the BuildCutout below.
 502 
 503     // first must access the should_post_on_exceptions_flag in this thread's JavaThread
 504     Node* jthread = _gvn.transform(new ThreadLocalNode());
 505     Node* adr = basic_plus_adr(top(), jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset()));
 506     Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw, MemNode::unordered);
 507 
 508     // Test the should_post_on_exceptions_flag vs. 0
 509     Node* chk = _gvn.transform( new CmpINode(should_post_flag, intcon(0)) );
 510     Node* tst = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
 511 
 512     // Branch to slow_path if should_post_on_exceptions_flag was true
 513     { BuildCutout unless(this, tst, PROB_MAX);
 514       // Do not try anything fancy if we're notifying the VM on every throw.
 515       // Cf. case Bytecodes::_athrow in parse2.cpp.
 516       uncommon_trap(reason, Deoptimization::Action_none,
 517                     (ciKlass*)NULL, (char*)NULL, must_throw);
 518     }
 519 
 520 }
 521 
 522 //------------------------------builtin_throw----------------------------------
 523 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) {
 524   bool must_throw = true;
 525 
 526   if (env()->jvmti_can_post_on_exceptions()) {
 527     // check if we must post exception events, take uncommon trap if so
 528     uncommon_trap_if_should_post_on_exceptions(reason, must_throw);
 529     // here if should_post_on_exceptions is false
 530     // continue on with the normal codegen
 531   }
 532 
 533   // If this particular condition has not yet happened at this
 534   // bytecode, then use the uncommon trap mechanism, and allow for
 535   // a future recompilation if several traps occur here.
 536   // If the throw is hot, try to use a more complicated inline mechanism
 537   // which keeps execution inside the compiled code.
 538   bool treat_throw_as_hot = false;
 539   ciMethodData* md = method()->method_data();
 540 
 541   if (ProfileTraps) {
 542     if (too_many_traps(reason)) {
 543       treat_throw_as_hot = true;
 544     }
 545     // (If there is no MDO at all, assume it is early in
 546     // execution, and that any deopts are part of the
 547     // startup transient, and don't need to be remembered.)
 548 
 549     // Also, if there is a local exception handler, treat all throws
 550     // as hot if there has been at least one in this method.
 551     if (C->trap_count(reason) != 0
 552         && method()->method_data()->trap_count(reason) != 0
 553         && has_ex_handler()) {
 554         treat_throw_as_hot = true;
 555     }
 556   }
 557 
 558   // If this throw happens frequently, an uncommon trap might cause
 559   // a performance pothole.  If there is a local exception handler,
 560   // and if this particular bytecode appears to be deoptimizing often,
 561   // let us handle the throw inline, with a preconstructed instance.
 562   // Note:   If the deopt count has blown up, the uncommon trap
 563   // runtime is going to flush this nmethod, not matter what.
 564   if (treat_throw_as_hot
 565       && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) {
 566     // If the throw is local, we use a pre-existing instance and
 567     // punt on the backtrace.  This would lead to a missing backtrace
 568     // (a repeat of 4292742) if the backtrace object is ever asked
 569     // for its backtrace.
 570     // Fixing this remaining case of 4292742 requires some flavor of
 571     // escape analysis.  Leave that for the future.
 572     ciInstance* ex_obj = NULL;
 573     switch (reason) {
 574     case Deoptimization::Reason_null_check:
 575       ex_obj = env()->NullPointerException_instance();
 576       break;
 577     case Deoptimization::Reason_div0_check:
 578       ex_obj = env()->ArithmeticException_instance();
 579       break;
 580     case Deoptimization::Reason_range_check:
 581       ex_obj = env()->ArrayIndexOutOfBoundsException_instance();
 582       break;
 583     case Deoptimization::Reason_class_check:
 584       if (java_bc() == Bytecodes::_aastore) {
 585         ex_obj = env()->ArrayStoreException_instance();
 586       } else {
 587         ex_obj = env()->ClassCastException_instance();
 588       }
 589       break;
 590     default:
 591       break;
 592     }
 593     if (failing()) { stop(); return; }  // exception allocation might fail
 594     if (ex_obj != NULL) {
 595       // Cheat with a preallocated exception object.
 596       if (C->log() != NULL)
 597         C->log()->elem("hot_throw preallocated='1' reason='%s'",
 598                        Deoptimization::trap_reason_name(reason));
 599       const TypeInstPtr* ex_con  = TypeInstPtr::make(ex_obj);
 600       Node*              ex_node = _gvn.transform(ConNode::make(ex_con));
 601 
 602       // Clear the detail message of the preallocated exception object.
 603       // Weblogic sometimes mutates the detail message of exceptions
 604       // using reflection.
 605       int offset = java_lang_Throwable::get_detailMessage_offset();
 606       const TypePtr* adr_typ = ex_con->add_offset(offset);
 607 
 608       Node *adr = basic_plus_adr(ex_node, ex_node, offset);
 609       const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass());
 610       // Conservatively release stores of object references.
 611       Node *store = store_oop_to_object(control(), ex_node, adr, adr_typ, null(), val_type, T_OBJECT, MemNode::release);
 612 
 613       add_exception_state(make_exception_state(ex_node));
 614       return;
 615     }
 616   }
 617 
 618   // %%% Maybe add entry to OptoRuntime which directly throws the exc.?
 619   // It won't be much cheaper than bailing to the interp., since we'll
 620   // have to pass up all the debug-info, and the runtime will have to
 621   // create the stack trace.
 622 
 623   // Usual case:  Bail to interpreter.
 624   // Reserve the right to recompile if we haven't seen anything yet.
 625 
 626   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? C->method() : NULL;
 627   Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile;
 628   if (treat_throw_as_hot
 629       && (method()->method_data()->trap_recompiled_at(bci(), m)
 630           || C->too_many_traps(reason))) {
 631     // We cannot afford to take more traps here.  Suffer in the interpreter.
 632     if (C->log() != NULL)
 633       C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'",
 634                      Deoptimization::trap_reason_name(reason),
 635                      C->trap_count(reason));
 636     action = Deoptimization::Action_none;
 637   }
 638 
 639   // "must_throw" prunes the JVM state to include only the stack, if there
 640   // are no local exception handlers.  This should cut down on register
 641   // allocation time and code size, by drastically reducing the number
 642   // of in-edges on the call to the uncommon trap.
 643 
 644   uncommon_trap(reason, action, (ciKlass*)NULL, (char*)NULL, must_throw);
 645 }
 646 
 647 
 648 //----------------------------PreserveJVMState---------------------------------
 649 PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) {
 650   debug_only(kit->verify_map());
 651   _kit    = kit;
 652   _map    = kit->map();   // preserve the map
 653   _sp     = kit->sp();
 654   kit->set_map(clone_map ? kit->clone_map() : NULL);
 655 #ifdef ASSERT
 656   _bci    = kit->bci();
 657   Parse* parser = kit->is_Parse();
 658   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 659   _block  = block;
 660 #endif
 661 }
 662 PreserveJVMState::~PreserveJVMState() {
 663   GraphKit* kit = _kit;
 664 #ifdef ASSERT
 665   assert(kit->bci() == _bci, "bci must not shift");
 666   Parse* parser = kit->is_Parse();
 667   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 668   assert(block == _block,    "block must not shift");
 669 #endif
 670   kit->set_map(_map);
 671   kit->set_sp(_sp);
 672 }
 673 
 674 
 675 //-----------------------------BuildCutout-------------------------------------
 676 BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt)
 677   : PreserveJVMState(kit)
 678 {
 679   assert(p->is_Con() || p->is_Bool(), "test must be a bool");
 680   SafePointNode* outer_map = _map;   // preserved map is caller's
 681   SafePointNode* inner_map = kit->map();
 682   IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt);
 683   outer_map->set_control(kit->gvn().transform( new IfTrueNode(iff) ));
 684   inner_map->set_control(kit->gvn().transform( new IfFalseNode(iff) ));
 685 }
 686 BuildCutout::~BuildCutout() {
 687   GraphKit* kit = _kit;
 688   assert(kit->stopped(), "cutout code must stop, throw, return, etc.");
 689 }
 690 
 691 //---------------------------PreserveReexecuteState----------------------------
 692 PreserveReexecuteState::PreserveReexecuteState(GraphKit* kit) {
 693   assert(!kit->stopped(), "must call stopped() before");
 694   _kit    =    kit;
 695   _sp     =    kit->sp();
 696   _reexecute = kit->jvms()->_reexecute;
 697 }
 698 PreserveReexecuteState::~PreserveReexecuteState() {
 699   if (_kit->stopped()) return;
 700   _kit->jvms()->_reexecute = _reexecute;
 701   _kit->set_sp(_sp);
 702 }
 703 
 704 //------------------------------clone_map--------------------------------------
 705 // Implementation of PreserveJVMState
 706 //
 707 // Only clone_map(...) here. If this function is only used in the
 708 // PreserveJVMState class we may want to get rid of this extra
 709 // function eventually and do it all there.
 710 
 711 SafePointNode* GraphKit::clone_map() {
 712   if (map() == NULL)  return NULL;
 713 
 714   // Clone the memory edge first
 715   Node* mem = MergeMemNode::make(map()->memory());
 716   gvn().set_type_bottom(mem);
 717 
 718   SafePointNode *clonemap = (SafePointNode*)map()->clone();
 719   JVMState* jvms = this->jvms();
 720   JVMState* clonejvms = jvms->clone_shallow(C);
 721   clonemap->set_memory(mem);
 722   clonemap->set_jvms(clonejvms);
 723   clonejvms->set_map(clonemap);
 724   record_for_igvn(clonemap);
 725   gvn().set_type_bottom(clonemap);
 726   return clonemap;
 727 }
 728 
 729 
 730 //-----------------------------set_map_clone-----------------------------------
 731 void GraphKit::set_map_clone(SafePointNode* m) {
 732   _map = m;
 733   _map = clone_map();
 734   _map->set_next_exception(NULL);
 735   debug_only(verify_map());
 736 }
 737 
 738 
 739 //----------------------------kill_dead_locals---------------------------------
 740 // Detect any locals which are known to be dead, and force them to top.
 741 void GraphKit::kill_dead_locals() {
 742   // Consult the liveness information for the locals.  If any
 743   // of them are unused, then they can be replaced by top().  This
 744   // should help register allocation time and cut down on the size
 745   // of the deoptimization information.
 746 
 747   // This call is made from many of the bytecode handling
 748   // subroutines called from the Big Switch in do_one_bytecode.
 749   // Every bytecode which might include a slow path is responsible
 750   // for killing its dead locals.  The more consistent we
 751   // are about killing deads, the fewer useless phis will be
 752   // constructed for them at various merge points.
 753 
 754   // bci can be -1 (InvocationEntryBci).  We return the entry
 755   // liveness for the method.
 756 
 757   if (method() == NULL || method()->code_size() == 0) {
 758     // We are building a graph for a call to a native method.
 759     // All locals are live.
 760     return;
 761   }
 762 
 763   ResourceMark rm;
 764 
 765   // Consult the liveness information for the locals.  If any
 766   // of them are unused, then they can be replaced by top().  This
 767   // should help register allocation time and cut down on the size
 768   // of the deoptimization information.
 769   MethodLivenessResult live_locals = method()->liveness_at_bci(bci());
 770 
 771   int len = (int)live_locals.size();
 772   assert(len <= jvms()->loc_size(), "too many live locals");
 773   for (int local = 0; local < len; local++) {
 774     if (!live_locals.at(local)) {
 775       set_local(local, top());
 776     }
 777   }
 778 }
 779 
 780 #ifdef ASSERT
 781 //-------------------------dead_locals_are_killed------------------------------
 782 // Return true if all dead locals are set to top in the map.
 783 // Used to assert "clean" debug info at various points.
 784 bool GraphKit::dead_locals_are_killed() {
 785   if (method() == NULL || method()->code_size() == 0) {
 786     // No locals need to be dead, so all is as it should be.
 787     return true;
 788   }
 789 
 790   // Make sure somebody called kill_dead_locals upstream.
 791   ResourceMark rm;
 792   for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
 793     if (jvms->loc_size() == 0)  continue;  // no locals to consult
 794     SafePointNode* map = jvms->map();
 795     ciMethod* method = jvms->method();
 796     int       bci    = jvms->bci();
 797     if (jvms == this->jvms()) {
 798       bci = this->bci();  // it might not yet be synched
 799     }
 800     MethodLivenessResult live_locals = method->liveness_at_bci(bci);
 801     int len = (int)live_locals.size();
 802     if (!live_locals.is_valid() || len == 0)
 803       // This method is trivial, or is poisoned by a breakpoint.
 804       return true;
 805     assert(len == jvms->loc_size(), "live map consistent with locals map");
 806     for (int local = 0; local < len; local++) {
 807       if (!live_locals.at(local) && map->local(jvms, local) != top()) {
 808         if (PrintMiscellaneous && (Verbose || WizardMode)) {
 809           tty->print_cr("Zombie local %d: ", local);
 810           jvms->dump();
 811         }
 812         return false;
 813       }
 814     }
 815   }
 816   return true;
 817 }
 818 
 819 #endif //ASSERT
 820 
 821 // Helper function for enforcing certain bytecodes to reexecute if
 822 // deoptimization happens
 823 static bool should_reexecute_implied_by_bytecode(JVMState *jvms, bool is_anewarray) {
 824   ciMethod* cur_method = jvms->method();
 825   int       cur_bci   = jvms->bci();
 826   if (cur_method != NULL && cur_bci != InvocationEntryBci) {
 827     Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci);
 828     return Interpreter::bytecode_should_reexecute(code) ||
 829            (is_anewarray && code == Bytecodes::_multianewarray);
 830     // Reexecute _multianewarray bytecode which was replaced with
 831     // sequence of [a]newarray. See Parse::do_multianewarray().
 832     //
 833     // Note: interpreter should not have it set since this optimization
 834     // is limited by dimensions and guarded by flag so in some cases
 835     // multianewarray() runtime calls will be generated and
 836     // the bytecode should not be reexecutes (stack will not be reset).
 837   } else
 838     return false;
 839 }
 840 
 841 // Helper function for adding JVMState and debug information to node
 842 void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) {
 843   // Add the safepoint edges to the call (or other safepoint).
 844 
 845   // Make sure dead locals are set to top.  This
 846   // should help register allocation time and cut down on the size
 847   // of the deoptimization information.
 848   assert(dead_locals_are_killed(), "garbage in debug info before safepoint");
 849 
 850   // Walk the inline list to fill in the correct set of JVMState's
 851   // Also fill in the associated edges for each JVMState.
 852 
 853   // If the bytecode needs to be reexecuted we need to put
 854   // the arguments back on the stack.
 855   const bool should_reexecute = jvms()->should_reexecute();
 856   JVMState* youngest_jvms = should_reexecute ? sync_jvms_for_reexecute() : sync_jvms();
 857 
 858   // NOTE: set_bci (called from sync_jvms) might reset the reexecute bit to
 859   // undefined if the bci is different.  This is normal for Parse but it
 860   // should not happen for LibraryCallKit because only one bci is processed.
 861   assert(!is_LibraryCallKit() || (jvms()->should_reexecute() == should_reexecute),
 862          "in LibraryCallKit the reexecute bit should not change");
 863 
 864   // If we are guaranteed to throw, we can prune everything but the
 865   // input to the current bytecode.
 866   bool can_prune_locals = false;
 867   uint stack_slots_not_pruned = 0;
 868   int inputs = 0, depth = 0;
 869   if (must_throw) {
 870     assert(method() == youngest_jvms->method(), "sanity");
 871     if (compute_stack_effects(inputs, depth)) {
 872       can_prune_locals = true;
 873       stack_slots_not_pruned = inputs;
 874     }
 875   }
 876 
 877   if (env()->should_retain_local_variables()) {
 878     // At any safepoint, this method can get breakpointed, which would
 879     // then require an immediate deoptimization.
 880     can_prune_locals = false;  // do not prune locals
 881     stack_slots_not_pruned = 0;
 882   }
 883 
 884   // do not scribble on the input jvms
 885   JVMState* out_jvms = youngest_jvms->clone_deep(C);
 886   call->set_jvms(out_jvms); // Start jvms list for call node
 887 
 888   // For a known set of bytecodes, the interpreter should reexecute them if
 889   // deoptimization happens. We set the reexecute state for them here
 890   if (out_jvms->is_reexecute_undefined() && //don't change if already specified
 891       should_reexecute_implied_by_bytecode(out_jvms, call->is_AllocateArray())) {
 892     out_jvms->set_should_reexecute(true); //NOTE: youngest_jvms not changed
 893   }
 894 
 895   // Presize the call:
 896   DEBUG_ONLY(uint non_debug_edges = call->req());
 897   call->add_req_batch(top(), youngest_jvms->debug_depth());
 898   assert(call->req() == non_debug_edges + youngest_jvms->debug_depth(), "");
 899 
 900   // Set up edges so that the call looks like this:
 901   //  Call [state:] ctl io mem fptr retadr
 902   //       [parms:] parm0 ... parmN
 903   //       [root:]  loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 904   //    [...mid:]   loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN [...]
 905   //       [young:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 906   // Note that caller debug info precedes callee debug info.
 907 
 908   // Fill pointer walks backwards from "young:" to "root:" in the diagram above:
 909   uint debug_ptr = call->req();
 910 
 911   // Loop over the map input edges associated with jvms, add them
 912   // to the call node, & reset all offsets to match call node array.
 913   for (JVMState* in_jvms = youngest_jvms; in_jvms != NULL; ) {
 914     uint debug_end   = debug_ptr;
 915     uint debug_start = debug_ptr - in_jvms->debug_size();
 916     debug_ptr = debug_start;  // back up the ptr
 917 
 918     uint p = debug_start;  // walks forward in [debug_start, debug_end)
 919     uint j, k, l;
 920     SafePointNode* in_map = in_jvms->map();
 921     out_jvms->set_map(call);
 922 
 923     if (can_prune_locals) {
 924       assert(in_jvms->method() == out_jvms->method(), "sanity");
 925       // If the current throw can reach an exception handler in this JVMS,
 926       // then we must keep everything live that can reach that handler.
 927       // As a quick and dirty approximation, we look for any handlers at all.
 928       if (in_jvms->method()->has_exception_handlers()) {
 929         can_prune_locals = false;
 930       }
 931     }
 932 
 933     // Add the Locals
 934     k = in_jvms->locoff();
 935     l = in_jvms->loc_size();
 936     out_jvms->set_locoff(p);
 937     if (!can_prune_locals) {
 938       for (j = 0; j < l; j++)
 939         call->set_req(p++, in_map->in(k+j));
 940     } else {
 941       p += l;  // already set to top above by add_req_batch
 942     }
 943 
 944     // Add the Expression Stack
 945     k = in_jvms->stkoff();
 946     l = in_jvms->sp();
 947     out_jvms->set_stkoff(p);
 948     if (!can_prune_locals) {
 949       for (j = 0; j < l; j++)
 950         call->set_req(p++, in_map->in(k+j));
 951     } else if (can_prune_locals && stack_slots_not_pruned != 0) {
 952       // Divide stack into {S0,...,S1}, where S0 is set to top.
 953       uint s1 = stack_slots_not_pruned;
 954       stack_slots_not_pruned = 0;  // for next iteration
 955       if (s1 > l)  s1 = l;
 956       uint s0 = l - s1;
 957       p += s0;  // skip the tops preinstalled by add_req_batch
 958       for (j = s0; j < l; j++)
 959         call->set_req(p++, in_map->in(k+j));
 960     } else {
 961       p += l;  // already set to top above by add_req_batch
 962     }
 963 
 964     // Add the Monitors
 965     k = in_jvms->monoff();
 966     l = in_jvms->mon_size();
 967     out_jvms->set_monoff(p);
 968     for (j = 0; j < l; j++)
 969       call->set_req(p++, in_map->in(k+j));
 970 
 971     // Copy any scalar object fields.
 972     k = in_jvms->scloff();
 973     l = in_jvms->scl_size();
 974     out_jvms->set_scloff(p);
 975     for (j = 0; j < l; j++)
 976       call->set_req(p++, in_map->in(k+j));
 977 
 978     // Finish the new jvms.
 979     out_jvms->set_endoff(p);
 980 
 981     assert(out_jvms->endoff()     == debug_end,             "fill ptr must match");
 982     assert(out_jvms->depth()      == in_jvms->depth(),      "depth must match");
 983     assert(out_jvms->loc_size()   == in_jvms->loc_size(),   "size must match");
 984     assert(out_jvms->mon_size()   == in_jvms->mon_size(),   "size must match");
 985     assert(out_jvms->scl_size()   == in_jvms->scl_size(),   "size must match");
 986     assert(out_jvms->debug_size() == in_jvms->debug_size(), "size must match");
 987 
 988     // Update the two tail pointers in parallel.
 989     out_jvms = out_jvms->caller();
 990     in_jvms  = in_jvms->caller();
 991   }
 992 
 993   assert(debug_ptr == non_debug_edges, "debug info must fit exactly");
 994 
 995   // Test the correctness of JVMState::debug_xxx accessors:
 996   assert(call->jvms()->debug_start() == non_debug_edges, "");
 997   assert(call->jvms()->debug_end()   == call->req(), "");
 998   assert(call->jvms()->debug_depth() == call->req() - non_debug_edges, "");
 999 }
1000 
1001 bool GraphKit::compute_stack_effects(int& inputs, int& depth) {
1002   Bytecodes::Code code = java_bc();
1003   if (code == Bytecodes::_wide) {
1004     code = method()->java_code_at_bci(bci() + 1);
1005   }
1006 
1007   BasicType rtype = T_ILLEGAL;
1008   int       rsize = 0;
1009 
1010   if (code != Bytecodes::_illegal) {
1011     depth = Bytecodes::depth(code); // checkcast=0, athrow=-1
1012     rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V
1013     if (rtype < T_CONFLICT)
1014       rsize = type2size[rtype];
1015   }
1016 
1017   switch (code) {
1018   case Bytecodes::_illegal:
1019     return false;
1020 
1021   case Bytecodes::_ldc:
1022   case Bytecodes::_ldc_w:
1023   case Bytecodes::_ldc2_w:
1024     inputs = 0;
1025     break;
1026 
1027   case Bytecodes::_dup:         inputs = 1;  break;
1028   case Bytecodes::_dup_x1:      inputs = 2;  break;
1029   case Bytecodes::_dup_x2:      inputs = 3;  break;
1030   case Bytecodes::_dup2:        inputs = 2;  break;
1031   case Bytecodes::_dup2_x1:     inputs = 3;  break;
1032   case Bytecodes::_dup2_x2:     inputs = 4;  break;
1033   case Bytecodes::_swap:        inputs = 2;  break;
1034   case Bytecodes::_arraylength: inputs = 1;  break;
1035 
1036   case Bytecodes::_getstatic:
1037   case Bytecodes::_putstatic:
1038   case Bytecodes::_getfield:
1039   case Bytecodes::_putfield:
1040     {
1041       bool ignored_will_link;
1042       ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
1043       int      size  = field->type()->size();
1044       bool is_get = (depth >= 0), is_static = (depth & 1);
1045       inputs = (is_static ? 0 : 1);
1046       if (is_get) {
1047         depth = size - inputs;
1048       } else {
1049         inputs += size;        // putxxx pops the value from the stack
1050         depth = - inputs;
1051       }
1052     }
1053     break;
1054 
1055   case Bytecodes::_invokevirtual:
1056   case Bytecodes::_invokespecial:
1057   case Bytecodes::_invokestatic:
1058   case Bytecodes::_invokedynamic:
1059   case Bytecodes::_invokeinterface:
1060     {
1061       bool ignored_will_link;
1062       ciSignature* declared_signature = NULL;
1063       ciMethod* ignored_callee = method()->get_method_at_bci(bci(), ignored_will_link, &declared_signature);
1064       assert(declared_signature != NULL, "cannot be null");
1065       inputs   = declared_signature->arg_size_for_bc(code);
1066       int size = declared_signature->return_type()->size();
1067       depth = size - inputs;
1068     }
1069     break;
1070 
1071   case Bytecodes::_multianewarray:
1072     {
1073       ciBytecodeStream iter(method());
1074       iter.reset_to_bci(bci());
1075       iter.next();
1076       inputs = iter.get_dimensions();
1077       assert(rsize == 1, "");
1078       depth = rsize - inputs;
1079     }
1080     break;
1081 
1082   case Bytecodes::_ireturn:
1083   case Bytecodes::_lreturn:
1084   case Bytecodes::_freturn:
1085   case Bytecodes::_dreturn:
1086   case Bytecodes::_areturn:
1087     assert(rsize == -depth, "");
1088     inputs = rsize;
1089     break;
1090 
1091   case Bytecodes::_jsr:
1092   case Bytecodes::_jsr_w:
1093     inputs = 0;
1094     depth  = 1;                  // S.B. depth=1, not zero
1095     break;
1096 
1097   default:
1098     // bytecode produces a typed result
1099     inputs = rsize - depth;
1100     assert(inputs >= 0, "");
1101     break;
1102   }
1103 
1104 #ifdef ASSERT
1105   // spot check
1106   int outputs = depth + inputs;
1107   assert(outputs >= 0, "sanity");
1108   switch (code) {
1109   case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break;
1110   case Bytecodes::_athrow:    assert(inputs == 1 && outputs == 0, ""); break;
1111   case Bytecodes::_aload_0:   assert(inputs == 0 && outputs == 1, ""); break;
1112   case Bytecodes::_return:    assert(inputs == 0 && outputs == 0, ""); break;
1113   case Bytecodes::_drem:      assert(inputs == 4 && outputs == 2, ""); break;
1114   default:                    break;
1115   }
1116 #endif //ASSERT
1117 
1118   return true;
1119 }
1120 
1121 
1122 
1123 //------------------------------basic_plus_adr---------------------------------
1124 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) {
1125   // short-circuit a common case
1126   if (offset == intcon(0))  return ptr;
1127   return _gvn.transform( new AddPNode(base, ptr, offset) );
1128 }
1129 
1130 Node* GraphKit::ConvI2L(Node* offset) {
1131   // short-circuit a common case
1132   jint offset_con = find_int_con(offset, Type::OffsetBot);
1133   if (offset_con != Type::OffsetBot) {
1134     return longcon((jlong) offset_con);
1135   }
1136   return _gvn.transform( new ConvI2LNode(offset));
1137 }
1138 
1139 Node* GraphKit::ConvI2UL(Node* offset) {
1140   juint offset_con = (juint) find_int_con(offset, Type::OffsetBot);
1141   if (offset_con != (juint) Type::OffsetBot) {
1142     return longcon((julong) offset_con);
1143   }
1144   Node* conv = _gvn.transform( new ConvI2LNode(offset));
1145   Node* mask = _gvn.transform(ConLNode::make((julong) max_juint));
1146   return _gvn.transform( new AndLNode(conv, mask) );
1147 }
1148 
1149 Node* GraphKit::ConvL2I(Node* offset) {
1150   // short-circuit a common case
1151   jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot);
1152   if (offset_con != (jlong)Type::OffsetBot) {
1153     return intcon((int) offset_con);
1154   }
1155   return _gvn.transform( new ConvL2INode(offset));
1156 }
1157 
1158 //-------------------------load_object_klass-----------------------------------
1159 Node* GraphKit::load_object_klass(Node* obj) {
1160   // Special-case a fresh allocation to avoid building nodes:
1161   Node* akls = AllocateNode::Ideal_klass(obj, &_gvn);
1162   if (akls != NULL)  return akls;
1163   Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1164   return _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), k_adr, TypeInstPtr::KLASS));
1165 }
1166 
1167 //-------------------------load_array_length-----------------------------------
1168 Node* GraphKit::load_array_length(Node* array) {
1169   // Special-case a fresh allocation to avoid building nodes:
1170   AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array, &_gvn);
1171   Node *alen;
1172   if (alloc == NULL) {
1173     Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes());
1174     alen = _gvn.transform( new LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS));
1175   } else {
1176     alen = alloc->Ideal_length();
1177     Node* ccast = alloc->make_ideal_length(_gvn.type(array)->is_oopptr(), &_gvn);
1178     if (ccast != alen) {
1179       alen = _gvn.transform(ccast);
1180     }
1181   }
1182   return alen;
1183 }
1184 
1185 //------------------------------do_null_check----------------------------------
1186 // Helper function to do a NULL pointer check.  Returned value is
1187 // the incoming address with NULL casted away.  You are allowed to use the
1188 // not-null value only if you are control dependent on the test.
1189 #ifndef PRODUCT
1190 extern int explicit_null_checks_inserted,
1191            explicit_null_checks_elided;
1192 #endif
1193 Node* GraphKit::null_check_common(Node* value, BasicType type,
1194                                   // optional arguments for variations:
1195                                   bool assert_null,
1196                                   Node* *null_control,
1197                                   bool speculative) {
1198   assert(!assert_null || null_control == NULL, "not both at once");
1199   if (stopped())  return top();
1200   NOT_PRODUCT(explicit_null_checks_inserted++);
1201 
1202   // Construct NULL check
1203   Node *chk = NULL;
1204   switch(type) {
1205     case T_LONG   : chk = new CmpLNode(value, _gvn.zerocon(T_LONG)); break;
1206     case T_INT    : chk = new CmpINode(value, _gvn.intcon(0)); break;
1207     case T_ARRAY  : // fall through
1208       type = T_OBJECT;  // simplify further tests
1209     case T_OBJECT : {
1210       const Type *t = _gvn.type( value );
1211 
1212       const TypeOopPtr* tp = t->isa_oopptr();
1213       if (tp != NULL && tp->klass() != NULL && !tp->klass()->is_loaded()
1214           // Only for do_null_check, not any of its siblings:
1215           && !assert_null && null_control == NULL) {
1216         // Usually, any field access or invocation on an unloaded oop type
1217         // will simply fail to link, since the statically linked class is
1218         // likely also to be unloaded.  However, in -Xcomp mode, sometimes
1219         // the static class is loaded but the sharper oop type is not.
1220         // Rather than checking for this obscure case in lots of places,
1221         // we simply observe that a null check on an unloaded class
1222         // will always be followed by a nonsense operation, so we
1223         // can just issue the uncommon trap here.
1224         // Our access to the unloaded class will only be correct
1225         // after it has been loaded and initialized, which requires
1226         // a trip through the interpreter.
1227 #ifndef PRODUCT
1228         if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); }
1229 #endif
1230         uncommon_trap(Deoptimization::Reason_unloaded,
1231                       Deoptimization::Action_reinterpret,
1232                       tp->klass(), "!loaded");
1233         return top();
1234       }
1235 
1236       if (assert_null) {
1237         // See if the type is contained in NULL_PTR.
1238         // If so, then the value is already null.
1239         if (t->higher_equal(TypePtr::NULL_PTR)) {
1240           NOT_PRODUCT(explicit_null_checks_elided++);
1241           return value;           // Elided null assert quickly!
1242         }
1243       } else {
1244         // See if mixing in the NULL pointer changes type.
1245         // If so, then the NULL pointer was not allowed in the original
1246         // type.  In other words, "value" was not-null.
1247         if (t->meet(TypePtr::NULL_PTR) != t->remove_speculative()) {
1248           // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
1249           NOT_PRODUCT(explicit_null_checks_elided++);
1250           return value;           // Elided null check quickly!
1251         }
1252       }
1253       chk = new CmpPNode( value, null() );
1254       break;
1255     }
1256 
1257     default:
1258       fatal("unexpected type: %s", type2name(type));
1259   }
1260   assert(chk != NULL, "sanity check");
1261   chk = _gvn.transform(chk);
1262 
1263   BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
1264   BoolNode *btst = new BoolNode( chk, btest);
1265   Node   *tst = _gvn.transform( btst );
1266 
1267   //-----------
1268   // if peephole optimizations occurred, a prior test existed.
1269   // If a prior test existed, maybe it dominates as we can avoid this test.
1270   if (tst != btst && type == T_OBJECT) {
1271     // At this point we want to scan up the CFG to see if we can
1272     // find an identical test (and so avoid this test altogether).
1273     Node *cfg = control();
1274     int depth = 0;
1275     while( depth < 16 ) {       // Limit search depth for speed
1276       if( cfg->Opcode() == Op_IfTrue &&
1277           cfg->in(0)->in(1) == tst ) {
1278         // Found prior test.  Use "cast_not_null" to construct an identical
1279         // CastPP (and hence hash to) as already exists for the prior test.
1280         // Return that casted value.
1281         if (assert_null) {
1282           replace_in_map(value, null());
1283           return null();  // do not issue the redundant test
1284         }
1285         Node *oldcontrol = control();
1286         set_control(cfg);
1287         Node *res = cast_not_null(value);
1288         set_control(oldcontrol);
1289         NOT_PRODUCT(explicit_null_checks_elided++);
1290         return res;
1291       }
1292       cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true);
1293       if (cfg == NULL)  break;  // Quit at region nodes
1294       depth++;
1295     }
1296   }
1297 
1298   //-----------
1299   // Branch to failure if null
1300   float ok_prob = PROB_MAX;  // a priori estimate:  nulls never happen
1301   Deoptimization::DeoptReason reason;
1302   if (assert_null) {
1303     reason = Deoptimization::reason_null_assert(speculative);
1304   } else if (type == T_OBJECT) {
1305     reason = Deoptimization::reason_null_check(speculative);
1306   } else {
1307     reason = Deoptimization::Reason_div0_check;
1308   }
1309   // %%% Since Reason_unhandled is not recorded on a per-bytecode basis,
1310   // ciMethodData::has_trap_at will return a conservative -1 if any
1311   // must-be-null assertion has failed.  This could cause performance
1312   // problems for a method after its first do_null_assert failure.
1313   // Consider using 'Reason_class_check' instead?
1314 
1315   // To cause an implicit null check, we set the not-null probability
1316   // to the maximum (PROB_MAX).  For an explicit check the probability
1317   // is set to a smaller value.
1318   if (null_control != NULL || too_many_traps(reason)) {
1319     // probability is less likely
1320     ok_prob =  PROB_LIKELY_MAG(3);
1321   } else if (!assert_null &&
1322              (ImplicitNullCheckThreshold > 0) &&
1323              method() != NULL &&
1324              (method()->method_data()->trap_count(reason)
1325               >= (uint)ImplicitNullCheckThreshold)) {
1326     ok_prob =  PROB_LIKELY_MAG(3);
1327   }
1328 
1329   if (null_control != NULL) {
1330     IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN);
1331     Node* null_true = _gvn.transform( new IfFalseNode(iff));
1332     set_control(      _gvn.transform( new IfTrueNode(iff)));
1333 #ifndef PRODUCT
1334     if (null_true == top()) {
1335       explicit_null_checks_elided++;
1336     }
1337 #endif
1338     (*null_control) = null_true;
1339   } else {
1340     BuildCutout unless(this, tst, ok_prob);
1341     // Check for optimizer eliding test at parse time
1342     if (stopped()) {
1343       // Failure not possible; do not bother making uncommon trap.
1344       NOT_PRODUCT(explicit_null_checks_elided++);
1345     } else if (assert_null) {
1346       uncommon_trap(reason,
1347                     Deoptimization::Action_make_not_entrant,
1348                     NULL, "assert_null");
1349     } else {
1350       replace_in_map(value, zerocon(type));
1351       builtin_throw(reason);
1352     }
1353   }
1354 
1355   // Must throw exception, fall-thru not possible?
1356   if (stopped()) {
1357     return top();               // No result
1358   }
1359 
1360   if (assert_null) {
1361     // Cast obj to null on this path.
1362     replace_in_map(value, zerocon(type));
1363     return zerocon(type);
1364   }
1365 
1366   // Cast obj to not-null on this path, if there is no null_control.
1367   // (If there is a null_control, a non-null value may come back to haunt us.)
1368   if (type == T_OBJECT) {
1369     Node* cast = cast_not_null(value, false);
1370     if (null_control == NULL || (*null_control) == top())
1371       replace_in_map(value, cast);
1372     value = cast;
1373   }
1374 
1375   return value;
1376 }
1377 
1378 
1379 //------------------------------cast_not_null----------------------------------
1380 // Cast obj to not-null on this path
1381 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) {
1382   const Type *t = _gvn.type(obj);
1383   const Type *t_not_null = t->join_speculative(TypePtr::NOTNULL);
1384   // Object is already not-null?
1385   if( t == t_not_null ) return obj;
1386 
1387   Node *cast = new CastPPNode(obj,t_not_null);
1388   cast->init_req(0, control());
1389   cast = _gvn.transform( cast );
1390 
1391   // Scan for instances of 'obj' in the current JVM mapping.
1392   // These instances are known to be not-null after the test.
1393   if (do_replace_in_map)
1394     replace_in_map(obj, cast);
1395 
1396   return cast;                  // Return casted value
1397 }
1398 
1399 // Sometimes in intrinsics, we implicitly know an object is not null
1400 // (there's no actual null check) so we can cast it to not null. In
1401 // the course of optimizations, the input to the cast can become null.
1402 // In that case that data path will die and we need the control path
1403 // to become dead as well to keep the graph consistent. So we have to
1404 // add a check for null for which one branch can't be taken. It uses
1405 // an Opaque4 node that will cause the check to be removed after loop
1406 // opts so the test goes away and the compiled code doesn't execute a
1407 // useless check.
1408 Node* GraphKit::must_be_not_null(Node* value, bool do_replace_in_map) {
1409   Node* chk = _gvn.transform(new CmpPNode(value, null()));
1410   Node *tst = _gvn.transform(new BoolNode(chk, BoolTest::ne));
1411   Node* opaq = _gvn.transform(new Opaque4Node(C, tst, intcon(1)));
1412   IfNode *iff = new IfNode(control(), opaq, PROB_MAX, COUNT_UNKNOWN);
1413   _gvn.set_type(iff, iff->Value(&_gvn));
1414   Node *if_f = _gvn.transform(new IfFalseNode(iff));
1415   Node *frame = _gvn.transform(new ParmNode(C->start(), TypeFunc::FramePtr));
1416   Node *halt = _gvn.transform(new HaltNode(if_f, frame));
1417   C->root()->add_req(halt);
1418   Node *if_t = _gvn.transform(new IfTrueNode(iff));
1419   set_control(if_t);
1420   return cast_not_null(value, do_replace_in_map);
1421 }
1422 
1423 
1424 //--------------------------replace_in_map-------------------------------------
1425 void GraphKit::replace_in_map(Node* old, Node* neww) {
1426   if (old == neww) {
1427     return;
1428   }
1429 
1430   map()->replace_edge(old, neww);
1431 
1432   // Note: This operation potentially replaces any edge
1433   // on the map.  This includes locals, stack, and monitors
1434   // of the current (innermost) JVM state.
1435 
1436   // don't let inconsistent types from profiling escape this
1437   // method
1438 
1439   const Type* told = _gvn.type(old);
1440   const Type* tnew = _gvn.type(neww);
1441 
1442   if (!tnew->higher_equal(told)) {
1443     return;
1444   }
1445 
1446   map()->record_replaced_node(old, neww);
1447 }
1448 
1449 
1450 //=============================================================================
1451 //--------------------------------memory---------------------------------------
1452 Node* GraphKit::memory(uint alias_idx) {
1453   MergeMemNode* mem = merged_memory();
1454   Node* p = mem->memory_at(alias_idx);
1455   _gvn.set_type(p, Type::MEMORY);  // must be mapped
1456   return p;
1457 }
1458 
1459 //-----------------------------reset_memory------------------------------------
1460 Node* GraphKit::reset_memory() {
1461   Node* mem = map()->memory();
1462   // do not use this node for any more parsing!
1463   debug_only( map()->set_memory((Node*)NULL) );
1464   return _gvn.transform( mem );
1465 }
1466 
1467 //------------------------------set_all_memory---------------------------------
1468 void GraphKit::set_all_memory(Node* newmem) {
1469   Node* mergemem = MergeMemNode::make(newmem);
1470   gvn().set_type_bottom(mergemem);
1471   map()->set_memory(mergemem);
1472 }
1473 
1474 //------------------------------set_all_memory_call----------------------------
1475 void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) {
1476   Node* newmem = _gvn.transform( new ProjNode(call, TypeFunc::Memory, separate_io_proj) );
1477   set_all_memory(newmem);
1478 }
1479 
1480 //=============================================================================
1481 //
1482 // parser factory methods for MemNodes
1483 //
1484 // These are layered on top of the factory methods in LoadNode and StoreNode,
1485 // and integrate with the parser's memory state and _gvn engine.
1486 //
1487 
1488 // factory methods in "int adr_idx"
1489 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
1490                           int adr_idx,
1491                           MemNode::MemOrd mo,
1492                           LoadNode::ControlDependency control_dependency,
1493                           bool require_atomic_access,
1494                           bool unaligned,
1495                           bool mismatched) {
1496   assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
1497   const TypePtr* adr_type = NULL; // debug-mode-only argument
1498   debug_only(adr_type = C->get_adr_type(adr_idx));
1499   Node* mem = memory(adr_idx);
1500   Node* ld;
1501   if (require_atomic_access && bt == T_LONG) {
1502     ld = LoadLNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1503   } else if (require_atomic_access && bt == T_DOUBLE) {
1504     ld = LoadDNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1505   } else {
1506     ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, mo, control_dependency, unaligned, mismatched);
1507   }
1508   ld = _gvn.transform(ld);
1509   if (((bt == T_OBJECT) && C->do_escape_analysis()) || C->eliminate_boxing()) {
1510     // Improve graph before escape analysis and boxing elimination.
1511     record_for_igvn(ld);
1512   }
1513   return ld;
1514 }
1515 
1516 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
1517                                 int adr_idx,
1518                                 MemNode::MemOrd mo,
1519                                 bool require_atomic_access,
1520                                 bool unaligned,
1521                                 bool mismatched) {
1522   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1523   const TypePtr* adr_type = NULL;
1524   debug_only(adr_type = C->get_adr_type(adr_idx));
1525   Node *mem = memory(adr_idx);
1526   Node* st;
1527   if (require_atomic_access && bt == T_LONG) {
1528     st = StoreLNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1529   } else if (require_atomic_access && bt == T_DOUBLE) {
1530     st = StoreDNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1531   } else {
1532     st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt, mo);
1533   }
1534   if (unaligned) {
1535     st->as_Store()->set_unaligned_access();
1536   }
1537   if (mismatched) {
1538     st->as_Store()->set_mismatched_access();
1539   }
1540   st = _gvn.transform(st);
1541   set_memory(st, adr_idx);
1542   // Back-to-back stores can only remove intermediate store with DU info
1543   // so push on worklist for optimizer.
1544   if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
1545     record_for_igvn(st);
1546 
1547   return st;
1548 }
1549 
1550 
1551 void GraphKit::pre_barrier(bool do_load,
1552                            Node* ctl,
1553                            Node* obj,
1554                            Node* adr,
1555                            uint  adr_idx,
1556                            Node* val,
1557                            const TypeOopPtr* val_type,
1558                            Node* pre_val,
1559                            BasicType bt) {
1560 
1561   BarrierSet* bs = Universe::heap()->barrier_set();
1562   set_control(ctl);
1563   switch (bs->kind()) {
1564     case BarrierSet::G1SATBCTLogging:
1565       g1_write_barrier_pre(do_load, obj, adr, adr_idx, val, val_type, pre_val, bt);
1566       break;
1567 
1568     case BarrierSet::CardTableModRef:
1569       break;
1570 
1571     default      :
1572       ShouldNotReachHere();
1573 
1574   }
1575 }
1576 
1577 bool GraphKit::can_move_pre_barrier() const {
1578   BarrierSet* bs = Universe::heap()->barrier_set();
1579   switch (bs->kind()) {
1580     case BarrierSet::G1SATBCTLogging:
1581       return true; // Can move it if no safepoint
1582 
1583     case BarrierSet::CardTableModRef:
1584       return true; // There is no pre-barrier
1585 
1586     default      :
1587       ShouldNotReachHere();
1588   }
1589   return false;
1590 }
1591 
1592 void GraphKit::post_barrier(Node* ctl,
1593                             Node* store,
1594                             Node* obj,
1595                             Node* adr,
1596                             uint  adr_idx,
1597                             Node* val,
1598                             BasicType bt,
1599                             bool use_precise) {
1600   BarrierSet* bs = Universe::heap()->barrier_set();
1601   set_control(ctl);
1602   switch (bs->kind()) {
1603     case BarrierSet::G1SATBCTLogging:
1604       g1_write_barrier_post(store, obj, adr, adr_idx, val, bt, use_precise);
1605       break;
1606 
1607     case BarrierSet::CardTableModRef:
1608       write_barrier_post(store, obj, adr, adr_idx, val, use_precise);
1609       break;
1610 
1611     default      :
1612       ShouldNotReachHere();
1613 
1614   }
1615 }
1616 
1617 Node* GraphKit::store_oop(Node* ctl,
1618                           Node* obj,
1619                           Node* adr,
1620                           const TypePtr* adr_type,
1621                           Node* val,
1622                           const TypeOopPtr* val_type,
1623                           BasicType bt,
1624                           bool use_precise,
1625                           MemNode::MemOrd mo,
1626                           bool mismatched) {
1627   // Transformation of a value which could be NULL pointer (CastPP #NULL)
1628   // could be delayed during Parse (for example, in adjust_map_after_if()).
1629   // Execute transformation here to avoid barrier generation in such case.
1630   if (_gvn.type(val) == TypePtr::NULL_PTR)
1631     val = _gvn.makecon(TypePtr::NULL_PTR);
1632 
1633   set_control(ctl);
1634   if (stopped()) return top(); // Dead path ?
1635 
1636   assert(bt == T_OBJECT, "sanity");
1637   assert(val != NULL, "not dead path");
1638   uint adr_idx = C->get_alias_index(adr_type);
1639   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1640 
1641   pre_barrier(true /* do_load */,
1642               control(), obj, adr, adr_idx, val, val_type,
1643               NULL /* pre_val */,
1644               bt);
1645 
1646   Node* store = store_to_memory(control(), adr, val, bt, adr_idx, mo, mismatched);
1647   post_barrier(control(), store, obj, adr, adr_idx, val, bt, use_precise);
1648   return store;
1649 }
1650 
1651 // Could be an array or object we don't know at compile time (unsafe ref.)
1652 Node* GraphKit::store_oop_to_unknown(Node* ctl,
1653                              Node* obj,   // containing obj
1654                              Node* adr,  // actual adress to store val at
1655                              const TypePtr* adr_type,
1656                              Node* val,
1657                              BasicType bt,
1658                              MemNode::MemOrd mo,
1659                              bool mismatched) {
1660   Compile::AliasType* at = C->alias_type(adr_type);
1661   const TypeOopPtr* val_type = NULL;
1662   if (adr_type->isa_instptr()) {
1663     if (at->field() != NULL) {
1664       // known field.  This code is a copy of the do_put_xxx logic.
1665       ciField* field = at->field();
1666       if (!field->type()->is_loaded()) {
1667         val_type = TypeInstPtr::BOTTOM;
1668       } else {
1669         val_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
1670       }
1671     }
1672   } else if (adr_type->isa_aryptr()) {
1673     val_type = adr_type->is_aryptr()->elem()->make_oopptr();
1674   }
1675   if (val_type == NULL) {
1676     val_type = TypeInstPtr::BOTTOM;
1677   }
1678   return store_oop(ctl, obj, adr, adr_type, val, val_type, bt, true, mo, mismatched);
1679 }
1680 
1681 
1682 //-------------------------array_element_address-------------------------
1683 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1684                                       const TypeInt* sizetype, Node* ctrl) {
1685   uint shift  = exact_log2(type2aelembytes(elembt));
1686   uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1687 
1688   // short-circuit a common case (saves lots of confusing waste motion)
1689   jint idx_con = find_int_con(idx, -1);
1690   if (idx_con >= 0) {
1691     intptr_t offset = header + ((intptr_t)idx_con << shift);
1692     return basic_plus_adr(ary, offset);
1693   }
1694 
1695   // must be correct type for alignment purposes
1696   Node* base  = basic_plus_adr(ary, header);
1697   idx = Compile::conv_I2X_index(&_gvn, idx, sizetype, ctrl);
1698   Node* scale = _gvn.transform( new LShiftXNode(idx, intcon(shift)) );
1699   return basic_plus_adr(ary, base, scale);
1700 }
1701 
1702 //-------------------------load_array_element-------------------------
1703 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) {
1704   const Type* elemtype = arytype->elem();
1705   BasicType elembt = elemtype->array_element_basic_type();
1706   Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1707   if (elembt == T_NARROWOOP) {
1708     elembt = T_OBJECT; // To satisfy switch in LoadNode::make()
1709   }
1710   Node* ld = make_load(ctl, adr, elemtype, elembt, arytype, MemNode::unordered);
1711   return ld;
1712 }
1713 
1714 //-------------------------set_arguments_for_java_call-------------------------
1715 // Arguments (pre-popped from the stack) are taken from the JVMS.
1716 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1717   // Add the call arguments:
1718   uint nargs = call->method()->arg_size();
1719   for (uint i = 0; i < nargs; i++) {
1720     Node* arg = argument(i);
1721     call->init_req(i + TypeFunc::Parms, arg);
1722   }
1723 }
1724 
1725 //---------------------------set_edges_for_java_call---------------------------
1726 // Connect a newly created call into the current JVMS.
1727 // A return value node (if any) is returned from set_edges_for_java_call.
1728 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {
1729 
1730   // Add the predefined inputs:
1731   call->init_req( TypeFunc::Control, control() );
1732   call->init_req( TypeFunc::I_O    , i_o() );
1733   call->init_req( TypeFunc::Memory , reset_memory() );
1734   call->init_req( TypeFunc::FramePtr, frameptr() );
1735   call->init_req( TypeFunc::ReturnAdr, top() );
1736 
1737   add_safepoint_edges(call, must_throw);
1738 
1739   Node* xcall = _gvn.transform(call);
1740 
1741   if (xcall == top()) {
1742     set_control(top());
1743     return;
1744   }
1745   assert(xcall == call, "call identity is stable");
1746 
1747   // Re-use the current map to produce the result.
1748 
1749   set_control(_gvn.transform(new ProjNode(call, TypeFunc::Control)));
1750   set_i_o(    _gvn.transform(new ProjNode(call, TypeFunc::I_O    , separate_io_proj)));
1751   set_all_memory_call(xcall, separate_io_proj);
1752 
1753   //return xcall;   // no need, caller already has it
1754 }
1755 
1756 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj) {
1757   if (stopped())  return top();  // maybe the call folded up?
1758 
1759   // Capture the return value, if any.
1760   Node* ret;
1761   if (call->method() == NULL ||
1762       call->method()->return_type()->basic_type() == T_VOID)
1763         ret = top();
1764   else  ret = _gvn.transform(new ProjNode(call, TypeFunc::Parms));
1765 
1766   // Note:  Since any out-of-line call can produce an exception,
1767   // we always insert an I_O projection from the call into the result.
1768 
1769   make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj);
1770 
1771   if (separate_io_proj) {
1772     // The caller requested separate projections be used by the fall
1773     // through and exceptional paths, so replace the projections for
1774     // the fall through path.
1775     set_i_o(_gvn.transform( new ProjNode(call, TypeFunc::I_O) ));
1776     set_all_memory(_gvn.transform( new ProjNode(call, TypeFunc::Memory) ));
1777   }
1778   return ret;
1779 }
1780 
1781 //--------------------set_predefined_input_for_runtime_call--------------------
1782 // Reading and setting the memory state is way conservative here.
1783 // The real problem is that I am not doing real Type analysis on memory,
1784 // so I cannot distinguish card mark stores from other stores.  Across a GC
1785 // point the Store Barrier and the card mark memory has to agree.  I cannot
1786 // have a card mark store and its barrier split across the GC point from
1787 // either above or below.  Here I get that to happen by reading ALL of memory.
1788 // A better answer would be to separate out card marks from other memory.
1789 // For now, return the input memory state, so that it can be reused
1790 // after the call, if this call has restricted memory effects.
1791 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) {
1792   // Set fixed predefined input arguments
1793   Node* memory = reset_memory();
1794   call->init_req( TypeFunc::Control,   control()  );
1795   call->init_req( TypeFunc::I_O,       top()      ); // does no i/o
1796   call->init_req( TypeFunc::Memory,    memory     ); // may gc ptrs
1797   call->init_req( TypeFunc::FramePtr,  frameptr() );
1798   call->init_req( TypeFunc::ReturnAdr, top()      );
1799   return memory;
1800 }
1801 
1802 //-------------------set_predefined_output_for_runtime_call--------------------
1803 // Set control and memory (not i_o) from the call.
1804 // If keep_mem is not NULL, use it for the output state,
1805 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1806 // If hook_mem is NULL, this call produces no memory effects at all.
1807 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1808 // then only that memory slice is taken from the call.
1809 // In the last case, we must put an appropriate memory barrier before
1810 // the call, so as to create the correct anti-dependencies on loads
1811 // preceding the call.
1812 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1813                                                       Node* keep_mem,
1814                                                       const TypePtr* hook_mem) {
1815   // no i/o
1816   set_control(_gvn.transform( new ProjNode(call,TypeFunc::Control) ));
1817   if (keep_mem) {
1818     // First clone the existing memory state
1819     set_all_memory(keep_mem);
1820     if (hook_mem != NULL) {
1821       // Make memory for the call
1822       Node* mem = _gvn.transform( new ProjNode(call, TypeFunc::Memory) );
1823       // Set the RawPtr memory state only.  This covers all the heap top/GC stuff
1824       // We also use hook_mem to extract specific effects from arraycopy stubs.
1825       set_memory(mem, hook_mem);
1826     }
1827     // ...else the call has NO memory effects.
1828 
1829     // Make sure the call advertises its memory effects precisely.
1830     // This lets us build accurate anti-dependences in gcm.cpp.
1831     assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
1832            "call node must be constructed correctly");
1833   } else {
1834     assert(hook_mem == NULL, "");
1835     // This is not a "slow path" call; all memory comes from the call.
1836     set_all_memory_call(call);
1837   }
1838 }
1839 
1840 
1841 // Replace the call with the current state of the kit.
1842 void GraphKit::replace_call(CallNode* call, Node* result, bool do_replaced_nodes) {
1843   JVMState* ejvms = NULL;
1844   if (has_exceptions()) {
1845     ejvms = transfer_exceptions_into_jvms();
1846   }
1847 
1848   ReplacedNodes replaced_nodes = map()->replaced_nodes();
1849   ReplacedNodes replaced_nodes_exception;
1850   Node* ex_ctl = top();
1851 
1852   SafePointNode* final_state = stop();
1853 
1854   // Find all the needed outputs of this call
1855   CallProjections callprojs;
1856   call->extract_projections(&callprojs, true);
1857 
1858   Node* init_mem = call->in(TypeFunc::Memory);
1859   Node* final_mem = final_state->in(TypeFunc::Memory);
1860   Node* final_ctl = final_state->in(TypeFunc::Control);
1861   Node* final_io = final_state->in(TypeFunc::I_O);
1862 
1863   // Replace all the old call edges with the edges from the inlining result
1864   if (callprojs.fallthrough_catchproj != NULL) {
1865     C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl);
1866   }
1867   if (callprojs.fallthrough_memproj != NULL) {
1868     if (final_mem->is_MergeMem()) {
1869       // Parser's exits MergeMem was not transformed but may be optimized
1870       final_mem = _gvn.transform(final_mem);
1871     }
1872     C->gvn_replace_by(callprojs.fallthrough_memproj,   final_mem);
1873   }
1874   if (callprojs.fallthrough_ioproj != NULL) {
1875     C->gvn_replace_by(callprojs.fallthrough_ioproj,    final_io);
1876   }
1877 
1878   // Replace the result with the new result if it exists and is used
1879   if (callprojs.resproj != NULL && result != NULL) {
1880     C->gvn_replace_by(callprojs.resproj, result);
1881   }
1882 
1883   if (ejvms == NULL) {
1884     // No exception edges to simply kill off those paths
1885     if (callprojs.catchall_catchproj != NULL) {
1886       C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
1887     }
1888     if (callprojs.catchall_memproj != NULL) {
1889       C->gvn_replace_by(callprojs.catchall_memproj,   C->top());
1890     }
1891     if (callprojs.catchall_ioproj != NULL) {
1892       C->gvn_replace_by(callprojs.catchall_ioproj,    C->top());
1893     }
1894     // Replace the old exception object with top
1895     if (callprojs.exobj != NULL) {
1896       C->gvn_replace_by(callprojs.exobj, C->top());
1897     }
1898   } else {
1899     GraphKit ekit(ejvms);
1900 
1901     // Load my combined exception state into the kit, with all phis transformed:
1902     SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();
1903     replaced_nodes_exception = ex_map->replaced_nodes();
1904 
1905     Node* ex_oop = ekit.use_exception_state(ex_map);
1906 
1907     if (callprojs.catchall_catchproj != NULL) {
1908       C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
1909       ex_ctl = ekit.control();
1910     }
1911     if (callprojs.catchall_memproj != NULL) {
1912       C->gvn_replace_by(callprojs.catchall_memproj,   ekit.reset_memory());
1913     }
1914     if (callprojs.catchall_ioproj != NULL) {
1915       C->gvn_replace_by(callprojs.catchall_ioproj,    ekit.i_o());
1916     }
1917 
1918     // Replace the old exception object with the newly created one
1919     if (callprojs.exobj != NULL) {
1920       C->gvn_replace_by(callprojs.exobj, ex_oop);
1921     }
1922   }
1923 
1924   // Disconnect the call from the graph
1925   call->disconnect_inputs(NULL, C);
1926   C->gvn_replace_by(call, C->top());
1927 
1928   // Clean up any MergeMems that feed other MergeMems since the
1929   // optimizer doesn't like that.
1930   if (final_mem->is_MergeMem()) {
1931     Node_List wl;
1932     for (SimpleDUIterator i(final_mem); i.has_next(); i.next()) {
1933       Node* m = i.get();
1934       if (m->is_MergeMem() && !wl.contains(m)) {
1935         wl.push(m);
1936       }
1937     }
1938     while (wl.size()  > 0) {
1939       _gvn.transform(wl.pop());
1940     }
1941   }
1942 
1943   if (callprojs.fallthrough_catchproj != NULL && !final_ctl->is_top() && do_replaced_nodes) {
1944     replaced_nodes.apply(C, final_ctl);
1945   }
1946   if (!ex_ctl->is_top() && do_replaced_nodes) {
1947     replaced_nodes_exception.apply(C, ex_ctl);
1948   }
1949 }
1950 
1951 
1952 //------------------------------increment_counter------------------------------
1953 // for statistics: increment a VM counter by 1
1954 
1955 void GraphKit::increment_counter(address counter_addr) {
1956   Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
1957   increment_counter(adr1);
1958 }
1959 
1960 void GraphKit::increment_counter(Node* counter_addr) {
1961   int adr_type = Compile::AliasIdxRaw;
1962   Node* ctrl = control();
1963   Node* cnt  = make_load(ctrl, counter_addr, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
1964   Node* incr = _gvn.transform(new AddINode(cnt, _gvn.intcon(1)));
1965   store_to_memory(ctrl, counter_addr, incr, T_INT, adr_type, MemNode::unordered);
1966 }
1967 
1968 
1969 //------------------------------uncommon_trap----------------------------------
1970 // Bail out to the interpreter in mid-method.  Implemented by calling the
1971 // uncommon_trap blob.  This helper function inserts a runtime call with the
1972 // right debug info.
1973 void GraphKit::uncommon_trap(int trap_request,
1974                              ciKlass* klass, const char* comment,
1975                              bool must_throw,
1976                              bool keep_exact_action) {
1977   if (failing())  stop();
1978   if (stopped())  return; // trap reachable?
1979 
1980   // Note:  If ProfileTraps is true, and if a deopt. actually
1981   // occurs here, the runtime will make sure an MDO exists.  There is
1982   // no need to call method()->ensure_method_data() at this point.
1983 
1984   // Set the stack pointer to the right value for reexecution:
1985   set_sp(reexecute_sp());
1986 
1987 #ifdef ASSERT
1988   if (!must_throw) {
1989     // Make sure the stack has at least enough depth to execute
1990     // the current bytecode.
1991     int inputs, ignored_depth;
1992     if (compute_stack_effects(inputs, ignored_depth)) {
1993       assert(sp() >= inputs, "must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
1994              Bytecodes::name(java_bc()), sp(), inputs);
1995     }
1996   }
1997 #endif
1998 
1999   Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
2000   Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
2001 
2002   switch (action) {
2003   case Deoptimization::Action_maybe_recompile:
2004   case Deoptimization::Action_reinterpret:
2005     // Temporary fix for 6529811 to allow virtual calls to be sure they
2006     // get the chance to go from mono->bi->mega
2007     if (!keep_exact_action &&
2008         Deoptimization::trap_request_index(trap_request) < 0 &&
2009         too_many_recompiles(reason)) {
2010       // This BCI is causing too many recompilations.
2011       if (C->log() != NULL) {
2012         C->log()->elem("observe that='trap_action_change' reason='%s' from='%s' to='none'",
2013                 Deoptimization::trap_reason_name(reason),
2014                 Deoptimization::trap_action_name(action));
2015       }
2016       action = Deoptimization::Action_none;
2017       trap_request = Deoptimization::make_trap_request(reason, action);
2018     } else {
2019       C->set_trap_can_recompile(true);
2020     }
2021     break;
2022   case Deoptimization::Action_make_not_entrant:
2023     C->set_trap_can_recompile(true);
2024     break;
2025   case Deoptimization::Action_none:
2026   case Deoptimization::Action_make_not_compilable:
2027     break;
2028   default:
2029 #ifdef ASSERT
2030     fatal("unknown action %d: %s", action, Deoptimization::trap_action_name(action));
2031 #endif
2032     break;
2033   }
2034 
2035   if (TraceOptoParse) {
2036     char buf[100];
2037     tty->print_cr("Uncommon trap %s at bci:%d",
2038                   Deoptimization::format_trap_request(buf, sizeof(buf),
2039                                                       trap_request), bci());
2040   }
2041 
2042   CompileLog* log = C->log();
2043   if (log != NULL) {
2044     int kid = (klass == NULL)? -1: log->identify(klass);
2045     log->begin_elem("uncommon_trap bci='%d'", bci());
2046     char buf[100];
2047     log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
2048                                                           trap_request));
2049     if (kid >= 0)         log->print(" klass='%d'", kid);
2050     if (comment != NULL)  log->print(" comment='%s'", comment);
2051     log->end_elem();
2052   }
2053 
2054   // Make sure any guarding test views this path as very unlikely
2055   Node *i0 = control()->in(0);
2056   if (i0 != NULL && i0->is_If()) {        // Found a guarding if test?
2057     IfNode *iff = i0->as_If();
2058     float f = iff->_prob;   // Get prob
2059     if (control()->Opcode() == Op_IfTrue) {
2060       if (f > PROB_UNLIKELY_MAG(4))
2061         iff->_prob = PROB_MIN;
2062     } else {
2063       if (f < PROB_LIKELY_MAG(4))
2064         iff->_prob = PROB_MAX;
2065     }
2066   }
2067 
2068   // Clear out dead values from the debug info.
2069   kill_dead_locals();
2070 
2071   // Now insert the uncommon trap subroutine call
2072   address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
2073   const TypePtr* no_memory_effects = NULL;
2074   // Pass the index of the class to be loaded
2075   Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
2076                                  (must_throw ? RC_MUST_THROW : 0),
2077                                  OptoRuntime::uncommon_trap_Type(),
2078                                  call_addr, "uncommon_trap", no_memory_effects,
2079                                  intcon(trap_request));
2080   assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
2081          "must extract request correctly from the graph");
2082   assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
2083 
2084   call->set_req(TypeFunc::ReturnAdr, returnadr());
2085   // The debug info is the only real input to this call.
2086 
2087   // Halt-and-catch fire here.  The above call should never return!
2088   HaltNode* halt = new HaltNode(control(), frameptr());
2089   _gvn.set_type_bottom(halt);
2090   root()->add_req(halt);
2091 
2092   stop_and_kill_map();
2093 }
2094 
2095 
2096 //--------------------------just_allocated_object------------------------------
2097 // Report the object that was just allocated.
2098 // It must be the case that there are no intervening safepoints.
2099 // We use this to determine if an object is so "fresh" that
2100 // it does not require card marks.
2101 Node* GraphKit::just_allocated_object(Node* current_control) {
2102   if (C->recent_alloc_ctl() == current_control)
2103     return C->recent_alloc_obj();
2104   return NULL;
2105 }
2106 
2107 
2108 void GraphKit::round_double_arguments(ciMethod* dest_method) {
2109   // (Note:  TypeFunc::make has a cache that makes this fast.)
2110   const TypeFunc* tf    = TypeFunc::make(dest_method);
2111   int             nargs = tf->domain()->cnt() - TypeFunc::Parms;
2112   for (int j = 0; j < nargs; j++) {
2113     const Type *targ = tf->domain()->field_at(j + TypeFunc::Parms);
2114     if( targ->basic_type() == T_DOUBLE ) {
2115       // If any parameters are doubles, they must be rounded before
2116       // the call, dstore_rounding does gvn.transform
2117       Node *arg = argument(j);
2118       arg = dstore_rounding(arg);
2119       set_argument(j, arg);
2120     }
2121   }
2122 }
2123 
2124 /**
2125  * Record profiling data exact_kls for Node n with the type system so
2126  * that it can propagate it (speculation)
2127  *
2128  * @param n          node that the type applies to
2129  * @param exact_kls  type from profiling
2130  * @param maybe_null did profiling see null?
2131  *
2132  * @return           node with improved type
2133  */
2134 Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls, ProfilePtrKind ptr_kind) {
2135   const Type* current_type = _gvn.type(n);
2136   assert(UseTypeSpeculation, "type speculation must be on");
2137 
2138   const TypePtr* speculative = current_type->speculative();
2139 
2140   // Should the klass from the profile be recorded in the speculative type?
2141   if (current_type->would_improve_type(exact_kls, jvms()->depth())) {
2142     const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls);
2143     const TypeOopPtr* xtype = tklass->as_instance_type();
2144     assert(xtype->klass_is_exact(), "Should be exact");
2145     // Any reason to believe n is not null (from this profiling or a previous one)?
2146     assert(ptr_kind != ProfileAlwaysNull, "impossible here");
2147     const TypePtr* ptr = (ptr_kind == ProfileMaybeNull && current_type->speculative_maybe_null()) ? TypePtr::BOTTOM : TypePtr::NOTNULL;
2148     // record the new speculative type's depth
2149     speculative = xtype->cast_to_ptr_type(ptr->ptr())->is_ptr();
2150     speculative = speculative->with_inline_depth(jvms()->depth());
2151   } else if (current_type->would_improve_ptr(ptr_kind)) {
2152     // Profiling report that null was never seen so we can change the
2153     // speculative type to non null ptr.
2154     if (ptr_kind == ProfileAlwaysNull) {
2155       speculative = TypePtr::NULL_PTR;
2156     } else {
2157       assert(ptr_kind == ProfileNeverNull, "nothing else is an improvement");
2158       const TypePtr* ptr = TypePtr::NOTNULL;
2159       if (speculative != NULL) {
2160         speculative = speculative->cast_to_ptr_type(ptr->ptr())->is_ptr();
2161       } else {
2162         speculative = ptr;
2163       }
2164     }
2165   }
2166 
2167   if (speculative != current_type->speculative()) {
2168     // Build a type with a speculative type (what we think we know
2169     // about the type but will need a guard when we use it)
2170     const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::OffsetBot, TypeOopPtr::InstanceBot, speculative);
2171     // We're changing the type, we need a new CheckCast node to carry
2172     // the new type. The new type depends on the control: what
2173     // profiling tells us is only valid from here as far as we can
2174     // tell.
2175     Node* cast = new CheckCastPPNode(control(), n, current_type->remove_speculative()->join_speculative(spec_type));
2176     cast = _gvn.transform(cast);
2177     replace_in_map(n, cast);
2178     n = cast;
2179   }
2180 
2181   return n;
2182 }
2183 
2184 /**
2185  * Record profiling data from receiver profiling at an invoke with the
2186  * type system so that it can propagate it (speculation)
2187  *
2188  * @param n  receiver node
2189  *
2190  * @return   node with improved type
2191  */
2192 Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) {
2193   if (!UseTypeSpeculation) {
2194     return n;
2195   }
2196   ciKlass* exact_kls = profile_has_unique_klass();
2197   ProfilePtrKind ptr_kind = ProfileMaybeNull;
2198   if ((java_bc() == Bytecodes::_checkcast ||
2199        java_bc() == Bytecodes::_instanceof ||
2200        java_bc() == Bytecodes::_aastore) &&
2201       method()->method_data()->is_mature()) {
2202     ciProfileData* data = method()->method_data()->bci_to_data(bci());
2203     if (data != NULL) {
2204       if (!data->as_BitData()->null_seen()) {
2205         ptr_kind = ProfileNeverNull;
2206       } else {
2207         assert(data->is_ReceiverTypeData(), "bad profile data type");
2208         ciReceiverTypeData* call = (ciReceiverTypeData*)data->as_ReceiverTypeData();
2209         uint i = 0;
2210         for (; i < call->row_limit(); i++) {
2211           ciKlass* receiver = call->receiver(i);
2212           if (receiver != NULL) {
2213             break;
2214           }
2215         }
2216         ptr_kind = (i == call->row_limit()) ? ProfileAlwaysNull : ProfileMaybeNull;
2217       }
2218     }
2219   }
2220   return record_profile_for_speculation(n, exact_kls, ptr_kind);
2221 }
2222 
2223 /**
2224  * Record profiling data from argument profiling at an invoke with the
2225  * type system so that it can propagate it (speculation)
2226  *
2227  * @param dest_method  target method for the call
2228  * @param bc           what invoke bytecode is this?
2229  */
2230 void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) {
2231   if (!UseTypeSpeculation) {
2232     return;
2233   }
2234   const TypeFunc* tf    = TypeFunc::make(dest_method);
2235   int             nargs = tf->domain()->cnt() - TypeFunc::Parms;
2236   int skip = Bytecodes::has_receiver(bc) ? 1 : 0;
2237   for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) {
2238     const Type *targ = tf->domain()->field_at(j + TypeFunc::Parms);
2239     if (targ->basic_type() == T_OBJECT || targ->basic_type() == T_ARRAY) {
2240       ProfilePtrKind ptr_kind = ProfileMaybeNull;
2241       ciKlass* better_type = NULL;
2242       if (method()->argument_profiled_type(bci(), i, better_type, ptr_kind)) {
2243         record_profile_for_speculation(argument(j), better_type, ptr_kind);
2244       }
2245       i++;
2246     }
2247   }
2248 }
2249 
2250 /**
2251  * Record profiling data from parameter profiling at an invoke with
2252  * the type system so that it can propagate it (speculation)
2253  */
2254 void GraphKit::record_profiled_parameters_for_speculation() {
2255   if (!UseTypeSpeculation) {
2256     return;
2257   }
2258   for (int i = 0, j = 0; i < method()->arg_size() ; i++) {
2259     if (_gvn.type(local(i))->isa_oopptr()) {
2260       ProfilePtrKind ptr_kind = ProfileMaybeNull;
2261       ciKlass* better_type = NULL;
2262       if (method()->parameter_profiled_type(j, better_type, ptr_kind)) {
2263         record_profile_for_speculation(local(i), better_type, ptr_kind);
2264       }
2265       j++;
2266     }
2267   }
2268 }
2269 
2270 /**
2271  * Record profiling data from return value profiling at an invoke with
2272  * the type system so that it can propagate it (speculation)
2273  */
2274 void GraphKit::record_profiled_return_for_speculation() {
2275   if (!UseTypeSpeculation) {
2276     return;
2277   }
2278   ProfilePtrKind ptr_kind = ProfileMaybeNull;
2279   ciKlass* better_type = NULL;
2280   if (method()->return_profiled_type(bci(), better_type, ptr_kind)) {
2281     // If profiling reports a single type for the return value,
2282     // feed it to the type system so it can propagate it as a
2283     // speculative type
2284     record_profile_for_speculation(stack(sp()-1), better_type, ptr_kind);
2285   }
2286 }
2287 
2288 void GraphKit::round_double_result(ciMethod* dest_method) {
2289   // A non-strict method may return a double value which has an extended
2290   // exponent, but this must not be visible in a caller which is 'strict'
2291   // If a strict caller invokes a non-strict callee, round a double result
2292 
2293   BasicType result_type = dest_method->return_type()->basic_type();
2294   assert( method() != NULL, "must have caller context");
2295   if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) {
2296     // Destination method's return value is on top of stack
2297     // dstore_rounding() does gvn.transform
2298     Node *result = pop_pair();
2299     result = dstore_rounding(result);
2300     push_pair(result);
2301   }
2302 }
2303 
2304 // rounding for strict float precision conformance
2305 Node* GraphKit::precision_rounding(Node* n) {
2306   return UseStrictFP && _method->flags().is_strict()
2307     && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding
2308     ? _gvn.transform( new RoundFloatNode(0, n) )
2309     : n;
2310 }
2311 
2312 // rounding for strict double precision conformance
2313 Node* GraphKit::dprecision_rounding(Node *n) {
2314   return UseStrictFP && _method->flags().is_strict()
2315     && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding
2316     ? _gvn.transform( new RoundDoubleNode(0, n) )
2317     : n;
2318 }
2319 
2320 // rounding for non-strict double stores
2321 Node* GraphKit::dstore_rounding(Node* n) {
2322   return Matcher::strict_fp_requires_explicit_rounding
2323     && UseSSE <= 1
2324     ? _gvn.transform( new RoundDoubleNode(0, n) )
2325     : n;
2326 }
2327 
2328 //=============================================================================
2329 // Generate a fast path/slow path idiom.  Graph looks like:
2330 // [foo] indicates that 'foo' is a parameter
2331 //
2332 //              [in]     NULL
2333 //                 \    /
2334 //                  CmpP
2335 //                  Bool ne
2336 //                   If
2337 //                  /  \
2338 //              True    False-<2>
2339 //              / |
2340 //             /  cast_not_null
2341 //           Load  |    |   ^
2342 //        [fast_test]   |   |
2343 // gvn to   opt_test    |   |
2344 //          /    \      |  <1>
2345 //      True     False  |
2346 //        |         \\  |
2347 //   [slow_call]     \[fast_result]
2348 //    Ctl   Val       \      \
2349 //     |               \      \
2350 //    Catch       <1>   \      \
2351 //   /    \        ^     \      \
2352 //  Ex    No_Ex    |      \      \
2353 //  |       \   \  |       \ <2>  \
2354 //  ...      \  [slow_res] |  |    \   [null_result]
2355 //            \         \--+--+---  |  |
2356 //             \           | /    \ | /
2357 //              --------Region     Phi
2358 //
2359 //=============================================================================
2360 // Code is structured as a series of driver functions all called 'do_XXX' that
2361 // call a set of helper functions.  Helper functions first, then drivers.
2362 
2363 //------------------------------null_check_oop---------------------------------
2364 // Null check oop.  Set null-path control into Region in slot 3.
2365 // Make a cast-not-nullness use the other not-null control.  Return cast.
2366 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2367                                bool never_see_null,
2368                                bool safe_for_replace,
2369                                bool speculative) {
2370   // Initial NULL check taken path
2371   (*null_control) = top();
2372   Node* cast = null_check_common(value, T_OBJECT, false, null_control, speculative);
2373 
2374   // Generate uncommon_trap:
2375   if (never_see_null && (*null_control) != top()) {
2376     // If we see an unexpected null at a check-cast we record it and force a
2377     // recompile; the offending check-cast will be compiled to handle NULLs.
2378     // If we see more than one offending BCI, then all checkcasts in the
2379     // method will be compiled to handle NULLs.
2380     PreserveJVMState pjvms(this);
2381     set_control(*null_control);
2382     replace_in_map(value, null());
2383     Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculative);
2384     uncommon_trap(reason,
2385                   Deoptimization::Action_make_not_entrant);
2386     (*null_control) = top();    // NULL path is dead
2387   }
2388   if ((*null_control) == top() && safe_for_replace) {
2389     replace_in_map(value, cast);
2390   }
2391 
2392   // Cast away null-ness on the result
2393   return cast;
2394 }
2395 
2396 //------------------------------opt_iff----------------------------------------
2397 // Optimize the fast-check IfNode.  Set the fast-path region slot 2.
2398 // Return slow-path control.
2399 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2400   IfNode *opt_iff = _gvn.transform(iff)->as_If();
2401 
2402   // Fast path taken; set region slot 2
2403   Node *fast_taken = _gvn.transform( new IfFalseNode(opt_iff) );
2404   region->init_req(2,fast_taken); // Capture fast-control
2405 
2406   // Fast path not-taken, i.e. slow path
2407   Node *slow_taken = _gvn.transform( new IfTrueNode(opt_iff) );
2408   return slow_taken;
2409 }
2410 
2411 //-----------------------------make_runtime_call-------------------------------
2412 Node* GraphKit::make_runtime_call(int flags,
2413                                   const TypeFunc* call_type, address call_addr,
2414                                   const char* call_name,
2415                                   const TypePtr* adr_type,
2416                                   // The following parms are all optional.
2417                                   // The first NULL ends the list.
2418                                   Node* parm0, Node* parm1,
2419                                   Node* parm2, Node* parm3,
2420                                   Node* parm4, Node* parm5,
2421                                   Node* parm6, Node* parm7) {
2422   // Slow-path call
2423   bool is_leaf = !(flags & RC_NO_LEAF);
2424   bool has_io  = (!is_leaf && !(flags & RC_NO_IO));
2425   if (call_name == NULL) {
2426     assert(!is_leaf, "must supply name for leaf");
2427     call_name = OptoRuntime::stub_name(call_addr);
2428   }
2429   CallNode* call;
2430   if (!is_leaf) {
2431     call = new CallStaticJavaNode(call_type, call_addr, call_name,
2432                                            bci(), adr_type);
2433   } else if (flags & RC_NO_FP) {
2434     call = new CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2435   } else {
2436     call = new CallLeafNode(call_type, call_addr, call_name, adr_type);
2437   }
2438 
2439   // The following is similar to set_edges_for_java_call,
2440   // except that the memory effects of the call are restricted to AliasIdxRaw.
2441 
2442   // Slow path call has no side-effects, uses few values
2443   bool wide_in  = !(flags & RC_NARROW_MEM);
2444   bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2445 
2446   Node* prev_mem = NULL;
2447   if (wide_in) {
2448     prev_mem = set_predefined_input_for_runtime_call(call);
2449   } else {
2450     assert(!wide_out, "narrow in => narrow out");
2451     Node* narrow_mem = memory(adr_type);
2452     prev_mem = reset_memory();
2453     map()->set_memory(narrow_mem);
2454     set_predefined_input_for_runtime_call(call);
2455   }
2456 
2457   // Hook each parm in order.  Stop looking at the first NULL.
2458   if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
2459   if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
2460   if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
2461   if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
2462   if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
2463   if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
2464   if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
2465   if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
2466     /* close each nested if ===> */  } } } } } } } }
2467   assert(call->in(call->req()-1) != NULL, "must initialize all parms");
2468 
2469   if (!is_leaf) {
2470     // Non-leaves can block and take safepoints:
2471     add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2472   }
2473   // Non-leaves can throw exceptions:
2474   if (has_io) {
2475     call->set_req(TypeFunc::I_O, i_o());
2476   }
2477 
2478   if (flags & RC_UNCOMMON) {
2479     // Set the count to a tiny probability.  Cf. Estimate_Block_Frequency.
2480     // (An "if" probability corresponds roughly to an unconditional count.
2481     // Sort of.)
2482     call->set_cnt(PROB_UNLIKELY_MAG(4));
2483   }
2484 
2485   Node* c = _gvn.transform(call);
2486   assert(c == call, "cannot disappear");
2487 
2488   if (wide_out) {
2489     // Slow path call has full side-effects.
2490     set_predefined_output_for_runtime_call(call);
2491   } else {
2492     // Slow path call has few side-effects, and/or sets few values.
2493     set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2494   }
2495 
2496   if (has_io) {
2497     set_i_o(_gvn.transform(new ProjNode(call, TypeFunc::I_O)));
2498   }
2499   return call;
2500 
2501 }
2502 
2503 //------------------------------merge_memory-----------------------------------
2504 // Merge memory from one path into the current memory state.
2505 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2506   for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2507     Node* old_slice = mms.force_memory();
2508     Node* new_slice = mms.memory2();
2509     if (old_slice != new_slice) {
2510       PhiNode* phi;
2511       if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region) {
2512         if (mms.is_empty()) {
2513           // clone base memory Phi's inputs for this memory slice
2514           assert(old_slice == mms.base_memory(), "sanity");
2515           phi = PhiNode::make(region, NULL, Type::MEMORY, mms.adr_type(C));
2516           _gvn.set_type(phi, Type::MEMORY);
2517           for (uint i = 1; i < phi->req(); i++) {
2518             phi->init_req(i, old_slice->in(i));
2519           }
2520         } else {
2521           phi = old_slice->as_Phi(); // Phi was generated already
2522         }
2523       } else {
2524         phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2525         _gvn.set_type(phi, Type::MEMORY);
2526       }
2527       phi->set_req(new_path, new_slice);
2528       mms.set_memory(phi);
2529     }
2530   }
2531 }
2532 
2533 //------------------------------make_slow_call_ex------------------------------
2534 // Make the exception handler hookups for the slow call
2535 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj, bool deoptimize) {
2536   if (stopped())  return;
2537 
2538   // Make a catch node with just two handlers:  fall-through and catch-all
2539   Node* i_o  = _gvn.transform( new ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2540   Node* catc = _gvn.transform( new CatchNode(control(), i_o, 2) );
2541   Node* norm = _gvn.transform( new CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
2542   Node* excp = _gvn.transform( new CatchProjNode(catc, CatchProjNode::catch_all_index,    CatchProjNode::no_handler_bci) );
2543 
2544   { PreserveJVMState pjvms(this);
2545     set_control(excp);
2546     set_i_o(i_o);
2547 
2548     if (excp != top()) {
2549       if (deoptimize) {
2550         // Deoptimize if an exception is caught. Don't construct exception state in this case.
2551         uncommon_trap(Deoptimization::Reason_unhandled,
2552                       Deoptimization::Action_none);
2553       } else {
2554         // Create an exception state also.
2555         // Use an exact type if the caller has specified a specific exception.
2556         const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2557         Node*       ex_oop  = new CreateExNode(ex_type, control(), i_o);
2558         add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2559       }
2560     }
2561   }
2562 
2563   // Get the no-exception control from the CatchNode.
2564   set_control(norm);
2565 }
2566 
2567 static IfNode* gen_subtype_check_compare(Node* ctrl, Node* in1, Node* in2, BoolTest::mask test, float p, PhaseGVN* gvn, BasicType bt) {
2568   Node* cmp = NULL;
2569   switch(bt) {
2570   case T_INT: cmp = new CmpINode(in1, in2); break;
2571   case T_ADDRESS: cmp = new CmpPNode(in1, in2); break;
2572   default: fatal("unexpected comparison type %s", type2name(bt));
2573   }
2574   gvn->transform(cmp);
2575   Node* bol = gvn->transform(new BoolNode(cmp, test));
2576   IfNode* iff = new IfNode(ctrl, bol, p, COUNT_UNKNOWN);
2577   gvn->transform(iff);
2578   if (!bol->is_Con()) gvn->record_for_igvn(iff);
2579   return iff;
2580 }
2581 
2582 
2583 //-------------------------------gen_subtype_check-----------------------------
2584 // Generate a subtyping check.  Takes as input the subtype and supertype.
2585 // Returns 2 values: sets the default control() to the true path and returns
2586 // the false path.  Only reads invariant memory; sets no (visible) memory.
2587 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2588 // but that's not exposed to the optimizer.  This call also doesn't take in an
2589 // Object; if you wish to check an Object you need to load the Object's class
2590 // prior to coming here.
2591 Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, MergeMemNode* mem, PhaseGVN* gvn) {
2592   Compile* C = gvn->C;
2593 
2594   if ((*ctrl)->is_top()) {
2595     return C->top();
2596   }
2597 
2598   // Fast check for identical types, perhaps identical constants.
2599   // The types can even be identical non-constants, in cases
2600   // involving Array.newInstance, Object.clone, etc.
2601   if (subklass == superklass)
2602     return C->top();             // false path is dead; no test needed.
2603 
2604   if (gvn->type(superklass)->singleton()) {
2605     ciKlass* superk = gvn->type(superklass)->is_klassptr()->klass();
2606     ciKlass* subk   = gvn->type(subklass)->is_klassptr()->klass();
2607 
2608     // In the common case of an exact superklass, try to fold up the
2609     // test before generating code.  You may ask, why not just generate
2610     // the code and then let it fold up?  The answer is that the generated
2611     // code will necessarily include null checks, which do not always
2612     // completely fold away.  If they are also needless, then they turn
2613     // into a performance loss.  Example:
2614     //    Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2615     // Here, the type of 'fa' is often exact, so the store check
2616     // of fa[1]=x will fold up, without testing the nullness of x.
2617     switch (C->static_subtype_check(superk, subk)) {
2618     case Compile::SSC_always_false:
2619       {
2620         Node* always_fail = *ctrl;
2621         *ctrl = gvn->C->top();
2622         return always_fail;
2623       }
2624     case Compile::SSC_always_true:
2625       return C->top();
2626     case Compile::SSC_easy_test:
2627       {
2628         // Just do a direct pointer compare and be done.
2629         IfNode* iff = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_STATIC_FREQUENT, gvn, T_ADDRESS);
2630         *ctrl = gvn->transform(new IfTrueNode(iff));
2631         return gvn->transform(new IfFalseNode(iff));
2632       }
2633     case Compile::SSC_full_test:
2634       break;
2635     default:
2636       ShouldNotReachHere();
2637     }
2638   }
2639 
2640   // %%% Possible further optimization:  Even if the superklass is not exact,
2641   // if the subklass is the unique subtype of the superklass, the check
2642   // will always succeed.  We could leave a dependency behind to ensure this.
2643 
2644   // First load the super-klass's check-offset
2645   Node *p1 = gvn->transform(new AddPNode(superklass, superklass, gvn->MakeConX(in_bytes(Klass::super_check_offset_offset()))));
2646   Node* m = mem->memory_at(C->get_alias_index(gvn->type(p1)->is_ptr()));
2647   Node *chk_off = gvn->transform(new LoadINode(NULL, m, p1, gvn->type(p1)->is_ptr(), TypeInt::INT, MemNode::unordered));
2648   int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
2649   bool might_be_cache = (gvn->find_int_con(chk_off, cacheoff_con) == cacheoff_con);
2650 
2651   // Load from the sub-klass's super-class display list, or a 1-word cache of
2652   // the secondary superclass list, or a failing value with a sentinel offset
2653   // if the super-klass is an interface or exceptionally deep in the Java
2654   // hierarchy and we have to scan the secondary superclass list the hard way.
2655   // Worst-case type is a little odd: NULL is allowed as a result (usually
2656   // klass loads can never produce a NULL).
2657   Node *chk_off_X = chk_off;
2658 #ifdef _LP64
2659   chk_off_X = gvn->transform(new ConvI2LNode(chk_off_X));
2660 #endif
2661   Node *p2 = gvn->transform(new AddPNode(subklass,subklass,chk_off_X));
2662   // For some types like interfaces the following loadKlass is from a 1-word
2663   // cache which is mutable so can't use immutable memory.  Other
2664   // types load from the super-class display table which is immutable.
2665   m = mem->memory_at(C->get_alias_index(gvn->type(p2)->is_ptr()));
2666   Node *kmem = might_be_cache ? m : C->immutable_memory();
2667   Node *nkls = gvn->transform(LoadKlassNode::make(*gvn, NULL, kmem, p2, gvn->type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL));
2668 
2669   // Compile speed common case: ARE a subtype and we canNOT fail
2670   if( superklass == nkls )
2671     return C->top();             // false path is dead; no test needed.
2672 
2673   // See if we get an immediate positive hit.  Happens roughly 83% of the
2674   // time.  Test to see if the value loaded just previously from the subklass
2675   // is exactly the superklass.
2676   IfNode *iff1 = gen_subtype_check_compare(*ctrl, superklass, nkls, BoolTest::eq, PROB_LIKELY(0.83f), gvn, T_ADDRESS);
2677   Node *iftrue1 = gvn->transform( new IfTrueNode (iff1));
2678   *ctrl = gvn->transform(new IfFalseNode(iff1));
2679 
2680   // Compile speed common case: Check for being deterministic right now.  If
2681   // chk_off is a constant and not equal to cacheoff then we are NOT a
2682   // subklass.  In this case we need exactly the 1 test above and we can
2683   // return those results immediately.
2684   if (!might_be_cache) {
2685     Node* not_subtype_ctrl = *ctrl;
2686     *ctrl = iftrue1; // We need exactly the 1 test above
2687     return not_subtype_ctrl;
2688   }
2689 
2690   // Gather the various success & failures here
2691   RegionNode *r_ok_subtype = new RegionNode(4);
2692   gvn->record_for_igvn(r_ok_subtype);
2693   RegionNode *r_not_subtype = new RegionNode(3);
2694   gvn->record_for_igvn(r_not_subtype);
2695 
2696   r_ok_subtype->init_req(1, iftrue1);
2697 
2698   // Check for immediate negative hit.  Happens roughly 11% of the time (which
2699   // is roughly 63% of the remaining cases).  Test to see if the loaded
2700   // check-offset points into the subklass display list or the 1-element
2701   // cache.  If it points to the display (and NOT the cache) and the display
2702   // missed then it's not a subtype.
2703   Node *cacheoff = gvn->intcon(cacheoff_con);
2704   IfNode *iff2 = gen_subtype_check_compare(*ctrl, chk_off, cacheoff, BoolTest::ne, PROB_LIKELY(0.63f), gvn, T_INT);
2705   r_not_subtype->init_req(1, gvn->transform(new IfTrueNode (iff2)));
2706   *ctrl = gvn->transform(new IfFalseNode(iff2));
2707 
2708   // Check for self.  Very rare to get here, but it is taken 1/3 the time.
2709   // No performance impact (too rare) but allows sharing of secondary arrays
2710   // which has some footprint reduction.
2711   IfNode *iff3 = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_LIKELY(0.36f), gvn, T_ADDRESS);
2712   r_ok_subtype->init_req(2, gvn->transform(new IfTrueNode(iff3)));
2713   *ctrl = gvn->transform(new IfFalseNode(iff3));
2714 
2715   // -- Roads not taken here: --
2716   // We could also have chosen to perform the self-check at the beginning
2717   // of this code sequence, as the assembler does.  This would not pay off
2718   // the same way, since the optimizer, unlike the assembler, can perform
2719   // static type analysis to fold away many successful self-checks.
2720   // Non-foldable self checks work better here in second position, because
2721   // the initial primary superclass check subsumes a self-check for most
2722   // types.  An exception would be a secondary type like array-of-interface,
2723   // which does not appear in its own primary supertype display.
2724   // Finally, we could have chosen to move the self-check into the
2725   // PartialSubtypeCheckNode, and from there out-of-line in a platform
2726   // dependent manner.  But it is worthwhile to have the check here,
2727   // where it can be perhaps be optimized.  The cost in code space is
2728   // small (register compare, branch).
2729 
2730   // Now do a linear scan of the secondary super-klass array.  Again, no real
2731   // performance impact (too rare) but it's gotta be done.
2732   // Since the code is rarely used, there is no penalty for moving it
2733   // out of line, and it can only improve I-cache density.
2734   // The decision to inline or out-of-line this final check is platform
2735   // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2736   Node* psc = gvn->transform(
2737     new PartialSubtypeCheckNode(*ctrl, subklass, superklass));
2738 
2739   IfNode *iff4 = gen_subtype_check_compare(*ctrl, psc, gvn->zerocon(T_OBJECT), BoolTest::ne, PROB_FAIR, gvn, T_ADDRESS);
2740   r_not_subtype->init_req(2, gvn->transform(new IfTrueNode (iff4)));
2741   r_ok_subtype ->init_req(3, gvn->transform(new IfFalseNode(iff4)));
2742 
2743   // Return false path; set default control to true path.
2744   *ctrl = gvn->transform(r_ok_subtype);
2745   return gvn->transform(r_not_subtype);
2746 }
2747 
2748 // Profile-driven exact type check:
2749 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
2750                                     float prob,
2751                                     Node* *casted_receiver) {
2752   const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2753   Node* recv_klass = load_object_klass(receiver);
2754   Node* want_klass = makecon(tklass);
2755   Node* cmp = _gvn.transform( new CmpPNode(recv_klass, want_klass) );
2756   Node* bol = _gvn.transform( new BoolNode(cmp, BoolTest::eq) );
2757   IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
2758   set_control( _gvn.transform( new IfTrueNode (iff) ));
2759   Node* fail = _gvn.transform( new IfFalseNode(iff) );
2760 
2761   const TypeOopPtr* recv_xtype = tklass->as_instance_type();
2762   assert(recv_xtype->klass_is_exact(), "");
2763 
2764   // Subsume downstream occurrences of receiver with a cast to
2765   // recv_xtype, since now we know what the type will be.
2766   Node* cast = new CheckCastPPNode(control(), receiver, recv_xtype);
2767   (*casted_receiver) = _gvn.transform(cast);
2768   // (User must make the replace_in_map call.)
2769 
2770   return fail;
2771 }
2772 
2773 
2774 //------------------------------seems_never_null-------------------------------
2775 // Use null_seen information if it is available from the profile.
2776 // If we see an unexpected null at a type check we record it and force a
2777 // recompile; the offending check will be recompiled to handle NULLs.
2778 // If we see several offending BCIs, then all checks in the
2779 // method will be recompiled.
2780 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data, bool& speculating) {
2781   speculating = !_gvn.type(obj)->speculative_maybe_null();
2782   Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculating);
2783   if (UncommonNullCast               // Cutout for this technique
2784       && obj != null()               // And not the -Xcomp stupid case?
2785       && !too_many_traps(reason)
2786       ) {
2787     if (speculating) {
2788       return true;
2789     }
2790     if (data == NULL)
2791       // Edge case:  no mature data.  Be optimistic here.
2792       return true;
2793     // If the profile has not seen a null, assume it won't happen.
2794     assert(java_bc() == Bytecodes::_checkcast ||
2795            java_bc() == Bytecodes::_instanceof ||
2796            java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
2797     return !data->as_BitData()->null_seen();
2798   }
2799   speculating = false;
2800   return false;
2801 }
2802 
2803 //------------------------maybe_cast_profiled_receiver-------------------------
2804 // If the profile has seen exactly one type, narrow to exactly that type.
2805 // Subsequent type checks will always fold up.
2806 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
2807                                              ciKlass* require_klass,
2808                                              ciKlass* spec_klass,
2809                                              bool safe_for_replace) {
2810   if (!UseTypeProfile || !TypeProfileCasts) return NULL;
2811 
2812   Deoptimization::DeoptReason reason = Deoptimization::reason_class_check(spec_klass != NULL);
2813 
2814   // Make sure we haven't already deoptimized from this tactic.
2815   if (too_many_traps(reason) || too_many_recompiles(reason))
2816     return NULL;
2817 
2818   // (No, this isn't a call, but it's enough like a virtual call
2819   // to use the same ciMethod accessor to get the profile info...)
2820   // If we have a speculative type use it instead of profiling (which
2821   // may not help us)
2822   ciKlass* exact_kls = spec_klass == NULL ? profile_has_unique_klass() : spec_klass;
2823   if (exact_kls != NULL) {// no cast failures here
2824     if (require_klass == NULL ||
2825         C->static_subtype_check(require_klass, exact_kls) == Compile::SSC_always_true) {
2826       // If we narrow the type to match what the type profile sees or
2827       // the speculative type, we can then remove the rest of the
2828       // cast.
2829       // This is a win, even if the exact_kls is very specific,
2830       // because downstream operations, such as method calls,
2831       // will often benefit from the sharper type.
2832       Node* exact_obj = not_null_obj; // will get updated in place...
2833       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2834                                             &exact_obj);
2835       { PreserveJVMState pjvms(this);
2836         set_control(slow_ctl);
2837         uncommon_trap_exact(reason, Deoptimization::Action_maybe_recompile);
2838       }
2839       if (safe_for_replace) {
2840         replace_in_map(not_null_obj, exact_obj);
2841       }
2842       return exact_obj;
2843     }
2844     // assert(ssc == Compile::SSC_always_true)... except maybe the profile lied to us.
2845   }
2846 
2847   return NULL;
2848 }
2849 
2850 /**
2851  * Cast obj to type and emit guard unless we had too many traps here
2852  * already
2853  *
2854  * @param obj       node being casted
2855  * @param type      type to cast the node to
2856  * @param not_null  true if we know node cannot be null
2857  */
2858 Node* GraphKit::maybe_cast_profiled_obj(Node* obj,
2859                                         ciKlass* type,
2860                                         bool not_null) {
2861   if (stopped()) {
2862     return obj;
2863   }
2864 
2865   // type == NULL if profiling tells us this object is always null
2866   if (type != NULL) {
2867     Deoptimization::DeoptReason class_reason = Deoptimization::Reason_speculate_class_check;
2868     Deoptimization::DeoptReason null_reason = Deoptimization::Reason_speculate_null_check;
2869 
2870     if (!too_many_traps(null_reason) && !too_many_recompiles(null_reason) &&
2871         !too_many_traps(class_reason) &&
2872         !too_many_recompiles(class_reason)) {
2873       Node* not_null_obj = NULL;
2874       // not_null is true if we know the object is not null and
2875       // there's no need for a null check
2876       if (!not_null) {
2877         Node* null_ctl = top();
2878         not_null_obj = null_check_oop(obj, &null_ctl, true, true, true);
2879         assert(null_ctl->is_top(), "no null control here");
2880       } else {
2881         not_null_obj = obj;
2882       }
2883 
2884       Node* exact_obj = not_null_obj;
2885       ciKlass* exact_kls = type;
2886       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2887                                             &exact_obj);
2888       {
2889         PreserveJVMState pjvms(this);
2890         set_control(slow_ctl);
2891         uncommon_trap_exact(class_reason, Deoptimization::Action_maybe_recompile);
2892       }
2893       replace_in_map(not_null_obj, exact_obj);
2894       obj = exact_obj;
2895     }
2896   } else {
2897     if (!too_many_traps(Deoptimization::Reason_null_assert) &&
2898         !too_many_recompiles(Deoptimization::Reason_null_assert)) {
2899       Node* exact_obj = null_assert(obj);
2900       replace_in_map(obj, exact_obj);
2901       obj = exact_obj;
2902     }
2903   }
2904   return obj;
2905 }
2906 
2907 //-------------------------------gen_instanceof--------------------------------
2908 // Generate an instance-of idiom.  Used by both the instance-of bytecode
2909 // and the reflective instance-of call.
2910 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replace) {
2911   kill_dead_locals();           // Benefit all the uncommon traps
2912   assert( !stopped(), "dead parse path should be checked in callers" );
2913   assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
2914          "must check for not-null not-dead klass in callers");
2915 
2916   // Make the merge point
2917   enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
2918   RegionNode* region = new RegionNode(PATH_LIMIT);
2919   Node*       phi    = new PhiNode(region, TypeInt::BOOL);
2920   C->set_has_split_ifs(true); // Has chance for split-if optimization
2921 
2922   ciProfileData* data = NULL;
2923   if (java_bc() == Bytecodes::_instanceof) {  // Only for the bytecode
2924     data = method()->method_data()->bci_to_data(bci());
2925   }
2926   bool speculative_not_null = false;
2927   bool never_see_null = (ProfileDynamicTypes  // aggressive use of profile
2928                          && seems_never_null(obj, data, speculative_not_null));
2929 
2930   // Null check; get casted pointer; set region slot 3
2931   Node* null_ctl = top();
2932   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
2933 
2934   // If not_null_obj is dead, only null-path is taken
2935   if (stopped()) {              // Doing instance-of on a NULL?
2936     set_control(null_ctl);
2937     return intcon(0);
2938   }
2939   region->init_req(_null_path, null_ctl);
2940   phi   ->init_req(_null_path, intcon(0)); // Set null path value
2941   if (null_ctl == top()) {
2942     // Do this eagerly, so that pattern matches like is_diamond_phi
2943     // will work even during parsing.
2944     assert(_null_path == PATH_LIMIT-1, "delete last");
2945     region->del_req(_null_path);
2946     phi   ->del_req(_null_path);
2947   }
2948 
2949   // Do we know the type check always succeed?
2950   bool known_statically = false;
2951   if (_gvn.type(superklass)->singleton()) {
2952     ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
2953     ciKlass* subk = _gvn.type(obj)->is_oopptr()->klass();
2954     if (subk != NULL && subk->is_loaded()) {
2955       int static_res = C->static_subtype_check(superk, subk);
2956       known_statically = (static_res == Compile::SSC_always_true || static_res == Compile::SSC_always_false);
2957     }
2958   }
2959 
2960   if (!known_statically) {
2961     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
2962     // We may not have profiling here or it may not help us. If we
2963     // have a speculative type use it to perform an exact cast.
2964     ciKlass* spec_obj_type = obj_type->speculative_type();
2965     if (spec_obj_type != NULL || (ProfileDynamicTypes && data != NULL)) {
2966       Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, NULL, spec_obj_type, safe_for_replace);
2967       if (stopped()) {            // Profile disagrees with this path.
2968         set_control(null_ctl);    // Null is the only remaining possibility.
2969         return intcon(0);
2970       }
2971       if (cast_obj != NULL) {
2972         not_null_obj = cast_obj;
2973       }
2974     }
2975   }
2976 
2977   // Load the object's klass
2978   Node* obj_klass = load_object_klass(not_null_obj);
2979 
2980   // Generate the subtype check
2981   Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);
2982 
2983   // Plug in the success path to the general merge in slot 1.
2984   region->init_req(_obj_path, control());
2985   phi   ->init_req(_obj_path, intcon(1));
2986 
2987   // Plug in the failing path to the general merge in slot 2.
2988   region->init_req(_fail_path, not_subtype_ctrl);
2989   phi   ->init_req(_fail_path, intcon(0));
2990 
2991   // Return final merged results
2992   set_control( _gvn.transform(region) );
2993   record_for_igvn(region);
2994 
2995   // If we know the type check always succeeds then we don't use the
2996   // profiling data at this bytecode. Don't lose it, feed it to the
2997   // type system as a speculative type.
2998   if (safe_for_replace) {
2999     Node* casted_obj = record_profiled_receiver_for_speculation(obj);
3000     replace_in_map(obj, casted_obj);
3001   }
3002 
3003   return _gvn.transform(phi);
3004 }
3005 
3006 //-------------------------------gen_checkcast---------------------------------
3007 // Generate a checkcast idiom.  Used by both the checkcast bytecode and the
3008 // array store bytecode.  Stack must be as-if BEFORE doing the bytecode so the
3009 // uncommon-trap paths work.  Adjust stack after this call.
3010 // If failure_control is supplied and not null, it is filled in with
3011 // the control edge for the cast failure.  Otherwise, an appropriate
3012 // uncommon trap or exception is thrown.
3013 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
3014                               Node* *failure_control) {
3015   kill_dead_locals();           // Benefit all the uncommon traps
3016   const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr();
3017   const Type *toop = TypeOopPtr::make_from_klass(tk->klass());
3018 
3019   // Fast cutout:  Check the case that the cast is vacuously true.
3020   // This detects the common cases where the test will short-circuit
3021   // away completely.  We do this before we perform the null check,
3022   // because if the test is going to turn into zero code, we don't
3023   // want a residual null check left around.  (Causes a slowdown,
3024   // for example, in some objArray manipulations, such as a[i]=a[j].)
3025   if (tk->singleton()) {
3026     const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
3027     if (objtp != NULL && objtp->klass() != NULL) {
3028       switch (C->static_subtype_check(tk->klass(), objtp->klass())) {
3029       case Compile::SSC_always_true:
3030         // If we know the type check always succeed then we don't use
3031         // the profiling data at this bytecode. Don't lose it, feed it
3032         // to the type system as a speculative type.
3033         return record_profiled_receiver_for_speculation(obj);
3034       case Compile::SSC_always_false:
3035         // It needs a null check because a null will *pass* the cast check.
3036         // A non-null value will always produce an exception.
3037         return null_assert(obj);
3038       }
3039     }
3040   }
3041 
3042   ciProfileData* data = NULL;
3043   bool safe_for_replace = false;
3044   if (failure_control == NULL) {        // use MDO in regular case only
3045     assert(java_bc() == Bytecodes::_aastore ||
3046            java_bc() == Bytecodes::_checkcast,
3047            "interpreter profiles type checks only for these BCs");
3048     data = method()->method_data()->bci_to_data(bci());
3049     safe_for_replace = true;
3050   }
3051 
3052   // Make the merge point
3053   enum { _obj_path = 1, _null_path, PATH_LIMIT };
3054   RegionNode* region = new RegionNode(PATH_LIMIT);
3055   Node*       phi    = new PhiNode(region, toop);
3056   C->set_has_split_ifs(true); // Has chance for split-if optimization
3057 
3058   // Use null-cast information if it is available
3059   bool speculative_not_null = false;
3060   bool never_see_null = ((failure_control == NULL)  // regular case only
3061                          && seems_never_null(obj, data, speculative_not_null));
3062 
3063   // Null check; get casted pointer; set region slot 3
3064   Node* null_ctl = top();
3065   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
3066 
3067   // If not_null_obj is dead, only null-path is taken
3068   if (stopped()) {              // Doing instance-of on a NULL?
3069     set_control(null_ctl);
3070     return null();
3071   }
3072   region->init_req(_null_path, null_ctl);
3073   phi   ->init_req(_null_path, null());  // Set null path value
3074   if (null_ctl == top()) {
3075     // Do this eagerly, so that pattern matches like is_diamond_phi
3076     // will work even during parsing.
3077     assert(_null_path == PATH_LIMIT-1, "delete last");
3078     region->del_req(_null_path);
3079     phi   ->del_req(_null_path);
3080   }
3081 
3082   Node* cast_obj = NULL;
3083   if (tk->klass_is_exact()) {
3084     // The following optimization tries to statically cast the speculative type of the object
3085     // (for example obtained during profiling) to the type of the superklass and then do a
3086     // dynamic check that the type of the object is what we expect. To work correctly
3087     // for checkcast and aastore the type of superklass should be exact.
3088     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
3089     // We may not have profiling here or it may not help us. If we have
3090     // a speculative type use it to perform an exact cast.
3091     ciKlass* spec_obj_type = obj_type->speculative_type();
3092     if (spec_obj_type != NULL || data != NULL) {
3093       cast_obj = maybe_cast_profiled_receiver(not_null_obj, tk->klass(), spec_obj_type, safe_for_replace);
3094       if (cast_obj != NULL) {
3095         if (failure_control != NULL) // failure is now impossible
3096           (*failure_control) = top();
3097         // adjust the type of the phi to the exact klass:
3098         phi->raise_bottom_type(_gvn.type(cast_obj)->meet_speculative(TypePtr::NULL_PTR));
3099       }
3100     }
3101   }
3102 
3103   if (cast_obj == NULL) {
3104     // Load the object's klass
3105     Node* obj_klass = load_object_klass(not_null_obj);
3106 
3107     // Generate the subtype check
3108     Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );
3109 
3110     // Plug in success path into the merge
3111     cast_obj = _gvn.transform(new CheckCastPPNode(control(), not_null_obj, toop));
3112     // Failure path ends in uncommon trap (or may be dead - failure impossible)
3113     if (failure_control == NULL) {
3114       if (not_subtype_ctrl != top()) { // If failure is possible
3115         PreserveJVMState pjvms(this);
3116         set_control(not_subtype_ctrl);
3117         builtin_throw(Deoptimization::Reason_class_check, obj_klass);
3118       }
3119     } else {
3120       (*failure_control) = not_subtype_ctrl;
3121     }
3122   }
3123 
3124   region->init_req(_obj_path, control());
3125   phi   ->init_req(_obj_path, cast_obj);
3126 
3127   // A merge of NULL or Casted-NotNull obj
3128   Node* res = _gvn.transform(phi);
3129 
3130   // Note I do NOT always 'replace_in_map(obj,result)' here.
3131   //  if( tk->klass()->can_be_primary_super()  )
3132     // This means that if I successfully store an Object into an array-of-String
3133     // I 'forget' that the Object is really now known to be a String.  I have to
3134     // do this because we don't have true union types for interfaces - if I store
3135     // a Baz into an array-of-Interface and then tell the optimizer it's an
3136     // Interface, I forget that it's also a Baz and cannot do Baz-like field
3137     // references to it.  FIX THIS WHEN UNION TYPES APPEAR!
3138   //  replace_in_map( obj, res );
3139 
3140   // Return final merged results
3141   set_control( _gvn.transform(region) );
3142   record_for_igvn(region);
3143 
3144   return record_profiled_receiver_for_speculation(res);
3145 }
3146 
3147 //------------------------------next_monitor-----------------------------------
3148 // What number should be given to the next monitor?
3149 int GraphKit::next_monitor() {
3150   int current = jvms()->monitor_depth()* C->sync_stack_slots();
3151   int next = current + C->sync_stack_slots();
3152   // Keep the toplevel high water mark current:
3153   if (C->fixed_slots() < next)  C->set_fixed_slots(next);
3154   return current;
3155 }
3156 
3157 //------------------------------insert_mem_bar---------------------------------
3158 // Memory barrier to avoid floating things around
3159 // The membar serves as a pinch point between both control and all memory slices.
3160 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
3161   MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
3162   mb->init_req(TypeFunc::Control, control());
3163   mb->init_req(TypeFunc::Memory,  reset_memory());
3164   Node* membar = _gvn.transform(mb);
3165   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3166   set_all_memory_call(membar);
3167   return membar;
3168 }
3169 
3170 //-------------------------insert_mem_bar_volatile----------------------------
3171 // Memory barrier to avoid floating things around
3172 // The membar serves as a pinch point between both control and memory(alias_idx).
3173 // If you want to make a pinch point on all memory slices, do not use this
3174 // function (even with AliasIdxBot); use insert_mem_bar() instead.
3175 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
3176   // When Parse::do_put_xxx updates a volatile field, it appends a series
3177   // of MemBarVolatile nodes, one for *each* volatile field alias category.
3178   // The first membar is on the same memory slice as the field store opcode.
3179   // This forces the membar to follow the store.  (Bug 6500685 broke this.)
3180   // All the other membars (for other volatile slices, including AliasIdxBot,
3181   // which stands for all unknown volatile slices) are control-dependent
3182   // on the first membar.  This prevents later volatile loads or stores
3183   // from sliding up past the just-emitted store.
3184 
3185   MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
3186   mb->set_req(TypeFunc::Control,control());
3187   if (alias_idx == Compile::AliasIdxBot) {
3188     mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
3189   } else {
3190     assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
3191     mb->set_req(TypeFunc::Memory, memory(alias_idx));
3192   }
3193   Node* membar = _gvn.transform(mb);
3194   set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3195   if (alias_idx == Compile::AliasIdxBot) {
3196     merged_memory()->set_base_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)));
3197   } else {
3198     set_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)),alias_idx);
3199   }
3200   return membar;
3201 }
3202 
3203 //------------------------------shared_lock------------------------------------
3204 // Emit locking code.
3205 FastLockNode* GraphKit::shared_lock(Node* obj) {
3206   // bci is either a monitorenter bc or InvocationEntryBci
3207   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3208   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3209 
3210   if( !GenerateSynchronizationCode )
3211     return NULL;                // Not locking things?
3212   if (stopped())                // Dead monitor?
3213     return NULL;
3214 
3215   assert(dead_locals_are_killed(), "should kill locals before sync. point");
3216 
3217   // Box the stack location
3218   Node* box = _gvn.transform(new BoxLockNode(next_monitor()));
3219   Node* mem = reset_memory();
3220 
3221   FastLockNode * flock = _gvn.transform(new FastLockNode(0, obj, box) )->as_FastLock();
3222   if (UseBiasedLocking && PrintPreciseBiasedLockingStatistics) {
3223     // Create the counters for this fast lock.
3224     flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3225   }
3226 
3227   // Create the rtm counters for this fast lock if needed.
3228   flock->create_rtm_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3229 
3230   // Add monitor to debug info for the slow path.  If we block inside the
3231   // slow path and de-opt, we need the monitor hanging around
3232   map()->push_monitor( flock );
3233 
3234   const TypeFunc *tf = LockNode::lock_type();
3235   LockNode *lock = new LockNode(C, tf);
3236 
3237   lock->init_req( TypeFunc::Control, control() );
3238   lock->init_req( TypeFunc::Memory , mem );
3239   lock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3240   lock->init_req( TypeFunc::FramePtr, frameptr() );
3241   lock->init_req( TypeFunc::ReturnAdr, top() );
3242 
3243   lock->init_req(TypeFunc::Parms + 0, obj);
3244   lock->init_req(TypeFunc::Parms + 1, box);
3245   lock->init_req(TypeFunc::Parms + 2, flock);
3246   add_safepoint_edges(lock);
3247 
3248   lock = _gvn.transform( lock )->as_Lock();
3249 
3250   // lock has no side-effects, sets few values
3251   set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
3252 
3253   insert_mem_bar(Op_MemBarAcquireLock);
3254 
3255   // Add this to the worklist so that the lock can be eliminated
3256   record_for_igvn(lock);
3257 
3258 #ifndef PRODUCT
3259   if (PrintLockStatistics) {
3260     // Update the counter for this lock.  Don't bother using an atomic
3261     // operation since we don't require absolute accuracy.
3262     lock->create_lock_counter(map()->jvms());
3263     increment_counter(lock->counter()->addr());
3264   }
3265 #endif
3266 
3267   return flock;
3268 }
3269 
3270 
3271 //------------------------------shared_unlock----------------------------------
3272 // Emit unlocking code.
3273 void GraphKit::shared_unlock(Node* box, Node* obj) {
3274   // bci is either a monitorenter bc or InvocationEntryBci
3275   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3276   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3277 
3278   if( !GenerateSynchronizationCode )
3279     return;
3280   if (stopped()) {               // Dead monitor?
3281     map()->pop_monitor();        // Kill monitor from debug info
3282     return;
3283   }
3284 
3285   // Memory barrier to avoid floating things down past the locked region
3286   insert_mem_bar(Op_MemBarReleaseLock);
3287 
3288   const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
3289   UnlockNode *unlock = new UnlockNode(C, tf);
3290 #ifdef ASSERT
3291   unlock->set_dbg_jvms(sync_jvms());
3292 #endif
3293   uint raw_idx = Compile::AliasIdxRaw;
3294   unlock->init_req( TypeFunc::Control, control() );
3295   unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
3296   unlock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3297   unlock->init_req( TypeFunc::FramePtr, frameptr() );
3298   unlock->init_req( TypeFunc::ReturnAdr, top() );
3299 
3300   unlock->init_req(TypeFunc::Parms + 0, obj);
3301   unlock->init_req(TypeFunc::Parms + 1, box);
3302   unlock = _gvn.transform(unlock)->as_Unlock();
3303 
3304   Node* mem = reset_memory();
3305 
3306   // unlock has no side-effects, sets few values
3307   set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
3308 
3309   // Kill monitor from debug info
3310   map()->pop_monitor( );
3311 }
3312 
3313 //-------------------------------get_layout_helper-----------------------------
3314 // If the given klass is a constant or known to be an array,
3315 // fetch the constant layout helper value into constant_value
3316 // and return (Node*)NULL.  Otherwise, load the non-constant
3317 // layout helper value, and return the node which represents it.
3318 // This two-faced routine is useful because allocation sites
3319 // almost always feature constant types.
3320 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
3321   const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr();
3322   if (!StressReflectiveCode && inst_klass != NULL) {
3323     ciKlass* klass = inst_klass->klass();
3324     bool    xklass = inst_klass->klass_is_exact();
3325     if (xklass || klass->is_array_klass()) {
3326       jint lhelper = klass->layout_helper();
3327       if (lhelper != Klass::_lh_neutral_value) {
3328         constant_value = lhelper;
3329         return (Node*) NULL;
3330       }
3331     }
3332   }
3333   constant_value = Klass::_lh_neutral_value;  // put in a known value
3334   Node* lhp = basic_plus_adr(klass_node, klass_node, in_bytes(Klass::layout_helper_offset()));
3335   return make_load(NULL, lhp, TypeInt::INT, T_INT, MemNode::unordered);
3336 }
3337 
3338 // We just put in an allocate/initialize with a big raw-memory effect.
3339 // Hook selected additional alias categories on the initialization.
3340 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
3341                                 MergeMemNode* init_in_merge,
3342                                 Node* init_out_raw) {
3343   DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
3344   assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
3345 
3346   Node* prevmem = kit.memory(alias_idx);
3347   init_in_merge->set_memory_at(alias_idx, prevmem);
3348   kit.set_memory(init_out_raw, alias_idx);
3349 }
3350 
3351 //---------------------------set_output_for_allocation-------------------------
3352 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
3353                                           const TypeOopPtr* oop_type,
3354                                           bool deoptimize_on_exception) {
3355   int rawidx = Compile::AliasIdxRaw;
3356   alloc->set_req( TypeFunc::FramePtr, frameptr() );
3357   add_safepoint_edges(alloc);
3358   Node* allocx = _gvn.transform(alloc);
3359   set_control( _gvn.transform(new ProjNode(allocx, TypeFunc::Control) ) );
3360   // create memory projection for i_o
3361   set_memory ( _gvn.transform( new ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
3362   make_slow_call_ex(allocx, env()->Throwable_klass(), true, deoptimize_on_exception);
3363 
3364   // create a memory projection as for the normal control path
3365   Node* malloc = _gvn.transform(new ProjNode(allocx, TypeFunc::Memory));
3366   set_memory(malloc, rawidx);
3367 
3368   // a normal slow-call doesn't change i_o, but an allocation does
3369   // we create a separate i_o projection for the normal control path
3370   set_i_o(_gvn.transform( new ProjNode(allocx, TypeFunc::I_O, false) ) );
3371   Node* rawoop = _gvn.transform( new ProjNode(allocx, TypeFunc::Parms) );
3372 
3373   // put in an initialization barrier
3374   InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
3375                                                  rawoop)->as_Initialize();
3376   assert(alloc->initialization() == init,  "2-way macro link must work");
3377   assert(init ->allocation()     == alloc, "2-way macro link must work");
3378   {
3379     // Extract memory strands which may participate in the new object's
3380     // initialization, and source them from the new InitializeNode.
3381     // This will allow us to observe initializations when they occur,
3382     // and link them properly (as a group) to the InitializeNode.
3383     assert(init->in(InitializeNode::Memory) == malloc, "");
3384     MergeMemNode* minit_in = MergeMemNode::make(malloc);
3385     init->set_req(InitializeNode::Memory, minit_in);
3386     record_for_igvn(minit_in); // fold it up later, if possible
3387     Node* minit_out = memory(rawidx);
3388     assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
3389     if (oop_type->isa_aryptr()) {
3390       const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
3391       int            elemidx  = C->get_alias_index(telemref);
3392       hook_memory_on_init(*this, elemidx, minit_in, minit_out);
3393     } else if (oop_type->isa_instptr()) {
3394       ciInstanceKlass* ik = oop_type->klass()->as_instance_klass();
3395       for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
3396         ciField* field = ik->nonstatic_field_at(i);
3397         if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
3398           continue;  // do not bother to track really large numbers of fields
3399         // Find (or create) the alias category for this field:
3400         int fieldidx = C->alias_type(field)->index();
3401         hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
3402       }
3403     }
3404   }
3405 
3406   // Cast raw oop to the real thing...
3407   Node* javaoop = new CheckCastPPNode(control(), rawoop, oop_type);
3408   javaoop = _gvn.transform(javaoop);
3409   C->set_recent_alloc(control(), javaoop);
3410   assert(just_allocated_object(control()) == javaoop, "just allocated");
3411 
3412 #ifdef ASSERT
3413   { // Verify that the AllocateNode::Ideal_allocation recognizers work:
3414     assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc,
3415            "Ideal_allocation works");
3416     assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc,
3417            "Ideal_allocation works");
3418     if (alloc->is_AllocateArray()) {
3419       assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(),
3420              "Ideal_allocation works");
3421       assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(),
3422              "Ideal_allocation works");
3423     } else {
3424       assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
3425     }
3426   }
3427 #endif //ASSERT
3428 
3429   return javaoop;
3430 }
3431 
3432 //---------------------------new_instance--------------------------------------
3433 // This routine takes a klass_node which may be constant (for a static type)
3434 // or may be non-constant (for reflective code).  It will work equally well
3435 // for either, and the graph will fold nicely if the optimizer later reduces
3436 // the type to a constant.
3437 // The optional arguments are for specialized use by intrinsics:
3438 //  - If 'extra_slow_test' if not null is an extra condition for the slow-path.
3439 //  - If 'return_size_val', report the the total object size to the caller.
3440 //  - deoptimize_on_exception controls how Java exceptions are handled (rethrow vs deoptimize)
3441 Node* GraphKit::new_instance(Node* klass_node,
3442                              Node* extra_slow_test,
3443                              Node* *return_size_val,
3444                              bool deoptimize_on_exception) {
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   } else {   // reflective case
3463     // This reflective path is used by Unsafe.allocateInstance.
3464     // (It may be stress-tested by specifying StressReflectiveCode.)
3465     // Basically, we want to get into the VM is there's an illegal argument.
3466     Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
3467     initial_slow_test = _gvn.transform( new AndINode(layout_val, bit) );
3468     if (extra_slow_test != intcon(0)) {
3469       initial_slow_test = _gvn.transform( new OrINode(initial_slow_test, extra_slow_test) );
3470     }
3471     // (Macro-expander will further convert this to a Bool, if necessary.)
3472   }
3473 
3474   // Find the size in bytes.  This is easy; it's the layout_helper.
3475   // The size value must be valid even if the slow path is taken.
3476   Node* size = NULL;
3477   if (layout_is_con) {
3478     size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
3479   } else {   // reflective case
3480     // This reflective path is used by clone and Unsafe.allocateInstance.
3481     size = ConvI2X(layout_val);
3482 
3483     // Clear the low bits to extract layout_helper_size_in_bytes:
3484     assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
3485     Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
3486     size = _gvn.transform( new AndXNode(size, mask) );
3487   }
3488   if (return_size_val != NULL) {
3489     (*return_size_val) = size;
3490   }
3491 
3492   // This is a precise notnull oop of the klass.
3493   // (Actually, it need not be precise if this is a reflective allocation.)
3494   // It's what we cast the result to.
3495   const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3496   if (!tklass)  tklass = TypeKlassPtr::OBJECT;
3497   const TypeOopPtr* oop_type = tklass->as_instance_type();
3498 
3499   // Now generate allocation code
3500 
3501   // The entire memory state is needed for slow path of the allocation
3502   // since GC and deoptimization can happened.
3503   Node *mem = reset_memory();
3504   set_all_memory(mem); // Create new memory state
3505 
3506   AllocateNode* alloc = new AllocateNode(C, AllocateNode::alloc_type(Type::TOP),
3507                                          control(), mem, i_o(),
3508                                          size, klass_node,
3509                                          initial_slow_test);
3510 
3511   return set_output_for_allocation(alloc, oop_type, deoptimize_on_exception);
3512 }
3513 
3514 //-------------------------------new_array-------------------------------------
3515 // helper for both newarray and anewarray
3516 // The 'length' parameter is (obviously) the length of the array.
3517 // See comments on new_instance for the meaning of the other arguments.
3518 Node* GraphKit::new_array(Node* klass_node,     // array klass (maybe variable)
3519                           Node* length,         // number of array elements
3520                           int   nargs,          // number of arguments to push back for uncommon trap
3521                           Node* *return_size_val,
3522                           bool deoptimize_on_exception) {
3523   jint  layout_con = Klass::_lh_neutral_value;
3524   Node* layout_val = get_layout_helper(klass_node, layout_con);
3525   int   layout_is_con = (layout_val == NULL);
3526 
3527   if (!layout_is_con && !StressReflectiveCode &&
3528       !too_many_traps(Deoptimization::Reason_class_check)) {
3529     // This is a reflective array creation site.
3530     // Optimistically assume that it is a subtype of Object[],
3531     // so that we can fold up all the address arithmetic.
3532     layout_con = Klass::array_layout_helper(T_OBJECT);
3533     Node* cmp_lh = _gvn.transform( new CmpINode(layout_val, intcon(layout_con)) );
3534     Node* bol_lh = _gvn.transform( new BoolNode(cmp_lh, BoolTest::eq) );
3535     { BuildCutout unless(this, bol_lh, PROB_MAX);
3536       inc_sp(nargs);
3537       uncommon_trap(Deoptimization::Reason_class_check,
3538                     Deoptimization::Action_maybe_recompile);
3539     }
3540     layout_val = NULL;
3541     layout_is_con = true;
3542   }
3543 
3544   // Generate the initial go-slow test.  Make sure we do not overflow
3545   // if length is huge (near 2Gig) or negative!  We do not need
3546   // exact double-words here, just a close approximation of needed
3547   // double-words.  We can't add any offset or rounding bits, lest we
3548   // take a size -1 of bytes and make it positive.  Use an unsigned
3549   // compare, so negative sizes look hugely positive.
3550   int fast_size_limit = FastAllocateSizeLimit;
3551   if (layout_is_con) {
3552     assert(!StressReflectiveCode, "stress mode does not use these paths");
3553     // Increase the size limit if we have exact knowledge of array type.
3554     int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3555     fast_size_limit <<= (LogBytesPerLong - log2_esize);
3556   }
3557 
3558   Node* initial_slow_cmp  = _gvn.transform( new CmpUNode( length, intcon( fast_size_limit ) ) );
3559   Node* initial_slow_test = _gvn.transform( new BoolNode( initial_slow_cmp, BoolTest::gt ) );
3560 
3561   // --- Size Computation ---
3562   // array_size = round_to_heap(array_header + (length << elem_shift));
3563   // where round_to_heap(x) == align_to(x, MinObjAlignmentInBytes)
3564   // and align_to(x, y) == ((x + y-1) & ~(y-1))
3565   // The rounding mask is strength-reduced, if possible.
3566   int round_mask = MinObjAlignmentInBytes - 1;
3567   Node* header_size = NULL;
3568   int   header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3569   // (T_BYTE has the weakest alignment and size restrictions...)
3570   if (layout_is_con) {
3571     int       hsize  = Klass::layout_helper_header_size(layout_con);
3572     int       eshift = Klass::layout_helper_log2_element_size(layout_con);
3573     BasicType etype  = Klass::layout_helper_element_type(layout_con);
3574     if ((round_mask & ~right_n_bits(eshift)) == 0)
3575       round_mask = 0;  // strength-reduce it if it goes away completely
3576     assert((hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3577     assert(header_size_min <= hsize, "generic minimum is smallest");
3578     header_size_min = hsize;
3579     header_size = intcon(hsize + round_mask);
3580   } else {
3581     Node* hss   = intcon(Klass::_lh_header_size_shift);
3582     Node* hsm   = intcon(Klass::_lh_header_size_mask);
3583     Node* hsize = _gvn.transform( new URShiftINode(layout_val, hss) );
3584     hsize       = _gvn.transform( new AndINode(hsize, hsm) );
3585     Node* mask  = intcon(round_mask);
3586     header_size = _gvn.transform( new AddINode(hsize, mask) );
3587   }
3588 
3589   Node* elem_shift = NULL;
3590   if (layout_is_con) {
3591     int eshift = Klass::layout_helper_log2_element_size(layout_con);
3592     if (eshift != 0)
3593       elem_shift = intcon(eshift);
3594   } else {
3595     // There is no need to mask or shift this value.
3596     // The semantics of LShiftINode include an implicit mask to 0x1F.
3597     assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3598     elem_shift = layout_val;
3599   }
3600 
3601   // Transition to native address size for all offset calculations:
3602   Node* lengthx = ConvI2X(length);
3603   Node* headerx = ConvI2X(header_size);
3604 #ifdef _LP64
3605   { const TypeInt* tilen = _gvn.find_int_type(length);
3606     if (tilen != NULL && tilen->_lo < 0) {
3607       // Add a manual constraint to a positive range.  Cf. array_element_address.
3608       jint size_max = fast_size_limit;
3609       if (size_max > tilen->_hi)  size_max = tilen->_hi;
3610       const TypeInt* tlcon = TypeInt::make(0, size_max, Type::WidenMin);
3611 
3612       // Only do a narrow I2L conversion if the range check passed.
3613       IfNode* iff = new IfNode(control(), initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
3614       _gvn.transform(iff);
3615       RegionNode* region = new RegionNode(3);
3616       _gvn.set_type(region, Type::CONTROL);
3617       lengthx = new PhiNode(region, TypeLong::LONG);
3618       _gvn.set_type(lengthx, TypeLong::LONG);
3619 
3620       // Range check passed. Use ConvI2L node with narrow type.
3621       Node* passed = IfFalse(iff);
3622       region->init_req(1, passed);
3623       // Make I2L conversion control dependent to prevent it from
3624       // floating above the range check during loop optimizations.
3625       lengthx->init_req(1, C->constrained_convI2L(&_gvn, length, tlcon, passed));
3626 
3627       // Range check failed. Use ConvI2L with wide type because length may be invalid.
3628       region->init_req(2, IfTrue(iff));
3629       lengthx->init_req(2, ConvI2X(length));
3630 
3631       set_control(region);
3632       record_for_igvn(region);
3633       record_for_igvn(lengthx);
3634     }
3635   }
3636 #endif
3637 
3638   // Combine header size (plus rounding) and body size.  Then round down.
3639   // This computation cannot overflow, because it is used only in two
3640   // places, one where the length is sharply limited, and the other
3641   // after a successful allocation.
3642   Node* abody = lengthx;
3643   if (elem_shift != NULL)
3644     abody     = _gvn.transform( new LShiftXNode(lengthx, elem_shift) );
3645   Node* size  = _gvn.transform( new AddXNode(headerx, abody) );
3646   if (round_mask != 0) {
3647     Node* mask = MakeConX(~round_mask);
3648     size       = _gvn.transform( new AndXNode(size, mask) );
3649   }
3650   // else if round_mask == 0, the size computation is self-rounding
3651 
3652   if (return_size_val != NULL) {
3653     // This is the size
3654     (*return_size_val) = size;
3655   }
3656 
3657   // Now generate allocation code
3658 
3659   // The entire memory state is needed for slow path of the allocation
3660   // since GC and deoptimization can happened.
3661   Node *mem = reset_memory();
3662   set_all_memory(mem); // Create new memory state
3663 
3664   if (initial_slow_test->is_Bool()) {
3665     // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
3666     initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
3667   }
3668 
3669   // Create the AllocateArrayNode and its result projections
3670   AllocateArrayNode* alloc
3671     = new AllocateArrayNode(C, AllocateArrayNode::alloc_type(TypeInt::INT),
3672                             control(), mem, i_o(),
3673                             size, klass_node,
3674                             initial_slow_test,
3675                             length);
3676 
3677   // Cast to correct type.  Note that the klass_node may be constant or not,
3678   // and in the latter case the actual array type will be inexact also.
3679   // (This happens via a non-constant argument to inline_native_newArray.)
3680   // In any case, the value of klass_node provides the desired array type.
3681   const TypeInt* length_type = _gvn.find_int_type(length);
3682   const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
3683   if (ary_type->isa_aryptr() && length_type != NULL) {
3684     // Try to get a better type than POS for the size
3685     ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
3686   }
3687 
3688   Node* javaoop = set_output_for_allocation(alloc, ary_type, deoptimize_on_exception);
3689 
3690   // Cast length on remaining path to be as narrow as possible
3691   if (map()->find_edge(length) >= 0) {
3692     Node* ccast = alloc->make_ideal_length(ary_type, &_gvn);
3693     if (ccast != length) {
3694       _gvn.set_type_bottom(ccast);
3695       record_for_igvn(ccast);
3696       replace_in_map(length, ccast);
3697     }
3698   }
3699 
3700   return javaoop;
3701 }
3702 
3703 // The following "Ideal_foo" functions are placed here because they recognize
3704 // the graph shapes created by the functions immediately above.
3705 
3706 //---------------------------Ideal_allocation----------------------------------
3707 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
3708 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) {
3709   if (ptr == NULL) {     // reduce dumb test in callers
3710     return NULL;
3711   }
3712   if (ptr->is_CheckCastPP()) { // strip only one raw-to-oop cast
3713     ptr = ptr->in(1);
3714     if (ptr == NULL) return NULL;
3715   }
3716   // Return NULL for allocations with several casts:
3717   //   j.l.reflect.Array.newInstance(jobject, jint)
3718   //   Object.clone()
3719   // to keep more precise type from last cast.
3720   if (ptr->is_Proj()) {
3721     Node* allo = ptr->in(0);
3722     if (allo != NULL && allo->is_Allocate()) {
3723       return allo->as_Allocate();
3724     }
3725   }
3726   // Report failure to match.
3727   return NULL;
3728 }
3729 
3730 // Fancy version which also strips off an offset (and reports it to caller).
3731 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase,
3732                                              intptr_t& offset) {
3733   Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
3734   if (base == NULL)  return NULL;
3735   return Ideal_allocation(base, phase);
3736 }
3737 
3738 // Trace Initialize <- Proj[Parm] <- Allocate
3739 AllocateNode* InitializeNode::allocation() {
3740   Node* rawoop = in(InitializeNode::RawAddress);
3741   if (rawoop->is_Proj()) {
3742     Node* alloc = rawoop->in(0);
3743     if (alloc->is_Allocate()) {
3744       return alloc->as_Allocate();
3745     }
3746   }
3747   return NULL;
3748 }
3749 
3750 // Trace Allocate -> Proj[Parm] -> Initialize
3751 InitializeNode* AllocateNode::initialization() {
3752   ProjNode* rawoop = proj_out_or_null(AllocateNode::RawAddress);
3753   if (rawoop == NULL)  return NULL;
3754   for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
3755     Node* init = rawoop->fast_out(i);
3756     if (init->is_Initialize()) {
3757       assert(init->as_Initialize()->allocation() == this, "2-way link");
3758       return init->as_Initialize();
3759     }
3760   }
3761   return NULL;
3762 }
3763 
3764 //----------------------------- loop predicates ---------------------------
3765 
3766 //------------------------------add_predicate_impl----------------------------
3767 void GraphKit::add_predicate_impl(Deoptimization::DeoptReason reason, int nargs) {
3768   // Too many traps seen?
3769   if (too_many_traps(reason)) {
3770 #ifdef ASSERT
3771     if (TraceLoopPredicate) {
3772       int tc = C->trap_count(reason);
3773       tty->print("too many traps=%s tcount=%d in ",
3774                     Deoptimization::trap_reason_name(reason), tc);
3775       method()->print(); // which method has too many predicate traps
3776       tty->cr();
3777     }
3778 #endif
3779     // We cannot afford to take more traps here,
3780     // do not generate predicate.
3781     return;
3782   }
3783 
3784   Node *cont    = _gvn.intcon(1);
3785   Node* opq     = _gvn.transform(new Opaque1Node(C, cont));
3786   Node *bol     = _gvn.transform(new Conv2BNode(opq));
3787   IfNode* iff   = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
3788   Node* iffalse = _gvn.transform(new IfFalseNode(iff));
3789   C->add_predicate_opaq(opq);
3790   {
3791     PreserveJVMState pjvms(this);
3792     set_control(iffalse);
3793     inc_sp(nargs);
3794     uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
3795   }
3796   Node* iftrue = _gvn.transform(new IfTrueNode(iff));
3797   set_control(iftrue);
3798 }
3799 
3800 //------------------------------add_predicate---------------------------------
3801 void GraphKit::add_predicate(int nargs) {
3802   if (UseLoopPredicate) {
3803     add_predicate_impl(Deoptimization::Reason_predicate, nargs);
3804   }
3805   // loop's limit check predicate should be near the loop.
3806   add_predicate_impl(Deoptimization::Reason_loop_limit_check, nargs);
3807 }
3808 
3809 //----------------------------- store barriers ----------------------------
3810 #define __ ideal.
3811 
3812 bool GraphKit::use_ReduceInitialCardMarks() {
3813   BarrierSet *bs = Universe::heap()->barrier_set();
3814   return bs->is_a(BarrierSet::CardTableModRef)
3815          && barrier_set_cast<CardTableModRefBS>(bs)->can_elide_tlab_store_barriers()
3816          && ReduceInitialCardMarks;
3817 }
3818 
3819 void GraphKit::sync_kit(IdealKit& ideal) {
3820   set_all_memory(__ merged_memory());
3821   set_i_o(__ i_o());
3822   set_control(__ ctrl());
3823 }
3824 
3825 void GraphKit::final_sync(IdealKit& ideal) {
3826   // Final sync IdealKit and graphKit.
3827   sync_kit(ideal);
3828 }
3829 
3830 Node* GraphKit::byte_map_base_node() {
3831   // Get base of card map
3832   jbyte* card_table_base = ci_card_table_address();
3833   if (card_table_base != NULL) {
3834     return makecon(TypeRawPtr::make((address)card_table_base));
3835   } else {
3836     return null();
3837   }
3838 }
3839 
3840 // vanilla/CMS post barrier
3841 // Insert a write-barrier store.  This is to let generational GC work; we have
3842 // to flag all oop-stores before the next GC point.
3843 void GraphKit::write_barrier_post(Node* oop_store,
3844                                   Node* obj,
3845                                   Node* adr,
3846                                   uint  adr_idx,
3847                                   Node* val,
3848                                   bool use_precise) {
3849   // No store check needed if we're storing a NULL or an old object
3850   // (latter case is probably a string constant). The concurrent
3851   // mark sweep garbage collector, however, needs to have all nonNull
3852   // oop updates flagged via card-marks.
3853   if (val != NULL && val->is_Con()) {
3854     // must be either an oop or NULL
3855     const Type* t = val->bottom_type();
3856     if (t == TypePtr::NULL_PTR || t == Type::TOP)
3857       // stores of null never (?) need barriers
3858       return;
3859   }
3860 
3861   if (use_ReduceInitialCardMarks()
3862       && obj == just_allocated_object(control())) {
3863     // We can skip marks on a freshly-allocated object in Eden.
3864     // Keep this code in sync with new_deferred_store_barrier() in runtime.cpp.
3865     // That routine informs GC to take appropriate compensating steps,
3866     // upon a slow-path allocation, so as to make this card-mark
3867     // elision safe.
3868     return;
3869   }
3870 
3871   if (!use_precise) {
3872     // All card marks for a (non-array) instance are in one place:
3873     adr = obj;
3874   }
3875   // (Else it's an array (or unknown), and we want more precise card marks.)
3876   assert(adr != NULL, "");
3877 
3878   IdealKit ideal(this, true);
3879 
3880   // Convert the pointer to an int prior to doing math on it
3881   Node* cast = __ CastPX(__ ctrl(), adr);
3882 
3883   // Divide by card size
3884   assert(Universe::heap()->barrier_set()->is_a(BarrierSet::CardTableModRef),
3885          "Only one we handle so far.");
3886   Node* card_offset = __ URShiftX( cast, __ ConI(CardTable::card_shift) );
3887 
3888   // Combine card table base and card offset
3889   Node* card_adr = __ AddP(__ top(), byte_map_base_node(), card_offset );
3890 
3891   // Get the alias_index for raw card-mark memory
3892   int adr_type = Compile::AliasIdxRaw;
3893   Node*   zero = __ ConI(0); // Dirty card value
3894   BasicType bt = T_BYTE;
3895 
3896   if (UseConcMarkSweepGC && UseCondCardMark) {
3897     insert_mem_bar(Op_MemBarVolatile);   // StoreLoad barrier
3898     __ sync_kit(this);
3899   }
3900 
3901   if (UseCondCardMark) {
3902     // The classic GC reference write barrier is typically implemented
3903     // as a store into the global card mark table.  Unfortunately
3904     // unconditional stores can result in false sharing and excessive
3905     // coherence traffic as well as false transactional aborts.
3906     // UseCondCardMark enables MP "polite" conditional card mark
3907     // stores.  In theory we could relax the load from ctrl() to
3908     // no_ctrl, but that doesn't buy much latitude.
3909     Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, bt, adr_type);
3910     __ if_then(card_val, BoolTest::ne, zero);
3911   }
3912 
3913   // Smash zero into card
3914   if( !UseConcMarkSweepGC ) {
3915     __ store(__ ctrl(), card_adr, zero, bt, adr_type, MemNode::unordered);
3916   } else {
3917     // Specialized path for CM store barrier
3918     __ storeCM(__ ctrl(), card_adr, zero, oop_store, adr_idx, bt, adr_type);
3919   }
3920 
3921   if (UseCondCardMark) {
3922     __ end_if();
3923   }
3924 
3925   // Final sync IdealKit and GraphKit.
3926   final_sync(ideal);
3927 }
3928 /*
3929  * Determine if the G1 pre-barrier can be removed. The pre-barrier is
3930  * required by SATB to make sure all objects live at the start of the
3931  * marking are kept alive, all reference updates need to any previous
3932  * reference stored before writing.
3933  *
3934  * If the previous value is NULL there is no need to save the old value.
3935  * References that are NULL are filtered during runtime by the barrier
3936  * code to avoid unnecessary queuing.
3937  *
3938  * However in the case of newly allocated objects it might be possible to
3939  * prove that the reference about to be overwritten is NULL during compile
3940  * time and avoid adding the barrier code completely.
3941  *
3942  * The compiler needs to determine that the object in which a field is about
3943  * to be written is newly allocated, and that no prior store to the same field
3944  * has happened since the allocation.
3945  *
3946  * Returns true if the pre-barrier can be removed
3947  */
3948 bool GraphKit::g1_can_remove_pre_barrier(PhaseTransform* phase, Node* adr,
3949                                          BasicType bt, uint adr_idx) {
3950   intptr_t offset = 0;
3951   Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
3952   AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
3953 
3954   if (offset == Type::OffsetBot) {
3955     return false; // cannot unalias unless there are precise offsets
3956   }
3957 
3958   if (alloc == NULL) {
3959     return false; // No allocation found
3960   }
3961 
3962   intptr_t size_in_bytes = type2aelembytes(bt);
3963 
3964   Node* mem = memory(adr_idx); // start searching here...
3965 
3966   for (int cnt = 0; cnt < 50; cnt++) {
3967 
3968     if (mem->is_Store()) {
3969 
3970       Node* st_adr = mem->in(MemNode::Address);
3971       intptr_t st_offset = 0;
3972       Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset);
3973 
3974       if (st_base == NULL) {
3975         break; // inscrutable pointer
3976       }
3977 
3978       // Break we have found a store with same base and offset as ours so break
3979       if (st_base == base && st_offset == offset) {
3980         break;
3981       }
3982 
3983       if (st_offset != offset && st_offset != Type::OffsetBot) {
3984         const int MAX_STORE = BytesPerLong;
3985         if (st_offset >= offset + size_in_bytes ||
3986             st_offset <= offset - MAX_STORE ||
3987             st_offset <= offset - mem->as_Store()->memory_size()) {
3988           // Success:  The offsets are provably independent.
3989           // (You may ask, why not just test st_offset != offset and be done?
3990           // The answer is that stores of different sizes can co-exist
3991           // in the same sequence of RawMem effects.  We sometimes initialize
3992           // a whole 'tile' of array elements with a single jint or jlong.)
3993           mem = mem->in(MemNode::Memory);
3994           continue; // advance through independent store memory
3995         }
3996       }
3997 
3998       if (st_base != base
3999           && MemNode::detect_ptr_independence(base, alloc, st_base,
4000                                               AllocateNode::Ideal_allocation(st_base, phase),
4001                                               phase)) {
4002         // Success:  The bases are provably independent.
4003         mem = mem->in(MemNode::Memory);
4004         continue; // advance through independent store memory
4005       }
4006     } else if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
4007 
4008       InitializeNode* st_init = mem->in(0)->as_Initialize();
4009       AllocateNode* st_alloc = st_init->allocation();
4010 
4011       // Make sure that we are looking at the same allocation site.
4012       // The alloc variable is guaranteed to not be null here from earlier check.
4013       if (alloc == st_alloc) {
4014         // Check that the initialization is storing NULL so that no previous store
4015         // has been moved up and directly write a reference
4016         Node* captured_store = st_init->find_captured_store(offset,
4017                                                             type2aelembytes(T_OBJECT),
4018                                                             phase);
4019         if (captured_store == NULL || captured_store == st_init->zero_memory()) {
4020           return true;
4021         }
4022       }
4023     }
4024 
4025     // Unless there is an explicit 'continue', we must bail out here,
4026     // because 'mem' is an inscrutable memory state (e.g., a call).
4027     break;
4028   }
4029 
4030   return false;
4031 }
4032 
4033 // G1 pre/post barriers
4034 void GraphKit::g1_write_barrier_pre(bool do_load,
4035                                     Node* obj,
4036                                     Node* adr,
4037                                     uint alias_idx,
4038                                     Node* val,
4039                                     const TypeOopPtr* val_type,
4040                                     Node* pre_val,
4041                                     BasicType bt) {
4042 
4043   // Some sanity checks
4044   // Note: val is unused in this routine.
4045 
4046   if (do_load) {
4047     // We need to generate the load of the previous value
4048     assert(obj != NULL, "must have a base");
4049     assert(adr != NULL, "where are loading from?");
4050     assert(pre_val == NULL, "loaded already?");
4051     assert(val_type != NULL, "need a type");
4052 
4053     if (use_ReduceInitialCardMarks()
4054         && g1_can_remove_pre_barrier(&_gvn, adr, bt, alias_idx)) {
4055       return;
4056     }
4057 
4058   } else {
4059     // In this case both val_type and alias_idx are unused.
4060     assert(pre_val != NULL, "must be loaded already");
4061     // Nothing to be done if pre_val is null.
4062     if (pre_val->bottom_type() == TypePtr::NULL_PTR) return;
4063     assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here");
4064   }
4065   assert(bt == T_OBJECT, "or we shouldn't be here");
4066 
4067   IdealKit ideal(this, true);
4068 
4069   Node* tls = __ thread(); // ThreadLocalStorage
4070 
4071   Node* no_ctrl = NULL;
4072   Node* no_base = __ top();
4073   Node* zero  = __ ConI(0);
4074   Node* zeroX = __ ConX(0);
4075 
4076   float likely  = PROB_LIKELY(0.999);
4077   float unlikely  = PROB_UNLIKELY(0.999);
4078 
4079   BasicType active_type = in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 ? T_INT : T_BYTE;
4080   assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 || in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "flag width");
4081 
4082   // Offsets into the thread
4083   const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +  // 648
4084                                           SATBMarkQueue::byte_offset_of_active());
4085   const int index_offset   = in_bytes(JavaThread::satb_mark_queue_offset() +  // 656
4086                                           SATBMarkQueue::byte_offset_of_index());
4087   const int buffer_offset  = in_bytes(JavaThread::satb_mark_queue_offset() +  // 652
4088                                           SATBMarkQueue::byte_offset_of_buf());
4089 
4090   // Now the actual pointers into the thread
4091   Node* marking_adr = __ AddP(no_base, tls, __ ConX(marking_offset));
4092   Node* buffer_adr  = __ AddP(no_base, tls, __ ConX(buffer_offset));
4093   Node* index_adr   = __ AddP(no_base, tls, __ ConX(index_offset));
4094 
4095   // Now some of the values
4096   Node* marking = __ load(__ ctrl(), marking_adr, TypeInt::INT, active_type, Compile::AliasIdxRaw);
4097 
4098   // if (!marking)
4099   __ if_then(marking, BoolTest::ne, zero, unlikely); {
4100     BasicType index_bt = TypeX_X->basic_type();
4101     assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 SATBMarkQueue::_index with wrong size.");
4102     Node* index   = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
4103 
4104     if (do_load) {
4105       // load original value
4106       // alias_idx correct??
4107       pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx);
4108     }
4109 
4110     // if (pre_val != NULL)
4111     __ if_then(pre_val, BoolTest::ne, null()); {
4112       Node* buffer  = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4113 
4114       // is the queue for this thread full?
4115       __ if_then(index, BoolTest::ne, zeroX, likely); {
4116 
4117         // decrement the index
4118         Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4119 
4120         // Now get the buffer location we will log the previous value into and store it
4121         Node *log_addr = __ AddP(no_base, buffer, next_index);
4122         __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered);
4123         // update the index
4124         __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered);
4125 
4126       } __ else_(); {
4127 
4128         // logging buffer is full, call the runtime
4129         const TypeFunc *tf = OptoRuntime::g1_wb_pre_Type();
4130         __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), "g1_wb_pre", pre_val, tls);
4131       } __ end_if();  // (!index)
4132     } __ end_if();  // (pre_val != NULL)
4133   } __ end_if();  // (!marking)
4134 
4135   // Final sync IdealKit and GraphKit.
4136   final_sync(ideal);
4137 }
4138 
4139 /*
4140  * G1 similar to any GC with a Young Generation requires a way to keep track of
4141  * references from Old Generation to Young Generation to make sure all live
4142  * objects are found. G1 also requires to keep track of object references
4143  * between different regions to enable evacuation of old regions, which is done
4144  * as part of mixed collections. References are tracked in remembered sets and
4145  * is continuously updated as reference are written to with the help of the
4146  * post-barrier.
4147  *
4148  * To reduce the number of updates to the remembered set the post-barrier
4149  * filters updates to fields in objects located in the Young Generation,
4150  * the same region as the reference, when the NULL is being written or
4151  * if the card is already marked as dirty by an earlier write.
4152  *
4153  * Under certain circumstances it is possible to avoid generating the
4154  * post-barrier completely if it is possible during compile time to prove
4155  * the object is newly allocated and that no safepoint exists between the
4156  * allocation and the store.
4157  *
4158  * In the case of slow allocation the allocation code must handle the barrier
4159  * as part of the allocation in the case the allocated object is not located
4160  * in the nursery, this would happen for humongous objects. This is similar to
4161  * how CMS is required to handle this case, see the comments for the method
4162  * CardTableModRefBS::on_allocation_slowpath_exit and OptoRuntime::new_deferred_store_barrier.
4163  * A deferred card mark is required for these objects and handled in the above
4164  * mentioned methods.
4165  *
4166  * Returns true if the post barrier can be removed
4167  */
4168 bool GraphKit::g1_can_remove_post_barrier(PhaseTransform* phase, Node* store,
4169                                           Node* adr) {
4170   intptr_t      offset = 0;
4171   Node*         base   = AddPNode::Ideal_base_and_offset(adr, phase, offset);
4172   AllocateNode* alloc  = AllocateNode::Ideal_allocation(base, phase);
4173 
4174   if (offset == Type::OffsetBot) {
4175     return false; // cannot unalias unless there are precise offsets
4176   }
4177 
4178   if (alloc == NULL) {
4179      return false; // No allocation found
4180   }
4181 
4182   // Start search from Store node
4183   Node* mem = store->in(MemNode::Control);
4184   if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
4185 
4186     InitializeNode* st_init = mem->in(0)->as_Initialize();
4187     AllocateNode*  st_alloc = st_init->allocation();
4188 
4189     // Make sure we are looking at the same allocation
4190     if (alloc == st_alloc) {
4191       return true;
4192     }
4193   }
4194 
4195   return false;
4196 }
4197 
4198 //
4199 // Update the card table and add card address to the queue
4200 //
4201 void GraphKit::g1_mark_card(IdealKit& ideal,
4202                             Node* card_adr,
4203                             Node* oop_store,
4204                             uint oop_alias_idx,
4205                             Node* index,
4206                             Node* index_adr,
4207                             Node* buffer,
4208                             const TypeFunc* tf) {
4209 
4210   Node* zero  = __ ConI(0);
4211   Node* zeroX = __ ConX(0);
4212   Node* no_base = __ top();
4213   BasicType card_bt = T_BYTE;
4214   // Smash zero into card. MUST BE ORDERED WRT TO STORE
4215   __ storeCM(__ ctrl(), card_adr, zero, oop_store, oop_alias_idx, card_bt, Compile::AliasIdxRaw);
4216 
4217   //  Now do the queue work
4218   __ if_then(index, BoolTest::ne, zeroX); {
4219 
4220     Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4221     Node* log_addr = __ AddP(no_base, buffer, next_index);
4222 
4223     // Order, see storeCM.
4224     __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw, MemNode::unordered);
4225     __ store(__ ctrl(), index_adr, next_index, TypeX_X->basic_type(), Compile::AliasIdxRaw, MemNode::unordered);
4226 
4227   } __ else_(); {
4228     __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), "g1_wb_post", card_adr, __ thread());
4229   } __ end_if();
4230 
4231 }
4232 
4233 void GraphKit::g1_write_barrier_post(Node* oop_store,
4234                                      Node* obj,
4235                                      Node* adr,
4236                                      uint alias_idx,
4237                                      Node* val,
4238                                      BasicType bt,
4239                                      bool use_precise) {
4240   // If we are writing a NULL then we need no post barrier
4241 
4242   if (val != NULL && val->is_Con() && val->bottom_type() == TypePtr::NULL_PTR) {
4243     // Must be NULL
4244     const Type* t = val->bottom_type();
4245     assert(t == Type::TOP || t == TypePtr::NULL_PTR, "must be NULL");
4246     // No post barrier if writing NULLx
4247     return;
4248   }
4249 
4250   if (use_ReduceInitialCardMarks() && obj == just_allocated_object(control())) {
4251     // We can skip marks on a freshly-allocated object in Eden.
4252     // Keep this code in sync with new_deferred_store_barrier() in runtime.cpp.
4253     // That routine informs GC to take appropriate compensating steps,
4254     // upon a slow-path allocation, so as to make this card-mark
4255     // elision safe.
4256     return;
4257   }
4258 
4259   if (use_ReduceInitialCardMarks()
4260       && g1_can_remove_post_barrier(&_gvn, oop_store, adr)) {
4261     return;
4262   }
4263 
4264   if (!use_precise) {
4265     // All card marks for a (non-array) instance are in one place:
4266     adr = obj;
4267   }
4268   // (Else it's an array (or unknown), and we want more precise card marks.)
4269   assert(adr != NULL, "");
4270 
4271   IdealKit ideal(this, true);
4272 
4273   Node* tls = __ thread(); // ThreadLocalStorage
4274 
4275   Node* no_base = __ top();
4276   float likely  = PROB_LIKELY(0.999);
4277   float unlikely  = PROB_UNLIKELY(0.999);
4278   Node* young_card = __ ConI((jint)G1CardTable::g1_young_card_val());
4279   Node* dirty_card = __ ConI((jint)CardTable::dirty_card_val());
4280   Node* zeroX = __ ConX(0);
4281 
4282   // Get the alias_index for raw card-mark memory
4283   const TypePtr* card_type = TypeRawPtr::BOTTOM;
4284 
4285   const TypeFunc *tf = OptoRuntime::g1_wb_post_Type();
4286 
4287   // Offsets into the thread
4288   const int index_offset  = in_bytes(JavaThread::dirty_card_queue_offset() +
4289                                      DirtyCardQueue::byte_offset_of_index());
4290   const int buffer_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
4291                                      DirtyCardQueue::byte_offset_of_buf());
4292 
4293   // Pointers into the thread
4294 
4295   Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
4296   Node* index_adr =  __ AddP(no_base, tls, __ ConX(index_offset));
4297 
4298   // Now some values
4299   // Use ctrl to avoid hoisting these values past a safepoint, which could
4300   // potentially reset these fields in the JavaThread.
4301   Node* index  = __ load(__ ctrl(), index_adr, TypeX_X, TypeX_X->basic_type(), Compile::AliasIdxRaw);
4302   Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4303 
4304   // Convert the store obj pointer to an int prior to doing math on it
4305   // Must use ctrl to prevent "integerized oop" existing across safepoint
4306   Node* cast =  __ CastPX(__ ctrl(), adr);
4307 
4308   // Divide pointer by card size
4309   Node* card_offset = __ URShiftX( cast, __ ConI(CardTable::card_shift) );
4310 
4311   // Combine card table base and card offset
4312   Node* card_adr = __ AddP(no_base, byte_map_base_node(), card_offset );
4313 
4314   // If we know the value being stored does it cross regions?
4315 
4316   if (val != NULL) {
4317     // Does the store cause us to cross regions?
4318 
4319     // Should be able to do an unsigned compare of region_size instead of
4320     // and extra shift. Do we have an unsigned compare??
4321     // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes);
4322     Node* xor_res =  __ URShiftX ( __ XorX( cast,  __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes));
4323 
4324     // if (xor_res == 0) same region so skip
4325     __ if_then(xor_res, BoolTest::ne, zeroX); {
4326 
4327       // No barrier if we are storing a NULL
4328       __ if_then(val, BoolTest::ne, null(), unlikely); {
4329 
4330         // Ok must mark the card if not already dirty
4331 
4332         // load the original value of the card
4333         Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4334 
4335         __ if_then(card_val, BoolTest::ne, young_card); {
4336           sync_kit(ideal);
4337           // Use Op_MemBarVolatile to achieve the effect of a StoreLoad barrier.
4338           insert_mem_bar(Op_MemBarVolatile, oop_store);
4339           __ sync_kit(this);
4340 
4341           Node* card_val_reload = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4342           __ if_then(card_val_reload, BoolTest::ne, dirty_card); {
4343             g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4344           } __ end_if();
4345         } __ end_if();
4346       } __ end_if();
4347     } __ end_if();
4348   } else {
4349     // The Object.clone() intrinsic uses this path if !ReduceInitialCardMarks.
4350     // We don't need a barrier here if the destination is a newly allocated object
4351     // in Eden. Otherwise, GC verification breaks because we assume that cards in Eden
4352     // are set to 'g1_young_gen' (see G1SATBCardTableModRefBS::verify_g1_young_region()).
4353     assert(!use_ReduceInitialCardMarks(), "can only happen with card marking");
4354     Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4355     __ if_then(card_val, BoolTest::ne, young_card); {
4356       g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4357     } __ end_if();
4358   }
4359 
4360   // Final sync IdealKit and GraphKit.
4361   final_sync(ideal);
4362 }
4363 #undef __
4364 
4365 
4366 Node* GraphKit::load_String_length(Node* ctrl, Node* str) {
4367   Node* len = load_array_length(load_String_value(ctrl, str));
4368   Node* coder = load_String_coder(ctrl, str);
4369   // Divide length by 2 if coder is UTF16
4370   return _gvn.transform(new RShiftINode(len, coder));
4371 }
4372 
4373 Node* GraphKit::load_String_value(Node* ctrl, Node* str) {
4374   int value_offset = java_lang_String::value_offset_in_bytes();
4375   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4376                                                      false, NULL, 0);
4377   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4378   const TypeAryPtr* value_type = TypeAryPtr::make(TypePtr::NotNull,
4379                                                   TypeAry::make(TypeInt::BYTE, TypeInt::POS),
4380                                                   ciTypeArrayKlass::make(T_BYTE), true, 0);
4381   int value_field_idx = C->get_alias_index(value_field_type);
4382   Node* load = make_load(ctrl, basic_plus_adr(str, str, value_offset),
4383                          value_type, T_OBJECT, value_field_idx, MemNode::unordered);
4384   // String.value field is known to be @Stable.
4385   if (UseImplicitStableValues) {
4386     load = cast_array_to_stable(load, value_type);
4387   }
4388   return load;
4389 }
4390 
4391 Node* GraphKit::load_String_coder(Node* ctrl, Node* str) {
4392   if (!CompactStrings) {
4393     return intcon(java_lang_String::CODER_UTF16);
4394   }
4395   int coder_offset = java_lang_String::coder_offset_in_bytes();
4396   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4397                                                      false, NULL, 0);
4398   const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4399   int coder_field_idx = C->get_alias_index(coder_field_type);
4400   return make_load(ctrl, basic_plus_adr(str, str, coder_offset),
4401                    TypeInt::BYTE, T_BYTE, coder_field_idx, MemNode::unordered);
4402 }
4403 
4404 void GraphKit::store_String_value(Node* ctrl, Node* str, Node* value) {
4405   int value_offset = java_lang_String::value_offset_in_bytes();
4406   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4407                                                      false, NULL, 0);
4408   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4409   store_oop_to_object(ctrl, str,  basic_plus_adr(str, value_offset), value_field_type,
4410       value, TypeAryPtr::BYTES, T_OBJECT, MemNode::unordered);
4411 }
4412 
4413 void GraphKit::store_String_coder(Node* ctrl, Node* str, Node* value) {
4414   int coder_offset = java_lang_String::coder_offset_in_bytes();
4415   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4416                                                      false, NULL, 0);
4417   const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4418   int coder_field_idx = C->get_alias_index(coder_field_type);
4419   store_to_memory(ctrl, basic_plus_adr(str, coder_offset),
4420                   value, T_BYTE, coder_field_idx, MemNode::unordered);
4421 }
4422 
4423 // Capture src and dst memory state with a MergeMemNode
4424 Node* GraphKit::capture_memory(const TypePtr* src_type, const TypePtr* dst_type) {
4425   if (src_type == dst_type) {
4426     // Types are equal, we don't need a MergeMemNode
4427     return memory(src_type);
4428   }
4429   MergeMemNode* merge = MergeMemNode::make(map()->memory());
4430   record_for_igvn(merge); // fold it up later, if possible
4431   int src_idx = C->get_alias_index(src_type);
4432   int dst_idx = C->get_alias_index(dst_type);
4433   merge->set_memory_at(src_idx, memory(src_idx));
4434   merge->set_memory_at(dst_idx, memory(dst_idx));
4435   return merge;
4436 }
4437 
4438 Node* GraphKit::compress_string(Node* src, const TypeAryPtr* src_type, Node* dst, Node* count) {
4439   assert(Matcher::match_rule_supported(Op_StrCompressedCopy), "Intrinsic not supported");
4440   assert(src_type == TypeAryPtr::BYTES || src_type == TypeAryPtr::CHARS, "invalid source type");
4441   // If input and output memory types differ, capture both states to preserve
4442   // the dependency between preceding and subsequent loads/stores.
4443   // For example, the following program:
4444   //  StoreB
4445   //  compress_string
4446   //  LoadB
4447   // has this memory graph (use->def):
4448   //  LoadB -> compress_string -> CharMem
4449   //             ... -> StoreB -> ByteMem
4450   // The intrinsic hides the dependency between LoadB and StoreB, causing
4451   // the load to read from memory not containing the result of the StoreB.
4452   // The correct memory graph should look like this:
4453   //  LoadB -> compress_string -> MergeMem(CharMem, StoreB(ByteMem))
4454   Node* mem = capture_memory(src_type, TypeAryPtr::BYTES);
4455   StrCompressedCopyNode* str = new StrCompressedCopyNode(control(), mem, src, dst, count);
4456   Node* res_mem = _gvn.transform(new SCMemProjNode(str));
4457   set_memory(res_mem, TypeAryPtr::BYTES);
4458   return str;
4459 }
4460 
4461 void GraphKit::inflate_string(Node* src, Node* dst, const TypeAryPtr* dst_type, Node* count) {
4462   assert(Matcher::match_rule_supported(Op_StrInflatedCopy), "Intrinsic not supported");
4463   assert(dst_type == TypeAryPtr::BYTES || dst_type == TypeAryPtr::CHARS, "invalid dest type");
4464   // Capture src and dst memory (see comment in 'compress_string').
4465   Node* mem = capture_memory(TypeAryPtr::BYTES, dst_type);
4466   StrInflatedCopyNode* str = new StrInflatedCopyNode(control(), mem, src, dst, count);
4467   set_memory(_gvn.transform(str), dst_type);
4468 }
4469 
4470 void GraphKit::inflate_string_slow(Node* src, Node* dst, Node* start, Node* count) {
4471   /**
4472    * int i_char = start;
4473    * for (int i_byte = 0; i_byte < count; i_byte++) {
4474    *   dst[i_char++] = (char)(src[i_byte] & 0xff);
4475    * }
4476    */
4477   add_predicate();
4478   RegionNode* head = new RegionNode(3);
4479   head->init_req(1, control());
4480   gvn().set_type(head, Type::CONTROL);
4481   record_for_igvn(head);
4482 
4483   Node* i_byte = new PhiNode(head, TypeInt::INT);
4484   i_byte->init_req(1, intcon(0));
4485   gvn().set_type(i_byte, TypeInt::INT);
4486   record_for_igvn(i_byte);
4487 
4488   Node* i_char = new PhiNode(head, TypeInt::INT);
4489   i_char->init_req(1, start);
4490   gvn().set_type(i_char, TypeInt::INT);
4491   record_for_igvn(i_char);
4492 
4493   Node* mem = PhiNode::make(head, memory(TypeAryPtr::BYTES), Type::MEMORY, TypeAryPtr::BYTES);
4494   gvn().set_type(mem, Type::MEMORY);
4495   record_for_igvn(mem);
4496   set_control(head);
4497   set_memory(mem, TypeAryPtr::BYTES);
4498   Node* ch = load_array_element(control(), src, i_byte, TypeAryPtr::BYTES);
4499   Node* st = store_to_memory(control(), array_element_address(dst, i_char, T_BYTE),
4500                              AndI(ch, intcon(0xff)), T_CHAR, TypeAryPtr::BYTES, MemNode::unordered,
4501                              false, false, true /* mismatched */);
4502 
4503   IfNode* iff = create_and_map_if(head, Bool(CmpI(i_byte, count), BoolTest::lt), PROB_FAIR, COUNT_UNKNOWN);
4504   head->init_req(2, IfTrue(iff));
4505   mem->init_req(2, st);
4506   i_byte->init_req(2, AddI(i_byte, intcon(1)));
4507   i_char->init_req(2, AddI(i_char, intcon(2)));
4508 
4509   set_control(IfFalse(iff));
4510   set_memory(st, TypeAryPtr::BYTES);
4511 }
4512 
4513 Node* GraphKit::make_constant_from_field(ciField* field, Node* obj) {
4514   if (!field->is_constant()) {
4515     return NULL; // Field not marked as constant.
4516   }
4517   ciInstance* holder = NULL;
4518   if (!field->is_static()) {
4519     ciObject* const_oop = obj->bottom_type()->is_oopptr()->const_oop();
4520     if (const_oop != NULL && const_oop->is_instance()) {
4521       holder = const_oop->as_instance();
4522     }
4523   }
4524   const Type* con_type = Type::make_constant_from_field(field, holder, field->layout_type(),
4525                                                         /*is_unsigned_load=*/false);
4526   if (con_type != NULL) {
4527     return makecon(con_type);
4528   }
4529   return NULL;
4530 }
4531 
4532 Node* GraphKit::cast_array_to_stable(Node* ary, const TypeAryPtr* ary_type) {
4533   // Reify the property as a CastPP node in Ideal graph to comply with monotonicity
4534   // assumption of CCP analysis.
4535   return _gvn.transform(new CastPPNode(ary, ary_type->cast_to_stable(true)));
4536 }