1 /*
   2  * Copyright (c) 2001, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "compiler/compileLog.hpp"
  27 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
  28 #include "gc_implementation/g1/heapRegion.hpp"
  29 #include "gc_interface/collectedHeap.hpp"
  30 #include "memory/barrierSet.hpp"
  31 #include "memory/cardTableModRefBS.hpp"
  32 #include "opto/addnode.hpp"
  33 #include "opto/graphKit.hpp"
  34 #include "opto/idealKit.hpp"
  35 #include "opto/locknode.hpp"
  36 #include "opto/machnode.hpp"
  37 #include "opto/parse.hpp"
  38 #include "opto/rootnode.hpp"
  39 #include "opto/runtime.hpp"
  40 #include "runtime/deoptimization.hpp"
  41 #include "runtime/sharedRuntime.hpp"
  42 
  43 //----------------------------GraphKit-----------------------------------------
  44 // Main utility constructor.
  45 GraphKit::GraphKit(JVMState* jvms)
  46   : Phase(Phase::Parser),
  47     _env(C->env()),
  48     _gvn(*C->initial_gvn())
  49 {
  50   _exceptions = jvms->map()->next_exception();
  51   if (_exceptions != NULL)  jvms->map()->set_next_exception(NULL);
  52   set_jvms(jvms);
  53 }
  54 
  55 // Private constructor for parser.
  56 GraphKit::GraphKit()
  57   : Phase(Phase::Parser),
  58     _env(C->env()),
  59     _gvn(*C->initial_gvn())
  60 {
  61   _exceptions = NULL;
  62   set_map(NULL);
  63   debug_only(_sp = -99);
  64   debug_only(set_bci(-99));
  65 }
  66 
  67 
  68 
  69 //---------------------------clean_stack---------------------------------------
  70 // Clear away rubbish from the stack area of the JVM state.
  71 // This destroys any arguments that may be waiting on the stack.
  72 void GraphKit::clean_stack(int from_sp) {
  73   SafePointNode* map      = this->map();
  74   JVMState*      jvms     = this->jvms();
  75   int            stk_size = jvms->stk_size();
  76   int            stkoff   = jvms->stkoff();
  77   Node*          top      = this->top();
  78   for (int i = from_sp; i < stk_size; i++) {
  79     if (map->in(stkoff + i) != top) {
  80       map->set_req(stkoff + i, top);
  81     }
  82   }
  83 }
  84 
  85 
  86 //--------------------------------sync_jvms-----------------------------------
  87 // Make sure our current jvms agrees with our parse state.
  88 JVMState* GraphKit::sync_jvms() const {
  89   JVMState* jvms = this->jvms();
  90   jvms->set_bci(bci());       // Record the new bci in the JVMState
  91   jvms->set_sp(sp());         // Record the new sp in the JVMState
  92   assert(jvms_in_sync(), "jvms is now in sync");
  93   return jvms;
  94 }
  95 
  96 //--------------------------------sync_jvms_for_reexecute---------------------
  97 // Make sure our current jvms agrees with our parse state.  This version
  98 // uses the reexecute_sp for reexecuting bytecodes.
  99 JVMState* GraphKit::sync_jvms_for_reexecute() {
 100   JVMState* jvms = this->jvms();
 101   jvms->set_bci(bci());          // Record the new bci in the JVMState
 102   jvms->set_sp(reexecute_sp());  // Record the new sp in the JVMState
 103   return jvms;
 104 }
 105 
 106 #ifdef ASSERT
 107 bool GraphKit::jvms_in_sync() const {
 108   Parse* parse = is_Parse();
 109   if (parse == NULL) {
 110     if (bci() !=      jvms()->bci())          return false;
 111     if (sp()  != (int)jvms()->sp())           return false;
 112     return true;
 113   }
 114   if (jvms()->method() != parse->method())    return false;
 115   if (jvms()->bci()    != parse->bci())       return false;
 116   int jvms_sp = jvms()->sp();
 117   if (jvms_sp          != parse->sp())        return false;
 118   int jvms_depth = jvms()->depth();
 119   if (jvms_depth       != parse->depth())     return false;
 120   return true;
 121 }
 122 
 123 // Local helper checks for special internal merge points
 124 // used to accumulate and merge exception states.
 125 // They are marked by the region's in(0) edge being the map itself.
 126 // Such merge points must never "escape" into the parser at large,
 127 // until they have been handed to gvn.transform.
 128 static bool is_hidden_merge(Node* reg) {
 129   if (reg == NULL)  return false;
 130   if (reg->is_Phi()) {
 131     reg = reg->in(0);
 132     if (reg == NULL)  return false;
 133   }
 134   return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root();
 135 }
 136 
 137 void GraphKit::verify_map() const {
 138   if (map() == NULL)  return;  // null map is OK
 139   assert(map()->req() <= jvms()->endoff(), "no extra garbage on map");
 140   assert(!map()->has_exceptions(),    "call add_exception_states_from 1st");
 141   assert(!is_hidden_merge(control()), "call use_exception_state, not set_map");
 142 }
 143 
 144 void GraphKit::verify_exception_state(SafePointNode* ex_map) {
 145   assert(ex_map->next_exception() == NULL, "not already part of a chain");
 146   assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop");
 147 }
 148 #endif
 149 
 150 //---------------------------stop_and_kill_map---------------------------------
 151 // Set _map to NULL, signalling a stop to further bytecode execution.
 152 // First smash the current map's control to a constant, to mark it dead.
 153 void GraphKit::stop_and_kill_map() {
 154   SafePointNode* dead_map = stop();
 155   if (dead_map != NULL) {
 156     dead_map->disconnect_inputs(NULL, C); // Mark the map as killed.
 157     assert(dead_map->is_killed(), "must be so marked");
 158   }
 159 }
 160 
 161 
 162 //--------------------------------stopped--------------------------------------
 163 // Tell if _map is NULL, or control is top.
 164 bool GraphKit::stopped() {
 165   if (map() == NULL)           return true;
 166   else if (control() == top()) return true;
 167   else                         return false;
 168 }
 169 
 170 
 171 //-----------------------------has_ex_handler----------------------------------
 172 // Tell if this method or any caller method has exception handlers.
 173 bool GraphKit::has_ex_handler() {
 174   for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) {
 175     if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) {
 176       return true;
 177     }
 178   }
 179   return false;
 180 }
 181 
 182 //------------------------------save_ex_oop------------------------------------
 183 // Save an exception without blowing stack contents or other JVM state.
 184 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) {
 185   assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again");
 186   ex_map->add_req(ex_oop);
 187   debug_only(verify_exception_state(ex_map));
 188 }
 189 
 190 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) {
 191   assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there");
 192   Node* ex_oop = ex_map->in(ex_map->req()-1);
 193   if (clear_it)  ex_map->del_req(ex_map->req()-1);
 194   return ex_oop;
 195 }
 196 
 197 //-----------------------------saved_ex_oop------------------------------------
 198 // Recover a saved exception from its map.
 199 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) {
 200   return common_saved_ex_oop(ex_map, false);
 201 }
 202 
 203 //--------------------------clear_saved_ex_oop---------------------------------
 204 // Erase a previously saved exception from its map.
 205 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) {
 206   return common_saved_ex_oop(ex_map, true);
 207 }
 208 
 209 #ifdef ASSERT
 210 //---------------------------has_saved_ex_oop----------------------------------
 211 // Erase a previously saved exception from its map.
 212 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) {
 213   return ex_map->req() == ex_map->jvms()->endoff()+1;
 214 }
 215 #endif
 216 
 217 //-------------------------make_exception_state--------------------------------
 218 // Turn the current JVM state into an exception state, appending the ex_oop.
 219 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) {
 220   sync_jvms();
 221   SafePointNode* ex_map = stop();  // do not manipulate this map any more
 222   set_saved_ex_oop(ex_map, ex_oop);
 223   return ex_map;
 224 }
 225 
 226 
 227 //--------------------------add_exception_state--------------------------------
 228 // Add an exception to my list of exceptions.
 229 void GraphKit::add_exception_state(SafePointNode* ex_map) {
 230   if (ex_map == NULL || ex_map->control() == top()) {
 231     return;
 232   }
 233 #ifdef ASSERT
 234   verify_exception_state(ex_map);
 235   if (has_exceptions()) {
 236     assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place");
 237   }
 238 #endif
 239 
 240   // If there is already an exception of exactly this type, merge with it.
 241   // In particular, null-checks and other low-level exceptions common up here.
 242   Node*       ex_oop  = saved_ex_oop(ex_map);
 243   const Type* ex_type = _gvn.type(ex_oop);
 244   if (ex_oop == top()) {
 245     // No action needed.
 246     return;
 247   }
 248   assert(ex_type->isa_instptr(), "exception must be an instance");
 249   for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) {
 250     const Type* ex_type2 = _gvn.type(saved_ex_oop(e2));
 251     // We check sp also because call bytecodes can generate exceptions
 252     // both before and after arguments are popped!
 253     if (ex_type2 == ex_type
 254         && e2->_jvms->sp() == ex_map->_jvms->sp()) {
 255       combine_exception_states(ex_map, e2);
 256       return;
 257     }
 258   }
 259 
 260   // No pre-existing exception of the same type.  Chain it on the list.
 261   push_exception_state(ex_map);
 262 }
 263 
 264 //-----------------------add_exception_states_from-----------------------------
 265 void GraphKit::add_exception_states_from(JVMState* jvms) {
 266   SafePointNode* ex_map = jvms->map()->next_exception();
 267   if (ex_map != NULL) {
 268     jvms->map()->set_next_exception(NULL);
 269     for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) {
 270       next_map = ex_map->next_exception();
 271       ex_map->set_next_exception(NULL);
 272       add_exception_state(ex_map);
 273     }
 274   }
 275 }
 276 
 277 //-----------------------transfer_exceptions_into_jvms-------------------------
 278 JVMState* GraphKit::transfer_exceptions_into_jvms() {
 279   if (map() == NULL) {
 280     // We need a JVMS to carry the exceptions, but the map has gone away.
 281     // Create a scratch JVMS, cloned from any of the exception states...
 282     if (has_exceptions()) {
 283       _map = _exceptions;
 284       _map = clone_map();
 285       _map->set_next_exception(NULL);
 286       clear_saved_ex_oop(_map);
 287       debug_only(verify_map());
 288     } else {
 289       // ...or created from scratch
 290       JVMState* jvms = new (C) JVMState(_method, NULL);
 291       jvms->set_bci(_bci);
 292       jvms->set_sp(_sp);
 293       jvms->set_map(new (C) SafePointNode(TypeFunc::Parms, jvms));
 294       set_jvms(jvms);
 295       for (uint i = 0; i < map()->req(); i++)  map()->init_req(i, top());
 296       set_all_memory(top());
 297       while (map()->req() < jvms->endoff())  map()->add_req(top());
 298     }
 299     // (This is a kludge, in case you didn't notice.)
 300     set_control(top());
 301   }
 302   JVMState* jvms = sync_jvms();
 303   assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet");
 304   jvms->map()->set_next_exception(_exceptions);
 305   _exceptions = NULL;   // done with this set of exceptions
 306   return jvms;
 307 }
 308 
 309 static inline void add_n_reqs(Node* dstphi, Node* srcphi) {
 310   assert(is_hidden_merge(dstphi), "must be a special merge node");
 311   assert(is_hidden_merge(srcphi), "must be a special merge node");
 312   uint limit = srcphi->req();
 313   for (uint i = PhiNode::Input; i < limit; i++) {
 314     dstphi->add_req(srcphi->in(i));
 315   }
 316 }
 317 static inline void add_one_req(Node* dstphi, Node* src) {
 318   assert(is_hidden_merge(dstphi), "must be a special merge node");
 319   assert(!is_hidden_merge(src), "must not be a special merge node");
 320   dstphi->add_req(src);
 321 }
 322 
 323 //-----------------------combine_exception_states------------------------------
 324 // This helper function combines exception states by building phis on a
 325 // specially marked state-merging region.  These regions and phis are
 326 // untransformed, and can build up gradually.  The region is marked by
 327 // having a control input of its exception map, rather than NULL.  Such
 328 // regions do not appear except in this function, and in use_exception_state.
 329 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) {
 330   if (failing())  return;  // dying anyway...
 331   JVMState* ex_jvms = ex_map->_jvms;
 332   assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains");
 333   assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals");
 334   assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes");
 335   assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS");
 336   assert(ex_jvms->scloff() == phi_map->_jvms->scloff(), "matching scalar replaced objects");
 337   assert(ex_map->req() == phi_map->req(), "matching maps");
 338   uint tos = ex_jvms->stkoff() + ex_jvms->sp();
 339   Node*         hidden_merge_mark = root();
 340   Node*         region  = phi_map->control();
 341   MergeMemNode* phi_mem = phi_map->merged_memory();
 342   MergeMemNode* ex_mem  = ex_map->merged_memory();
 343   if (region->in(0) != hidden_merge_mark) {
 344     // The control input is not (yet) a specially-marked region in phi_map.
 345     // Make it so, and build some phis.
 346     region = new (C) RegionNode(2);
 347     _gvn.set_type(region, Type::CONTROL);
 348     region->set_req(0, hidden_merge_mark);  // marks an internal ex-state
 349     region->init_req(1, phi_map->control());
 350     phi_map->set_control(region);
 351     Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO);
 352     record_for_igvn(io_phi);
 353     _gvn.set_type(io_phi, Type::ABIO);
 354     phi_map->set_i_o(io_phi);
 355     for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) {
 356       Node* m = mms.memory();
 357       Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C));
 358       record_for_igvn(m_phi);
 359       _gvn.set_type(m_phi, Type::MEMORY);
 360       mms.set_memory(m_phi);
 361     }
 362   }
 363 
 364   // Either or both of phi_map and ex_map might already be converted into phis.
 365   Node* ex_control = ex_map->control();
 366   // if there is special marking on ex_map also, we add multiple edges from src
 367   bool add_multiple = (ex_control->in(0) == hidden_merge_mark);
 368   // how wide was the destination phi_map, originally?
 369   uint orig_width = region->req();
 370 
 371   if (add_multiple) {
 372     add_n_reqs(region, ex_control);
 373     add_n_reqs(phi_map->i_o(), ex_map->i_o());
 374   } else {
 375     // ex_map has no merges, so we just add single edges everywhere
 376     add_one_req(region, ex_control);
 377     add_one_req(phi_map->i_o(), ex_map->i_o());
 378   }
 379   for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) {
 380     if (mms.is_empty()) {
 381       // get a copy of the base memory, and patch some inputs into it
 382       const TypePtr* adr_type = mms.adr_type(C);
 383       Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
 384       assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
 385       mms.set_memory(phi);
 386       // Prepare to append interesting stuff onto the newly sliced phi:
 387       while (phi->req() > orig_width)  phi->del_req(phi->req()-1);
 388     }
 389     // Append stuff from ex_map:
 390     if (add_multiple) {
 391       add_n_reqs(mms.memory(), mms.memory2());
 392     } else {
 393       add_one_req(mms.memory(), mms.memory2());
 394     }
 395   }
 396   uint limit = ex_map->req();
 397   for (uint i = TypeFunc::Parms; i < limit; i++) {
 398     // Skip everything in the JVMS after tos.  (The ex_oop follows.)
 399     if (i == tos)  i = ex_jvms->monoff();
 400     Node* src = ex_map->in(i);
 401     Node* dst = phi_map->in(i);
 402     if (src != dst) {
 403       PhiNode* phi;
 404       if (dst->in(0) != region) {
 405         dst = phi = PhiNode::make(region, dst, _gvn.type(dst));
 406         record_for_igvn(phi);
 407         _gvn.set_type(phi, phi->type());
 408         phi_map->set_req(i, dst);
 409         // Prepare to append interesting stuff onto the new phi:
 410         while (dst->req() > orig_width)  dst->del_req(dst->req()-1);
 411       } else {
 412         assert(dst->is_Phi(), "nobody else uses a hidden region");
 413         phi = dst->as_Phi();
 414       }
 415       if (add_multiple && src->in(0) == ex_control) {
 416         // Both are phis.
 417         add_n_reqs(dst, src);
 418       } else {
 419         while (dst->req() < region->req())  add_one_req(dst, src);
 420       }
 421       const Type* srctype = _gvn.type(src);
 422       if (phi->type() != srctype) {
 423         const Type* dsttype = phi->type()->meet_speculative(srctype);
 424         if (phi->type() != dsttype) {
 425           phi->set_type(dsttype);
 426           _gvn.set_type(phi, dsttype);
 427         }
 428       }
 429     }
 430   }
 431   phi_map->merge_replaced_nodes_with(ex_map);
 432 }
 433 
 434 //--------------------------use_exception_state--------------------------------
 435 Node* GraphKit::use_exception_state(SafePointNode* phi_map) {
 436   if (failing()) { stop(); return top(); }
 437   Node* region = phi_map->control();
 438   Node* hidden_merge_mark = root();
 439   assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation");
 440   Node* ex_oop = clear_saved_ex_oop(phi_map);
 441   if (region->in(0) == hidden_merge_mark) {
 442     // Special marking for internal ex-states.  Process the phis now.
 443     region->set_req(0, region);  // now it's an ordinary region
 444     set_jvms(phi_map->jvms());   // ...so now we can use it as a map
 445     // Note: Setting the jvms also sets the bci and sp.
 446     set_control(_gvn.transform(region));
 447     uint tos = jvms()->stkoff() + sp();
 448     for (uint i = 1; i < tos; i++) {
 449       Node* x = phi_map->in(i);
 450       if (x->in(0) == region) {
 451         assert(x->is_Phi(), "expected a special phi");
 452         phi_map->set_req(i, _gvn.transform(x));
 453       }
 454     }
 455     for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
 456       Node* x = mms.memory();
 457       if (x->in(0) == region) {
 458         assert(x->is_Phi(), "nobody else uses a hidden region");
 459         mms.set_memory(_gvn.transform(x));
 460       }
 461     }
 462     if (ex_oop->in(0) == region) {
 463       assert(ex_oop->is_Phi(), "expected a special phi");
 464       ex_oop = _gvn.transform(ex_oop);
 465     }
 466   } else {
 467     set_jvms(phi_map->jvms());
 468   }
 469 
 470   assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared");
 471   assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared");
 472   return ex_oop;
 473 }
 474 
 475 //---------------------------------java_bc-------------------------------------
 476 Bytecodes::Code GraphKit::java_bc() const {
 477   ciMethod* method = this->method();
 478   int       bci    = this->bci();
 479   if (method != NULL && bci != InvocationEntryBci)
 480     return method->java_code_at_bci(bci);
 481   else
 482     return Bytecodes::_illegal;
 483 }
 484 
 485 void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
 486                                                           bool must_throw) {
 487     // if the exception capability is set, then we will generate code
 488     // to check the JavaThread.should_post_on_exceptions flag to see
 489     // if we actually need to report exception events (for this
 490     // thread).  If we don't need to report exception events, we will
 491     // take the normal fast path provided by add_exception_events.  If
 492     // exception event reporting is enabled for this thread, we will
 493     // take the uncommon_trap in the BuildCutout below.
 494 
 495     // first must access the should_post_on_exceptions_flag in this thread's JavaThread
 496     Node* jthread = _gvn.transform(new (C) ThreadLocalNode());
 497     Node* adr = basic_plus_adr(top(), jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset()));
 498     Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw, MemNode::unordered);
 499 
 500     // Test the should_post_on_exceptions_flag vs. 0
 501     Node* chk = _gvn.transform( new (C) CmpINode(should_post_flag, intcon(0)) );
 502     Node* tst = _gvn.transform( new (C) BoolNode(chk, BoolTest::eq) );
 503 
 504     // Branch to slow_path if should_post_on_exceptions_flag was true
 505     { BuildCutout unless(this, tst, PROB_MAX);
 506       // Do not try anything fancy if we're notifying the VM on every throw.
 507       // Cf. case Bytecodes::_athrow in parse2.cpp.
 508       uncommon_trap(reason, Deoptimization::Action_none,
 509                     (ciKlass*)NULL, (char*)NULL, must_throw);
 510     }
 511 
 512 }
 513 
 514 //------------------------------builtin_throw----------------------------------
 515 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) {
 516   bool must_throw = true;
 517 
 518   if (env()->jvmti_can_post_on_exceptions()) {
 519     // check if we must post exception events, take uncommon trap if so
 520     uncommon_trap_if_should_post_on_exceptions(reason, must_throw);
 521     // here if should_post_on_exceptions is false
 522     // continue on with the normal codegen
 523   }
 524 
 525   // If this particular condition has not yet happened at this
 526   // bytecode, then use the uncommon trap mechanism, and allow for
 527   // a future recompilation if several traps occur here.
 528   // If the throw is hot, try to use a more complicated inline mechanism
 529   // which keeps execution inside the compiled code.
 530   bool treat_throw_as_hot = false;
 531   ciMethodData* md = method()->method_data();
 532 
 533   if (ProfileTraps) {
 534     if (too_many_traps(reason)) {
 535       treat_throw_as_hot = true;
 536     }
 537     // (If there is no MDO at all, assume it is early in
 538     // execution, and that any deopts are part of the
 539     // startup transient, and don't need to be remembered.)
 540 
 541     // Also, if there is a local exception handler, treat all throws
 542     // as hot if there has been at least one in this method.
 543     if (C->trap_count(reason) != 0
 544         && method()->method_data()->trap_count(reason) != 0
 545         && has_ex_handler()) {
 546         treat_throw_as_hot = true;
 547     }
 548   }
 549 
 550   // If this throw happens frequently, an uncommon trap might cause
 551   // a performance pothole.  If there is a local exception handler,
 552   // and if this particular bytecode appears to be deoptimizing often,
 553   // let us handle the throw inline, with a preconstructed instance.
 554   // Note:   If the deopt count has blown up, the uncommon trap
 555   // runtime is going to flush this nmethod, not matter what.
 556   if (treat_throw_as_hot
 557       && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) {
 558     // If the throw is local, we use a pre-existing instance and
 559     // punt on the backtrace.  This would lead to a missing backtrace
 560     // (a repeat of 4292742) if the backtrace object is ever asked
 561     // for its backtrace.
 562     // Fixing this remaining case of 4292742 requires some flavor of
 563     // escape analysis.  Leave that for the future.
 564     ciInstance* ex_obj = NULL;
 565     switch (reason) {
 566     case Deoptimization::Reason_null_check:
 567       ex_obj = env()->NullPointerException_instance();
 568       break;
 569     case Deoptimization::Reason_div0_check:
 570       ex_obj = env()->ArithmeticException_instance();
 571       break;
 572     case Deoptimization::Reason_range_check:
 573       ex_obj = env()->ArrayIndexOutOfBoundsException_instance();
 574       break;
 575     case Deoptimization::Reason_class_check:
 576       if (java_bc() == Bytecodes::_aastore) {
 577         ex_obj = env()->ArrayStoreException_instance();
 578       } else {
 579         ex_obj = env()->ClassCastException_instance();
 580       }
 581       break;
 582     }
 583     if (failing()) { stop(); return; }  // exception allocation might fail
 584     if (ex_obj != NULL) {
 585       // Cheat with a preallocated exception object.
 586       if (C->log() != NULL)
 587         C->log()->elem("hot_throw preallocated='1' reason='%s'",
 588                        Deoptimization::trap_reason_name(reason));
 589       const TypeInstPtr* ex_con  = TypeInstPtr::make(ex_obj);
 590       Node*              ex_node = _gvn.transform( ConNode::make(C, ex_con) );
 591 
 592       // Clear the detail message of the preallocated exception object.
 593       // Weblogic sometimes mutates the detail message of exceptions
 594       // using reflection.
 595       int offset = java_lang_Throwable::get_detailMessage_offset();
 596       const TypePtr* adr_typ = ex_con->add_offset(offset);
 597 
 598       Node *adr = basic_plus_adr(ex_node, ex_node, offset);
 599       const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass());
 600       // Conservatively release stores of object references.
 601       Node *store = store_oop_to_object(control(), ex_node, adr, adr_typ, null(), val_type, T_OBJECT, MemNode::release);
 602 
 603       add_exception_state(make_exception_state(ex_node));
 604       return;
 605     }
 606   }
 607 
 608   // %%% Maybe add entry to OptoRuntime which directly throws the exc.?
 609   // It won't be much cheaper than bailing to the interp., since we'll
 610   // have to pass up all the debug-info, and the runtime will have to
 611   // create the stack trace.
 612 
 613   // Usual case:  Bail to interpreter.
 614   // Reserve the right to recompile if we haven't seen anything yet.
 615 
 616   assert(!Deoptimization::reason_is_speculate(reason), "unsupported");
 617   Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile;
 618   if (treat_throw_as_hot
 619       && (method()->method_data()->trap_recompiled_at(bci(), NULL)
 620           || C->too_many_traps(reason))) {
 621     // We cannot afford to take more traps here.  Suffer in the interpreter.
 622     if (C->log() != NULL)
 623       C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'",
 624                      Deoptimization::trap_reason_name(reason),
 625                      C->trap_count(reason));
 626     action = Deoptimization::Action_none;
 627   }
 628 
 629   // "must_throw" prunes the JVM state to include only the stack, if there
 630   // are no local exception handlers.  This should cut down on register
 631   // allocation time and code size, by drastically reducing the number
 632   // of in-edges on the call to the uncommon trap.
 633 
 634   uncommon_trap(reason, action, (ciKlass*)NULL, (char*)NULL, must_throw);
 635 }
 636 
 637 
 638 //----------------------------PreserveJVMState---------------------------------
 639 PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) {
 640   debug_only(kit->verify_map());
 641   _kit    = kit;
 642   _map    = kit->map();   // preserve the map
 643   _sp     = kit->sp();
 644   kit->set_map(clone_map ? kit->clone_map() : NULL);
 645 #ifdef ASSERT
 646   _bci    = kit->bci();
 647   Parse* parser = kit->is_Parse();
 648   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 649   _block  = block;
 650 #endif
 651 }
 652 PreserveJVMState::~PreserveJVMState() {
 653   GraphKit* kit = _kit;
 654 #ifdef ASSERT
 655   assert(kit->bci() == _bci, "bci must not shift");
 656   Parse* parser = kit->is_Parse();
 657   int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
 658   assert(block == _block,    "block must not shift");
 659 #endif
 660   kit->set_map(_map);
 661   kit->set_sp(_sp);
 662 }
 663 
 664 
 665 //-----------------------------BuildCutout-------------------------------------
 666 BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt)
 667   : PreserveJVMState(kit)
 668 {
 669   assert(p->is_Con() || p->is_Bool(), "test must be a bool");
 670   SafePointNode* outer_map = _map;   // preserved map is caller's
 671   SafePointNode* inner_map = kit->map();
 672   IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt);
 673   outer_map->set_control(kit->gvn().transform( new (kit->C) IfTrueNode(iff) ));
 674   inner_map->set_control(kit->gvn().transform( new (kit->C) IfFalseNode(iff) ));
 675 }
 676 BuildCutout::~BuildCutout() {
 677   GraphKit* kit = _kit;
 678   assert(kit->stopped(), "cutout code must stop, throw, return, etc.");
 679 }
 680 
 681 //---------------------------PreserveReexecuteState----------------------------
 682 PreserveReexecuteState::PreserveReexecuteState(GraphKit* kit) {
 683   assert(!kit->stopped(), "must call stopped() before");
 684   _kit    =    kit;
 685   _sp     =    kit->sp();
 686   _reexecute = kit->jvms()->_reexecute;
 687 }
 688 PreserveReexecuteState::~PreserveReexecuteState() {
 689   if (_kit->stopped()) return;
 690   _kit->jvms()->_reexecute = _reexecute;
 691   _kit->set_sp(_sp);
 692 }
 693 
 694 //------------------------------clone_map--------------------------------------
 695 // Implementation of PreserveJVMState
 696 //
 697 // Only clone_map(...) here. If this function is only used in the
 698 // PreserveJVMState class we may want to get rid of this extra
 699 // function eventually and do it all there.
 700 
 701 SafePointNode* GraphKit::clone_map() {
 702   if (map() == NULL)  return NULL;
 703 
 704   // Clone the memory edge first
 705   Node* mem = MergeMemNode::make(C, map()->memory());
 706   gvn().set_type_bottom(mem);
 707 
 708   SafePointNode *clonemap = (SafePointNode*)map()->clone();
 709   JVMState* jvms = this->jvms();
 710   JVMState* clonejvms = jvms->clone_shallow(C);
 711   clonemap->set_memory(mem);
 712   clonemap->set_jvms(clonejvms);
 713   clonejvms->set_map(clonemap);
 714   record_for_igvn(clonemap);
 715   gvn().set_type_bottom(clonemap);
 716   return clonemap;
 717 }
 718 
 719 
 720 //-----------------------------set_map_clone-----------------------------------
 721 void GraphKit::set_map_clone(SafePointNode* m) {
 722   _map = m;
 723   _map = clone_map();
 724   _map->set_next_exception(NULL);
 725   debug_only(verify_map());
 726 }
 727 
 728 
 729 //----------------------------kill_dead_locals---------------------------------
 730 // Detect any locals which are known to be dead, and force them to top.
 731 void GraphKit::kill_dead_locals() {
 732   // Consult the liveness information for the locals.  If any
 733   // of them are unused, then they can be replaced by top().  This
 734   // should help register allocation time and cut down on the size
 735   // of the deoptimization information.
 736 
 737   // This call is made from many of the bytecode handling
 738   // subroutines called from the Big Switch in do_one_bytecode.
 739   // Every bytecode which might include a slow path is responsible
 740   // for killing its dead locals.  The more consistent we
 741   // are about killing deads, the fewer useless phis will be
 742   // constructed for them at various merge points.
 743 
 744   // bci can be -1 (InvocationEntryBci).  We return the entry
 745   // liveness for the method.
 746 
 747   if (method() == NULL || method()->code_size() == 0) {
 748     // We are building a graph for a call to a native method.
 749     // All locals are live.
 750     return;
 751   }
 752 
 753   ResourceMark rm;
 754 
 755   // Consult the liveness information for the locals.  If any
 756   // of them are unused, then they can be replaced by top().  This
 757   // should help register allocation time and cut down on the size
 758   // of the deoptimization information.
 759   MethodLivenessResult live_locals = method()->liveness_at_bci(bci());
 760 
 761   int len = (int)live_locals.size();
 762   assert(len <= jvms()->loc_size(), "too many live locals");
 763   for (int local = 0; local < len; local++) {
 764     if (!live_locals.at(local)) {
 765       set_local(local, top());
 766     }
 767   }
 768 }
 769 
 770 #ifdef ASSERT
 771 //-------------------------dead_locals_are_killed------------------------------
 772 // Return true if all dead locals are set to top in the map.
 773 // Used to assert "clean" debug info at various points.
 774 bool GraphKit::dead_locals_are_killed() {
 775   if (method() == NULL || method()->code_size() == 0) {
 776     // No locals need to be dead, so all is as it should be.
 777     return true;
 778   }
 779 
 780   // Make sure somebody called kill_dead_locals upstream.
 781   ResourceMark rm;
 782   for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
 783     if (jvms->loc_size() == 0)  continue;  // no locals to consult
 784     SafePointNode* map = jvms->map();
 785     ciMethod* method = jvms->method();
 786     int       bci    = jvms->bci();
 787     if (jvms == this->jvms()) {
 788       bci = this->bci();  // it might not yet be synched
 789     }
 790     MethodLivenessResult live_locals = method->liveness_at_bci(bci);
 791     int len = (int)live_locals.size();
 792     if (!live_locals.is_valid() || len == 0)
 793       // This method is trivial, or is poisoned by a breakpoint.
 794       return true;
 795     assert(len == jvms->loc_size(), "live map consistent with locals map");
 796     for (int local = 0; local < len; local++) {
 797       if (!live_locals.at(local) && map->local(jvms, local) != top()) {
 798         if (PrintMiscellaneous && (Verbose || WizardMode)) {
 799           tty->print_cr("Zombie local %d: ", local);
 800           jvms->dump();
 801         }
 802         return false;
 803       }
 804     }
 805   }
 806   return true;
 807 }
 808 
 809 #endif //ASSERT
 810 
 811 // Helper function for enforcing certain bytecodes to reexecute if
 812 // deoptimization happens
 813 static bool should_reexecute_implied_by_bytecode(JVMState *jvms, bool is_anewarray) {
 814   ciMethod* cur_method = jvms->method();
 815   int       cur_bci   = jvms->bci();
 816   if (cur_method != NULL && cur_bci != InvocationEntryBci) {
 817     Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci);
 818     return Interpreter::bytecode_should_reexecute(code) ||
 819            is_anewarray && code == Bytecodes::_multianewarray;
 820     // Reexecute _multianewarray bytecode which was replaced with
 821     // sequence of [a]newarray. See Parse::do_multianewarray().
 822     //
 823     // Note: interpreter should not have it set since this optimization
 824     // is limited by dimensions and guarded by flag so in some cases
 825     // multianewarray() runtime calls will be generated and
 826     // the bytecode should not be reexecutes (stack will not be reset).
 827   } else
 828     return false;
 829 }
 830 
 831 // Helper function for adding JVMState and debug information to node
 832 void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) {
 833   // Add the safepoint edges to the call (or other safepoint).
 834 
 835   // Make sure dead locals are set to top.  This
 836   // should help register allocation time and cut down on the size
 837   // of the deoptimization information.
 838   assert(dead_locals_are_killed(), "garbage in debug info before safepoint");
 839 
 840   // Walk the inline list to fill in the correct set of JVMState's
 841   // Also fill in the associated edges for each JVMState.
 842 
 843   // If the bytecode needs to be reexecuted we need to put
 844   // the arguments back on the stack.
 845   const bool should_reexecute = jvms()->should_reexecute();
 846   JVMState* youngest_jvms = should_reexecute ? sync_jvms_for_reexecute() : sync_jvms();
 847 
 848   // NOTE: set_bci (called from sync_jvms) might reset the reexecute bit to
 849   // undefined if the bci is different.  This is normal for Parse but it
 850   // should not happen for LibraryCallKit because only one bci is processed.
 851   assert(!is_LibraryCallKit() || (jvms()->should_reexecute() == should_reexecute),
 852          "in LibraryCallKit the reexecute bit should not change");
 853 
 854   // If we are guaranteed to throw, we can prune everything but the
 855   // input to the current bytecode.
 856   bool can_prune_locals = false;
 857   uint stack_slots_not_pruned = 0;
 858   int inputs = 0, depth = 0;
 859   if (must_throw) {
 860     assert(method() == youngest_jvms->method(), "sanity");
 861     if (compute_stack_effects(inputs, depth)) {
 862       can_prune_locals = true;
 863       stack_slots_not_pruned = inputs;
 864     }
 865   }
 866 
 867   if (env()->jvmti_can_access_local_variables()) {
 868     // At any safepoint, this method can get breakpointed, which would
 869     // then require an immediate deoptimization.
 870     can_prune_locals = false;  // do not prune locals
 871     stack_slots_not_pruned = 0;
 872   }
 873 
 874   // do not scribble on the input jvms
 875   JVMState* out_jvms = youngest_jvms->clone_deep(C);
 876   call->set_jvms(out_jvms); // Start jvms list for call node
 877 
 878   // For a known set of bytecodes, the interpreter should reexecute them if
 879   // deoptimization happens. We set the reexecute state for them here
 880   if (out_jvms->is_reexecute_undefined() && //don't change if already specified
 881       should_reexecute_implied_by_bytecode(out_jvms, call->is_AllocateArray())) {
 882     out_jvms->set_should_reexecute(true); //NOTE: youngest_jvms not changed
 883   }
 884 
 885   // Presize the call:
 886   DEBUG_ONLY(uint non_debug_edges = call->req());
 887   call->add_req_batch(top(), youngest_jvms->debug_depth());
 888   assert(call->req() == non_debug_edges + youngest_jvms->debug_depth(), "");
 889 
 890   // Set up edges so that the call looks like this:
 891   //  Call [state:] ctl io mem fptr retadr
 892   //       [parms:] parm0 ... parmN
 893   //       [root:]  loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 894   //    [...mid:]   loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN [...]
 895   //       [young:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
 896   // Note that caller debug info precedes callee debug info.
 897 
 898   // Fill pointer walks backwards from "young:" to "root:" in the diagram above:
 899   uint debug_ptr = call->req();
 900 
 901   // Loop over the map input edges associated with jvms, add them
 902   // to the call node, & reset all offsets to match call node array.
 903   for (JVMState* in_jvms = youngest_jvms; in_jvms != NULL; ) {
 904     uint debug_end   = debug_ptr;
 905     uint debug_start = debug_ptr - in_jvms->debug_size();
 906     debug_ptr = debug_start;  // back up the ptr
 907 
 908     uint p = debug_start;  // walks forward in [debug_start, debug_end)
 909     uint j, k, l;
 910     SafePointNode* in_map = in_jvms->map();
 911     out_jvms->set_map(call);
 912 
 913     if (can_prune_locals) {
 914       assert(in_jvms->method() == out_jvms->method(), "sanity");
 915       // If the current throw can reach an exception handler in this JVMS,
 916       // then we must keep everything live that can reach that handler.
 917       // As a quick and dirty approximation, we look for any handlers at all.
 918       if (in_jvms->method()->has_exception_handlers()) {
 919         can_prune_locals = false;
 920       }
 921     }
 922 
 923     // Add the Locals
 924     k = in_jvms->locoff();
 925     l = in_jvms->loc_size();
 926     out_jvms->set_locoff(p);
 927     if (!can_prune_locals) {
 928       for (j = 0; j < l; j++)
 929         call->set_req(p++, in_map->in(k+j));
 930     } else {
 931       p += l;  // already set to top above by add_req_batch
 932     }
 933 
 934     // Add the Expression Stack
 935     k = in_jvms->stkoff();
 936     l = in_jvms->sp();
 937     out_jvms->set_stkoff(p);
 938     if (!can_prune_locals) {
 939       for (j = 0; j < l; j++)
 940         call->set_req(p++, in_map->in(k+j));
 941     } else if (can_prune_locals && stack_slots_not_pruned != 0) {
 942       // Divide stack into {S0,...,S1}, where S0 is set to top.
 943       uint s1 = stack_slots_not_pruned;
 944       stack_slots_not_pruned = 0;  // for next iteration
 945       if (s1 > l)  s1 = l;
 946       uint s0 = l - s1;
 947       p += s0;  // skip the tops preinstalled by add_req_batch
 948       for (j = s0; j < l; j++)
 949         call->set_req(p++, in_map->in(k+j));
 950     } else {
 951       p += l;  // already set to top above by add_req_batch
 952     }
 953 
 954     // Add the Monitors
 955     k = in_jvms->monoff();
 956     l = in_jvms->mon_size();
 957     out_jvms->set_monoff(p);
 958     for (j = 0; j < l; j++)
 959       call->set_req(p++, in_map->in(k+j));
 960 
 961     // Copy any scalar object fields.
 962     k = in_jvms->scloff();
 963     l = in_jvms->scl_size();
 964     out_jvms->set_scloff(p);
 965     for (j = 0; j < l; j++)
 966       call->set_req(p++, in_map->in(k+j));
 967 
 968     // Finish the new jvms.
 969     out_jvms->set_endoff(p);
 970 
 971     assert(out_jvms->endoff()     == debug_end,             "fill ptr must match");
 972     assert(out_jvms->depth()      == in_jvms->depth(),      "depth must match");
 973     assert(out_jvms->loc_size()   == in_jvms->loc_size(),   "size must match");
 974     assert(out_jvms->mon_size()   == in_jvms->mon_size(),   "size must match");
 975     assert(out_jvms->scl_size()   == in_jvms->scl_size(),   "size must match");
 976     assert(out_jvms->debug_size() == in_jvms->debug_size(), "size must match");
 977 
 978     // Update the two tail pointers in parallel.
 979     out_jvms = out_jvms->caller();
 980     in_jvms  = in_jvms->caller();
 981   }
 982 
 983   assert(debug_ptr == non_debug_edges, "debug info must fit exactly");
 984 
 985   // Test the correctness of JVMState::debug_xxx accessors:
 986   assert(call->jvms()->debug_start() == non_debug_edges, "");
 987   assert(call->jvms()->debug_end()   == call->req(), "");
 988   assert(call->jvms()->debug_depth() == call->req() - non_debug_edges, "");
 989 }
 990 
 991 bool GraphKit::compute_stack_effects(int& inputs, int& depth) {
 992   Bytecodes::Code code = java_bc();
 993   if (code == Bytecodes::_wide) {
 994     code = method()->java_code_at_bci(bci() + 1);
 995   }
 996 
 997   BasicType rtype = T_ILLEGAL;
 998   int       rsize = 0;
 999 
1000   if (code != Bytecodes::_illegal) {
1001     depth = Bytecodes::depth(code); // checkcast=0, athrow=-1
1002     rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V
1003     if (rtype < T_CONFLICT)
1004       rsize = type2size[rtype];
1005   }
1006 
1007   switch (code) {
1008   case Bytecodes::_illegal:
1009     return false;
1010 
1011   case Bytecodes::_ldc:
1012   case Bytecodes::_ldc_w:
1013   case Bytecodes::_ldc2_w:
1014     inputs = 0;
1015     break;
1016 
1017   case Bytecodes::_dup:         inputs = 1;  break;
1018   case Bytecodes::_dup_x1:      inputs = 2;  break;
1019   case Bytecodes::_dup_x2:      inputs = 3;  break;
1020   case Bytecodes::_dup2:        inputs = 2;  break;
1021   case Bytecodes::_dup2_x1:     inputs = 3;  break;
1022   case Bytecodes::_dup2_x2:     inputs = 4;  break;
1023   case Bytecodes::_swap:        inputs = 2;  break;
1024   case Bytecodes::_arraylength: inputs = 1;  break;
1025 
1026   case Bytecodes::_getstatic:
1027   case Bytecodes::_putstatic:
1028   case Bytecodes::_getfield:
1029   case Bytecodes::_putfield:
1030     {
1031       bool ignored_will_link;
1032       ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
1033       int      size  = field->type()->size();
1034       bool is_get = (depth >= 0), is_static = (depth & 1);
1035       inputs = (is_static ? 0 : 1);
1036       if (is_get) {
1037         depth = size - inputs;
1038       } else {
1039         inputs += size;        // putxxx pops the value from the stack
1040         depth = - inputs;
1041       }
1042     }
1043     break;
1044 
1045   case Bytecodes::_invokevirtual:
1046   case Bytecodes::_invokespecial:
1047   case Bytecodes::_invokestatic:
1048   case Bytecodes::_invokedynamic:
1049   case Bytecodes::_invokeinterface:
1050     {
1051       bool ignored_will_link;
1052       ciSignature* declared_signature = NULL;
1053       ciMethod* ignored_callee = method()->get_method_at_bci(bci(), ignored_will_link, &declared_signature);
1054       assert(declared_signature != NULL, "cannot be null");
1055       inputs   = declared_signature->arg_size_for_bc(code);
1056       int size = declared_signature->return_type()->size();
1057       depth = size - inputs;
1058     }
1059     break;
1060 
1061   case Bytecodes::_multianewarray:
1062     {
1063       ciBytecodeStream iter(method());
1064       iter.reset_to_bci(bci());
1065       iter.next();
1066       inputs = iter.get_dimensions();
1067       assert(rsize == 1, "");
1068       depth = rsize - inputs;
1069     }
1070     break;
1071 
1072   case Bytecodes::_ireturn:
1073   case Bytecodes::_lreturn:
1074   case Bytecodes::_freturn:
1075   case Bytecodes::_dreturn:
1076   case Bytecodes::_areturn:
1077     assert(rsize = -depth, "");
1078     inputs = rsize;
1079     break;
1080 
1081   case Bytecodes::_jsr:
1082   case Bytecodes::_jsr_w:
1083     inputs = 0;
1084     depth  = 1;                  // S.B. depth=1, not zero
1085     break;
1086 
1087   default:
1088     // bytecode produces a typed result
1089     inputs = rsize - depth;
1090     assert(inputs >= 0, "");
1091     break;
1092   }
1093 
1094 #ifdef ASSERT
1095   // spot check
1096   int outputs = depth + inputs;
1097   assert(outputs >= 0, "sanity");
1098   switch (code) {
1099   case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break;
1100   case Bytecodes::_athrow:    assert(inputs == 1 && outputs == 0, ""); break;
1101   case Bytecodes::_aload_0:   assert(inputs == 0 && outputs == 1, ""); break;
1102   case Bytecodes::_return:    assert(inputs == 0 && outputs == 0, ""); break;
1103   case Bytecodes::_drem:      assert(inputs == 4 && outputs == 2, ""); break;
1104   }
1105 #endif //ASSERT
1106 
1107   return true;
1108 }
1109 
1110 
1111 
1112 //------------------------------basic_plus_adr---------------------------------
1113 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) {
1114   // short-circuit a common case
1115   if (offset == intcon(0))  return ptr;
1116   return _gvn.transform( new (C) AddPNode(base, ptr, offset) );
1117 }
1118 
1119 Node* GraphKit::ConvI2L(Node* offset) {
1120   // short-circuit a common case
1121   jint offset_con = find_int_con(offset, Type::OffsetBot);
1122   if (offset_con != Type::OffsetBot) {
1123     return longcon((jlong) offset_con);
1124   }
1125   return _gvn.transform( new (C) ConvI2LNode(offset));
1126 }
1127 
1128 Node* GraphKit::ConvI2UL(Node* offset) {
1129   juint offset_con = (juint) find_int_con(offset, Type::OffsetBot);
1130   if (offset_con != (juint) Type::OffsetBot) {
1131     return longcon((julong) offset_con);
1132   }
1133   Node* conv = _gvn.transform( new (C) ConvI2LNode(offset));
1134   Node* mask = _gvn.transform( ConLNode::make(C, (julong) max_juint) );
1135   return _gvn.transform( new (C) AndLNode(conv, mask) );
1136 }
1137 
1138 Node* GraphKit::ConvL2I(Node* offset) {
1139   // short-circuit a common case
1140   jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot);
1141   if (offset_con != (jlong)Type::OffsetBot) {
1142     return intcon((int) offset_con);
1143   }
1144   return _gvn.transform( new (C) ConvL2INode(offset));
1145 }
1146 
1147 //-------------------------load_object_klass-----------------------------------
1148 Node* GraphKit::load_object_klass(Node* obj) {
1149   // Special-case a fresh allocation to avoid building nodes:
1150   Node* akls = AllocateNode::Ideal_klass(obj, &_gvn);
1151   if (akls != NULL)  return akls;
1152   Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1153   return _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), k_adr, TypeInstPtr::KLASS));
1154 }
1155 
1156 //-------------------------load_array_length-----------------------------------
1157 Node* GraphKit::load_array_length(Node* array) {
1158   // Special-case a fresh allocation to avoid building nodes:
1159   AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array, &_gvn);
1160   Node *alen;
1161   if (alloc == NULL) {
1162     Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes());
1163     alen = _gvn.transform( new (C) LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS));
1164   } else {
1165     alen = alloc->Ideal_length();
1166     Node* ccast = alloc->make_ideal_length(_gvn.type(array)->is_oopptr(), &_gvn);
1167     if (ccast != alen) {
1168       alen = _gvn.transform(ccast);
1169     }
1170   }
1171   return alen;
1172 }
1173 
1174 //------------------------------do_null_check----------------------------------
1175 // Helper function to do a NULL pointer check.  Returned value is
1176 // the incoming address with NULL casted away.  You are allowed to use the
1177 // not-null value only if you are control dependent on the test.
1178 extern int explicit_null_checks_inserted,
1179            explicit_null_checks_elided;
1180 Node* GraphKit::null_check_common(Node* value, BasicType type,
1181                                   // optional arguments for variations:
1182                                   bool assert_null,
1183                                   Node* *null_control) {
1184   assert(!assert_null || null_control == NULL, "not both at once");
1185   if (stopped())  return top();
1186   if (!GenerateCompilerNullChecks && !assert_null && null_control == NULL) {
1187     // For some performance testing, we may wish to suppress null checking.
1188     value = cast_not_null(value);   // Make it appear to be non-null (4962416).
1189     return value;
1190   }
1191   explicit_null_checks_inserted++;
1192 
1193   // Construct NULL check
1194   Node *chk = NULL;
1195   switch(type) {
1196     case T_LONG   : chk = new (C) CmpLNode(value, _gvn.zerocon(T_LONG)); break;
1197     case T_INT    : chk = new (C) CmpINode(value, _gvn.intcon(0)); break;
1198     case T_ARRAY  : // fall through
1199       type = T_OBJECT;  // simplify further tests
1200     case T_OBJECT : {
1201       const Type *t = _gvn.type( value );
1202 
1203       const TypeOopPtr* tp = t->isa_oopptr();
1204       if (tp != NULL && tp->klass() != NULL && !tp->klass()->is_loaded()
1205           // Only for do_null_check, not any of its siblings:
1206           && !assert_null && null_control == NULL) {
1207         // Usually, any field access or invocation on an unloaded oop type
1208         // will simply fail to link, since the statically linked class is
1209         // likely also to be unloaded.  However, in -Xcomp mode, sometimes
1210         // the static class is loaded but the sharper oop type is not.
1211         // Rather than checking for this obscure case in lots of places,
1212         // we simply observe that a null check on an unloaded class
1213         // will always be followed by a nonsense operation, so we
1214         // can just issue the uncommon trap here.
1215         // Our access to the unloaded class will only be correct
1216         // after it has been loaded and initialized, which requires
1217         // a trip through the interpreter.
1218 #ifndef PRODUCT
1219         if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); }
1220 #endif
1221         uncommon_trap(Deoptimization::Reason_unloaded,
1222                       Deoptimization::Action_reinterpret,
1223                       tp->klass(), "!loaded");
1224         return top();
1225       }
1226 
1227       if (assert_null) {
1228         // See if the type is contained in NULL_PTR.
1229         // If so, then the value is already null.
1230         if (t->higher_equal(TypePtr::NULL_PTR)) {
1231           explicit_null_checks_elided++;
1232           return value;           // Elided null assert quickly!
1233         }
1234       } else {
1235         // See if mixing in the NULL pointer changes type.
1236         // If so, then the NULL pointer was not allowed in the original
1237         // type.  In other words, "value" was not-null.
1238         if (t->meet(TypePtr::NULL_PTR) != t->remove_speculative()) {
1239           // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
1240           explicit_null_checks_elided++;
1241           return value;           // Elided null check quickly!
1242         }
1243       }
1244       chk = new (C) CmpPNode( value, null() );
1245       break;
1246     }
1247 
1248     default:
1249       fatal(err_msg_res("unexpected type: %s", type2name(type)));
1250   }
1251   assert(chk != NULL, "sanity check");
1252   chk = _gvn.transform(chk);
1253 
1254   BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
1255   BoolNode *btst = new (C) BoolNode( chk, btest);
1256   Node   *tst = _gvn.transform( btst );
1257 
1258   //-----------
1259   // if peephole optimizations occurred, a prior test existed.
1260   // If a prior test existed, maybe it dominates as we can avoid this test.
1261   if (tst != btst && type == T_OBJECT) {
1262     // At this point we want to scan up the CFG to see if we can
1263     // find an identical test (and so avoid this test altogether).
1264     Node *cfg = control();
1265     int depth = 0;
1266     while( depth < 16 ) {       // Limit search depth for speed
1267       if( cfg->Opcode() == Op_IfTrue &&
1268           cfg->in(0)->in(1) == tst ) {
1269         // Found prior test.  Use "cast_not_null" to construct an identical
1270         // CastPP (and hence hash to) as already exists for the prior test.
1271         // Return that casted value.
1272         if (assert_null) {
1273           replace_in_map(value, null());
1274           return null();  // do not issue the redundant test
1275         }
1276         Node *oldcontrol = control();
1277         set_control(cfg);
1278         Node *res = cast_not_null(value);
1279         set_control(oldcontrol);
1280         explicit_null_checks_elided++;
1281         return res;
1282       }
1283       cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true);
1284       if (cfg == NULL)  break;  // Quit at region nodes
1285       depth++;
1286     }
1287   }
1288 
1289   //-----------
1290   // Branch to failure if null
1291   float ok_prob = PROB_MAX;  // a priori estimate:  nulls never happen
1292   Deoptimization::DeoptReason reason;
1293   if (assert_null)
1294     reason = Deoptimization::Reason_null_assert;
1295   else if (type == T_OBJECT)
1296     reason = Deoptimization::Reason_null_check;
1297   else
1298     reason = Deoptimization::Reason_div0_check;
1299 
1300   // %%% Since Reason_unhandled is not recorded on a per-bytecode basis,
1301   // ciMethodData::has_trap_at will return a conservative -1 if any
1302   // must-be-null assertion has failed.  This could cause performance
1303   // problems for a method after its first do_null_assert failure.
1304   // Consider using 'Reason_class_check' instead?
1305 
1306   // To cause an implicit null check, we set the not-null probability
1307   // to the maximum (PROB_MAX).  For an explicit check the probability
1308   // is set to a smaller value.
1309   if (null_control != NULL || too_many_traps(reason)) {
1310     // probability is less likely
1311     ok_prob =  PROB_LIKELY_MAG(3);
1312   } else if (!assert_null &&
1313              (ImplicitNullCheckThreshold > 0) &&
1314              method() != NULL &&
1315              (method()->method_data()->trap_count(reason)
1316               >= (uint)ImplicitNullCheckThreshold)) {
1317     ok_prob =  PROB_LIKELY_MAG(3);
1318   }
1319 
1320   if (null_control != NULL) {
1321     IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN);
1322     Node* null_true = _gvn.transform( new (C) IfFalseNode(iff));
1323     set_control(      _gvn.transform( new (C) IfTrueNode(iff)));
1324     if (null_true == top())
1325       explicit_null_checks_elided++;
1326     (*null_control) = null_true;
1327   } else {
1328     BuildCutout unless(this, tst, ok_prob);
1329     // Check for optimizer eliding test at parse time
1330     if (stopped()) {
1331       // Failure not possible; do not bother making uncommon trap.
1332       explicit_null_checks_elided++;
1333     } else if (assert_null) {
1334       uncommon_trap(reason,
1335                     Deoptimization::Action_make_not_entrant,
1336                     NULL, "assert_null");
1337     } else {
1338       replace_in_map(value, zerocon(type));
1339       builtin_throw(reason);
1340     }
1341   }
1342 
1343   // Must throw exception, fall-thru not possible?
1344   if (stopped()) {
1345     return top();               // No result
1346   }
1347 
1348   if (assert_null) {
1349     // Cast obj to null on this path.
1350     replace_in_map(value, zerocon(type));
1351     return zerocon(type);
1352   }
1353 
1354   // Cast obj to not-null on this path, if there is no null_control.
1355   // (If there is a null_control, a non-null value may come back to haunt us.)
1356   if (type == T_OBJECT) {
1357     Node* cast = cast_not_null(value, false);
1358     if (null_control == NULL || (*null_control) == top())
1359       replace_in_map(value, cast);
1360     value = cast;
1361   }
1362 
1363   return value;
1364 }
1365 
1366 
1367 //------------------------------cast_not_null----------------------------------
1368 // Cast obj to not-null on this path
1369 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) {
1370   const Type *t = _gvn.type(obj);
1371   const Type *t_not_null = t->join_speculative(TypePtr::NOTNULL);
1372   // Object is already not-null?
1373   if( t == t_not_null ) return obj;
1374 
1375   Node *cast = new (C) CastPPNode(obj,t_not_null);
1376   cast->init_req(0, control());
1377   cast = _gvn.transform( cast );
1378 
1379   // Scan for instances of 'obj' in the current JVM mapping.
1380   // These instances are known to be not-null after the test.
1381   if (do_replace_in_map)
1382     replace_in_map(obj, cast);
1383 
1384   return cast;                  // Return casted value
1385 }
1386 
1387 
1388 //--------------------------replace_in_map-------------------------------------
1389 void GraphKit::replace_in_map(Node* old, Node* neww) {
1390   if (old == neww) {
1391     return;
1392   }
1393 
1394   map()->replace_edge(old, neww);
1395 
1396   // Note: This operation potentially replaces any edge
1397   // on the map.  This includes locals, stack, and monitors
1398   // of the current (innermost) JVM state.
1399 
1400   // don't let inconsistent types from profiling escape this
1401   // method
1402 
1403   const Type* told = _gvn.type(old);
1404   const Type* tnew = _gvn.type(neww);
1405 
1406   if (!tnew->higher_equal(told)) {
1407     return;
1408   }
1409 
1410   map()->record_replaced_node(old, neww);
1411 }
1412 
1413 
1414 //=============================================================================
1415 //--------------------------------memory---------------------------------------
1416 Node* GraphKit::memory(uint alias_idx) {
1417   MergeMemNode* mem = merged_memory();
1418   Node* p = mem->memory_at(alias_idx);
1419   _gvn.set_type(p, Type::MEMORY);  // must be mapped
1420   return p;
1421 }
1422 
1423 //-----------------------------reset_memory------------------------------------
1424 Node* GraphKit::reset_memory() {
1425   Node* mem = map()->memory();
1426   // do not use this node for any more parsing!
1427   debug_only( map()->set_memory((Node*)NULL) );
1428   return _gvn.transform( mem );
1429 }
1430 
1431 //------------------------------set_all_memory---------------------------------
1432 void GraphKit::set_all_memory(Node* newmem) {
1433   Node* mergemem = MergeMemNode::make(C, newmem);
1434   gvn().set_type_bottom(mergemem);
1435   map()->set_memory(mergemem);
1436 }
1437 
1438 //------------------------------set_all_memory_call----------------------------
1439 void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) {
1440   Node* newmem = _gvn.transform( new (C) ProjNode(call, TypeFunc::Memory, separate_io_proj) );
1441   set_all_memory(newmem);
1442 }
1443 
1444 //=============================================================================
1445 //
1446 // parser factory methods for MemNodes
1447 //
1448 // These are layered on top of the factory methods in LoadNode and StoreNode,
1449 // and integrate with the parser's memory state and _gvn engine.
1450 //
1451 
1452 // factory methods in "int adr_idx"
1453 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
1454                           int adr_idx,
1455                           MemNode::MemOrd mo, LoadNode::ControlDependency control_dependency, bool require_atomic_access) {
1456   assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
1457   const TypePtr* adr_type = NULL; // debug-mode-only argument
1458   debug_only(adr_type = C->get_adr_type(adr_idx));
1459   Node* mem = memory(adr_idx);
1460   Node* ld;
1461   if (require_atomic_access && bt == T_LONG) {
1462     ld = LoadLNode::make_atomic(C, ctl, mem, adr, adr_type, t, mo, control_dependency);
1463   } else if (require_atomic_access && bt == T_DOUBLE) {
1464     ld = LoadDNode::make_atomic(C, ctl, mem, adr, adr_type, t, mo, control_dependency);
1465   } else {
1466     ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, mo, control_dependency);
1467   }
1468   ld = _gvn.transform(ld);
1469   if ((bt == T_OBJECT) && C->do_escape_analysis() || C->eliminate_boxing()) {
1470     // Improve graph before escape analysis and boxing elimination.
1471     record_for_igvn(ld);
1472   }
1473   return ld;
1474 }
1475 
1476 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
1477                                 int adr_idx,
1478                                 MemNode::MemOrd mo,
1479                                 bool require_atomic_access) {
1480   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1481   const TypePtr* adr_type = NULL;
1482   debug_only(adr_type = C->get_adr_type(adr_idx));
1483   Node *mem = memory(adr_idx);
1484   Node* st;
1485   if (require_atomic_access && bt == T_LONG) {
1486     st = StoreLNode::make_atomic(C, ctl, mem, adr, adr_type, val, mo);
1487   } else if (require_atomic_access && bt == T_DOUBLE) {
1488     st = StoreDNode::make_atomic(C, ctl, mem, adr, adr_type, val, mo);
1489   } else {
1490     st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt, mo);
1491   }
1492   st = _gvn.transform(st);
1493   set_memory(st, adr_idx);
1494   // Back-to-back stores can only remove intermediate store with DU info
1495   // so push on worklist for optimizer.
1496   if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
1497     record_for_igvn(st);
1498 
1499   return st;
1500 }
1501 
1502 
1503 void GraphKit::pre_barrier(bool do_load,
1504                            Node* ctl,
1505                            Node* obj,
1506                            Node* adr,
1507                            uint  adr_idx,
1508                            Node* val,
1509                            const TypeOopPtr* val_type,
1510                            Node* pre_val,
1511                            BasicType bt) {
1512 
1513   BarrierSet* bs = Universe::heap()->barrier_set();
1514   set_control(ctl);
1515   switch (bs->kind()) {
1516     case BarrierSet::G1SATBCT:
1517     case BarrierSet::G1SATBCTLogging:
1518       g1_write_barrier_pre(do_load, obj, adr, adr_idx, val, val_type, pre_val, bt);
1519       break;
1520 
1521     case BarrierSet::CardTableModRef:
1522     case BarrierSet::CardTableExtension:
1523     case BarrierSet::ModRef:
1524       break;
1525 
1526     case BarrierSet::Other:
1527     default      :
1528       ShouldNotReachHere();
1529 
1530   }
1531 }
1532 
1533 bool GraphKit::can_move_pre_barrier() const {
1534   BarrierSet* bs = Universe::heap()->barrier_set();
1535   switch (bs->kind()) {
1536     case BarrierSet::G1SATBCT:
1537     case BarrierSet::G1SATBCTLogging:
1538       return true; // Can move it if no safepoint
1539 
1540     case BarrierSet::CardTableModRef:
1541     case BarrierSet::CardTableExtension:
1542     case BarrierSet::ModRef:
1543       return true; // There is no pre-barrier
1544 
1545     case BarrierSet::Other:
1546     default      :
1547       ShouldNotReachHere();
1548   }
1549   return false;
1550 }
1551 
1552 void GraphKit::post_barrier(Node* ctl,
1553                             Node* store,
1554                             Node* obj,
1555                             Node* adr,
1556                             uint  adr_idx,
1557                             Node* val,
1558                             BasicType bt,
1559                             bool use_precise) {
1560   BarrierSet* bs = Universe::heap()->barrier_set();
1561   set_control(ctl);
1562   switch (bs->kind()) {
1563     case BarrierSet::G1SATBCT:
1564     case BarrierSet::G1SATBCTLogging:
1565       g1_write_barrier_post(store, obj, adr, adr_idx, val, bt, use_precise);
1566       break;
1567 
1568     case BarrierSet::CardTableModRef:
1569     case BarrierSet::CardTableExtension:
1570       write_barrier_post(store, obj, adr, adr_idx, val, use_precise);
1571       break;
1572 
1573     case BarrierSet::ModRef:
1574       break;
1575 
1576     case BarrierSet::Other:
1577     default      :
1578       ShouldNotReachHere();
1579 
1580   }
1581 }
1582 
1583 Node* GraphKit::store_oop(Node* ctl,
1584                           Node* obj,
1585                           Node* adr,
1586                           const TypePtr* adr_type,
1587                           Node* val,
1588                           const TypeOopPtr* val_type,
1589                           BasicType bt,
1590                           bool use_precise,
1591                           MemNode::MemOrd mo) {
1592   // Transformation of a value which could be NULL pointer (CastPP #NULL)
1593   // could be delayed during Parse (for example, in adjust_map_after_if()).
1594   // Execute transformation here to avoid barrier generation in such case.
1595   if (_gvn.type(val) == TypePtr::NULL_PTR)
1596     val = _gvn.makecon(TypePtr::NULL_PTR);
1597 
1598   set_control(ctl);
1599   if (stopped()) return top(); // Dead path ?
1600 
1601   assert(bt == T_OBJECT, "sanity");
1602   assert(val != NULL, "not dead path");
1603   uint adr_idx = C->get_alias_index(adr_type);
1604   assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1605 
1606   pre_barrier(true /* do_load */,
1607               control(), obj, adr, adr_idx, val, val_type,
1608               NULL /* pre_val */,
1609               bt);
1610 
1611   Node* store = store_to_memory(control(), adr, val, bt, adr_idx, mo);
1612   post_barrier(control(), store, obj, adr, adr_idx, val, bt, use_precise);
1613   return store;
1614 }
1615 
1616 // Could be an array or object we don't know at compile time (unsafe ref.)
1617 Node* GraphKit::store_oop_to_unknown(Node* ctl,
1618                              Node* obj,   // containing obj
1619                              Node* adr,  // actual adress to store val at
1620                              const TypePtr* adr_type,
1621                              Node* val,
1622                              BasicType bt,
1623                              MemNode::MemOrd mo) {
1624   Compile::AliasType* at = C->alias_type(adr_type);
1625   const TypeOopPtr* val_type = NULL;
1626   if (adr_type->isa_instptr()) {
1627     if (at->field() != NULL) {
1628       // known field.  This code is a copy of the do_put_xxx logic.
1629       ciField* field = at->field();
1630       if (!field->type()->is_loaded()) {
1631         val_type = TypeInstPtr::BOTTOM;
1632       } else {
1633         val_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
1634       }
1635     }
1636   } else if (adr_type->isa_aryptr()) {
1637     val_type = adr_type->is_aryptr()->elem()->make_oopptr();
1638   }
1639   if (val_type == NULL) {
1640     val_type = TypeInstPtr::BOTTOM;
1641   }
1642   return store_oop(ctl, obj, adr, adr_type, val, val_type, bt, true, mo);
1643 }
1644 
1645 
1646 //-------------------------array_element_address-------------------------
1647 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1648                                       const TypeInt* sizetype, Node* ctrl) {
1649   uint shift  = exact_log2(type2aelembytes(elembt));
1650   uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1651 
1652   // short-circuit a common case (saves lots of confusing waste motion)
1653   jint idx_con = find_int_con(idx, -1);
1654   if (idx_con >= 0) {
1655     intptr_t offset = header + ((intptr_t)idx_con << shift);
1656     return basic_plus_adr(ary, offset);
1657   }
1658 
1659   // must be correct type for alignment purposes
1660   Node* base  = basic_plus_adr(ary, header);
1661 #ifdef _LP64
1662   // The scaled index operand to AddP must be a clean 64-bit value.
1663   // Java allows a 32-bit int to be incremented to a negative
1664   // value, which appears in a 64-bit register as a large
1665   // positive number.  Using that large positive number as an
1666   // operand in pointer arithmetic has bad consequences.
1667   // On the other hand, 32-bit overflow is rare, and the possibility
1668   // can often be excluded, if we annotate the ConvI2L node with
1669   // a type assertion that its value is known to be a small positive
1670   // number.  (The prior range check has ensured this.)
1671   // This assertion is used by ConvI2LNode::Ideal.
1672   int index_max = max_jint - 1;  // array size is max_jint, index is one less
1673   if (sizetype != NULL) index_max = sizetype->_hi - 1;
1674   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
1675   idx = C->constrained_convI2L(&_gvn, idx, iidxtype, ctrl);
1676 #endif
1677   Node* scale = _gvn.transform( new (C) LShiftXNode(idx, intcon(shift)) );
1678   return basic_plus_adr(ary, base, scale);
1679 }
1680 
1681 //-------------------------load_array_element-------------------------
1682 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) {
1683   const Type* elemtype = arytype->elem();
1684   BasicType elembt = elemtype->array_element_basic_type();
1685   Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1686   Node* ld = make_load(ctl, adr, elemtype, elembt, arytype, MemNode::unordered);
1687   return ld;
1688 }
1689 
1690 //-------------------------set_arguments_for_java_call-------------------------
1691 // Arguments (pre-popped from the stack) are taken from the JVMS.
1692 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1693   // Add the call arguments:
1694   uint nargs = call->method()->arg_size();
1695   for (uint i = 0; i < nargs; i++) {
1696     Node* arg = argument(i);
1697     call->init_req(i + TypeFunc::Parms, arg);
1698   }
1699 }
1700 
1701 //---------------------------set_edges_for_java_call---------------------------
1702 // Connect a newly created call into the current JVMS.
1703 // A return value node (if any) is returned from set_edges_for_java_call.
1704 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {
1705 
1706   // Add the predefined inputs:
1707   call->init_req( TypeFunc::Control, control() );
1708   call->init_req( TypeFunc::I_O    , i_o() );
1709   call->init_req( TypeFunc::Memory , reset_memory() );
1710   call->init_req( TypeFunc::FramePtr, frameptr() );
1711   call->init_req( TypeFunc::ReturnAdr, top() );
1712 
1713   add_safepoint_edges(call, must_throw);
1714 
1715   Node* xcall = _gvn.transform(call);
1716 
1717   if (xcall == top()) {
1718     set_control(top());
1719     return;
1720   }
1721   assert(xcall == call, "call identity is stable");
1722 
1723   // Re-use the current map to produce the result.
1724 
1725   set_control(_gvn.transform(new (C) ProjNode(call, TypeFunc::Control)));
1726   set_i_o(    _gvn.transform(new (C) ProjNode(call, TypeFunc::I_O    , separate_io_proj)));
1727   set_all_memory_call(xcall, separate_io_proj);
1728 
1729   //return xcall;   // no need, caller already has it
1730 }
1731 
1732 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj) {
1733   if (stopped())  return top();  // maybe the call folded up?
1734 
1735   // Capture the return value, if any.
1736   Node* ret;
1737   if (call->method() == NULL ||
1738       call->method()->return_type()->basic_type() == T_VOID)
1739         ret = top();
1740   else  ret = _gvn.transform(new (C) ProjNode(call, TypeFunc::Parms));
1741 
1742   // Note:  Since any out-of-line call can produce an exception,
1743   // we always insert an I_O projection from the call into the result.
1744 
1745   make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj);
1746 
1747   if (separate_io_proj) {
1748     // The caller requested separate projections be used by the fall
1749     // through and exceptional paths, so replace the projections for
1750     // the fall through path.
1751     set_i_o(_gvn.transform( new (C) ProjNode(call, TypeFunc::I_O) ));
1752     set_all_memory(_gvn.transform( new (C) ProjNode(call, TypeFunc::Memory) ));
1753   }
1754   return ret;
1755 }
1756 
1757 //--------------------set_predefined_input_for_runtime_call--------------------
1758 // Reading and setting the memory state is way conservative here.
1759 // The real problem is that I am not doing real Type analysis on memory,
1760 // so I cannot distinguish card mark stores from other stores.  Across a GC
1761 // point the Store Barrier and the card mark memory has to agree.  I cannot
1762 // have a card mark store and its barrier split across the GC point from
1763 // either above or below.  Here I get that to happen by reading ALL of memory.
1764 // A better answer would be to separate out card marks from other memory.
1765 // For now, return the input memory state, so that it can be reused
1766 // after the call, if this call has restricted memory effects.
1767 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) {
1768   // Set fixed predefined input arguments
1769   Node* memory = reset_memory();
1770   call->init_req( TypeFunc::Control,   control()  );
1771   call->init_req( TypeFunc::I_O,       top()      ); // does no i/o
1772   call->init_req( TypeFunc::Memory,    memory     ); // may gc ptrs
1773   call->init_req( TypeFunc::FramePtr,  frameptr() );
1774   call->init_req( TypeFunc::ReturnAdr, top()      );
1775   return memory;
1776 }
1777 
1778 //-------------------set_predefined_output_for_runtime_call--------------------
1779 // Set control and memory (not i_o) from the call.
1780 // If keep_mem is not NULL, use it for the output state,
1781 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1782 // If hook_mem is NULL, this call produces no memory effects at all.
1783 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1784 // then only that memory slice is taken from the call.
1785 // In the last case, we must put an appropriate memory barrier before
1786 // the call, so as to create the correct anti-dependencies on loads
1787 // preceding the call.
1788 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1789                                                       Node* keep_mem,
1790                                                       const TypePtr* hook_mem) {
1791   // no i/o
1792   set_control(_gvn.transform( new (C) ProjNode(call,TypeFunc::Control) ));
1793   if (keep_mem) {
1794     // First clone the existing memory state
1795     set_all_memory(keep_mem);
1796     if (hook_mem != NULL) {
1797       // Make memory for the call
1798       Node* mem = _gvn.transform( new (C) ProjNode(call, TypeFunc::Memory) );
1799       // Set the RawPtr memory state only.  This covers all the heap top/GC stuff
1800       // We also use hook_mem to extract specific effects from arraycopy stubs.
1801       set_memory(mem, hook_mem);
1802     }
1803     // ...else the call has NO memory effects.
1804 
1805     // Make sure the call advertises its memory effects precisely.
1806     // This lets us build accurate anti-dependences in gcm.cpp.
1807     assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
1808            "call node must be constructed correctly");
1809   } else {
1810     assert(hook_mem == NULL, "");
1811     // This is not a "slow path" call; all memory comes from the call.
1812     set_all_memory_call(call);
1813   }
1814 }
1815 
1816 
1817 // Replace the call with the current state of the kit.
1818 void GraphKit::replace_call(CallNode* call, Node* result, bool do_replaced_nodes) {
1819   JVMState* ejvms = NULL;
1820   if (has_exceptions()) {
1821     ejvms = transfer_exceptions_into_jvms();
1822   }
1823 
1824   ReplacedNodes replaced_nodes = map()->replaced_nodes();
1825   ReplacedNodes replaced_nodes_exception;
1826   Node* ex_ctl = top();
1827 
1828   SafePointNode* final_state = stop();
1829 
1830   // Find all the needed outputs of this call
1831   CallProjections callprojs;
1832   call->extract_projections(&callprojs, true);
1833 
1834   Node* init_mem = call->in(TypeFunc::Memory);
1835   Node* final_mem = final_state->in(TypeFunc::Memory);
1836   Node* final_ctl = final_state->in(TypeFunc::Control);
1837   Node* final_io = final_state->in(TypeFunc::I_O);
1838 
1839   // Replace all the old call edges with the edges from the inlining result
1840   if (callprojs.fallthrough_catchproj != NULL) {
1841     C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl);
1842   }
1843   if (callprojs.fallthrough_memproj != NULL) {
1844     if (final_mem->is_MergeMem()) {
1845       // Parser's exits MergeMem was not transformed but may be optimized
1846       final_mem = _gvn.transform(final_mem);
1847     }
1848     C->gvn_replace_by(callprojs.fallthrough_memproj,   final_mem);
1849   }
1850   if (callprojs.fallthrough_ioproj != NULL) {
1851     C->gvn_replace_by(callprojs.fallthrough_ioproj,    final_io);
1852   }
1853 
1854   // Replace the result with the new result if it exists and is used
1855   if (callprojs.resproj != NULL && result != NULL) {
1856     C->gvn_replace_by(callprojs.resproj, result);
1857   }
1858 
1859   if (ejvms == NULL) {
1860     // No exception edges to simply kill off those paths
1861     if (callprojs.catchall_catchproj != NULL) {
1862       C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
1863     }
1864     if (callprojs.catchall_memproj != NULL) {
1865       C->gvn_replace_by(callprojs.catchall_memproj,   C->top());
1866     }
1867     if (callprojs.catchall_ioproj != NULL) {
1868       C->gvn_replace_by(callprojs.catchall_ioproj,    C->top());
1869     }
1870     // Replace the old exception object with top
1871     if (callprojs.exobj != NULL) {
1872       C->gvn_replace_by(callprojs.exobj, C->top());
1873     }
1874   } else {
1875     GraphKit ekit(ejvms);
1876 
1877     // Load my combined exception state into the kit, with all phis transformed:
1878     SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();
1879     replaced_nodes_exception = ex_map->replaced_nodes();
1880 
1881     Node* ex_oop = ekit.use_exception_state(ex_map);
1882 
1883     if (callprojs.catchall_catchproj != NULL) {
1884       C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
1885       ex_ctl = ekit.control();
1886     }
1887     if (callprojs.catchall_memproj != NULL) {
1888       C->gvn_replace_by(callprojs.catchall_memproj,   ekit.reset_memory());
1889     }
1890     if (callprojs.catchall_ioproj != NULL) {
1891       C->gvn_replace_by(callprojs.catchall_ioproj,    ekit.i_o());
1892     }
1893 
1894     // Replace the old exception object with the newly created one
1895     if (callprojs.exobj != NULL) {
1896       C->gvn_replace_by(callprojs.exobj, ex_oop);
1897     }
1898   }
1899 
1900   // Disconnect the call from the graph
1901   call->disconnect_inputs(NULL, C);
1902   C->gvn_replace_by(call, C->top());
1903 
1904   // Clean up any MergeMems that feed other MergeMems since the
1905   // optimizer doesn't like that.
1906   if (final_mem->is_MergeMem()) {
1907     Node_List wl;
1908     for (SimpleDUIterator i(final_mem); i.has_next(); i.next()) {
1909       Node* m = i.get();
1910       if (m->is_MergeMem() && !wl.contains(m)) {
1911         wl.push(m);
1912       }
1913     }
1914     while (wl.size()  > 0) {
1915       _gvn.transform(wl.pop());
1916     }
1917   }
1918 
1919   if (callprojs.fallthrough_catchproj != NULL && !final_ctl->is_top() && do_replaced_nodes) {
1920     replaced_nodes.apply(C, final_ctl);
1921   }
1922   if (!ex_ctl->is_top() && do_replaced_nodes) {
1923     replaced_nodes_exception.apply(C, ex_ctl);
1924   }
1925 }
1926 
1927 
1928 //------------------------------increment_counter------------------------------
1929 // for statistics: increment a VM counter by 1
1930 
1931 void GraphKit::increment_counter(address counter_addr) {
1932   Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
1933   increment_counter(adr1);
1934 }
1935 
1936 void GraphKit::increment_counter(Node* counter_addr) {
1937   int adr_type = Compile::AliasIdxRaw;
1938   Node* ctrl = control();
1939   Node* cnt  = make_load(ctrl, counter_addr, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
1940   Node* incr = _gvn.transform(new (C) AddINode(cnt, _gvn.intcon(1)));
1941   store_to_memory(ctrl, counter_addr, incr, T_INT, adr_type, MemNode::unordered);
1942 }
1943 
1944 
1945 //------------------------------uncommon_trap----------------------------------
1946 // Bail out to the interpreter in mid-method.  Implemented by calling the
1947 // uncommon_trap blob.  This helper function inserts a runtime call with the
1948 // right debug info.
1949 void GraphKit::uncommon_trap(int trap_request,
1950                              ciKlass* klass, const char* comment,
1951                              bool must_throw,
1952                              bool keep_exact_action) {
1953   if (failing())  stop();
1954   if (stopped())  return; // trap reachable?
1955 
1956   // Note:  If ProfileTraps is true, and if a deopt. actually
1957   // occurs here, the runtime will make sure an MDO exists.  There is
1958   // no need to call method()->ensure_method_data() at this point.
1959 
1960   // Set the stack pointer to the right value for reexecution:
1961   set_sp(reexecute_sp());
1962 
1963 #ifdef ASSERT
1964   if (!must_throw) {
1965     // Make sure the stack has at least enough depth to execute
1966     // the current bytecode.
1967     int inputs, ignored_depth;
1968     if (compute_stack_effects(inputs, ignored_depth)) {
1969       assert(sp() >= inputs, err_msg_res("must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
1970              Bytecodes::name(java_bc()), sp(), inputs));
1971     }
1972   }
1973 #endif
1974 
1975   Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
1976   Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
1977 
1978   switch (action) {
1979   case Deoptimization::Action_maybe_recompile:
1980   case Deoptimization::Action_reinterpret:
1981     // Temporary fix for 6529811 to allow virtual calls to be sure they
1982     // get the chance to go from mono->bi->mega
1983     if (!keep_exact_action &&
1984         Deoptimization::trap_request_index(trap_request) < 0 &&
1985         too_many_recompiles(reason)) {
1986       // This BCI is causing too many recompilations.
1987       if (C->log() != NULL) {
1988         C->log()->elem("observe that='trap_action_change' reason='%s' from='%s' to='none'",
1989                 Deoptimization::trap_reason_name(reason),
1990                 Deoptimization::trap_action_name(action));
1991       }
1992       action = Deoptimization::Action_none;
1993       trap_request = Deoptimization::make_trap_request(reason, action);
1994     } else {
1995       C->set_trap_can_recompile(true);
1996     }
1997     break;
1998   case Deoptimization::Action_make_not_entrant:
1999     C->set_trap_can_recompile(true);
2000     break;
2001 #ifdef ASSERT
2002   case Deoptimization::Action_none:
2003   case Deoptimization::Action_make_not_compilable:
2004     break;
2005   default:
2006     fatal(err_msg_res("unknown action %d: %s", action, Deoptimization::trap_action_name(action)));
2007     break;
2008 #endif
2009   }
2010 
2011   if (TraceOptoParse) {
2012     char buf[100];
2013     tty->print_cr("Uncommon trap %s at bci:%d",
2014                   Deoptimization::format_trap_request(buf, sizeof(buf),
2015                                                       trap_request), bci());
2016   }
2017 
2018   CompileLog* log = C->log();
2019   if (log != NULL) {
2020     int kid = (klass == NULL)? -1: log->identify(klass);
2021     log->begin_elem("uncommon_trap bci='%d'", bci());
2022     char buf[100];
2023     log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
2024                                                           trap_request));
2025     if (kid >= 0)         log->print(" klass='%d'", kid);
2026     if (comment != NULL)  log->print(" comment='%s'", comment);
2027     log->end_elem();
2028   }
2029 
2030   // Make sure any guarding test views this path as very unlikely
2031   Node *i0 = control()->in(0);
2032   if (i0 != NULL && i0->is_If()) {        // Found a guarding if test?
2033     IfNode *iff = i0->as_If();
2034     float f = iff->_prob;   // Get prob
2035     if (control()->Opcode() == Op_IfTrue) {
2036       if (f > PROB_UNLIKELY_MAG(4))
2037         iff->_prob = PROB_MIN;
2038     } else {
2039       if (f < PROB_LIKELY_MAG(4))
2040         iff->_prob = PROB_MAX;
2041     }
2042   }
2043 
2044   // Clear out dead values from the debug info.
2045   kill_dead_locals();
2046 
2047   // Now insert the uncommon trap subroutine call
2048   address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
2049   const TypePtr* no_memory_effects = NULL;
2050   // Pass the index of the class to be loaded
2051   Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
2052                                  (must_throw ? RC_MUST_THROW : 0),
2053                                  OptoRuntime::uncommon_trap_Type(),
2054                                  call_addr, "uncommon_trap", no_memory_effects,
2055                                  intcon(trap_request));
2056   assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
2057          "must extract request correctly from the graph");
2058   assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
2059 
2060   call->set_req(TypeFunc::ReturnAdr, returnadr());
2061   // The debug info is the only real input to this call.
2062 
2063   // Halt-and-catch fire here.  The above call should never return!
2064   HaltNode* halt = new(C) HaltNode(control(), frameptr());
2065   _gvn.set_type_bottom(halt);
2066   root()->add_req(halt);
2067 
2068   stop_and_kill_map();
2069 }
2070 
2071 
2072 //--------------------------just_allocated_object------------------------------
2073 // Report the object that was just allocated.
2074 // It must be the case that there are no intervening safepoints.
2075 // We use this to determine if an object is so "fresh" that
2076 // it does not require card marks.
2077 Node* GraphKit::just_allocated_object(Node* current_control) {
2078   if (C->recent_alloc_ctl() == current_control)
2079     return C->recent_alloc_obj();
2080   return NULL;
2081 }
2082 
2083 
2084 void GraphKit::round_double_arguments(ciMethod* dest_method) {
2085   // (Note:  TypeFunc::make has a cache that makes this fast.)
2086   const TypeFunc* tf    = TypeFunc::make(dest_method);
2087   int             nargs = tf->_domain->_cnt - TypeFunc::Parms;
2088   for (int j = 0; j < nargs; j++) {
2089     const Type *targ = tf->_domain->field_at(j + TypeFunc::Parms);
2090     if( targ->basic_type() == T_DOUBLE ) {
2091       // If any parameters are doubles, they must be rounded before
2092       // the call, dstore_rounding does gvn.transform
2093       Node *arg = argument(j);
2094       arg = dstore_rounding(arg);
2095       set_argument(j, arg);
2096     }
2097   }
2098 }
2099 
2100 /**
2101  * Record profiling data exact_kls for Node n with the type system so
2102  * that it can propagate it (speculation)
2103  *
2104  * @param n          node that the type applies to
2105  * @param exact_kls  type from profiling
2106  *
2107  * @return           node with improved type
2108  */
2109 Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls) {
2110   const Type* current_type = _gvn.type(n);
2111   assert(UseTypeSpeculation, "type speculation must be on");
2112 
2113   const TypeOopPtr* speculative = current_type->speculative();
2114 
2115   if (current_type->would_improve_type(exact_kls, jvms()->depth())) {
2116     const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls);
2117     const TypeOopPtr* xtype = tklass->as_instance_type();
2118     assert(xtype->klass_is_exact(), "Should be exact");
2119     // record the new speculative type's depth
2120     speculative = xtype->with_inline_depth(jvms()->depth());
2121   }
2122 
2123   if (speculative != current_type->speculative()) {
2124     // Build a type with a speculative type (what we think we know
2125     // about the type but will need a guard when we use it)
2126     const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::OffsetBot, TypeOopPtr::InstanceBot, speculative);
2127     // We're changing the type, we need a new CheckCast node to carry
2128     // the new type. The new type depends on the control: what
2129     // profiling tells us is only valid from here as far as we can
2130     // tell.
2131     Node* cast = new(C) CheckCastPPNode(control(), n, current_type->remove_speculative()->join_speculative(spec_type));
2132     cast = _gvn.transform(cast);
2133     replace_in_map(n, cast);
2134     n = cast;
2135   }
2136 
2137   return n;
2138 }
2139 
2140 /**
2141  * Record profiling data from receiver profiling at an invoke with the
2142  * type system so that it can propagate it (speculation)
2143  *
2144  * @param n  receiver node
2145  *
2146  * @return   node with improved type
2147  */
2148 Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) {
2149   if (!UseTypeSpeculation) {
2150     return n;
2151   }
2152   ciKlass* exact_kls = profile_has_unique_klass();
2153   return record_profile_for_speculation(n, exact_kls);
2154 }
2155 
2156 /**
2157  * Record profiling data from argument profiling at an invoke with the
2158  * type system so that it can propagate it (speculation)
2159  *
2160  * @param dest_method  target method for the call
2161  * @param bc           what invoke bytecode is this?
2162  */
2163 void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) {
2164   if (!UseTypeSpeculation) {
2165     return;
2166   }
2167   const TypeFunc* tf    = TypeFunc::make(dest_method);
2168   int             nargs = tf->_domain->_cnt - TypeFunc::Parms;
2169   int skip = Bytecodes::has_receiver(bc) ? 1 : 0;
2170   for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) {
2171     const Type *targ = tf->_domain->field_at(j + TypeFunc::Parms);
2172     if (targ->basic_type() == T_OBJECT || targ->basic_type() == T_ARRAY) {
2173       ciKlass* better_type = method()->argument_profiled_type(bci(), i);
2174       if (better_type != NULL) {
2175         record_profile_for_speculation(argument(j), better_type);
2176       }
2177       i++;
2178     }
2179   }
2180 }
2181 
2182 /**
2183  * Record profiling data from parameter profiling at an invoke with
2184  * the type system so that it can propagate it (speculation)
2185  */
2186 void GraphKit::record_profiled_parameters_for_speculation() {
2187   if (!UseTypeSpeculation) {
2188     return;
2189   }
2190   for (int i = 0, j = 0; i < method()->arg_size() ; i++) {
2191     if (_gvn.type(local(i))->isa_oopptr()) {
2192       ciKlass* better_type = method()->parameter_profiled_type(j);
2193       if (better_type != NULL) {
2194         record_profile_for_speculation(local(i), better_type);
2195       }
2196       j++;
2197     }
2198   }
2199 }
2200 
2201 void GraphKit::round_double_result(ciMethod* dest_method) {
2202   // A non-strict method may return a double value which has an extended
2203   // exponent, but this must not be visible in a caller which is 'strict'
2204   // If a strict caller invokes a non-strict callee, round a double result
2205 
2206   BasicType result_type = dest_method->return_type()->basic_type();
2207   assert( method() != NULL, "must have caller context");
2208   if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) {
2209     // Destination method's return value is on top of stack
2210     // dstore_rounding() does gvn.transform
2211     Node *result = pop_pair();
2212     result = dstore_rounding(result);
2213     push_pair(result);
2214   }
2215 }
2216 
2217 // rounding for strict float precision conformance
2218 Node* GraphKit::precision_rounding(Node* n) {
2219   return UseStrictFP && _method->flags().is_strict()
2220     && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding
2221     ? _gvn.transform( new (C) RoundFloatNode(0, n) )
2222     : n;
2223 }
2224 
2225 // rounding for strict double precision conformance
2226 Node* GraphKit::dprecision_rounding(Node *n) {
2227   return UseStrictFP && _method->flags().is_strict()
2228     && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding
2229     ? _gvn.transform( new (C) RoundDoubleNode(0, n) )
2230     : n;
2231 }
2232 
2233 // rounding for non-strict double stores
2234 Node* GraphKit::dstore_rounding(Node* n) {
2235   return Matcher::strict_fp_requires_explicit_rounding
2236     && UseSSE <= 1
2237     ? _gvn.transform( new (C) RoundDoubleNode(0, n) )
2238     : n;
2239 }
2240 
2241 //=============================================================================
2242 // Generate a fast path/slow path idiom.  Graph looks like:
2243 // [foo] indicates that 'foo' is a parameter
2244 //
2245 //              [in]     NULL
2246 //                 \    /
2247 //                  CmpP
2248 //                  Bool ne
2249 //                   If
2250 //                  /  \
2251 //              True    False-<2>
2252 //              / |
2253 //             /  cast_not_null
2254 //           Load  |    |   ^
2255 //        [fast_test]   |   |
2256 // gvn to   opt_test    |   |
2257 //          /    \      |  <1>
2258 //      True     False  |
2259 //        |         \\  |
2260 //   [slow_call]     \[fast_result]
2261 //    Ctl   Val       \      \
2262 //     |               \      \
2263 //    Catch       <1>   \      \
2264 //   /    \        ^     \      \
2265 //  Ex    No_Ex    |      \      \
2266 //  |       \   \  |       \ <2>  \
2267 //  ...      \  [slow_res] |  |    \   [null_result]
2268 //            \         \--+--+---  |  |
2269 //             \           | /    \ | /
2270 //              --------Region     Phi
2271 //
2272 //=============================================================================
2273 // Code is structured as a series of driver functions all called 'do_XXX' that
2274 // call a set of helper functions.  Helper functions first, then drivers.
2275 
2276 //------------------------------null_check_oop---------------------------------
2277 // Null check oop.  Set null-path control into Region in slot 3.
2278 // Make a cast-not-nullness use the other not-null control.  Return cast.
2279 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2280                                bool never_see_null, bool safe_for_replace) {
2281   // Initial NULL check taken path
2282   (*null_control) = top();
2283   Node* cast = null_check_common(value, T_OBJECT, false, null_control);
2284 
2285   // Generate uncommon_trap:
2286   if (never_see_null && (*null_control) != top()) {
2287     // If we see an unexpected null at a check-cast we record it and force a
2288     // recompile; the offending check-cast will be compiled to handle NULLs.
2289     // If we see more than one offending BCI, then all checkcasts in the
2290     // method will be compiled to handle NULLs.
2291     PreserveJVMState pjvms(this);
2292     set_control(*null_control);
2293     replace_in_map(value, null());
2294     uncommon_trap(Deoptimization::Reason_null_check,
2295                   Deoptimization::Action_make_not_entrant);
2296     (*null_control) = top();    // NULL path is dead
2297   }
2298   if ((*null_control) == top() && safe_for_replace) {
2299     replace_in_map(value, cast);
2300   }
2301 
2302   // Cast away null-ness on the result
2303   return cast;
2304 }
2305 
2306 //------------------------------opt_iff----------------------------------------
2307 // Optimize the fast-check IfNode.  Set the fast-path region slot 2.
2308 // Return slow-path control.
2309 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2310   IfNode *opt_iff = _gvn.transform(iff)->as_If();
2311 
2312   // Fast path taken; set region slot 2
2313   Node *fast_taken = _gvn.transform( new (C) IfFalseNode(opt_iff) );
2314   region->init_req(2,fast_taken); // Capture fast-control
2315 
2316   // Fast path not-taken, i.e. slow path
2317   Node *slow_taken = _gvn.transform( new (C) IfTrueNode(opt_iff) );
2318   return slow_taken;
2319 }
2320 
2321 //-----------------------------make_runtime_call-------------------------------
2322 Node* GraphKit::make_runtime_call(int flags,
2323                                   const TypeFunc* call_type, address call_addr,
2324                                   const char* call_name,
2325                                   const TypePtr* adr_type,
2326                                   // The following parms are all optional.
2327                                   // The first NULL ends the list.
2328                                   Node* parm0, Node* parm1,
2329                                   Node* parm2, Node* parm3,
2330                                   Node* parm4, Node* parm5,
2331                                   Node* parm6, Node* parm7) {
2332   // Slow-path call
2333   bool is_leaf = !(flags & RC_NO_LEAF);
2334   bool has_io  = (!is_leaf && !(flags & RC_NO_IO));
2335   if (call_name == NULL) {
2336     assert(!is_leaf, "must supply name for leaf");
2337     call_name = OptoRuntime::stub_name(call_addr);
2338   }
2339   CallNode* call;
2340   if (!is_leaf) {
2341     call = new(C) CallStaticJavaNode(call_type, call_addr, call_name,
2342                                            bci(), adr_type);
2343   } else if (flags & RC_NO_FP) {
2344     call = new(C) CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2345   } else {
2346     call = new(C) CallLeafNode(call_type, call_addr, call_name, adr_type);
2347   }
2348 
2349   // The following is similar to set_edges_for_java_call,
2350   // except that the memory effects of the call are restricted to AliasIdxRaw.
2351 
2352   // Slow path call has no side-effects, uses few values
2353   bool wide_in  = !(flags & RC_NARROW_MEM);
2354   bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2355 
2356   Node* prev_mem = NULL;
2357   if (wide_in) {
2358     prev_mem = set_predefined_input_for_runtime_call(call);
2359   } else {
2360     assert(!wide_out, "narrow in => narrow out");
2361     Node* narrow_mem = memory(adr_type);
2362     prev_mem = reset_memory();
2363     map()->set_memory(narrow_mem);
2364     set_predefined_input_for_runtime_call(call);
2365   }
2366 
2367   // Hook each parm in order.  Stop looking at the first NULL.
2368   if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
2369   if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
2370   if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
2371   if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
2372   if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
2373   if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
2374   if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
2375   if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
2376     /* close each nested if ===> */  } } } } } } } }
2377   assert(call->in(call->req()-1) != NULL, "must initialize all parms");
2378 
2379   if (!is_leaf) {
2380     // Non-leaves can block and take safepoints:
2381     add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2382   }
2383   // Non-leaves can throw exceptions:
2384   if (has_io) {
2385     call->set_req(TypeFunc::I_O, i_o());
2386   }
2387 
2388   if (flags & RC_UNCOMMON) {
2389     // Set the count to a tiny probability.  Cf. Estimate_Block_Frequency.
2390     // (An "if" probability corresponds roughly to an unconditional count.
2391     // Sort of.)
2392     call->set_cnt(PROB_UNLIKELY_MAG(4));
2393   }
2394 
2395   Node* c = _gvn.transform(call);
2396   assert(c == call, "cannot disappear");
2397 
2398   if (wide_out) {
2399     // Slow path call has full side-effects.
2400     set_predefined_output_for_runtime_call(call);
2401   } else {
2402     // Slow path call has few side-effects, and/or sets few values.
2403     set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2404   }
2405 
2406   if (has_io) {
2407     set_i_o(_gvn.transform(new (C) ProjNode(call, TypeFunc::I_O)));
2408   }
2409   return call;
2410 
2411 }
2412 
2413 //------------------------------merge_memory-----------------------------------
2414 // Merge memory from one path into the current memory state.
2415 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2416   for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2417     Node* old_slice = mms.force_memory();
2418     Node* new_slice = mms.memory2();
2419     if (old_slice != new_slice) {
2420       PhiNode* phi;
2421       if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region) {
2422         if (mms.is_empty()) {
2423           // clone base memory Phi's inputs for this memory slice
2424           assert(old_slice == mms.base_memory(), "sanity");
2425           phi = PhiNode::make(region, NULL, Type::MEMORY, mms.adr_type(C));
2426           _gvn.set_type(phi, Type::MEMORY);
2427           for (uint i = 1; i < phi->req(); i++) {
2428             phi->init_req(i, old_slice->in(i));
2429           }
2430         } else {
2431           phi = old_slice->as_Phi(); // Phi was generated already
2432         }
2433       } else {
2434         phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2435         _gvn.set_type(phi, Type::MEMORY);
2436       }
2437       phi->set_req(new_path, new_slice);
2438       mms.set_memory(phi);
2439     }
2440   }
2441 }
2442 
2443 //------------------------------make_slow_call_ex------------------------------
2444 // Make the exception handler hookups for the slow call
2445 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj, bool deoptimize) {
2446   if (stopped())  return;
2447 
2448   // Make a catch node with just two handlers:  fall-through and catch-all
2449   Node* i_o  = _gvn.transform( new (C) ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2450   Node* catc = _gvn.transform( new (C) CatchNode(control(), i_o, 2) );
2451   Node* norm = _gvn.transform( new (C) CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
2452   Node* excp = _gvn.transform( new (C) CatchProjNode(catc, CatchProjNode::catch_all_index,    CatchProjNode::no_handler_bci) );
2453 
2454   { PreserveJVMState pjvms(this);
2455     set_control(excp);
2456     set_i_o(i_o);
2457 
2458     if (excp != top()) {
2459       if (deoptimize) {
2460         // Deoptimize if an exception is caught. Don't construct exception state in this case.
2461         uncommon_trap(Deoptimization::Reason_unhandled,
2462                       Deoptimization::Action_none);
2463       } else {
2464         // Create an exception state also.
2465         // Use an exact type if the caller has specified a specific exception.
2466         const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2467         Node*       ex_oop  = new (C) CreateExNode(ex_type, control(), i_o);
2468         add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2469       }
2470     }
2471   }
2472 
2473   // Get the no-exception control from the CatchNode.
2474   set_control(norm);
2475 }
2476 
2477 
2478 //-------------------------------gen_subtype_check-----------------------------
2479 // Generate a subtyping check.  Takes as input the subtype and supertype.
2480 // Returns 2 values: sets the default control() to the true path and returns
2481 // the false path.  Only reads invariant memory; sets no (visible) memory.
2482 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2483 // but that's not exposed to the optimizer.  This call also doesn't take in an
2484 // Object; if you wish to check an Object you need to load the Object's class
2485 // prior to coming here.
2486 Node* GraphKit::gen_subtype_check(Node* subklass, Node* superklass) {
2487   // Fast check for identical types, perhaps identical constants.
2488   // The types can even be identical non-constants, in cases
2489   // involving Array.newInstance, Object.clone, etc.
2490   if (subklass == superklass)
2491     return top();             // false path is dead; no test needed.
2492 
2493   if (_gvn.type(superklass)->singleton()) {
2494     ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
2495     ciKlass* subk   = _gvn.type(subklass)->is_klassptr()->klass();
2496 
2497     // In the common case of an exact superklass, try to fold up the
2498     // test before generating code.  You may ask, why not just generate
2499     // the code and then let it fold up?  The answer is that the generated
2500     // code will necessarily include null checks, which do not always
2501     // completely fold away.  If they are also needless, then they turn
2502     // into a performance loss.  Example:
2503     //    Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2504     // Here, the type of 'fa' is often exact, so the store check
2505     // of fa[1]=x will fold up, without testing the nullness of x.
2506     switch (static_subtype_check(superk, subk)) {
2507     case SSC_always_false:
2508       {
2509         Node* always_fail = control();
2510         set_control(top());
2511         return always_fail;
2512       }
2513     case SSC_always_true:
2514       return top();
2515     case SSC_easy_test:
2516       {
2517         // Just do a direct pointer compare and be done.
2518         Node* cmp = _gvn.transform( new(C) CmpPNode(subklass, superklass) );
2519         Node* bol = _gvn.transform( new(C) BoolNode(cmp, BoolTest::eq) );
2520         IfNode* iff = create_and_xform_if(control(), bol, PROB_STATIC_FREQUENT, COUNT_UNKNOWN);
2521         set_control( _gvn.transform( new(C) IfTrueNode (iff) ) );
2522         return       _gvn.transform( new(C) IfFalseNode(iff) );
2523       }
2524     case SSC_full_test:
2525       break;
2526     default:
2527       ShouldNotReachHere();
2528     }
2529   }
2530 
2531   // %%% Possible further optimization:  Even if the superklass is not exact,
2532   // if the subklass is the unique subtype of the superklass, the check
2533   // will always succeed.  We could leave a dependency behind to ensure this.
2534 
2535   // First load the super-klass's check-offset
2536   Node *p1 = basic_plus_adr( superklass, superklass, in_bytes(Klass::super_check_offset_offset()) );
2537   Node *chk_off = _gvn.transform(new (C) LoadINode(NULL, memory(p1), p1, _gvn.type(p1)->is_ptr(),
2538                                                    TypeInt::INT, MemNode::unordered));
2539   int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
2540   bool might_be_cache = (find_int_con(chk_off, cacheoff_con) == cacheoff_con);
2541 
2542   // Load from the sub-klass's super-class display list, or a 1-word cache of
2543   // the secondary superclass list, or a failing value with a sentinel offset
2544   // if the super-klass is an interface or exceptionally deep in the Java
2545   // hierarchy and we have to scan the secondary superclass list the hard way.
2546   // Worst-case type is a little odd: NULL is allowed as a result (usually
2547   // klass loads can never produce a NULL).
2548   Node *chk_off_X = ConvI2X(chk_off);
2549   Node *p2 = _gvn.transform( new (C) AddPNode(subklass,subklass,chk_off_X) );
2550   // For some types like interfaces the following loadKlass is from a 1-word
2551   // cache which is mutable so can't use immutable memory.  Other
2552   // types load from the super-class display table which is immutable.
2553   Node *kmem = might_be_cache ? memory(p2) : immutable_memory();
2554   Node* nkls = _gvn.transform(LoadKlassNode::make(_gvn, NULL, kmem, p2, _gvn.type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL));
2555 
2556   // Compile speed common case: ARE a subtype and we canNOT fail
2557   if( superklass == nkls )
2558     return top();             // false path is dead; no test needed.
2559 
2560   // See if we get an immediate positive hit.  Happens roughly 83% of the
2561   // time.  Test to see if the value loaded just previously from the subklass
2562   // is exactly the superklass.
2563   Node *cmp1 = _gvn.transform( new (C) CmpPNode( superklass, nkls ) );
2564   Node *bol1 = _gvn.transform( new (C) BoolNode( cmp1, BoolTest::eq ) );
2565   IfNode *iff1 = create_and_xform_if( control(), bol1, PROB_LIKELY(0.83f), COUNT_UNKNOWN );
2566   Node *iftrue1 = _gvn.transform( new (C) IfTrueNode ( iff1 ) );
2567   set_control(    _gvn.transform( new (C) IfFalseNode( iff1 ) ) );
2568 
2569   // Compile speed common case: Check for being deterministic right now.  If
2570   // chk_off is a constant and not equal to cacheoff then we are NOT a
2571   // subklass.  In this case we need exactly the 1 test above and we can
2572   // return those results immediately.
2573   if (!might_be_cache) {
2574     Node* not_subtype_ctrl = control();
2575     set_control(iftrue1); // We need exactly the 1 test above
2576     return not_subtype_ctrl;
2577   }
2578 
2579   // Gather the various success & failures here
2580   RegionNode *r_ok_subtype = new (C) RegionNode(4);
2581   record_for_igvn(r_ok_subtype);
2582   RegionNode *r_not_subtype = new (C) RegionNode(3);
2583   record_for_igvn(r_not_subtype);
2584 
2585   r_ok_subtype->init_req(1, iftrue1);
2586 
2587   // Check for immediate negative hit.  Happens roughly 11% of the time (which
2588   // is roughly 63% of the remaining cases).  Test to see if the loaded
2589   // check-offset points into the subklass display list or the 1-element
2590   // cache.  If it points to the display (and NOT the cache) and the display
2591   // missed then it's not a subtype.
2592   Node *cacheoff = _gvn.intcon(cacheoff_con);
2593   Node *cmp2 = _gvn.transform( new (C) CmpINode( chk_off, cacheoff ) );
2594   Node *bol2 = _gvn.transform( new (C) BoolNode( cmp2, BoolTest::ne ) );
2595   IfNode *iff2 = create_and_xform_if( control(), bol2, PROB_LIKELY(0.63f), COUNT_UNKNOWN );
2596   r_not_subtype->init_req(1, _gvn.transform( new (C) IfTrueNode (iff2) ) );
2597   set_control(                _gvn.transform( new (C) IfFalseNode(iff2) ) );
2598 
2599   // Check for self.  Very rare to get here, but it is taken 1/3 the time.
2600   // No performance impact (too rare) but allows sharing of secondary arrays
2601   // which has some footprint reduction.
2602   Node *cmp3 = _gvn.transform( new (C) CmpPNode( subklass, superklass ) );
2603   Node *bol3 = _gvn.transform( new (C) BoolNode( cmp3, BoolTest::eq ) );
2604   IfNode *iff3 = create_and_xform_if( control(), bol3, PROB_LIKELY(0.36f), COUNT_UNKNOWN );
2605   r_ok_subtype->init_req(2, _gvn.transform( new (C) IfTrueNode ( iff3 ) ) );
2606   set_control(               _gvn.transform( new (C) IfFalseNode( iff3 ) ) );
2607 
2608   // -- Roads not taken here: --
2609   // We could also have chosen to perform the self-check at the beginning
2610   // of this code sequence, as the assembler does.  This would not pay off
2611   // the same way, since the optimizer, unlike the assembler, can perform
2612   // static type analysis to fold away many successful self-checks.
2613   // Non-foldable self checks work better here in second position, because
2614   // the initial primary superclass check subsumes a self-check for most
2615   // types.  An exception would be a secondary type like array-of-interface,
2616   // which does not appear in its own primary supertype display.
2617   // Finally, we could have chosen to move the self-check into the
2618   // PartialSubtypeCheckNode, and from there out-of-line in a platform
2619   // dependent manner.  But it is worthwhile to have the check here,
2620   // where it can be perhaps be optimized.  The cost in code space is
2621   // small (register compare, branch).
2622 
2623   // Now do a linear scan of the secondary super-klass array.  Again, no real
2624   // performance impact (too rare) but it's gotta be done.
2625   // Since the code is rarely used, there is no penalty for moving it
2626   // out of line, and it can only improve I-cache density.
2627   // The decision to inline or out-of-line this final check is platform
2628   // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2629   Node* psc = _gvn.transform(
2630     new (C) PartialSubtypeCheckNode(control(), subklass, superklass) );
2631 
2632   Node *cmp4 = _gvn.transform( new (C) CmpPNode( psc, null() ) );
2633   Node *bol4 = _gvn.transform( new (C) BoolNode( cmp4, BoolTest::ne ) );
2634   IfNode *iff4 = create_and_xform_if( control(), bol4, PROB_FAIR, COUNT_UNKNOWN );
2635   r_not_subtype->init_req(2, _gvn.transform( new (C) IfTrueNode (iff4) ) );
2636   r_ok_subtype ->init_req(3, _gvn.transform( new (C) IfFalseNode(iff4) ) );
2637 
2638   // Return false path; set default control to true path.
2639   set_control( _gvn.transform(r_ok_subtype) );
2640   return _gvn.transform(r_not_subtype);
2641 }
2642 
2643 //----------------------------static_subtype_check-----------------------------
2644 // Shortcut important common cases when superklass is exact:
2645 // (0) superklass is java.lang.Object (can occur in reflective code)
2646 // (1) subklass is already limited to a subtype of superklass => always ok
2647 // (2) subklass does not overlap with superklass => always fail
2648 // (3) superklass has NO subtypes and we can check with a simple compare.
2649 int GraphKit::static_subtype_check(ciKlass* superk, ciKlass* subk) {
2650   if (StressReflectiveCode) {
2651     return SSC_full_test;       // Let caller generate the general case.
2652   }
2653 
2654   if (superk == env()->Object_klass()) {
2655     return SSC_always_true;     // (0) this test cannot fail
2656   }
2657 
2658   ciType* superelem = superk;
2659   if (superelem->is_array_klass())
2660     superelem = superelem->as_array_klass()->base_element_type();
2661 
2662   if (!subk->is_interface()) {  // cannot trust static interface types yet
2663     if (subk->is_subtype_of(superk)) {
2664       return SSC_always_true;   // (1) false path dead; no dynamic test needed
2665     }
2666     if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
2667         !superk->is_subtype_of(subk)) {
2668       return SSC_always_false;
2669     }
2670   }
2671 
2672   // If casting to an instance klass, it must have no subtypes
2673   if (superk->is_interface()) {
2674     // Cannot trust interfaces yet.
2675     // %%% S.B. superk->nof_implementors() == 1
2676   } else if (superelem->is_instance_klass()) {
2677     ciInstanceKlass* ik = superelem->as_instance_klass();
2678     if (!ik->has_subklass() && !ik->is_interface()) {
2679       if (!ik->is_final()) {
2680         // Add a dependency if there is a chance of a later subclass.
2681         C->dependencies()->assert_leaf_type(ik);
2682       }
2683       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
2684     }
2685   } else {
2686     // A primitive array type has no subtypes.
2687     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
2688   }
2689 
2690   return SSC_full_test;
2691 }
2692 
2693 // Profile-driven exact type check:
2694 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
2695                                     float prob,
2696                                     Node* *casted_receiver) {
2697   const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2698   Node* recv_klass = load_object_klass(receiver);
2699   Node* want_klass = makecon(tklass);
2700   Node* cmp = _gvn.transform( new(C) CmpPNode(recv_klass, want_klass) );
2701   Node* bol = _gvn.transform( new(C) BoolNode(cmp, BoolTest::eq) );
2702   IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
2703   set_control( _gvn.transform( new(C) IfTrueNode (iff) ));
2704   Node* fail = _gvn.transform( new(C) IfFalseNode(iff) );
2705 
2706   const TypeOopPtr* recv_xtype = tklass->as_instance_type();
2707   assert(recv_xtype->klass_is_exact(), "");
2708 
2709   // Subsume downstream occurrences of receiver with a cast to
2710   // recv_xtype, since now we know what the type will be.
2711   Node* cast = new(C) CheckCastPPNode(control(), receiver, recv_xtype);
2712   (*casted_receiver) = _gvn.transform(cast);
2713   // (User must make the replace_in_map call.)
2714 
2715   return fail;
2716 }
2717 
2718 
2719 //------------------------------seems_never_null-------------------------------
2720 // Use null_seen information if it is available from the profile.
2721 // If we see an unexpected null at a type check we record it and force a
2722 // recompile; the offending check will be recompiled to handle NULLs.
2723 // If we see several offending BCIs, then all checks in the
2724 // method will be recompiled.
2725 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data) {
2726   if (UncommonNullCast               // Cutout for this technique
2727       && obj != null()               // And not the -Xcomp stupid case?
2728       && !too_many_traps(Deoptimization::Reason_null_check)
2729       ) {
2730     if (data == NULL)
2731       // Edge case:  no mature data.  Be optimistic here.
2732       return true;
2733     // If the profile has not seen a null, assume it won't happen.
2734     assert(java_bc() == Bytecodes::_checkcast ||
2735            java_bc() == Bytecodes::_instanceof ||
2736            java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
2737     return !data->as_BitData()->null_seen();
2738   }
2739   return false;
2740 }
2741 
2742 //------------------------maybe_cast_profiled_receiver-------------------------
2743 // If the profile has seen exactly one type, narrow to exactly that type.
2744 // Subsequent type checks will always fold up.
2745 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
2746                                              ciKlass* require_klass,
2747                                              ciKlass* spec_klass,
2748                                              bool safe_for_replace) {
2749   if (!UseTypeProfile || !TypeProfileCasts) return NULL;
2750 
2751   Deoptimization::DeoptReason reason = spec_klass == NULL ? Deoptimization::Reason_class_check : Deoptimization::Reason_speculate_class_check;
2752 
2753   // Make sure we haven't already deoptimized from this tactic.
2754   if (too_many_traps(reason) || too_many_recompiles(reason))
2755     return NULL;
2756 
2757   // (No, this isn't a call, but it's enough like a virtual call
2758   // to use the same ciMethod accessor to get the profile info...)
2759   // If we have a speculative type use it instead of profiling (which
2760   // may not help us)
2761   ciKlass* exact_kls = spec_klass == NULL ? profile_has_unique_klass() : spec_klass;
2762   if (exact_kls != NULL) {// no cast failures here
2763     if (require_klass == NULL ||
2764         static_subtype_check(require_klass, exact_kls) == SSC_always_true) {
2765       // If we narrow the type to match what the type profile sees or
2766       // the speculative type, we can then remove the rest of the
2767       // cast.
2768       // This is a win, even if the exact_kls is very specific,
2769       // because downstream operations, such as method calls,
2770       // will often benefit from the sharper type.
2771       Node* exact_obj = not_null_obj; // will get updated in place...
2772       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2773                                             &exact_obj);
2774       { PreserveJVMState pjvms(this);
2775         set_control(slow_ctl);
2776         uncommon_trap_exact(reason, Deoptimization::Action_maybe_recompile);
2777       }
2778       if (safe_for_replace) {
2779         replace_in_map(not_null_obj, exact_obj);
2780       }
2781       return exact_obj;
2782     }
2783     // assert(ssc == SSC_always_true)... except maybe the profile lied to us.
2784   }
2785 
2786   return NULL;
2787 }
2788 
2789 /**
2790  * Cast obj to type and emit guard unless we had too many traps here
2791  * already
2792  *
2793  * @param obj       node being casted
2794  * @param type      type to cast the node to
2795  * @param not_null  true if we know node cannot be null
2796  */
2797 Node* GraphKit::maybe_cast_profiled_obj(Node* obj,
2798                                         ciKlass* type,
2799                                         bool not_null) {
2800   // type == NULL if profiling tells us this object is always null
2801   if (type != NULL) {
2802     Deoptimization::DeoptReason class_reason = Deoptimization::Reason_speculate_class_check;
2803     Deoptimization::DeoptReason null_reason = Deoptimization::Reason_null_check;
2804     if (!too_many_traps(null_reason) && !too_many_recompiles(null_reason) &&
2805         !too_many_traps(class_reason) && !too_many_recompiles(class_reason)) {
2806       Node* not_null_obj = NULL;
2807       // not_null is true if we know the object is not null and
2808       // there's no need for a null check
2809       if (!not_null) {
2810         Node* null_ctl = top();
2811         not_null_obj = null_check_oop(obj, &null_ctl, true, true);
2812         assert(null_ctl->is_top(), "no null control here");
2813       } else {
2814         not_null_obj = obj;
2815       }
2816 
2817       Node* exact_obj = not_null_obj;
2818       ciKlass* exact_kls = type;
2819       Node* slow_ctl  = type_check_receiver(exact_obj, exact_kls, 1.0,
2820                                             &exact_obj);
2821       {
2822         PreserveJVMState pjvms(this);
2823         set_control(slow_ctl);
2824         uncommon_trap_exact(class_reason, Deoptimization::Action_maybe_recompile);
2825       }
2826       replace_in_map(not_null_obj, exact_obj);
2827       obj = exact_obj;
2828     }
2829   } else {
2830     if (!too_many_traps(Deoptimization::Reason_null_assert) &&
2831         !too_many_recompiles(Deoptimization::Reason_null_assert)) {
2832       Node* exact_obj = null_assert(obj);
2833       replace_in_map(obj, exact_obj);
2834       obj = exact_obj;
2835     }
2836   }
2837   return obj;
2838 }
2839 
2840 //-------------------------------gen_instanceof--------------------------------
2841 // Generate an instance-of idiom.  Used by both the instance-of bytecode
2842 // and the reflective instance-of call.
2843 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replace) {
2844   kill_dead_locals();           // Benefit all the uncommon traps
2845   assert( !stopped(), "dead parse path should be checked in callers" );
2846   assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
2847          "must check for not-null not-dead klass in callers");
2848 
2849   // Make the merge point
2850   enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
2851   RegionNode* region = new(C) RegionNode(PATH_LIMIT);
2852   Node*       phi    = new(C) PhiNode(region, TypeInt::BOOL);
2853   C->set_has_split_ifs(true); // Has chance for split-if optimization
2854 
2855   ciProfileData* data = NULL;
2856   if (java_bc() == Bytecodes::_instanceof) {  // Only for the bytecode
2857     data = method()->method_data()->bci_to_data(bci());
2858   }
2859   bool never_see_null = (ProfileDynamicTypes  // aggressive use of profile
2860                          && seems_never_null(obj, data));
2861 
2862   // Null check; get casted pointer; set region slot 3
2863   Node* null_ctl = top();
2864   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace);
2865 
2866   // If not_null_obj is dead, only null-path is taken
2867   if (stopped()) {              // Doing instance-of on a NULL?
2868     set_control(null_ctl);
2869     return intcon(0);
2870   }
2871   region->init_req(_null_path, null_ctl);
2872   phi   ->init_req(_null_path, intcon(0)); // Set null path value
2873   if (null_ctl == top()) {
2874     // Do this eagerly, so that pattern matches like is_diamond_phi
2875     // will work even during parsing.
2876     assert(_null_path == PATH_LIMIT-1, "delete last");
2877     region->del_req(_null_path);
2878     phi   ->del_req(_null_path);
2879   }
2880 
2881   // Do we know the type check always succeed?
2882   bool known_statically = false;
2883   if (_gvn.type(superklass)->singleton()) {
2884     ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
2885     ciKlass* subk = _gvn.type(obj)->is_oopptr()->klass();
2886     if (subk != NULL && subk->is_loaded()) {
2887       int static_res = static_subtype_check(superk, subk);
2888       known_statically = (static_res == SSC_always_true || static_res == SSC_always_false);
2889     }
2890   }
2891 
2892   if (known_statically && UseTypeSpeculation) {
2893     // If we know the type check always succeeds then we don't use the
2894     // profiling data at this bytecode. Don't lose it, feed it to the
2895     // type system as a speculative type.
2896     not_null_obj = record_profiled_receiver_for_speculation(not_null_obj);
2897   } else {
2898     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
2899     // We may not have profiling here or it may not help us. If we
2900     // have a speculative type use it to perform an exact cast.
2901     ciKlass* spec_obj_type = obj_type->speculative_type();
2902     if (spec_obj_type != NULL || (ProfileDynamicTypes && data != NULL)) {
2903       Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, NULL, spec_obj_type, safe_for_replace);
2904       if (stopped()) {            // Profile disagrees with this path.
2905         set_control(null_ctl);    // Null is the only remaining possibility.
2906         return intcon(0);
2907       }
2908       if (cast_obj != NULL) {
2909         not_null_obj = cast_obj;
2910       }
2911     }
2912   }
2913 
2914   // Load the object's klass
2915   Node* obj_klass = load_object_klass(not_null_obj);
2916 
2917   // Generate the subtype check
2918   Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);
2919 
2920   // Plug in the success path to the general merge in slot 1.
2921   region->init_req(_obj_path, control());
2922   phi   ->init_req(_obj_path, intcon(1));
2923 
2924   // Plug in the failing path to the general merge in slot 2.
2925   region->init_req(_fail_path, not_subtype_ctrl);
2926   phi   ->init_req(_fail_path, intcon(0));
2927 
2928   // Return final merged results
2929   set_control( _gvn.transform(region) );
2930   record_for_igvn(region);
2931   return _gvn.transform(phi);
2932 }
2933 
2934 //-------------------------------gen_checkcast---------------------------------
2935 // Generate a checkcast idiom.  Used by both the checkcast bytecode and the
2936 // array store bytecode.  Stack must be as-if BEFORE doing the bytecode so the
2937 // uncommon-trap paths work.  Adjust stack after this call.
2938 // If failure_control is supplied and not null, it is filled in with
2939 // the control edge for the cast failure.  Otherwise, an appropriate
2940 // uncommon trap or exception is thrown.
2941 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
2942                               Node* *failure_control) {
2943   kill_dead_locals();           // Benefit all the uncommon traps
2944   const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr();
2945   const Type *toop = TypeOopPtr::make_from_klass(tk->klass());
2946 
2947   // Fast cutout:  Check the case that the cast is vacuously true.
2948   // This detects the common cases where the test will short-circuit
2949   // away completely.  We do this before we perform the null check,
2950   // because if the test is going to turn into zero code, we don't
2951   // want a residual null check left around.  (Causes a slowdown,
2952   // for example, in some objArray manipulations, such as a[i]=a[j].)
2953   if (tk->singleton()) {
2954     const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
2955     if (objtp != NULL && objtp->klass() != NULL) {
2956       switch (static_subtype_check(tk->klass(), objtp->klass())) {
2957       case SSC_always_true:
2958         // If we know the type check always succeed then we don't use
2959         // the profiling data at this bytecode. Don't lose it, feed it
2960         // to the type system as a speculative type.
2961         return record_profiled_receiver_for_speculation(obj);
2962       case SSC_always_false:
2963         // It needs a null check because a null will *pass* the cast check.
2964         // A non-null value will always produce an exception.
2965         return null_assert(obj);
2966       }
2967     }
2968   }
2969 
2970   ciProfileData* data = NULL;
2971   bool safe_for_replace = false;
2972   if (failure_control == NULL) {        // use MDO in regular case only
2973     assert(java_bc() == Bytecodes::_aastore ||
2974            java_bc() == Bytecodes::_checkcast,
2975            "interpreter profiles type checks only for these BCs");
2976     data = method()->method_data()->bci_to_data(bci());
2977     safe_for_replace = true;
2978   }
2979 
2980   // Make the merge point
2981   enum { _obj_path = 1, _null_path, PATH_LIMIT };
2982   RegionNode* region = new (C) RegionNode(PATH_LIMIT);
2983   Node*       phi    = new (C) PhiNode(region, toop);
2984   C->set_has_split_ifs(true); // Has chance for split-if optimization
2985 
2986   // Use null-cast information if it is available
2987   bool never_see_null = ((failure_control == NULL)  // regular case only
2988                          && seems_never_null(obj, data));
2989 
2990   // Null check; get casted pointer; set region slot 3
2991   Node* null_ctl = top();
2992   Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace);
2993 
2994   // If not_null_obj is dead, only null-path is taken
2995   if (stopped()) {              // Doing instance-of on a NULL?
2996     set_control(null_ctl);
2997     return null();
2998   }
2999   region->init_req(_null_path, null_ctl);
3000   phi   ->init_req(_null_path, null());  // Set null path value
3001   if (null_ctl == top()) {
3002     // Do this eagerly, so that pattern matches like is_diamond_phi
3003     // will work even during parsing.
3004     assert(_null_path == PATH_LIMIT-1, "delete last");
3005     region->del_req(_null_path);
3006     phi   ->del_req(_null_path);
3007   }
3008 
3009   Node* cast_obj = NULL;
3010   if (tk->klass_is_exact()) {
3011     // The following optimization tries to statically cast the speculative type of the object
3012     // (for example obtained during profiling) to the type of the superklass and then do a
3013     // dynamic check that the type of the object is what we expect. To work correctly
3014     // for checkcast and aastore the type of superklass should be exact.
3015     const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
3016     // We may not have profiling here or it may not help us. If we have
3017     // a speculative type use it to perform an exact cast.
3018     ciKlass* spec_obj_type = obj_type->speculative_type();
3019     if (spec_obj_type != NULL ||
3020         (data != NULL &&
3021          // Counter has never been decremented (due to cast failure).
3022          // ...This is a reasonable thing to expect.  It is true of
3023          // all casts inserted by javac to implement generic types.
3024          data->as_CounterData()->count() >= 0)) {
3025       cast_obj = maybe_cast_profiled_receiver(not_null_obj, tk->klass(), spec_obj_type, safe_for_replace);
3026       if (cast_obj != NULL) {
3027         if (failure_control != NULL) // failure is now impossible
3028           (*failure_control) = top();
3029         // adjust the type of the phi to the exact klass:
3030         phi->raise_bottom_type(_gvn.type(cast_obj)->meet_speculative(TypePtr::NULL_PTR));
3031       }
3032     }
3033   }
3034 
3035   if (cast_obj == NULL) {
3036     // Load the object's klass
3037     Node* obj_klass = load_object_klass(not_null_obj);
3038 
3039     // Generate the subtype check
3040     Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );
3041 
3042     // Plug in success path into the merge
3043     cast_obj = _gvn.transform(new (C) CheckCastPPNode(control(),
3044                                                          not_null_obj, toop));
3045     // Failure path ends in uncommon trap (or may be dead - failure impossible)
3046     if (failure_control == NULL) {
3047       if (not_subtype_ctrl != top()) { // If failure is possible
3048         PreserveJVMState pjvms(this);
3049         set_control(not_subtype_ctrl);
3050         builtin_throw(Deoptimization::Reason_class_check, obj_klass);
3051       }
3052     } else {
3053       (*failure_control) = not_subtype_ctrl;
3054     }
3055   }
3056 
3057   region->init_req(_obj_path, control());
3058   phi   ->init_req(_obj_path, cast_obj);
3059 
3060   // A merge of NULL or Casted-NotNull obj
3061   Node* res = _gvn.transform(phi);
3062 
3063   // Note I do NOT always 'replace_in_map(obj,result)' here.
3064   //  if( tk->klass()->can_be_primary_super()  )
3065     // This means that if I successfully store an Object into an array-of-String
3066     // I 'forget' that the Object is really now known to be a String.  I have to
3067     // do this because we don't have true union types for interfaces - if I store
3068     // a Baz into an array-of-Interface and then tell the optimizer it's an
3069     // Interface, I forget that it's also a Baz and cannot do Baz-like field
3070     // references to it.  FIX THIS WHEN UNION TYPES APPEAR!
3071   //  replace_in_map( obj, res );
3072 
3073   // Return final merged results
3074   set_control( _gvn.transform(region) );
3075   record_for_igvn(region);
3076   return res;
3077 }
3078 
3079 //------------------------------next_monitor-----------------------------------
3080 // What number should be given to the next monitor?
3081 int GraphKit::next_monitor() {
3082   int current = jvms()->monitor_depth()* C->sync_stack_slots();
3083   int next = current + C->sync_stack_slots();
3084   // Keep the toplevel high water mark current:
3085   if (C->fixed_slots() < next)  C->set_fixed_slots(next);
3086   return current;
3087 }
3088 
3089 //------------------------------insert_mem_bar---------------------------------
3090 // Memory barrier to avoid floating things around
3091 // The membar serves as a pinch point between both control and all memory slices.
3092 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
3093   MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
3094   mb->init_req(TypeFunc::Control, control());
3095   mb->init_req(TypeFunc::Memory,  reset_memory());
3096   Node* membar = _gvn.transform(mb);
3097   set_control(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Control)));
3098   set_all_memory_call(membar);
3099   return membar;
3100 }
3101 
3102 //-------------------------insert_mem_bar_volatile----------------------------
3103 // Memory barrier to avoid floating things around
3104 // The membar serves as a pinch point between both control and memory(alias_idx).
3105 // If you want to make a pinch point on all memory slices, do not use this
3106 // function (even with AliasIdxBot); use insert_mem_bar() instead.
3107 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
3108   // When Parse::do_put_xxx updates a volatile field, it appends a series
3109   // of MemBarVolatile nodes, one for *each* volatile field alias category.
3110   // The first membar is on the same memory slice as the field store opcode.
3111   // This forces the membar to follow the store.  (Bug 6500685 broke this.)
3112   // All the other membars (for other volatile slices, including AliasIdxBot,
3113   // which stands for all unknown volatile slices) are control-dependent
3114   // on the first membar.  This prevents later volatile loads or stores
3115   // from sliding up past the just-emitted store.
3116 
3117   MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
3118   mb->set_req(TypeFunc::Control,control());
3119   if (alias_idx == Compile::AliasIdxBot) {
3120     mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
3121   } else {
3122     assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
3123     mb->set_req(TypeFunc::Memory, memory(alias_idx));
3124   }
3125   Node* membar = _gvn.transform(mb);
3126   set_control(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Control)));
3127   if (alias_idx == Compile::AliasIdxBot) {
3128     merged_memory()->set_base_memory(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Memory)));
3129   } else {
3130     set_memory(_gvn.transform(new (C) ProjNode(membar, TypeFunc::Memory)),alias_idx);
3131   }
3132   return membar;
3133 }
3134 
3135 //------------------------------shared_lock------------------------------------
3136 // Emit locking code.
3137 FastLockNode* GraphKit::shared_lock(Node* obj) {
3138   // bci is either a monitorenter bc or InvocationEntryBci
3139   // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3140   assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3141 
3142   if( !GenerateSynchronizationCode )
3143     return NULL;                // Not locking things?
3144   if (stopped())                // Dead monitor?
3145     return NULL;
3146 
3147   assert(dead_locals_are_killed(), "should kill locals before sync. point");
3148 
3149   // Box the stack location
3150   Node* box = _gvn.transform(new (C) BoxLockNode(next_monitor()));
3151   Node* mem = reset_memory();
3152 
3153   FastLockNode * flock = _gvn.transform(new (C) FastLockNode(0, obj, box) )->as_FastLock();
3154   if (UseBiasedLocking && PrintPreciseBiasedLockingStatistics) {
3155     // Create the counters for this fast lock.
3156     flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3157   }
3158 
3159   // Create the rtm counters for this fast lock if needed.
3160   flock->create_rtm_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3161 
3162   // Add monitor to debug info for the slow path.  If we block inside the
3163   // slow path and de-opt, we need the monitor hanging around
3164   map()->push_monitor( flock );
3165 
3166   const TypeFunc *tf = LockNode::lock_type();
3167   LockNode *lock = new (C) LockNode(C, tf);
3168 
3169   lock->init_req( TypeFunc::Control, control() );
3170   lock->init_req( TypeFunc::Memory , mem );
3171   lock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3172   lock->init_req( TypeFunc::FramePtr, frameptr() );
3173   lock->init_req( TypeFunc::ReturnAdr, top() );
3174 
3175   lock->init_req(TypeFunc::Parms + 0, obj);
3176   lock->init_req(TypeFunc::Parms + 1, box);
3177   lock->init_req(TypeFunc::Parms + 2, flock);
3178   add_safepoint_edges(lock);
3179 
3180   lock = _gvn.transform( lock )->as_Lock();
3181 
3182   // lock has no side-effects, sets few values
3183   set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
3184 
3185   insert_mem_bar(Op_MemBarAcquireLock);
3186 
3187   // Add this to the worklist so that the lock can be eliminated
3188   record_for_igvn(lock);
3189 
3190 #ifndef PRODUCT
3191   if (PrintLockStatistics) {
3192     // Update the counter for this lock.  Don't bother using an atomic
3193     // operation since we don't require absolute accuracy.
3194     lock->create_lock_counter(map()->jvms());
3195     increment_counter(lock->counter()->addr());
3196   }
3197 #endif
3198 
3199   return flock;
3200 }
3201 
3202 
3203 //------------------------------shared_unlock----------------------------------
3204 // Emit unlocking code.
3205 void GraphKit::shared_unlock(Node* box, 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;
3212   if (stopped()) {               // Dead monitor?
3213     map()->pop_monitor();        // Kill monitor from debug info
3214     return;
3215   }
3216 
3217   // Memory barrier to avoid floating things down past the locked region
3218   insert_mem_bar(Op_MemBarReleaseLock);
3219 
3220   const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
3221   UnlockNode *unlock = new (C) UnlockNode(C, tf);
3222 #ifdef ASSERT
3223   unlock->set_dbg_jvms(sync_jvms());
3224 #endif
3225   uint raw_idx = Compile::AliasIdxRaw;
3226   unlock->init_req( TypeFunc::Control, control() );
3227   unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
3228   unlock->init_req( TypeFunc::I_O    , top() )     ;   // does no i/o
3229   unlock->init_req( TypeFunc::FramePtr, frameptr() );
3230   unlock->init_req( TypeFunc::ReturnAdr, top() );
3231 
3232   unlock->init_req(TypeFunc::Parms + 0, obj);
3233   unlock->init_req(TypeFunc::Parms + 1, box);
3234   unlock = _gvn.transform(unlock)->as_Unlock();
3235 
3236   Node* mem = reset_memory();
3237 
3238   // unlock has no side-effects, sets few values
3239   set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
3240 
3241   // Kill monitor from debug info
3242   map()->pop_monitor( );
3243 }
3244 
3245 //-------------------------------get_layout_helper-----------------------------
3246 // If the given klass is a constant or known to be an array,
3247 // fetch the constant layout helper value into constant_value
3248 // and return (Node*)NULL.  Otherwise, load the non-constant
3249 // layout helper value, and return the node which represents it.
3250 // This two-faced routine is useful because allocation sites
3251 // almost always feature constant types.
3252 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
3253   const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr();
3254   if (!StressReflectiveCode && inst_klass != NULL) {
3255     ciKlass* klass = inst_klass->klass();
3256     bool    xklass = inst_klass->klass_is_exact();
3257     if (xklass || klass->is_array_klass()) {
3258       jint lhelper = klass->layout_helper();
3259       if (lhelper != Klass::_lh_neutral_value) {
3260         constant_value = lhelper;
3261         return (Node*) NULL;
3262       }
3263     }
3264   }
3265   constant_value = Klass::_lh_neutral_value;  // put in a known value
3266   Node* lhp = basic_plus_adr(klass_node, klass_node, in_bytes(Klass::layout_helper_offset()));
3267   return make_load(NULL, lhp, TypeInt::INT, T_INT, MemNode::unordered);
3268 }
3269 
3270 // We just put in an allocate/initialize with a big raw-memory effect.
3271 // Hook selected additional alias categories on the initialization.
3272 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
3273                                 MergeMemNode* init_in_merge,
3274                                 Node* init_out_raw) {
3275   DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
3276   assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
3277 
3278   Node* prevmem = kit.memory(alias_idx);
3279   init_in_merge->set_memory_at(alias_idx, prevmem);
3280   kit.set_memory(init_out_raw, alias_idx);
3281 }
3282 
3283 //---------------------------set_output_for_allocation-------------------------
3284 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
3285                                           const TypeOopPtr* oop_type,
3286                                           bool deoptimize_on_exception) {
3287   int rawidx = Compile::AliasIdxRaw;
3288   alloc->set_req( TypeFunc::FramePtr, frameptr() );
3289   add_safepoint_edges(alloc);
3290   Node* allocx = _gvn.transform(alloc);
3291   set_control( _gvn.transform(new (C) ProjNode(allocx, TypeFunc::Control) ) );
3292   // create memory projection for i_o
3293   set_memory ( _gvn.transform( new (C) ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
3294   make_slow_call_ex(allocx, env()->Throwable_klass(), true, deoptimize_on_exception);
3295 
3296   // create a memory projection as for the normal control path
3297   Node* malloc = _gvn.transform(new (C) ProjNode(allocx, TypeFunc::Memory));
3298   set_memory(malloc, rawidx);
3299 
3300   // a normal slow-call doesn't change i_o, but an allocation does
3301   // we create a separate i_o projection for the normal control path
3302   set_i_o(_gvn.transform( new (C) ProjNode(allocx, TypeFunc::I_O, false) ) );
3303   Node* rawoop = _gvn.transform( new (C) ProjNode(allocx, TypeFunc::Parms) );
3304 
3305   // put in an initialization barrier
3306   InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
3307                                                  rawoop)->as_Initialize();
3308   assert(alloc->initialization() == init,  "2-way macro link must work");
3309   assert(init ->allocation()     == alloc, "2-way macro link must work");
3310   {
3311     // Extract memory strands which may participate in the new object's
3312     // initialization, and source them from the new InitializeNode.
3313     // This will allow us to observe initializations when they occur,
3314     // and link them properly (as a group) to the InitializeNode.
3315     assert(init->in(InitializeNode::Memory) == malloc, "");
3316     MergeMemNode* minit_in = MergeMemNode::make(C, malloc);
3317     init->set_req(InitializeNode::Memory, minit_in);
3318     record_for_igvn(minit_in); // fold it up later, if possible
3319     Node* minit_out = memory(rawidx);
3320     assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
3321     if (oop_type->isa_aryptr()) {
3322       const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
3323       int            elemidx  = C->get_alias_index(telemref);
3324       hook_memory_on_init(*this, elemidx, minit_in, minit_out);
3325     } else if (oop_type->isa_instptr()) {
3326       ciInstanceKlass* ik = oop_type->klass()->as_instance_klass();
3327       for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
3328         ciField* field = ik->nonstatic_field_at(i);
3329         if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
3330           continue;  // do not bother to track really large numbers of fields
3331         // Find (or create) the alias category for this field:
3332         int fieldidx = C->alias_type(field)->index();
3333         hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
3334       }
3335     }
3336   }
3337 
3338   // Cast raw oop to the real thing...
3339   Node* javaoop = new (C) CheckCastPPNode(control(), rawoop, oop_type);
3340   javaoop = _gvn.transform(javaoop);
3341   C->set_recent_alloc(control(), javaoop);
3342   assert(just_allocated_object(control()) == javaoop, "just allocated");
3343 
3344 #ifdef ASSERT
3345   { // Verify that the AllocateNode::Ideal_allocation recognizers work:
3346     assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc,
3347            "Ideal_allocation works");
3348     assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc,
3349            "Ideal_allocation works");
3350     if (alloc->is_AllocateArray()) {
3351       assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(),
3352              "Ideal_allocation works");
3353       assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(),
3354              "Ideal_allocation works");
3355     } else {
3356       assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
3357     }
3358   }
3359 #endif //ASSERT
3360 
3361   return javaoop;
3362 }
3363 
3364 //---------------------------new_instance--------------------------------------
3365 // This routine takes a klass_node which may be constant (for a static type)
3366 // or may be non-constant (for reflective code).  It will work equally well
3367 // for either, and the graph will fold nicely if the optimizer later reduces
3368 // the type to a constant.
3369 // The optional arguments are for specialized use by intrinsics:
3370 //  - If 'extra_slow_test' if not null is an extra condition for the slow-path.
3371 //  - If 'return_size_val', report the the total object size to the caller.
3372 //  - deoptimize_on_exception controls how Java exceptions are handled (rethrow vs deoptimize)
3373 Node* GraphKit::new_instance(Node* klass_node,
3374                              Node* extra_slow_test,
3375                              Node* *return_size_val,
3376                              bool deoptimize_on_exception) {
3377   // Compute size in doublewords
3378   // The size is always an integral number of doublewords, represented
3379   // as a positive bytewise size stored in the klass's layout_helper.
3380   // The layout_helper also encodes (in a low bit) the need for a slow path.
3381   jint  layout_con = Klass::_lh_neutral_value;
3382   Node* layout_val = get_layout_helper(klass_node, layout_con);
3383   int   layout_is_con = (layout_val == NULL);
3384 
3385   if (extra_slow_test == NULL)  extra_slow_test = intcon(0);
3386   // Generate the initial go-slow test.  It's either ALWAYS (return a
3387   // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective
3388   // case) a computed value derived from the layout_helper.
3389   Node* initial_slow_test = NULL;
3390   if (layout_is_con) {
3391     assert(!StressReflectiveCode, "stress mode does not use these paths");
3392     bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
3393     initial_slow_test = must_go_slow? intcon(1): extra_slow_test;
3394 
3395   } else {   // reflective case
3396     // This reflective path is used by Unsafe.allocateInstance.
3397     // (It may be stress-tested by specifying StressReflectiveCode.)
3398     // Basically, we want to get into the VM is there's an illegal argument.
3399     Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
3400     initial_slow_test = _gvn.transform( new (C) AndINode(layout_val, bit) );
3401     if (extra_slow_test != intcon(0)) {
3402       initial_slow_test = _gvn.transform( new (C) OrINode(initial_slow_test, extra_slow_test) );
3403     }
3404     // (Macro-expander will further convert this to a Bool, if necessary.)
3405   }
3406 
3407   // Find the size in bytes.  This is easy; it's the layout_helper.
3408   // The size value must be valid even if the slow path is taken.
3409   Node* size = NULL;
3410   if (layout_is_con) {
3411     size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
3412   } else {   // reflective case
3413     // This reflective path is used by clone and Unsafe.allocateInstance.
3414     size = ConvI2X(layout_val);
3415 
3416     // Clear the low bits to extract layout_helper_size_in_bytes:
3417     assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
3418     Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
3419     size = _gvn.transform( new (C) AndXNode(size, mask) );
3420   }
3421   if (return_size_val != NULL) {
3422     (*return_size_val) = size;
3423   }
3424 
3425   // This is a precise notnull oop of the klass.
3426   // (Actually, it need not be precise if this is a reflective allocation.)
3427   // It's what we cast the result to.
3428   const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3429   if (!tklass)  tklass = TypeKlassPtr::OBJECT;
3430   const TypeOopPtr* oop_type = tklass->as_instance_type();
3431 
3432   // Now generate allocation code
3433 
3434   // The entire memory state is needed for slow path of the allocation
3435   // since GC and deoptimization can happened.
3436   Node *mem = reset_memory();
3437   set_all_memory(mem); // Create new memory state
3438 
3439   AllocateNode* alloc
3440     = new (C) AllocateNode(C, AllocateNode::alloc_type(Type::TOP),
3441                            control(), mem, i_o(),
3442                            size, klass_node,
3443                            initial_slow_test);
3444 
3445   return set_output_for_allocation(alloc, oop_type, deoptimize_on_exception);
3446 }
3447 
3448 //-------------------------------new_array-------------------------------------
3449 // helper for both newarray and anewarray
3450 // The 'length' parameter is (obviously) the length of the array.
3451 // See comments on new_instance for the meaning of the other arguments.
3452 Node* GraphKit::new_array(Node* klass_node,     // array klass (maybe variable)
3453                           Node* length,         // number of array elements
3454                           int   nargs,          // number of arguments to push back for uncommon trap
3455                           Node* *return_size_val,
3456                           bool deoptimize_on_exception) {
3457   jint  layout_con = Klass::_lh_neutral_value;
3458   Node* layout_val = get_layout_helper(klass_node, layout_con);
3459   int   layout_is_con = (layout_val == NULL);
3460 
3461   if (!layout_is_con && !StressReflectiveCode &&
3462       !too_many_traps(Deoptimization::Reason_class_check)) {
3463     // This is a reflective array creation site.
3464     // Optimistically assume that it is a subtype of Object[],
3465     // so that we can fold up all the address arithmetic.
3466     layout_con = Klass::array_layout_helper(T_OBJECT);
3467     Node* cmp_lh = _gvn.transform( new(C) CmpINode(layout_val, intcon(layout_con)) );
3468     Node* bol_lh = _gvn.transform( new(C) BoolNode(cmp_lh, BoolTest::eq) );
3469     { BuildCutout unless(this, bol_lh, PROB_MAX);
3470       inc_sp(nargs);
3471       uncommon_trap(Deoptimization::Reason_class_check,
3472                     Deoptimization::Action_maybe_recompile);
3473     }
3474     layout_val = NULL;
3475     layout_is_con = true;
3476   }
3477 
3478   // Generate the initial go-slow test.  Make sure we do not overflow
3479   // if length is huge (near 2Gig) or negative!  We do not need
3480   // exact double-words here, just a close approximation of needed
3481   // double-words.  We can't add any offset or rounding bits, lest we
3482   // take a size -1 of bytes and make it positive.  Use an unsigned
3483   // compare, so negative sizes look hugely positive.
3484   int fast_size_limit = FastAllocateSizeLimit;
3485   if (layout_is_con) {
3486     assert(!StressReflectiveCode, "stress mode does not use these paths");
3487     // Increase the size limit if we have exact knowledge of array type.
3488     int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3489     fast_size_limit <<= (LogBytesPerLong - log2_esize);
3490   }
3491 
3492   Node* initial_slow_cmp  = _gvn.transform( new (C) CmpUNode( length, intcon( fast_size_limit ) ) );
3493   Node* initial_slow_test = _gvn.transform( new (C) BoolNode( initial_slow_cmp, BoolTest::gt ) );
3494 
3495   // --- Size Computation ---
3496   // array_size = round_to_heap(array_header + (length << elem_shift));
3497   // where round_to_heap(x) == round_to(x, MinObjAlignmentInBytes)
3498   // and round_to(x, y) == ((x + y-1) & ~(y-1))
3499   // The rounding mask is strength-reduced, if possible.
3500   int round_mask = MinObjAlignmentInBytes - 1;
3501   Node* header_size = NULL;
3502   int   header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3503   // (T_BYTE has the weakest alignment and size restrictions...)
3504   if (layout_is_con) {
3505     int       hsize  = Klass::layout_helper_header_size(layout_con);
3506     int       eshift = Klass::layout_helper_log2_element_size(layout_con);
3507     BasicType etype  = Klass::layout_helper_element_type(layout_con);
3508     if ((round_mask & ~right_n_bits(eshift)) == 0)
3509       round_mask = 0;  // strength-reduce it if it goes away completely
3510     assert((hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3511     assert(header_size_min <= hsize, "generic minimum is smallest");
3512     header_size_min = hsize;
3513     header_size = intcon(hsize + round_mask);
3514   } else {
3515     Node* hss   = intcon(Klass::_lh_header_size_shift);
3516     Node* hsm   = intcon(Klass::_lh_header_size_mask);
3517     Node* hsize = _gvn.transform( new(C) URShiftINode(layout_val, hss) );
3518     hsize       = _gvn.transform( new(C) AndINode(hsize, hsm) );
3519     Node* mask  = intcon(round_mask);
3520     header_size = _gvn.transform( new(C) AddINode(hsize, mask) );
3521   }
3522 
3523   Node* elem_shift = NULL;
3524   if (layout_is_con) {
3525     int eshift = Klass::layout_helper_log2_element_size(layout_con);
3526     if (eshift != 0)
3527       elem_shift = intcon(eshift);
3528   } else {
3529     // There is no need to mask or shift this value.
3530     // The semantics of LShiftINode include an implicit mask to 0x1F.
3531     assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3532     elem_shift = layout_val;
3533   }
3534 
3535   // Transition to native address size for all offset calculations:
3536   Node* lengthx = ConvI2X(length);
3537   Node* headerx = ConvI2X(header_size);
3538 #ifdef _LP64
3539   { const TypeInt* tilen = _gvn.find_int_type(length);
3540     if (tilen != NULL && tilen->_lo < 0) {
3541       // Add a manual constraint to a positive range.  Cf. array_element_address.
3542       jlong size_max = fast_size_limit;
3543       if (size_max > tilen->_hi)  size_max = tilen->_hi;
3544       const TypeInt* tlcon = TypeInt::make(0, size_max, Type::WidenMin);
3545 
3546       // Only do a narrow I2L conversion if the range check passed.
3547       IfNode* iff = new (C) IfNode(control(), initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
3548       _gvn.transform(iff);
3549       RegionNode* region = new (C) RegionNode(3);
3550       _gvn.set_type(region, Type::CONTROL);
3551       lengthx = new (C) PhiNode(region, TypeLong::LONG);
3552       _gvn.set_type(lengthx, TypeLong::LONG);
3553 
3554       // Range check passed. Use ConvI2L node with narrow type.
3555       Node* passed = IfFalse(iff);
3556       region->init_req(1, passed);
3557       // Make I2L conversion control dependent to prevent it from
3558       // floating above the range check during loop optimizations.
3559       lengthx->init_req(1, C->constrained_convI2L(&_gvn, length, tlcon, passed));
3560 
3561       // Range check failed. Use ConvI2L with wide type because length may be invalid.
3562       region->init_req(2, IfTrue(iff));
3563       lengthx->init_req(2, ConvI2X(length));
3564 
3565       set_control(region);
3566       record_for_igvn(region);
3567       record_for_igvn(lengthx);
3568     }
3569   }
3570 #endif
3571 
3572   // Combine header size (plus rounding) and body size.  Then round down.
3573   // This computation cannot overflow, because it is used only in two
3574   // places, one where the length is sharply limited, and the other
3575   // after a successful allocation.
3576   Node* abody = lengthx;
3577   if (elem_shift != NULL)
3578     abody     = _gvn.transform( new(C) LShiftXNode(lengthx, elem_shift) );
3579   Node* size  = _gvn.transform( new(C) AddXNode(headerx, abody) );
3580   if (round_mask != 0) {
3581     Node* mask = MakeConX(~round_mask);
3582     size       = _gvn.transform( new(C) AndXNode(size, mask) );
3583   }
3584   // else if round_mask == 0, the size computation is self-rounding
3585 
3586   if (return_size_val != NULL) {
3587     // This is the size
3588     (*return_size_val) = size;
3589   }
3590 
3591   // Now generate allocation code
3592 
3593   // The entire memory state is needed for slow path of the allocation
3594   // since GC and deoptimization can happened.
3595   Node *mem = reset_memory();
3596   set_all_memory(mem); // Create new memory state
3597 
3598   if (initial_slow_test->is_Bool()) {
3599     // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
3600     initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
3601   }
3602 
3603   // Create the AllocateArrayNode and its result projections
3604   AllocateArrayNode* alloc
3605     = new (C) AllocateArrayNode(C, AllocateArrayNode::alloc_type(TypeInt::INT),
3606                                 control(), mem, i_o(),
3607                                 size, klass_node,
3608                                 initial_slow_test,
3609                                 length);
3610 
3611   // Cast to correct type.  Note that the klass_node may be constant or not,
3612   // and in the latter case the actual array type will be inexact also.
3613   // (This happens via a non-constant argument to inline_native_newArray.)
3614   // In any case, the value of klass_node provides the desired array type.
3615   const TypeInt* length_type = _gvn.find_int_type(length);
3616   const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
3617   if (ary_type->isa_aryptr() && length_type != NULL) {
3618     // Try to get a better type than POS for the size
3619     ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
3620   }
3621 
3622   Node* javaoop = set_output_for_allocation(alloc, ary_type, deoptimize_on_exception);
3623 
3624   // Cast length on remaining path to be as narrow as possible
3625   if (map()->find_edge(length) >= 0) {
3626     Node* ccast = alloc->make_ideal_length(ary_type, &_gvn);
3627     if (ccast != length) {
3628       _gvn.set_type_bottom(ccast);
3629       record_for_igvn(ccast);
3630       replace_in_map(length, ccast);
3631     }
3632   }
3633 
3634   return javaoop;
3635 }
3636 
3637 // The following "Ideal_foo" functions are placed here because they recognize
3638 // the graph shapes created by the functions immediately above.
3639 
3640 //---------------------------Ideal_allocation----------------------------------
3641 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
3642 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) {
3643   if (ptr == NULL) {     // reduce dumb test in callers
3644     return NULL;
3645   }
3646   if (ptr->is_CheckCastPP()) { // strip only one raw-to-oop cast
3647     ptr = ptr->in(1);
3648     if (ptr == NULL) return NULL;
3649   }
3650   // Return NULL for allocations with several casts:
3651   //   j.l.reflect.Array.newInstance(jobject, jint)
3652   //   Object.clone()
3653   // to keep more precise type from last cast.
3654   if (ptr->is_Proj()) {
3655     Node* allo = ptr->in(0);
3656     if (allo != NULL && allo->is_Allocate()) {
3657       return allo->as_Allocate();
3658     }
3659   }
3660   // Report failure to match.
3661   return NULL;
3662 }
3663 
3664 // Fancy version which also strips off an offset (and reports it to caller).
3665 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase,
3666                                              intptr_t& offset) {
3667   Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
3668   if (base == NULL)  return NULL;
3669   return Ideal_allocation(base, phase);
3670 }
3671 
3672 // Trace Initialize <- Proj[Parm] <- Allocate
3673 AllocateNode* InitializeNode::allocation() {
3674   Node* rawoop = in(InitializeNode::RawAddress);
3675   if (rawoop->is_Proj()) {
3676     Node* alloc = rawoop->in(0);
3677     if (alloc->is_Allocate()) {
3678       return alloc->as_Allocate();
3679     }
3680   }
3681   return NULL;
3682 }
3683 
3684 // Trace Allocate -> Proj[Parm] -> Initialize
3685 InitializeNode* AllocateNode::initialization() {
3686   ProjNode* rawoop = proj_out(AllocateNode::RawAddress);
3687   if (rawoop == NULL)  return NULL;
3688   for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
3689     Node* init = rawoop->fast_out(i);
3690     if (init->is_Initialize()) {
3691       assert(init->as_Initialize()->allocation() == this, "2-way link");
3692       return init->as_Initialize();
3693     }
3694   }
3695   return NULL;
3696 }
3697 
3698 //----------------------------- loop predicates ---------------------------
3699 
3700 //------------------------------add_predicate_impl----------------------------
3701 void GraphKit::add_predicate_impl(Deoptimization::DeoptReason reason, int nargs) {
3702   // Too many traps seen?
3703   if (too_many_traps(reason)) {
3704 #ifdef ASSERT
3705     if (TraceLoopPredicate) {
3706       int tc = C->trap_count(reason);
3707       tty->print("too many traps=%s tcount=%d in ",
3708                     Deoptimization::trap_reason_name(reason), tc);
3709       method()->print(); // which method has too many predicate traps
3710       tty->cr();
3711     }
3712 #endif
3713     // We cannot afford to take more traps here,
3714     // do not generate predicate.
3715     return;
3716   }
3717 
3718   Node *cont    = _gvn.intcon(1);
3719   Node* opq     = _gvn.transform(new (C) Opaque1Node(C, cont));
3720   Node *bol     = _gvn.transform(new (C) Conv2BNode(opq));
3721   IfNode* iff   = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
3722   Node* iffalse = _gvn.transform(new (C) IfFalseNode(iff));
3723   C->add_predicate_opaq(opq);
3724   {
3725     PreserveJVMState pjvms(this);
3726     set_control(iffalse);
3727     inc_sp(nargs);
3728     uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
3729   }
3730   Node* iftrue = _gvn.transform(new (C) IfTrueNode(iff));
3731   set_control(iftrue);
3732 }
3733 
3734 //------------------------------add_predicate---------------------------------
3735 void GraphKit::add_predicate(int nargs) {
3736   if (UseLoopPredicate) {
3737     add_predicate_impl(Deoptimization::Reason_predicate, nargs);
3738   }
3739   // loop's limit check predicate should be near the loop.
3740   if (LoopLimitCheck) {
3741     add_predicate_impl(Deoptimization::Reason_loop_limit_check, nargs);
3742   }
3743 }
3744 
3745 //----------------------------- store barriers ----------------------------
3746 #define __ ideal.
3747 
3748 void GraphKit::sync_kit(IdealKit& ideal) {
3749   set_all_memory(__ merged_memory());
3750   set_i_o(__ i_o());
3751   set_control(__ ctrl());
3752 }
3753 
3754 void GraphKit::final_sync(IdealKit& ideal) {
3755   // Final sync IdealKit and graphKit.
3756   sync_kit(ideal);
3757 }
3758 
3759 // vanilla/CMS post barrier
3760 // Insert a write-barrier store.  This is to let generational GC work; we have
3761 // to flag all oop-stores before the next GC point.
3762 void GraphKit::write_barrier_post(Node* oop_store,
3763                                   Node* obj,
3764                                   Node* adr,
3765                                   uint  adr_idx,
3766                                   Node* val,
3767                                   bool use_precise) {
3768   // No store check needed if we're storing a NULL or an old object
3769   // (latter case is probably a string constant). The concurrent
3770   // mark sweep garbage collector, however, needs to have all nonNull
3771   // oop updates flagged via card-marks.
3772   if (val != NULL && val->is_Con()) {
3773     // must be either an oop or NULL
3774     const Type* t = val->bottom_type();
3775     if (t == TypePtr::NULL_PTR || t == Type::TOP)
3776       // stores of null never (?) need barriers
3777       return;
3778   }
3779 
3780   if (use_ReduceInitialCardMarks()
3781       && obj == just_allocated_object(control())) {
3782     // We can skip marks on a freshly-allocated object in Eden.
3783     // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
3784     // That routine informs GC to take appropriate compensating steps,
3785     // upon a slow-path allocation, so as to make this card-mark
3786     // elision safe.
3787     return;
3788   }
3789 
3790   if (!use_precise) {
3791     // All card marks for a (non-array) instance are in one place:
3792     adr = obj;
3793   }
3794   // (Else it's an array (or unknown), and we want more precise card marks.)
3795   assert(adr != NULL, "");
3796 
3797   IdealKit ideal(this, true);
3798 
3799   // Convert the pointer to an int prior to doing math on it
3800   Node* cast = __ CastPX(__ ctrl(), adr);
3801 
3802   // Divide by card size
3803   assert(Universe::heap()->barrier_set()->kind() == BarrierSet::CardTableModRef,
3804          "Only one we handle so far.");
3805   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
3806 
3807   // Combine card table base and card offset
3808   Node* card_adr = __ AddP(__ top(), byte_map_base_node(), card_offset );
3809 
3810   // Get the alias_index for raw card-mark memory
3811   int adr_type = Compile::AliasIdxRaw;
3812   Node*   zero = __ ConI(0); // Dirty card value
3813   BasicType bt = T_BYTE;
3814 
3815   if (UseCondCardMark) {
3816     // The classic GC reference write barrier is typically implemented
3817     // as a store into the global card mark table.  Unfortunately
3818     // unconditional stores can result in false sharing and excessive
3819     // coherence traffic as well as false transactional aborts.
3820     // UseCondCardMark enables MP "polite" conditional card mark
3821     // stores.  In theory we could relax the load from ctrl() to
3822     // no_ctrl, but that doesn't buy much latitude.
3823     Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, bt, adr_type);
3824     __ if_then(card_val, BoolTest::ne, zero);
3825   }
3826 
3827   // Smash zero into card
3828   if( !UseConcMarkSweepGC ) {
3829     __ store(__ ctrl(), card_adr, zero, bt, adr_type, MemNode::release);
3830   } else {
3831     // Specialized path for CM store barrier
3832     __ storeCM(__ ctrl(), card_adr, zero, oop_store, adr_idx, bt, adr_type);
3833   }
3834 
3835   if (UseCondCardMark) {
3836     __ end_if();
3837   }
3838 
3839   // Final sync IdealKit and GraphKit.
3840   final_sync(ideal);
3841 }
3842 
3843 // G1 pre/post barriers
3844 void GraphKit::g1_write_barrier_pre(bool do_load,
3845                                     Node* obj,
3846                                     Node* adr,
3847                                     uint alias_idx,
3848                                     Node* val,
3849                                     const TypeOopPtr* val_type,
3850                                     Node* pre_val,
3851                                     BasicType bt) {
3852 
3853   // Some sanity checks
3854   // Note: val is unused in this routine.
3855 
3856   if (do_load) {
3857     // We need to generate the load of the previous value
3858     assert(obj != NULL, "must have a base");
3859     assert(adr != NULL, "where are loading from?");
3860     assert(pre_val == NULL, "loaded already?");
3861     assert(val_type != NULL, "need a type");
3862   } else {
3863     // In this case both val_type and alias_idx are unused.
3864     assert(pre_val != NULL, "must be loaded already");
3865     // Nothing to be done if pre_val is null.
3866     if (pre_val->bottom_type() == TypePtr::NULL_PTR) return;
3867     assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here");
3868   }
3869   assert(bt == T_OBJECT, "or we shouldn't be here");
3870 
3871   IdealKit ideal(this, true);
3872 
3873   Node* tls = __ thread(); // ThreadLocalStorage
3874 
3875   Node* no_ctrl = NULL;
3876   Node* no_base = __ top();
3877   Node* zero  = __ ConI(0);
3878   Node* zeroX = __ ConX(0);
3879 
3880   float likely  = PROB_LIKELY(0.999);
3881   float unlikely  = PROB_UNLIKELY(0.999);
3882 
3883   BasicType active_type = in_bytes(PtrQueue::byte_width_of_active()) == 4 ? T_INT : T_BYTE;
3884   assert(in_bytes(PtrQueue::byte_width_of_active()) == 4 || in_bytes(PtrQueue::byte_width_of_active()) == 1, "flag width");
3885 
3886   // Offsets into the thread
3887   const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +  // 648
3888                                           PtrQueue::byte_offset_of_active());
3889   const int index_offset   = in_bytes(JavaThread::satb_mark_queue_offset() +  // 656
3890                                           PtrQueue::byte_offset_of_index());
3891   const int buffer_offset  = in_bytes(JavaThread::satb_mark_queue_offset() +  // 652
3892                                           PtrQueue::byte_offset_of_buf());
3893 
3894   // Now the actual pointers into the thread
3895   Node* marking_adr = __ AddP(no_base, tls, __ ConX(marking_offset));
3896   Node* buffer_adr  = __ AddP(no_base, tls, __ ConX(buffer_offset));
3897   Node* index_adr   = __ AddP(no_base, tls, __ ConX(index_offset));
3898 
3899   // Now some of the values
3900   Node* marking = __ load(__ ctrl(), marking_adr, TypeInt::INT, active_type, Compile::AliasIdxRaw);
3901 
3902   // if (!marking)
3903   __ if_then(marking, BoolTest::ne, zero, unlikely); {
3904     BasicType index_bt = TypeX_X->basic_type();
3905     assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 PtrQueue::_index with wrong size.");
3906     Node* index   = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
3907 
3908     if (do_load) {
3909       // load original value
3910       // alias_idx correct??
3911       pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx);
3912     }
3913 
3914     // if (pre_val != NULL)
3915     __ if_then(pre_val, BoolTest::ne, null()); {
3916       Node* buffer  = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
3917 
3918       // is the queue for this thread full?
3919       __ if_then(index, BoolTest::ne, zeroX, likely); {
3920 
3921         // decrement the index
3922         Node* next_index = _gvn.transform(new (C) SubXNode(index, __ ConX(sizeof(intptr_t))));
3923 
3924         // Now get the buffer location we will log the previous value into and store it
3925         Node *log_addr = __ AddP(no_base, buffer, next_index);
3926         __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered);
3927         // update the index
3928         __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered);
3929 
3930       } __ else_(); {
3931 
3932         // logging buffer is full, call the runtime
3933         const TypeFunc *tf = OptoRuntime::g1_wb_pre_Type();
3934         __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), "g1_wb_pre", pre_val, tls);
3935       } __ end_if();  // (!index)
3936     } __ end_if();  // (pre_val != NULL)
3937   } __ end_if();  // (!marking)
3938 
3939   // Final sync IdealKit and GraphKit.
3940   final_sync(ideal);
3941 }
3942 
3943 //
3944 // Update the card table and add card address to the queue
3945 //
3946 void GraphKit::g1_mark_card(IdealKit& ideal,
3947                             Node* card_adr,
3948                             Node* oop_store,
3949                             uint oop_alias_idx,
3950                             Node* index,
3951                             Node* index_adr,
3952                             Node* buffer,
3953                             const TypeFunc* tf) {
3954 
3955   Node* zero  = __ ConI(0);
3956   Node* zeroX = __ ConX(0);
3957   Node* no_base = __ top();
3958   BasicType card_bt = T_BYTE;
3959   // Smash zero into card. MUST BE ORDERED WRT TO STORE
3960   __ storeCM(__ ctrl(), card_adr, zero, oop_store, oop_alias_idx, card_bt, Compile::AliasIdxRaw);
3961 
3962   //  Now do the queue work
3963   __ if_then(index, BoolTest::ne, zeroX); {
3964 
3965     Node* next_index = _gvn.transform(new (C) SubXNode(index, __ ConX(sizeof(intptr_t))));
3966     Node* log_addr = __ AddP(no_base, buffer, next_index);
3967 
3968     // Order, see storeCM.
3969     __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw, MemNode::unordered);
3970     __ store(__ ctrl(), index_adr, next_index, TypeX_X->basic_type(), Compile::AliasIdxRaw, MemNode::unordered);
3971 
3972   } __ else_(); {
3973     __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), "g1_wb_post", card_adr, __ thread());
3974   } __ end_if();
3975 
3976 }
3977 
3978 void GraphKit::g1_write_barrier_post(Node* oop_store,
3979                                      Node* obj,
3980                                      Node* adr,
3981                                      uint alias_idx,
3982                                      Node* val,
3983                                      BasicType bt,
3984                                      bool use_precise) {
3985   // If we are writing a NULL then we need no post barrier
3986 
3987   if (val != NULL && val->is_Con() && val->bottom_type() == TypePtr::NULL_PTR) {
3988     // Must be NULL
3989     const Type* t = val->bottom_type();
3990     assert(t == Type::TOP || t == TypePtr::NULL_PTR, "must be NULL");
3991     // No post barrier if writing NULLx
3992     return;
3993   }
3994 
3995   if (!use_precise) {
3996     // All card marks for a (non-array) instance are in one place:
3997     adr = obj;
3998   }
3999   // (Else it's an array (or unknown), and we want more precise card marks.)
4000   assert(adr != NULL, "");
4001 
4002   IdealKit ideal(this, true);
4003 
4004   Node* tls = __ thread(); // ThreadLocalStorage
4005 
4006   Node* no_base = __ top();
4007   float likely  = PROB_LIKELY(0.999);
4008   float unlikely  = PROB_UNLIKELY(0.999);
4009   Node* young_card = __ ConI((jint)G1SATBCardTableModRefBS::g1_young_card_val());
4010   Node* dirty_card = __ ConI((jint)CardTableModRefBS::dirty_card_val());
4011   Node* zeroX = __ ConX(0);
4012 
4013   // Get the alias_index for raw card-mark memory
4014   const TypePtr* card_type = TypeRawPtr::BOTTOM;
4015 
4016   const TypeFunc *tf = OptoRuntime::g1_wb_post_Type();
4017 
4018   // Offsets into the thread
4019   const int index_offset  = in_bytes(JavaThread::dirty_card_queue_offset() +
4020                                      PtrQueue::byte_offset_of_index());
4021   const int buffer_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
4022                                      PtrQueue::byte_offset_of_buf());
4023 
4024   // Pointers into the thread
4025 
4026   Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
4027   Node* index_adr =  __ AddP(no_base, tls, __ ConX(index_offset));
4028 
4029   // Now some values
4030   // Use ctrl to avoid hoisting these values past a safepoint, which could
4031   // potentially reset these fields in the JavaThread.
4032   Node* index  = __ load(__ ctrl(), index_adr, TypeX_X, TypeX_X->basic_type(), Compile::AliasIdxRaw);
4033   Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4034 
4035   // Convert the store obj pointer to an int prior to doing math on it
4036   // Must use ctrl to prevent "integerized oop" existing across safepoint
4037   Node* cast =  __ CastPX(__ ctrl(), adr);
4038 
4039   // Divide pointer by card size
4040   Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
4041 
4042   // Combine card table base and card offset
4043   Node* card_adr = __ AddP(no_base, byte_map_base_node(), card_offset );
4044 
4045   // If we know the value being stored does it cross regions?
4046 
4047   if (val != NULL) {
4048     // Does the store cause us to cross regions?
4049 
4050     // Should be able to do an unsigned compare of region_size instead of
4051     // and extra shift. Do we have an unsigned compare??
4052     // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes);
4053     Node* xor_res =  __ URShiftX ( __ XorX( cast,  __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes));
4054 
4055     // if (xor_res == 0) same region so skip
4056     __ if_then(xor_res, BoolTest::ne, zeroX); {
4057 
4058       // No barrier if we are storing a NULL
4059       __ if_then(val, BoolTest::ne, null(), unlikely); {
4060 
4061         // Ok must mark the card if not already dirty
4062 
4063         // load the original value of the card
4064         Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4065 
4066         __ if_then(card_val, BoolTest::ne, young_card); {
4067           sync_kit(ideal);
4068           // Use Op_MemBarVolatile to achieve the effect of a StoreLoad barrier.
4069           insert_mem_bar(Op_MemBarVolatile, oop_store);
4070           __ sync_kit(this);
4071 
4072           Node* card_val_reload = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4073           __ if_then(card_val_reload, BoolTest::ne, dirty_card); {
4074             g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4075           } __ end_if();
4076         } __ end_if();
4077       } __ end_if();
4078     } __ end_if();
4079   } else {
4080     // Object.clone() instrinsic uses this path.
4081     g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4082   }
4083 
4084   // Final sync IdealKit and GraphKit.
4085   final_sync(ideal);
4086 }
4087 #undef __
4088 
4089 
4090 
4091 Node* GraphKit::load_String_offset(Node* ctrl, Node* str) {
4092   if (java_lang_String::has_offset_field()) {
4093     int offset_offset = java_lang_String::offset_offset_in_bytes();
4094     const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4095                                                        false, NULL, 0);
4096     const TypePtr* offset_field_type = string_type->add_offset(offset_offset);
4097     int offset_field_idx = C->get_alias_index(offset_field_type);
4098     return make_load(ctrl,
4099                      basic_plus_adr(str, str, offset_offset),
4100                      TypeInt::INT, T_INT, offset_field_idx, MemNode::unordered);
4101   } else {
4102     return intcon(0);
4103   }
4104 }
4105 
4106 Node* GraphKit::load_String_length(Node* ctrl, Node* str) {
4107   if (java_lang_String::has_count_field()) {
4108     int count_offset = java_lang_String::count_offset_in_bytes();
4109     const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4110                                                        false, NULL, 0);
4111     const TypePtr* count_field_type = string_type->add_offset(count_offset);
4112     int count_field_idx = C->get_alias_index(count_field_type);
4113     return make_load(ctrl,
4114                      basic_plus_adr(str, str, count_offset),
4115                      TypeInt::INT, T_INT, count_field_idx, MemNode::unordered);
4116   } else {
4117     return load_array_length(load_String_value(ctrl, str));
4118   }
4119 }
4120 
4121 Node* GraphKit::load_String_value(Node* ctrl, Node* str) {
4122   int value_offset = java_lang_String::value_offset_in_bytes();
4123   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4124                                                      false, NULL, 0);
4125   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4126   const TypeAryPtr*  value_type = TypeAryPtr::make(TypePtr::NotNull,
4127                                                    TypeAry::make(TypeInt::CHAR,TypeInt::POS),
4128                                                    ciTypeArrayKlass::make(T_CHAR), true, 0);
4129   int value_field_idx = C->get_alias_index(value_field_type);
4130   Node* load = make_load(ctrl, basic_plus_adr(str, str, value_offset),
4131                          value_type, T_OBJECT, value_field_idx, MemNode::unordered);
4132   // String.value field is known to be @Stable.
4133   if (UseImplicitStableValues) {
4134     load = cast_array_to_stable(load, value_type);
4135   }
4136   return load;
4137 }
4138 
4139 void GraphKit::store_String_offset(Node* ctrl, Node* str, Node* value) {
4140   int offset_offset = java_lang_String::offset_offset_in_bytes();
4141   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4142                                                      false, NULL, 0);
4143   const TypePtr* offset_field_type = string_type->add_offset(offset_offset);
4144   int offset_field_idx = C->get_alias_index(offset_field_type);
4145   store_to_memory(ctrl, basic_plus_adr(str, offset_offset),
4146                   value, T_INT, offset_field_idx, MemNode::unordered);
4147 }
4148 
4149 void GraphKit::store_String_value(Node* ctrl, Node* str, Node* value) {
4150   int value_offset = java_lang_String::value_offset_in_bytes();
4151   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4152                                                      false, NULL, 0);
4153   const TypePtr* value_field_type = string_type->add_offset(value_offset);
4154 
4155   store_oop_to_object(ctrl, str,  basic_plus_adr(str, value_offset), value_field_type,
4156       value, TypeAryPtr::CHARS, T_OBJECT, MemNode::unordered);
4157 }
4158 
4159 void GraphKit::store_String_length(Node* ctrl, Node* str, Node* value) {
4160   int count_offset = java_lang_String::count_offset_in_bytes();
4161   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4162                                                      false, NULL, 0);
4163   const TypePtr* count_field_type = string_type->add_offset(count_offset);
4164   int count_field_idx = C->get_alias_index(count_field_type);
4165   store_to_memory(ctrl, basic_plus_adr(str, count_offset),
4166                   value, T_INT, count_field_idx, MemNode::unordered);
4167 }
4168 
4169 Node* GraphKit::cast_array_to_stable(Node* ary, const TypeAryPtr* ary_type) {
4170   // Reify the property as a CastPP node in Ideal graph to comply with monotonicity
4171   // assumption of CCP analysis.
4172   return _gvn.transform(new(C) CastPPNode(ary, ary_type->cast_to_stable(true)));
4173 }