1 /*
   2  * Copyright (c) 1998, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "ci/ciMethodData.hpp"
  27 #include "classfile/systemDictionary.hpp"
  28 #include "classfile/vmSymbols.hpp"
  29 #include "compiler/compileLog.hpp"
  30 #include "interpreter/linkResolver.hpp"
  31 #include "memory/resourceArea.hpp"
  32 #include "memory/universe.hpp"
  33 #include "oops/oop.inline.hpp"
  34 #include "opto/addnode.hpp"
  35 #include "opto/castnode.hpp"
  36 #include "opto/convertnode.hpp"
  37 #include "opto/divnode.hpp"
  38 #include "opto/idealGraphPrinter.hpp"
  39 #include "opto/idealKit.hpp"
  40 #include "opto/matcher.hpp"
  41 #include "opto/memnode.hpp"
  42 #include "opto/mulnode.hpp"
  43 #include "opto/opaquenode.hpp"
  44 #include "opto/parse.hpp"
  45 #include "opto/runtime.hpp"
  46 #include "opto/valuetypenode.hpp"
  47 #include "runtime/deoptimization.hpp"
  48 #include "runtime/sharedRuntime.hpp"
  49 
  50 #ifndef PRODUCT
  51 extern int explicit_null_checks_inserted,
  52            explicit_null_checks_elided;
  53 #endif
  54 
  55 //---------------------------------array_load----------------------------------
  56 void Parse::array_load(BasicType bt) {
  57   const Type* elemtype = Type::TOP;
  58   Node* adr = array_addressing(bt, 0, &elemtype);
  59   if (stopped())  return;     // guaranteed null or range check
  60 
  61   Node* idx = pop();
  62   Node* ary = pop();
  63 
  64   // Handle value type arrays
  65   const TypeOopPtr* elemptr = elemtype->make_oopptr();
  66   const TypeAryPtr* ary_t = _gvn.type(ary)->is_aryptr();
  67   if (elemtype->isa_valuetype() != NULL) {
  68     // Load from flattened value type array
  69     ciValueKlass* vk = elemtype->is_valuetype()->value_klass();
  70     Node* vt = ValueTypeNode::make_from_flattened(this, vk, ary, adr);
  71     push(vt);
  72     return;
  73   } else if (elemptr != NULL && elemptr->is_valuetypeptr()) {
  74     // Load from non-flattened value type array (elements can never be null)
  75     bt = T_VALUETYPE;
  76     assert(elemptr->meet(TypePtr::NULL_PTR) != elemptr, "value type array elements should never be null");
  77   } else if (ValueArrayFlatten && elemptr != NULL && elemptr->can_be_value_type() &&
  78              !ary_t->klass_is_exact()) {
  79     // Cannot statically determine if array is flattened, emit runtime check
  80     IdealKit ideal(this);
  81     IdealVariable res(ideal);
  82     ideal.declarations_done();
  83     Node* kls = load_object_klass(ary);
  84     Node* tag = load_lh_array_tag(kls);
  85     ideal.if_then(tag, BoolTest::ne, intcon(Klass::_lh_array_tag_vt_value)); {
  86       // non flattened
  87       sync_kit(ideal);
  88       const TypeAryPtr* adr_type = TypeAryPtr::get_array_body_type(bt);
  89       elemtype = ary_t->elem()->make_oopptr();
  90       Node* ld = access_load_at(ary, adr, adr_type, elemtype, bt,
  91                                 IN_HEAP | IS_ARRAY | C2_CONTROL_DEPENDENT_LOAD);
  92       ideal.sync_kit(this);
  93       ideal.set(res, ld);
  94     } ideal.else_(); {
  95       // flattened
  96       sync_kit(ideal);
  97       Node* k_adr = basic_plus_adr(kls, in_bytes(ArrayKlass::element_klass_offset()));
  98       Node* elem_klass = _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), k_adr, TypeInstPtr::KLASS));
  99       Node* obj_size  = NULL;
 100       kill_dead_locals();
 101       inc_sp(2);
 102       Node* alloc_obj = new_instance(elem_klass, NULL, &obj_size, /*deoptimize_on_exception=*/true);
 103       dec_sp(2);
 104 
 105       AllocateNode* alloc = AllocateNode::Ideal_allocation(alloc_obj, &_gvn);
 106       assert(alloc->maybe_set_complete(&_gvn), "");
 107       alloc->initialization()->set_complete_with_arraycopy();
 108       BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 109       // Unknown value type so might have reference fields
 110       if (!bs->array_copy_requires_gc_barriers(false, T_OBJECT, false, BarrierSetC2::Parsing)) {
 111         int base_off = sizeof(instanceOopDesc);
 112         Node* dst_base = basic_plus_adr(alloc_obj, base_off);
 113         Node* countx = obj_size;
 114         countx = _gvn.transform(new SubXNode(countx, MakeConX(base_off)));
 115         countx = _gvn.transform(new URShiftXNode(countx, intcon(LogBytesPerLong)));
 116 
 117         assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
 118         Node* lhp = basic_plus_adr(kls, in_bytes(Klass::layout_helper_offset()));
 119         Node* elem_shift = make_load(NULL, lhp, TypeInt::INT, T_INT, MemNode::unordered);
 120         uint header = arrayOopDesc::base_offset_in_bytes(T_VALUETYPE);
 121         Node* base  = basic_plus_adr(ary, header);
 122         idx = Compile::conv_I2X_index(&_gvn, idx, TypeInt::POS, control());
 123         Node* scale = _gvn.transform(new LShiftXNode(idx, elem_shift));
 124         Node* adr = basic_plus_adr(ary, base, scale);
 125 
 126         access_clone(adr, dst_base, countx, false);
 127       } else {
 128         ideal.sync_kit(this);
 129         ideal.make_leaf_call(OptoRuntime::load_unknown_value_Type(),
 130                              CAST_FROM_FN_PTR(address, OptoRuntime::load_unknown_value),
 131                              "load_unknown_value",
 132                              ary, idx, alloc_obj);
 133         sync_kit(ideal);
 134       }
 135 
 136       insert_mem_bar(Op_MemBarStoreStore, alloc->proj_out_or_null(AllocateNode::RawAddress));
 137 
 138       ideal.sync_kit(this);
 139       ideal.set(res, alloc_obj);
 140     } ideal.end_if();
 141     sync_kit(ideal);
 142     push_node(bt, ideal.value(res));
 143     return;
 144   }
 145 
 146   if (elemtype == TypeInt::BOOL) {
 147     bt = T_BOOLEAN;
 148   } else if (bt == T_OBJECT) {
 149     elemtype = ary_t->elem()->make_oopptr();
 150   }
 151 
 152   const TypeAryPtr* adr_type = TypeAryPtr::get_array_body_type(bt);
 153   Node* ld = access_load_at(ary, adr, adr_type, elemtype, bt,
 154                             IN_HEAP | IS_ARRAY | C2_CONTROL_DEPENDENT_LOAD);
 155   if (bt == T_VALUETYPE) {
 156     // Loading a non-flattened (but flattenable) value type from an array
 157     assert(!gvn().type(ld)->maybe_null(), "value type array elements should never be null");
 158     if (elemptr->value_klass()->is_scalarizable()) {
 159       ld = ValueTypeNode::make_from_oop(this, ld, elemptr->value_klass());
 160     }
 161   }
 162 
 163   push_node(bt, ld);
 164 }
 165 
 166 
 167 //--------------------------------array_store----------------------------------
 168 void Parse::array_store(BasicType bt) {
 169   const Type* elemtype = Type::TOP;
 170   Node* adr = array_addressing(bt, type2size[bt], &elemtype);
 171   if (stopped())  return;     // guaranteed null or range check
 172   Node* cast_val = NULL;
 173   if (bt == T_OBJECT) {
 174     cast_val = array_store_check();
 175     if (stopped()) return;
 176   }
 177   Node* val = pop_node(bt); // Value to store
 178   Node* idx = pop();        // Index in the array
 179   Node* ary = pop();        // The array itself
 180 
 181   const TypeAryPtr* ary_t = _gvn.type(ary)->is_aryptr();
 182   if (bt == T_OBJECT) {
 183     const TypeOopPtr* elemptr = elemtype->make_oopptr();
 184     const Type* val_t = _gvn.type(val);
 185     if (elemtype->isa_valuetype() != NULL) {
 186       // Store to flattened value type array
 187       if (!cast_val->is_ValueType()) {
 188         inc_sp(3);
 189         cast_val = null_check(cast_val);
 190         if (stopped()) return;
 191         dec_sp(3);
 192         cast_val = ValueTypeNode::make_from_oop(this, cast_val, elemtype->is_valuetype()->value_klass());
 193       }
 194       cast_val->as_ValueType()->store_flattened(this, ary, adr);
 195       return;
 196     } else if (elemptr->is_valuetypeptr()) {
 197       // Store to non-flattened value type array
 198       if (!cast_val->is_ValueType()) {
 199         // Can not store null into a value type array
 200         inc_sp(3);
 201         cast_val = null_check(cast_val);
 202         if (stopped()) return;
 203         dec_sp(3);
 204       }
 205     } else if (elemptr->can_be_value_type() && !ary_t->klass_is_exact() &&
 206                (val->is_ValueType() || val_t == TypePtr::NULL_PTR || val_t->is_oopptr()->can_be_value_type())) {
 207       if (ValueArrayFlatten) {
 208         IdealKit ideal(this);
 209         Node* kls = load_object_klass(ary);
 210         Node* layout_val = load_lh_array_tag(kls);
 211         ideal.if_then(layout_val, BoolTest::ne, intcon(Klass::_lh_array_tag_vt_value)); {
 212           // non flattened
 213           sync_kit(ideal);
 214 
 215           if (!val->is_ValueType() && TypePtr::NULL_PTR->higher_equal(val_t)) {
 216             gen_value_type_array_guard(ary, val, 3);
 217           }
 218 
 219           const TypeAryPtr* adr_type = TypeAryPtr::get_array_body_type(bt);
 220           elemtype = ary_t->elem()->make_oopptr();
 221           access_store_at(ary, adr, adr_type, val, elemtype, bt, MO_UNORDERED | IN_HEAP | IS_ARRAY);
 222           ideal.sync_kit(this);
 223         } ideal.else_(); {
 224           // flattened
 225           // Object/interface array must be flattened, cast it
 226           if (val->is_ValueType()) {
 227             sync_kit(ideal);
 228             const TypeValueType* vt = _gvn.type(val)->is_valuetype();
 229             ciArrayKlass* array_klass = ciArrayKlass::make(vt->value_klass());
 230             const TypeAryPtr* arytype = TypeOopPtr::make_from_klass(array_klass)->isa_aryptr();
 231             ary = _gvn.transform(new CheckCastPPNode(control(), ary, arytype));
 232             adr = array_element_address(ary, idx, T_OBJECT, arytype->size(), control());
 233             val->as_ValueType()->store_flattened(this, ary, adr);
 234             ideal.sync_kit(this);
 235           } else {
 236             if (TypePtr::NULL_PTR->higher_equal(val_t)) {
 237               sync_kit(ideal);
 238               Node* null_ctl = top();
 239               val = null_check_oop(val, &null_ctl);
 240               if (null_ctl != top()) {
 241                 PreserveJVMState pjvms(this);
 242                 inc_sp(3);
 243                 set_control(null_ctl);
 244                 uncommon_trap(Deoptimization::Reason_null_check, Deoptimization::Action_none);
 245                 dec_sp(3);
 246               }
 247               ideal.sync_kit(this);
 248             }
 249             if (!ideal.ctrl()->is_top()) {
 250               ideal.make_leaf_call(OptoRuntime::store_unknown_value_Type(),
 251                                    CAST_FROM_FN_PTR(address, OptoRuntime::store_unknown_value),
 252                                    "store_unknown_value",
 253                                    val, ary, idx);
 254             }
 255           }
 256         } ideal.end_if();
 257         sync_kit(ideal);
 258         return;
 259       } else {
 260         if (!val->is_ValueType() && TypePtr::NULL_PTR->higher_equal(val_t)) {
 261           gen_value_type_array_guard(ary, val, 3);
 262         }
 263       }
 264     }
 265   }
 266 
 267   if (elemtype == TypeInt::BOOL) {
 268     bt = T_BOOLEAN;
 269   } else if (bt == T_OBJECT) {
 270     elemtype = ary_t->elem()->make_oopptr();
 271   }
 272 
 273   const TypeAryPtr* adr_type = TypeAryPtr::get_array_body_type(bt);
 274 
 275   access_store_at(ary, adr, adr_type, val, elemtype, bt, MO_UNORDERED | IN_HEAP | IS_ARRAY);
 276 }
 277 
 278 
 279 //------------------------------array_addressing-------------------------------
 280 // Pull array and index from the stack.  Compute pointer-to-element.
 281 Node* Parse::array_addressing(BasicType type, int vals, const Type* *result2) {
 282   Node *idx   = peek(0+vals);   // Get from stack without popping
 283   Node *ary   = peek(1+vals);   // in case of exception
 284 
 285   // Null check the array base, with correct stack contents
 286   ary = null_check(ary, T_ARRAY);
 287   // Compile-time detect of null-exception?
 288   if (stopped())  return top();
 289 
 290   const TypeAryPtr* arytype  = _gvn.type(ary)->is_aryptr();
 291   const TypeInt*    sizetype = arytype->size();
 292   const Type*       elemtype = arytype->elem();
 293 
 294   if (UseUniqueSubclasses && result2 != NULL) {
 295     const Type* el = elemtype->make_ptr();
 296     if (el && el->isa_instptr()) {
 297       const TypeInstPtr* toop = el->is_instptr();
 298       if (toop->klass()->as_instance_klass()->unique_concrete_subklass()) {
 299         // If we load from "AbstractClass[]" we must see "ConcreteSubClass".
 300         const Type* subklass = Type::get_const_type(toop->klass());
 301         elemtype = subklass->join_speculative(el);
 302       }
 303     }
 304   }
 305 
 306   // Check for big class initializers with all constant offsets
 307   // feeding into a known-size array.
 308   const TypeInt* idxtype = _gvn.type(idx)->is_int();
 309   // See if the highest idx value is less than the lowest array bound,
 310   // and if the idx value cannot be negative:
 311   bool need_range_check = true;
 312   if (idxtype->_hi < sizetype->_lo && idxtype->_lo >= 0) {
 313     need_range_check = false;
 314     if (C->log() != NULL)   C->log()->elem("observe that='!need_range_check'");
 315   }
 316 
 317   ciKlass * arytype_klass = arytype->klass();
 318   if ((arytype_klass != NULL) && (!arytype_klass->is_loaded())) {
 319     // Only fails for some -Xcomp runs
 320     // The class is unloaded.  We have to run this bytecode in the interpreter.
 321     uncommon_trap(Deoptimization::Reason_unloaded,
 322                   Deoptimization::Action_reinterpret,
 323                   arytype->klass(), "!loaded array");
 324     return top();
 325   }
 326 
 327   // Do the range check
 328   if (GenerateRangeChecks && need_range_check) {
 329     Node* tst;
 330     if (sizetype->_hi <= 0) {
 331       // The greatest array bound is negative, so we can conclude that we're
 332       // compiling unreachable code, but the unsigned compare trick used below
 333       // only works with non-negative lengths.  Instead, hack "tst" to be zero so
 334       // the uncommon_trap path will always be taken.
 335       tst = _gvn.intcon(0);
 336     } else {
 337       // Range is constant in array-oop, so we can use the original state of mem
 338       Node* len = load_array_length(ary);
 339 
 340       // Test length vs index (standard trick using unsigned compare)
 341       Node* chk = _gvn.transform( new CmpUNode(idx, len) );
 342       BoolTest::mask btest = BoolTest::lt;
 343       tst = _gvn.transform( new BoolNode(chk, btest) );
 344     }
 345     RangeCheckNode* rc = new RangeCheckNode(control(), tst, PROB_MAX, COUNT_UNKNOWN);
 346     _gvn.set_type(rc, rc->Value(&_gvn));
 347     if (!tst->is_Con()) {
 348       record_for_igvn(rc);
 349     }
 350     set_control(_gvn.transform(new IfTrueNode(rc)));
 351     // Branch to failure if out of bounds
 352     {
 353       PreserveJVMState pjvms(this);
 354       set_control(_gvn.transform(new IfFalseNode(rc)));
 355       if (C->allow_range_check_smearing()) {
 356         // Do not use builtin_throw, since range checks are sometimes
 357         // made more stringent by an optimistic transformation.
 358         // This creates "tentative" range checks at this point,
 359         // which are not guaranteed to throw exceptions.
 360         // See IfNode::Ideal, is_range_check, adjust_check.
 361         uncommon_trap(Deoptimization::Reason_range_check,
 362                       Deoptimization::Action_make_not_entrant,
 363                       NULL, "range_check");
 364       } else {
 365         // If we have already recompiled with the range-check-widening
 366         // heroic optimization turned off, then we must really be throwing
 367         // range check exceptions.
 368         builtin_throw(Deoptimization::Reason_range_check, idx);
 369       }
 370     }
 371   }
 372   // Check for always knowing you are throwing a range-check exception
 373   if (stopped())  return top();
 374 
 375   // Make array address computation control dependent to prevent it
 376   // from floating above the range check during loop optimizations.
 377   Node* ptr = array_element_address(ary, idx, type, sizetype, control());
 378 
 379   if (result2 != NULL)  *result2 = elemtype;
 380 
 381   assert(ptr != top(), "top should go hand-in-hand with stopped");
 382 
 383   return ptr;
 384 }
 385 
 386 
 387 // returns IfNode
 388 IfNode* Parse::jump_if_fork_int(Node* a, Node* b, BoolTest::mask mask, float prob, float cnt) {
 389   Node   *cmp = _gvn.transform(new CmpINode(a, b)); // two cases: shiftcount > 32 and shiftcount <= 32
 390   Node   *tst = _gvn.transform(new BoolNode(cmp, mask));
 391   IfNode *iff = create_and_map_if(control(), tst, prob, cnt);
 392   return iff;
 393 }
 394 
 395 // return Region node
 396 Node* Parse::jump_if_join(Node* iffalse, Node* iftrue) {
 397   Node *region  = new RegionNode(3); // 2 results
 398   record_for_igvn(region);
 399   region->init_req(1, iffalse);
 400   region->init_req(2, iftrue );
 401   _gvn.set_type(region, Type::CONTROL);
 402   region = _gvn.transform(region);
 403   set_control (region);
 404   return region;
 405 }
 406 
 407 // sentinel value for the target bci to mark never taken branches
 408 // (according to profiling)
 409 static const int never_reached = INT_MAX;
 410 
 411 //------------------------------helper for tableswitch-------------------------
 412 void Parse::jump_if_true_fork(IfNode *iff, int dest_bci_if_true, int prof_table_index, bool unc) {
 413   // True branch, use existing map info
 414   { PreserveJVMState pjvms(this);
 415     Node *iftrue  = _gvn.transform( new IfTrueNode (iff) );
 416     set_control( iftrue );
 417     if (unc) {
 418       repush_if_args();
 419       uncommon_trap(Deoptimization::Reason_unstable_if,
 420                     Deoptimization::Action_reinterpret,
 421                     NULL,
 422                     "taken always");
 423     } else {
 424       assert(dest_bci_if_true != never_reached, "inconsistent dest");
 425       profile_switch_case(prof_table_index);
 426       merge_new_path(dest_bci_if_true);
 427     }
 428   }
 429 
 430   // False branch
 431   Node *iffalse = _gvn.transform( new IfFalseNode(iff) );
 432   set_control( iffalse );
 433 }
 434 
 435 void Parse::jump_if_false_fork(IfNode *iff, int dest_bci_if_true, int prof_table_index, bool unc) {
 436   // True branch, use existing map info
 437   { PreserveJVMState pjvms(this);
 438     Node *iffalse  = _gvn.transform( new IfFalseNode (iff) );
 439     set_control( iffalse );
 440     if (unc) {
 441       repush_if_args();
 442       uncommon_trap(Deoptimization::Reason_unstable_if,
 443                     Deoptimization::Action_reinterpret,
 444                     NULL,
 445                     "taken never");
 446     } else {
 447       assert(dest_bci_if_true != never_reached, "inconsistent dest");
 448       profile_switch_case(prof_table_index);
 449       merge_new_path(dest_bci_if_true);
 450     }
 451   }
 452 
 453   // False branch
 454   Node *iftrue = _gvn.transform( new IfTrueNode(iff) );
 455   set_control( iftrue );
 456 }
 457 
 458 void Parse::jump_if_always_fork(int dest_bci, int prof_table_index, bool unc) {
 459   // False branch, use existing map and control()
 460   if (unc) {
 461     repush_if_args();
 462     uncommon_trap(Deoptimization::Reason_unstable_if,
 463                   Deoptimization::Action_reinterpret,
 464                   NULL,
 465                   "taken never");
 466   } else {
 467     assert(dest_bci != never_reached, "inconsistent dest");
 468     profile_switch_case(prof_table_index);
 469     merge_new_path(dest_bci);
 470   }
 471 }
 472 
 473 
 474 extern "C" {
 475   static int jint_cmp(const void *i, const void *j) {
 476     int a = *(jint *)i;
 477     int b = *(jint *)j;
 478     return a > b ? 1 : a < b ? -1 : 0;
 479   }
 480 }
 481 
 482 
 483 // Default value for methodData switch indexing. Must be a negative value to avoid
 484 // conflict with any legal switch index.
 485 #define NullTableIndex -1
 486 
 487 class SwitchRange : public StackObj {
 488   // a range of integers coupled with a bci destination
 489   jint _lo;                     // inclusive lower limit
 490   jint _hi;                     // inclusive upper limit
 491   int _dest;
 492   int _table_index;             // index into method data table
 493   float _cnt;                   // how many times this range was hit according to profiling
 494 
 495 public:
 496   jint lo() const              { return _lo;   }
 497   jint hi() const              { return _hi;   }
 498   int  dest() const            { return _dest; }
 499   int  table_index() const     { return _table_index; }
 500   bool is_singleton() const    { return _lo == _hi; }
 501   float cnt() const            { return _cnt; }
 502 
 503   void setRange(jint lo, jint hi, int dest, int table_index, float cnt) {
 504     assert(lo <= hi, "must be a non-empty range");
 505     _lo = lo, _hi = hi; _dest = dest; _table_index = table_index; _cnt = cnt;
 506     assert(_cnt >= 0, "");
 507   }
 508   bool adjoinRange(jint lo, jint hi, int dest, int table_index, float cnt, bool trim_ranges) {
 509     assert(lo <= hi, "must be a non-empty range");
 510     if (lo == _hi+1 && table_index == _table_index) {
 511       // see merge_ranges() comment below
 512       if (trim_ranges) {
 513         if (cnt == 0) {
 514           if (_cnt != 0) {
 515             return false;
 516           }
 517           if (dest != _dest) {
 518             _dest = never_reached;
 519           }
 520         } else {
 521           if (_cnt == 0) {
 522             return false;
 523           }
 524           if (dest != _dest) {
 525             return false;
 526           }
 527         }
 528       } else {
 529         if (dest != _dest) {
 530           return false;
 531         }
 532       }
 533       _hi = hi;
 534       _cnt += cnt;
 535       return true;
 536     }
 537     return false;
 538   }
 539 
 540   void set (jint value, int dest, int table_index, float cnt) {
 541     setRange(value, value, dest, table_index, cnt);
 542   }
 543   bool adjoin(jint value, int dest, int table_index, float cnt, bool trim_ranges) {
 544     return adjoinRange(value, value, dest, table_index, cnt, trim_ranges);
 545   }
 546   bool adjoin(SwitchRange& other) {
 547     return adjoinRange(other._lo, other._hi, other._dest, other._table_index, other._cnt, false);
 548   }
 549 
 550   void print() {
 551     if (is_singleton())
 552       tty->print(" {%d}=>%d (cnt=%f)", lo(), dest(), cnt());
 553     else if (lo() == min_jint)
 554       tty->print(" {..%d}=>%d (cnt=%f)", hi(), dest(), cnt());
 555     else if (hi() == max_jint)
 556       tty->print(" {%d..}=>%d (cnt=%f)", lo(), dest(), cnt());
 557     else
 558       tty->print(" {%d..%d}=>%d (cnt=%f)", lo(), hi(), dest(), cnt());
 559   }
 560 };
 561 
 562 // We try to minimize the number of ranges and the size of the taken
 563 // ones using profiling data. When ranges are created,
 564 // SwitchRange::adjoinRange() only allows 2 adjoining ranges to merge
 565 // if both were never hit or both were hit to build longer unreached
 566 // ranges. Here, we now merge adjoining ranges with the same
 567 // destination and finally set destination of unreached ranges to the
 568 // special value never_reached because it can help minimize the number
 569 // of tests that are necessary.
 570 //
 571 // For instance:
 572 // [0, 1] to target1 sometimes taken
 573 // [1, 2] to target1 never taken
 574 // [2, 3] to target2 never taken
 575 // would lead to:
 576 // [0, 1] to target1 sometimes taken
 577 // [1, 3] never taken
 578 //
 579 // (first 2 ranges to target1 are not merged)
 580 static void merge_ranges(SwitchRange* ranges, int& rp) {
 581   if (rp == 0) {
 582     return;
 583   }
 584   int shift = 0;
 585   for (int j = 0; j < rp; j++) {
 586     SwitchRange& r1 = ranges[j-shift];
 587     SwitchRange& r2 = ranges[j+1];
 588     if (r1.adjoin(r2)) {
 589       shift++;
 590     } else if (shift > 0) {
 591       ranges[j+1-shift] = r2;
 592     }
 593   }
 594   rp -= shift;
 595   for (int j = 0; j <= rp; j++) {
 596     SwitchRange& r = ranges[j];
 597     if (r.cnt() == 0 && r.dest() != never_reached) {
 598       r.setRange(r.lo(), r.hi(), never_reached, r.table_index(), r.cnt());
 599     }
 600   }
 601 }
 602 
 603 //-------------------------------do_tableswitch--------------------------------
 604 void Parse::do_tableswitch() {
 605   Node* lookup = pop();
 606   // Get information about tableswitch
 607   int default_dest = iter().get_dest_table(0);
 608   int lo_index     = iter().get_int_table(1);
 609   int hi_index     = iter().get_int_table(2);
 610   int len          = hi_index - lo_index + 1;
 611 
 612   if (len < 1) {
 613     // If this is a backward branch, add safepoint
 614     maybe_add_safepoint(default_dest);
 615     merge(default_dest);
 616     return;
 617   }
 618 
 619   ciMethodData* methodData = method()->method_data();
 620   ciMultiBranchData* profile = NULL;
 621   if (methodData->is_mature() && UseSwitchProfiling) {
 622     ciProfileData* data = methodData->bci_to_data(bci());
 623     if (data != NULL && data->is_MultiBranchData()) {
 624       profile = (ciMultiBranchData*)data;
 625     }
 626   }
 627   bool trim_ranges = !method_data_update() && !C->too_many_traps(method(), bci(), Deoptimization::Reason_unstable_if);
 628 
 629   // generate decision tree, using trichotomy when possible
 630   int rnum = len+2;
 631   bool makes_backward_branch = false;
 632   SwitchRange* ranges = NEW_RESOURCE_ARRAY(SwitchRange, rnum);
 633   int rp = -1;
 634   if (lo_index != min_jint) {
 635     uint cnt = 1;
 636     if (profile != NULL) {
 637       cnt = profile->default_count() / (hi_index != max_jint ? 2 : 1);
 638     }
 639     ranges[++rp].setRange(min_jint, lo_index-1, default_dest, NullTableIndex, cnt);
 640   }
 641   for (int j = 0; j < len; j++) {
 642     jint match_int = lo_index+j;
 643     int  dest      = iter().get_dest_table(j+3);
 644     makes_backward_branch |= (dest <= bci());
 645     int  table_index = method_data_update() ? j : NullTableIndex;
 646     uint cnt = 1;
 647     if (profile != NULL) {
 648       cnt = profile->count_at(j);
 649     }
 650     if (rp < 0 || !ranges[rp].adjoin(match_int, dest, table_index, cnt, trim_ranges)) {
 651       ranges[++rp].set(match_int, dest, table_index, cnt);
 652     }
 653   }
 654   jint highest = lo_index+(len-1);
 655   assert(ranges[rp].hi() == highest, "");
 656   if (highest != max_jint) {
 657     uint cnt = 1;
 658     if (profile != NULL) {
 659       cnt = profile->default_count() / (lo_index != min_jint ? 2 : 1);
 660     }
 661     if (!ranges[rp].adjoinRange(highest+1, max_jint, default_dest, NullTableIndex, cnt, trim_ranges)) {
 662       ranges[++rp].setRange(highest+1, max_jint, default_dest, NullTableIndex, cnt);
 663     }
 664   }
 665   assert(rp < len+2, "not too many ranges");
 666 
 667   if (trim_ranges) {
 668     merge_ranges(ranges, rp);
 669   }
 670 
 671   // Safepoint in case if backward branch observed
 672   if( makes_backward_branch && UseLoopSafepoints )
 673     add_safepoint();
 674 
 675   jump_switch_ranges(lookup, &ranges[0], &ranges[rp]);
 676 }
 677 
 678 
 679 //------------------------------do_lookupswitch--------------------------------
 680 void Parse::do_lookupswitch() {
 681   Node *lookup = pop();         // lookup value
 682   // Get information about lookupswitch
 683   int default_dest = iter().get_dest_table(0);
 684   int len          = iter().get_int_table(1);
 685 
 686   if (len < 1) {    // If this is a backward branch, add safepoint
 687     maybe_add_safepoint(default_dest);
 688     merge(default_dest);
 689     return;
 690   }
 691 
 692   ciMethodData* methodData = method()->method_data();
 693   ciMultiBranchData* profile = NULL;
 694   if (methodData->is_mature() && UseSwitchProfiling) {
 695     ciProfileData* data = methodData->bci_to_data(bci());
 696     if (data != NULL && data->is_MultiBranchData()) {
 697       profile = (ciMultiBranchData*)data;
 698     }
 699   }
 700   bool trim_ranges = !method_data_update() && !C->too_many_traps(method(), bci(), Deoptimization::Reason_unstable_if);
 701 
 702   // generate decision tree, using trichotomy when possible
 703   jint* table = NEW_RESOURCE_ARRAY(jint, len*3);
 704   {
 705     for (int j = 0; j < len; j++) {
 706       table[3*j+0] = iter().get_int_table(2+2*j);
 707       table[3*j+1] = iter().get_dest_table(2+2*j+1);
 708       table[3*j+2] = profile == NULL ? 1 : profile->count_at(j);
 709     }
 710     qsort(table, len, 3*sizeof(table[0]), jint_cmp);
 711   }
 712 
 713   float defaults = 0;
 714   jint prev = min_jint;
 715   for (int j = 0; j < len; j++) {
 716     jint match_int = table[3*j+0];
 717     if (match_int != prev) {
 718       defaults += (float)match_int - prev;
 719     }
 720     prev = match_int+1;
 721   }
 722   if (prev-1 != max_jint) {
 723     defaults += (float)max_jint - prev + 1;
 724   }
 725   float default_cnt = 1;
 726   if (profile != NULL) {
 727     default_cnt = profile->default_count()/defaults;
 728   }
 729 
 730   int rnum = len*2+1;
 731   bool makes_backward_branch = false;
 732   SwitchRange* ranges = NEW_RESOURCE_ARRAY(SwitchRange, rnum);
 733   int rp = -1;
 734   for (int j = 0; j < len; j++) {
 735     jint match_int   = table[3*j+0];
 736     int  dest        = table[3*j+1];
 737     int  cnt         = table[3*j+2];
 738     int  next_lo     = rp < 0 ? min_jint : ranges[rp].hi()+1;
 739     int  table_index = method_data_update() ? j : NullTableIndex;
 740     makes_backward_branch |= (dest <= bci());
 741     float c = default_cnt * ((float)match_int - next_lo);
 742     if (match_int != next_lo && (rp < 0 || !ranges[rp].adjoinRange(next_lo, match_int-1, default_dest, NullTableIndex, c, trim_ranges))) {
 743       assert(default_dest != never_reached, "sentinel value for dead destinations");
 744       ranges[++rp].setRange(next_lo, match_int-1, default_dest, NullTableIndex, c);
 745     }
 746     if (rp < 0 || !ranges[rp].adjoin(match_int, dest, table_index, cnt, trim_ranges)) {
 747       assert(dest != never_reached, "sentinel value for dead destinations");
 748       ranges[++rp].set(match_int, dest, table_index, cnt);
 749     }
 750   }
 751   jint highest = table[3*(len-1)];
 752   assert(ranges[rp].hi() == highest, "");
 753   if (highest != max_jint &&
 754       !ranges[rp].adjoinRange(highest+1, max_jint, default_dest, NullTableIndex, default_cnt * ((float)max_jint - highest), trim_ranges)) {
 755     ranges[++rp].setRange(highest+1, max_jint, default_dest, NullTableIndex, default_cnt * ((float)max_jint - highest));
 756   }
 757   assert(rp < rnum, "not too many ranges");
 758 
 759   if (trim_ranges) {
 760     merge_ranges(ranges, rp);
 761   }
 762 
 763   // Safepoint in case backward branch observed
 764   if (makes_backward_branch && UseLoopSafepoints)
 765     add_safepoint();
 766 
 767   jump_switch_ranges(lookup, &ranges[0], &ranges[rp]);
 768 }
 769 
 770 static float if_prob(float taken_cnt, float total_cnt) {
 771   assert(taken_cnt <= total_cnt, "");
 772   if (total_cnt == 0) {
 773     return PROB_FAIR;
 774   }
 775   float p = taken_cnt / total_cnt;
 776   return MIN2(MAX2(p, PROB_MIN), PROB_MAX);
 777 }
 778 
 779 static float if_cnt(float cnt) {
 780   if (cnt == 0) {
 781     return COUNT_UNKNOWN;
 782   }
 783   return cnt;
 784 }
 785 
 786 static float sum_of_cnts(SwitchRange *lo, SwitchRange *hi) {
 787   float total_cnt = 0;
 788   for (SwitchRange* sr = lo; sr <= hi; sr++) {
 789     total_cnt += sr->cnt();
 790   }
 791   return total_cnt;
 792 }
 793 
 794 class SwitchRanges : public ResourceObj {
 795 public:
 796   SwitchRange* _lo;
 797   SwitchRange* _hi;
 798   SwitchRange* _mid;
 799   float _cost;
 800 
 801   enum {
 802     Start,
 803     LeftDone,
 804     RightDone,
 805     Done
 806   } _state;
 807 
 808   SwitchRanges(SwitchRange *lo, SwitchRange *hi)
 809     : _lo(lo), _hi(hi), _mid(NULL),
 810       _cost(0), _state(Start) {
 811   }
 812 
 813   SwitchRanges()
 814     : _lo(NULL), _hi(NULL), _mid(NULL),
 815       _cost(0), _state(Start) {}
 816 };
 817 
 818 // Estimate cost of performing a binary search on lo..hi
 819 static float compute_tree_cost(SwitchRange *lo, SwitchRange *hi, float total_cnt) {
 820   GrowableArray<SwitchRanges> tree;
 821   SwitchRanges root(lo, hi);
 822   tree.push(root);
 823 
 824   float cost = 0;
 825   do {
 826     SwitchRanges& r = *tree.adr_at(tree.length()-1);
 827     if (r._hi != r._lo) {
 828       if (r._mid == NULL) {
 829         float r_cnt = sum_of_cnts(r._lo, r._hi);
 830 
 831         if (r_cnt == 0) {
 832           tree.pop();
 833           cost = 0;
 834           continue;
 835         }
 836 
 837         SwitchRange* mid = NULL;
 838         mid = r._lo;
 839         for (float cnt = 0; ; ) {
 840           assert(mid <= r._hi, "out of bounds");
 841           cnt += mid->cnt();
 842           if (cnt > r_cnt / 2) {
 843             break;
 844           }
 845           mid++;
 846         }
 847         assert(mid <= r._hi, "out of bounds");
 848         r._mid = mid;
 849         r._cost = r_cnt / total_cnt;
 850       }
 851       r._cost += cost;
 852       if (r._state < SwitchRanges::LeftDone && r._mid > r._lo) {
 853         cost = 0;
 854         r._state = SwitchRanges::LeftDone;
 855         tree.push(SwitchRanges(r._lo, r._mid-1));
 856       } else if (r._state < SwitchRanges::RightDone) {
 857         cost = 0;
 858         r._state = SwitchRanges::RightDone;
 859         tree.push(SwitchRanges(r._mid == r._lo ? r._mid+1 : r._mid, r._hi));
 860       } else {
 861         tree.pop();
 862         cost = r._cost;
 863       }
 864     } else {
 865       tree.pop();
 866       cost = r._cost;
 867     }
 868   } while (tree.length() > 0);
 869 
 870 
 871   return cost;
 872 }
 873 
 874 // It sometimes pays off to test most common ranges before the binary search
 875 void Parse::linear_search_switch_ranges(Node* key_val, SwitchRange*& lo, SwitchRange*& hi) {
 876   uint nr = hi - lo + 1;
 877   float total_cnt = sum_of_cnts(lo, hi);
 878 
 879   float min = compute_tree_cost(lo, hi, total_cnt);
 880   float extra = 1;
 881   float sub = 0;
 882 
 883   SwitchRange* array1 = lo;
 884   SwitchRange* array2 = NEW_RESOURCE_ARRAY(SwitchRange, nr);
 885 
 886   SwitchRange* ranges = NULL;
 887 
 888   while (nr >= 2) {
 889     assert(lo == array1 || lo == array2, "one the 2 already allocated arrays");
 890     ranges = (lo == array1) ? array2 : array1;
 891 
 892     // Find highest frequency range
 893     SwitchRange* candidate = lo;
 894     for (SwitchRange* sr = lo+1; sr <= hi; sr++) {
 895       if (sr->cnt() > candidate->cnt()) {
 896         candidate = sr;
 897       }
 898     }
 899     SwitchRange most_freq = *candidate;
 900     if (most_freq.cnt() == 0) {
 901       break;
 902     }
 903 
 904     // Copy remaining ranges into another array
 905     int shift = 0;
 906     for (uint i = 0; i < nr; i++) {
 907       SwitchRange* sr = &lo[i];
 908       if (sr != candidate) {
 909         ranges[i-shift] = *sr;
 910       } else {
 911         shift++;
 912         if (i > 0 && i < nr-1) {
 913           SwitchRange prev = lo[i-1];
 914           prev.setRange(prev.lo(), sr->hi(), prev.dest(), prev.table_index(), prev.cnt());
 915           if (prev.adjoin(lo[i+1])) {
 916             shift++;
 917             i++;
 918           }
 919           ranges[i-shift] = prev;
 920         }
 921       }
 922     }
 923     nr -= shift;
 924 
 925     // Evaluate cost of testing the most common range and performing a
 926     // binary search on the other ranges
 927     float cost = extra + compute_tree_cost(&ranges[0], &ranges[nr-1], total_cnt);
 928     if (cost >= min) {
 929       break;
 930     }
 931     // swap arrays
 932     lo = &ranges[0];
 933     hi = &ranges[nr-1];
 934 
 935     // It pays off: emit the test for the most common range
 936     assert(most_freq.cnt() > 0, "must be taken");
 937     Node* val = _gvn.transform(new SubINode(key_val, _gvn.intcon(most_freq.lo())));
 938     Node* cmp = _gvn.transform(new CmpUNode(val, _gvn.intcon(most_freq.hi() - most_freq.lo())));
 939     Node* tst = _gvn.transform(new BoolNode(cmp, BoolTest::le));
 940     IfNode* iff = create_and_map_if(control(), tst, if_prob(most_freq.cnt(), total_cnt), if_cnt(most_freq.cnt()));
 941     jump_if_true_fork(iff, most_freq.dest(), most_freq.table_index(), false);
 942 
 943     sub += most_freq.cnt() / total_cnt;
 944     extra += 1 - sub;
 945     min = cost;
 946   }
 947 }
 948 
 949 //----------------------------create_jump_tables-------------------------------
 950 bool Parse::create_jump_tables(Node* key_val, SwitchRange* lo, SwitchRange* hi) {
 951   // Are jumptables enabled
 952   if (!UseJumpTables)  return false;
 953 
 954   // Are jumptables supported
 955   if (!Matcher::has_match_rule(Op_Jump))  return false;
 956 
 957   // Don't make jump table if profiling
 958   if (method_data_update())  return false;
 959 
 960   bool trim_ranges = !C->too_many_traps(method(), bci(), Deoptimization::Reason_unstable_if);
 961 
 962   // Decide if a guard is needed to lop off big ranges at either (or
 963   // both) end(s) of the input set. We'll call this the default target
 964   // even though we can't be sure that it is the true "default".
 965 
 966   bool needs_guard = false;
 967   int default_dest;
 968   int64_t total_outlier_size = 0;
 969   int64_t hi_size = ((int64_t)hi->hi()) - ((int64_t)hi->lo()) + 1;
 970   int64_t lo_size = ((int64_t)lo->hi()) - ((int64_t)lo->lo()) + 1;
 971 
 972   if (lo->dest() == hi->dest()) {
 973     total_outlier_size = hi_size + lo_size;
 974     default_dest = lo->dest();
 975   } else if (lo_size > hi_size) {
 976     total_outlier_size = lo_size;
 977     default_dest = lo->dest();
 978   } else {
 979     total_outlier_size = hi_size;
 980     default_dest = hi->dest();
 981   }
 982 
 983   float total = sum_of_cnts(lo, hi);
 984   float cost = compute_tree_cost(lo, hi, total);
 985 
 986   // If a guard test will eliminate very sparse end ranges, then
 987   // it is worth the cost of an extra jump.
 988   float trimmed_cnt = 0;
 989   if (total_outlier_size > (MaxJumpTableSparseness * 4)) {
 990     needs_guard = true;
 991     if (default_dest == lo->dest()) {
 992       trimmed_cnt += lo->cnt();
 993       lo++;
 994     }
 995     if (default_dest == hi->dest()) {
 996       trimmed_cnt += hi->cnt();
 997       hi--;
 998     }
 999   }
1000 
1001   // Find the total number of cases and ranges
1002   int64_t num_cases = ((int64_t)hi->hi()) - ((int64_t)lo->lo()) + 1;
1003   int num_range = hi - lo + 1;
1004 
1005   // Don't create table if: too large, too small, or too sparse.
1006   if (num_cases > MaxJumpTableSize)
1007     return false;
1008   if (UseSwitchProfiling) {
1009     // MinJumpTableSize is set so with a well balanced binary tree,
1010     // when the number of ranges is MinJumpTableSize, it's cheaper to
1011     // go through a JumpNode that a tree of IfNodes. Average cost of a
1012     // tree of IfNodes with MinJumpTableSize is
1013     // log2f(MinJumpTableSize) comparisons. So if the cost computed
1014     // from profile data is less than log2f(MinJumpTableSize) then
1015     // going with the binary search is cheaper.
1016     if (cost < log2f(MinJumpTableSize)) {
1017       return false;
1018     }
1019   } else {
1020     if (num_cases < MinJumpTableSize)
1021       return false;
1022   }
1023   if (num_cases > (MaxJumpTableSparseness * num_range))
1024     return false;
1025 
1026   // Normalize table lookups to zero
1027   int lowval = lo->lo();
1028   key_val = _gvn.transform( new SubINode(key_val, _gvn.intcon(lowval)) );
1029 
1030   // Generate a guard to protect against input keyvals that aren't
1031   // in the switch domain.
1032   if (needs_guard) {
1033     Node*   size = _gvn.intcon(num_cases);
1034     Node*   cmp = _gvn.transform(new CmpUNode(key_val, size));
1035     Node*   tst = _gvn.transform(new BoolNode(cmp, BoolTest::ge));
1036     IfNode* iff = create_and_map_if(control(), tst, if_prob(trimmed_cnt, total), if_cnt(trimmed_cnt));
1037     jump_if_true_fork(iff, default_dest, NullTableIndex, trim_ranges && trimmed_cnt == 0);
1038 
1039     total -= trimmed_cnt;
1040   }
1041 
1042   // Create an ideal node JumpTable that has projections
1043   // of all possible ranges for a switch statement
1044   // The key_val input must be converted to a pointer offset and scaled.
1045   // Compare Parse::array_addressing above.
1046 
1047   // Clean the 32-bit int into a real 64-bit offset.
1048   // Otherwise, the jint value 0 might turn into an offset of 0x0800000000.
1049   const TypeInt* ikeytype = TypeInt::make(0, num_cases, Type::WidenMin);
1050   // Make I2L conversion control dependent to prevent it from
1051   // floating above the range check during loop optimizations.
1052   key_val = C->conv_I2X_index(&_gvn, key_val, ikeytype, control());
1053 
1054   // Shift the value by wordsize so we have an index into the table, rather
1055   // than a switch value
1056   Node *shiftWord = _gvn.MakeConX(wordSize);
1057   key_val = _gvn.transform( new MulXNode( key_val, shiftWord));
1058 
1059   // Create the JumpNode
1060   Arena* arena = C->comp_arena();
1061   float* probs = (float*)arena->Amalloc(sizeof(float)*num_cases);
1062   int i = 0;
1063   if (total == 0) {
1064     for (SwitchRange* r = lo; r <= hi; r++) {
1065       for (int64_t j = r->lo(); j <= r->hi(); j++, i++) {
1066         probs[i] = 1.0F / num_cases;
1067       }
1068     }
1069   } else {
1070     for (SwitchRange* r = lo; r <= hi; r++) {
1071       float prob = r->cnt()/total;
1072       for (int64_t j = r->lo(); j <= r->hi(); j++, i++) {
1073         probs[i] = prob / (r->hi() - r->lo() + 1);
1074       }
1075     }
1076   }
1077 
1078   ciMethodData* methodData = method()->method_data();
1079   ciMultiBranchData* profile = NULL;
1080   if (methodData->is_mature()) {
1081     ciProfileData* data = methodData->bci_to_data(bci());
1082     if (data != NULL && data->is_MultiBranchData()) {
1083       profile = (ciMultiBranchData*)data;
1084     }
1085   }
1086 
1087   Node* jtn = _gvn.transform(new JumpNode(control(), key_val, num_cases, probs, profile == NULL ? COUNT_UNKNOWN : total));
1088 
1089   // These are the switch destinations hanging off the jumpnode
1090   i = 0;
1091   for (SwitchRange* r = lo; r <= hi; r++) {
1092     for (int64_t j = r->lo(); j <= r->hi(); j++, i++) {
1093       Node* input = _gvn.transform(new JumpProjNode(jtn, i, r->dest(), (int)(j - lowval)));
1094       {
1095         PreserveJVMState pjvms(this);
1096         set_control(input);
1097         jump_if_always_fork(r->dest(), r->table_index(), trim_ranges && r->cnt() == 0);
1098       }
1099     }
1100   }
1101   assert(i == num_cases, "miscount of cases");
1102   stop_and_kill_map();  // no more uses for this JVMS
1103   return true;
1104 }
1105 
1106 //----------------------------jump_switch_ranges-------------------------------
1107 void Parse::jump_switch_ranges(Node* key_val, SwitchRange *lo, SwitchRange *hi, int switch_depth) {
1108   Block* switch_block = block();
1109   bool trim_ranges = !method_data_update() && !C->too_many_traps(method(), bci(), Deoptimization::Reason_unstable_if);
1110 
1111   if (switch_depth == 0) {
1112     // Do special processing for the top-level call.
1113     assert(lo->lo() == min_jint, "initial range must exhaust Type::INT");
1114     assert(hi->hi() == max_jint, "initial range must exhaust Type::INT");
1115 
1116     // Decrement pred-numbers for the unique set of nodes.
1117 #ifdef ASSERT
1118     if (!trim_ranges) {
1119       // Ensure that the block's successors are a (duplicate-free) set.
1120       int successors_counted = 0;  // block occurrences in [hi..lo]
1121       int unique_successors = switch_block->num_successors();
1122       for (int i = 0; i < unique_successors; i++) {
1123         Block* target = switch_block->successor_at(i);
1124 
1125         // Check that the set of successors is the same in both places.
1126         int successors_found = 0;
1127         for (SwitchRange* p = lo; p <= hi; p++) {
1128           if (p->dest() == target->start())  successors_found++;
1129         }
1130         assert(successors_found > 0, "successor must be known");
1131         successors_counted += successors_found;
1132       }
1133       assert(successors_counted == (hi-lo)+1, "no unexpected successors");
1134     }
1135 #endif
1136 
1137     // Maybe prune the inputs, based on the type of key_val.
1138     jint min_val = min_jint;
1139     jint max_val = max_jint;
1140     const TypeInt* ti = key_val->bottom_type()->isa_int();
1141     if (ti != NULL) {
1142       min_val = ti->_lo;
1143       max_val = ti->_hi;
1144       assert(min_val <= max_val, "invalid int type");
1145     }
1146     while (lo->hi() < min_val) {
1147       lo++;
1148     }
1149     if (lo->lo() < min_val)  {
1150       lo->setRange(min_val, lo->hi(), lo->dest(), lo->table_index(), lo->cnt());
1151     }
1152     while (hi->lo() > max_val) {
1153       hi--;
1154     }
1155     if (hi->hi() > max_val) {
1156       hi->setRange(hi->lo(), max_val, hi->dest(), hi->table_index(), hi->cnt());
1157     }
1158 
1159     linear_search_switch_ranges(key_val, lo, hi);
1160   }
1161 
1162 #ifndef PRODUCT
1163   if (switch_depth == 0) {
1164     _max_switch_depth = 0;
1165     _est_switch_depth = log2_intptr((hi-lo+1)-1)+1;
1166   }
1167 #endif
1168 
1169   assert(lo <= hi, "must be a non-empty set of ranges");
1170   if (lo == hi) {
1171     jump_if_always_fork(lo->dest(), lo->table_index(), trim_ranges && lo->cnt() == 0);
1172   } else {
1173     assert(lo->hi() == (lo+1)->lo()-1, "contiguous ranges");
1174     assert(hi->lo() == (hi-1)->hi()+1, "contiguous ranges");
1175 
1176     if (create_jump_tables(key_val, lo, hi)) return;
1177 
1178     SwitchRange* mid = NULL;
1179     float total_cnt = sum_of_cnts(lo, hi);
1180 
1181     int nr = hi - lo + 1;
1182     if (UseSwitchProfiling) {
1183       // Don't keep the binary search tree balanced: pick up mid point
1184       // that split frequencies in half.
1185       float cnt = 0;
1186       for (SwitchRange* sr = lo; sr <= hi; sr++) {
1187         cnt += sr->cnt();
1188         if (cnt >= total_cnt / 2) {
1189           mid = sr;
1190           break;
1191         }
1192       }
1193     } else {
1194       mid = lo + nr/2;
1195 
1196       // if there is an easy choice, pivot at a singleton:
1197       if (nr > 3 && !mid->is_singleton() && (mid-1)->is_singleton())  mid--;
1198 
1199       assert(lo < mid && mid <= hi, "good pivot choice");
1200       assert(nr != 2 || mid == hi,   "should pick higher of 2");
1201       assert(nr != 3 || mid == hi-1, "should pick middle of 3");
1202     }
1203 
1204 
1205     Node *test_val = _gvn.intcon(mid == lo ? mid->hi() : mid->lo());
1206 
1207     if (mid->is_singleton()) {
1208       IfNode *iff_ne = jump_if_fork_int(key_val, test_val, BoolTest::ne, 1-if_prob(mid->cnt(), total_cnt), if_cnt(mid->cnt()));
1209       jump_if_false_fork(iff_ne, mid->dest(), mid->table_index(), trim_ranges && mid->cnt() == 0);
1210 
1211       // Special Case:  If there are exactly three ranges, and the high
1212       // and low range each go to the same place, omit the "gt" test,
1213       // since it will not discriminate anything.
1214       bool eq_test_only = (hi == lo+2 && hi->dest() == lo->dest() && mid == hi-1) || mid == lo;
1215 
1216       // if there is a higher range, test for it and process it:
1217       if (mid < hi && !eq_test_only) {
1218         // two comparisons of same values--should enable 1 test for 2 branches
1219         // Use BoolTest::le instead of BoolTest::gt
1220         float cnt = sum_of_cnts(lo, mid-1);
1221         IfNode *iff_le  = jump_if_fork_int(key_val, test_val, BoolTest::le, if_prob(cnt, total_cnt), if_cnt(cnt));
1222         Node   *iftrue  = _gvn.transform( new IfTrueNode(iff_le) );
1223         Node   *iffalse = _gvn.transform( new IfFalseNode(iff_le) );
1224         { PreserveJVMState pjvms(this);
1225           set_control(iffalse);
1226           jump_switch_ranges(key_val, mid+1, hi, switch_depth+1);
1227         }
1228         set_control(iftrue);
1229       }
1230 
1231     } else {
1232       // mid is a range, not a singleton, so treat mid..hi as a unit
1233       float cnt = sum_of_cnts(mid == lo ? mid+1 : mid, hi);
1234       IfNode *iff_ge = jump_if_fork_int(key_val, test_val, mid == lo ? BoolTest::gt : BoolTest::ge, if_prob(cnt, total_cnt), if_cnt(cnt));
1235 
1236       // if there is a higher range, test for it and process it:
1237       if (mid == hi) {
1238         jump_if_true_fork(iff_ge, mid->dest(), mid->table_index(), trim_ranges && cnt == 0);
1239       } else {
1240         Node *iftrue  = _gvn.transform( new IfTrueNode(iff_ge) );
1241         Node *iffalse = _gvn.transform( new IfFalseNode(iff_ge) );
1242         { PreserveJVMState pjvms(this);
1243           set_control(iftrue);
1244           jump_switch_ranges(key_val, mid == lo ? mid+1 : mid, hi, switch_depth+1);
1245         }
1246         set_control(iffalse);
1247       }
1248     }
1249 
1250     // in any case, process the lower range
1251     if (mid == lo) {
1252       if (mid->is_singleton()) {
1253         jump_switch_ranges(key_val, lo+1, hi, switch_depth+1);
1254       } else {
1255         jump_if_always_fork(lo->dest(), lo->table_index(), trim_ranges && lo->cnt() == 0);
1256       }
1257     } else {
1258       jump_switch_ranges(key_val, lo, mid-1, switch_depth+1);
1259     }
1260   }
1261 
1262   // Decrease pred_count for each successor after all is done.
1263   if (switch_depth == 0) {
1264     int unique_successors = switch_block->num_successors();
1265     for (int i = 0; i < unique_successors; i++) {
1266       Block* target = switch_block->successor_at(i);
1267       // Throw away the pre-allocated path for each unique successor.
1268       target->next_path_num();
1269     }
1270   }
1271 
1272 #ifndef PRODUCT
1273   _max_switch_depth = MAX2(switch_depth, _max_switch_depth);
1274   if (TraceOptoParse && Verbose && WizardMode && switch_depth == 0) {
1275     SwitchRange* r;
1276     int nsing = 0;
1277     for( r = lo; r <= hi; r++ ) {
1278       if( r->is_singleton() )  nsing++;
1279     }
1280     tty->print(">>> ");
1281     _method->print_short_name();
1282     tty->print_cr(" switch decision tree");
1283     tty->print_cr("    %d ranges (%d singletons), max_depth=%d, est_depth=%d",
1284                   (int) (hi-lo+1), nsing, _max_switch_depth, _est_switch_depth);
1285     if (_max_switch_depth > _est_switch_depth) {
1286       tty->print_cr("******** BAD SWITCH DEPTH ********");
1287     }
1288     tty->print("   ");
1289     for( r = lo; r <= hi; r++ ) {
1290       r->print();
1291     }
1292     tty->cr();
1293   }
1294 #endif
1295 }
1296 
1297 void Parse::modf() {
1298   Node *f2 = pop();
1299   Node *f1 = pop();
1300   Node* c = make_runtime_call(RC_LEAF, OptoRuntime::modf_Type(),
1301                               CAST_FROM_FN_PTR(address, SharedRuntime::frem),
1302                               "frem", NULL, //no memory effects
1303                               f1, f2);
1304   Node* res = _gvn.transform(new ProjNode(c, TypeFunc::Parms + 0));
1305 
1306   push(res);
1307 }
1308 
1309 void Parse::modd() {
1310   Node *d2 = pop_pair();
1311   Node *d1 = pop_pair();
1312   Node* c = make_runtime_call(RC_LEAF, OptoRuntime::Math_DD_D_Type(),
1313                               CAST_FROM_FN_PTR(address, SharedRuntime::drem),
1314                               "drem", NULL, //no memory effects
1315                               d1, top(), d2, top());
1316   Node* res_d   = _gvn.transform(new ProjNode(c, TypeFunc::Parms + 0));
1317 
1318 #ifdef ASSERT
1319   Node* res_top = _gvn.transform(new ProjNode(c, TypeFunc::Parms + 1));
1320   assert(res_top == top(), "second value must be top");
1321 #endif
1322 
1323   push_pair(res_d);
1324 }
1325 
1326 void Parse::l2f() {
1327   Node* f2 = pop();
1328   Node* f1 = pop();
1329   Node* c = make_runtime_call(RC_LEAF, OptoRuntime::l2f_Type(),
1330                               CAST_FROM_FN_PTR(address, SharedRuntime::l2f),
1331                               "l2f", NULL, //no memory effects
1332                               f1, f2);
1333   Node* res = _gvn.transform(new ProjNode(c, TypeFunc::Parms + 0));
1334 
1335   push(res);
1336 }
1337 
1338 void Parse::do_irem() {
1339   // Must keep both values on the expression-stack during null-check
1340   zero_check_int(peek());
1341   // Compile-time detect of null-exception?
1342   if (stopped())  return;
1343 
1344   Node* b = pop();
1345   Node* a = pop();
1346 
1347   const Type *t = _gvn.type(b);
1348   if (t != Type::TOP) {
1349     const TypeInt *ti = t->is_int();
1350     if (ti->is_con()) {
1351       int divisor = ti->get_con();
1352       // check for positive power of 2
1353       if (divisor > 0 &&
1354           (divisor & ~(divisor-1)) == divisor) {
1355         // yes !
1356         Node *mask = _gvn.intcon((divisor - 1));
1357         // Sigh, must handle negative dividends
1358         Node *zero = _gvn.intcon(0);
1359         IfNode *ifff = jump_if_fork_int(a, zero, BoolTest::lt, PROB_FAIR, COUNT_UNKNOWN);
1360         Node *iff = _gvn.transform( new IfFalseNode(ifff) );
1361         Node *ift = _gvn.transform( new IfTrueNode (ifff) );
1362         Node *reg = jump_if_join(ift, iff);
1363         Node *phi = PhiNode::make(reg, NULL, TypeInt::INT);
1364         // Negative path; negate/and/negate
1365         Node *neg = _gvn.transform( new SubINode(zero, a) );
1366         Node *andn= _gvn.transform( new AndINode(neg, mask) );
1367         Node *negn= _gvn.transform( new SubINode(zero, andn) );
1368         phi->init_req(1, negn);
1369         // Fast positive case
1370         Node *andx = _gvn.transform( new AndINode(a, mask) );
1371         phi->init_req(2, andx);
1372         // Push the merge
1373         push( _gvn.transform(phi) );
1374         return;
1375       }
1376     }
1377   }
1378   // Default case
1379   push( _gvn.transform( new ModINode(control(),a,b) ) );
1380 }
1381 
1382 // Handle jsr and jsr_w bytecode
1383 void Parse::do_jsr() {
1384   assert(bc() == Bytecodes::_jsr || bc() == Bytecodes::_jsr_w, "wrong bytecode");
1385 
1386   // Store information about current state, tagged with new _jsr_bci
1387   int return_bci = iter().next_bci();
1388   int jsr_bci    = (bc() == Bytecodes::_jsr) ? iter().get_dest() : iter().get_far_dest();
1389 
1390   // Update method data
1391   profile_taken_branch(jsr_bci);
1392 
1393   // The way we do things now, there is only one successor block
1394   // for the jsr, because the target code is cloned by ciTypeFlow.
1395   Block* target = successor_for_bci(jsr_bci);
1396 
1397   // What got pushed?
1398   const Type* ret_addr = target->peek();
1399   assert(ret_addr->singleton(), "must be a constant (cloned jsr body)");
1400 
1401   // Effect on jsr on stack
1402   push(_gvn.makecon(ret_addr));
1403 
1404   // Flow to the jsr.
1405   merge(jsr_bci);
1406 }
1407 
1408 // Handle ret bytecode
1409 void Parse::do_ret() {
1410   // Find to whom we return.
1411   assert(block()->num_successors() == 1, "a ret can only go one place now");
1412   Block* target = block()->successor_at(0);
1413   assert(!target->is_ready(), "our arrival must be expected");
1414   profile_ret(target->flow()->start());
1415   int pnum = target->next_path_num();
1416   merge_common(target, pnum);
1417 }
1418 
1419 static bool has_injected_profile(BoolTest::mask btest, Node* test, int& taken, int& not_taken) {
1420   if (btest != BoolTest::eq && btest != BoolTest::ne) {
1421     // Only ::eq and ::ne are supported for profile injection.
1422     return false;
1423   }
1424   if (test->is_Cmp() &&
1425       test->in(1)->Opcode() == Op_ProfileBoolean) {
1426     ProfileBooleanNode* profile = (ProfileBooleanNode*)test->in(1);
1427     int false_cnt = profile->false_count();
1428     int  true_cnt = profile->true_count();
1429 
1430     // Counts matching depends on the actual test operation (::eq or ::ne).
1431     // No need to scale the counts because profile injection was designed
1432     // to feed exact counts into VM.
1433     taken     = (btest == BoolTest::eq) ? false_cnt :  true_cnt;
1434     not_taken = (btest == BoolTest::eq) ?  true_cnt : false_cnt;
1435 
1436     profile->consume();
1437     return true;
1438   }
1439   return false;
1440 }
1441 //--------------------------dynamic_branch_prediction--------------------------
1442 // Try to gather dynamic branch prediction behavior.  Return a probability
1443 // of the branch being taken and set the "cnt" field.  Returns a -1.0
1444 // if we need to use static prediction for some reason.
1445 float Parse::dynamic_branch_prediction(float &cnt, BoolTest::mask btest, Node* test) {
1446   ResourceMark rm;
1447 
1448   cnt  = COUNT_UNKNOWN;
1449 
1450   int     taken = 0;
1451   int not_taken = 0;
1452 
1453   bool use_mdo = !has_injected_profile(btest, test, taken, not_taken);
1454 
1455   if (use_mdo) {
1456     // Use MethodData information if it is available
1457     // FIXME: free the ProfileData structure
1458     ciMethodData* methodData = method()->method_data();
1459     if (!methodData->is_mature())  return PROB_UNKNOWN;
1460     ciProfileData* data = methodData->bci_to_data(bci());
1461     if (data == NULL) {
1462       return PROB_UNKNOWN;
1463     }
1464     if (!data->is_JumpData())  return PROB_UNKNOWN;
1465 
1466     // get taken and not taken values
1467     taken = data->as_JumpData()->taken();
1468     not_taken = 0;
1469     if (data->is_BranchData()) {
1470       not_taken = data->as_BranchData()->not_taken();
1471     }
1472 
1473     // scale the counts to be commensurate with invocation counts:
1474     taken = method()->scale_count(taken);
1475     not_taken = method()->scale_count(not_taken);
1476   }
1477 
1478   // Give up if too few (or too many, in which case the sum will overflow) counts to be meaningful.
1479   // We also check that individual counters are positive first, otherwise the sum can become positive.
1480   if (taken < 0 || not_taken < 0 || taken + not_taken < 40) {
1481     if (C->log() != NULL) {
1482       C->log()->elem("branch target_bci='%d' taken='%d' not_taken='%d'", iter().get_dest(), taken, not_taken);
1483     }
1484     return PROB_UNKNOWN;
1485   }
1486 
1487   // Compute frequency that we arrive here
1488   float sum = taken + not_taken;
1489   // Adjust, if this block is a cloned private block but the
1490   // Jump counts are shared.  Taken the private counts for
1491   // just this path instead of the shared counts.
1492   if( block()->count() > 0 )
1493     sum = block()->count();
1494   cnt = sum / FreqCountInvocations;
1495 
1496   // Pin probability to sane limits
1497   float prob;
1498   if( !taken )
1499     prob = (0+PROB_MIN) / 2;
1500   else if( !not_taken )
1501     prob = (1+PROB_MAX) / 2;
1502   else {                         // Compute probability of true path
1503     prob = (float)taken / (float)(taken + not_taken);
1504     if (prob > PROB_MAX)  prob = PROB_MAX;
1505     if (prob < PROB_MIN)   prob = PROB_MIN;
1506   }
1507 
1508   assert((cnt > 0.0f) && (prob > 0.0f),
1509          "Bad frequency assignment in if");
1510 
1511   if (C->log() != NULL) {
1512     const char* prob_str = NULL;
1513     if (prob >= PROB_MAX)  prob_str = (prob == PROB_MAX) ? "max" : "always";
1514     if (prob <= PROB_MIN)  prob_str = (prob == PROB_MIN) ? "min" : "never";
1515     char prob_str_buf[30];
1516     if (prob_str == NULL) {
1517       jio_snprintf(prob_str_buf, sizeof(prob_str_buf), "%20.2f", prob);
1518       prob_str = prob_str_buf;
1519     }
1520     C->log()->elem("branch target_bci='%d' taken='%d' not_taken='%d' cnt='%f' prob='%s'",
1521                    iter().get_dest(), taken, not_taken, cnt, prob_str);
1522   }
1523   return prob;
1524 }
1525 
1526 //-----------------------------branch_prediction-------------------------------
1527 float Parse::branch_prediction(float& cnt,
1528                                BoolTest::mask btest,
1529                                int target_bci,
1530                                Node* test) {
1531   float prob = dynamic_branch_prediction(cnt, btest, test);
1532   // If prob is unknown, switch to static prediction
1533   if (prob != PROB_UNKNOWN)  return prob;
1534 
1535   prob = PROB_FAIR;                   // Set default value
1536   if (btest == BoolTest::eq)          // Exactly equal test?
1537     prob = PROB_STATIC_INFREQUENT;    // Assume its relatively infrequent
1538   else if (btest == BoolTest::ne)
1539     prob = PROB_STATIC_FREQUENT;      // Assume its relatively frequent
1540 
1541   // If this is a conditional test guarding a backwards branch,
1542   // assume its a loop-back edge.  Make it a likely taken branch.
1543   if (target_bci < bci()) {
1544     if (is_osr_parse()) {    // Could be a hot OSR'd loop; force deopt
1545       // Since it's an OSR, we probably have profile data, but since
1546       // branch_prediction returned PROB_UNKNOWN, the counts are too small.
1547       // Let's make a special check here for completely zero counts.
1548       ciMethodData* methodData = method()->method_data();
1549       if (!methodData->is_empty()) {
1550         ciProfileData* data = methodData->bci_to_data(bci());
1551         // Only stop for truly zero counts, which mean an unknown part
1552         // of the OSR-ed method, and we want to deopt to gather more stats.
1553         // If you have ANY counts, then this loop is simply 'cold' relative
1554         // to the OSR loop.
1555         if (data == NULL ||
1556             (data->as_BranchData()->taken() +  data->as_BranchData()->not_taken() == 0)) {
1557           // This is the only way to return PROB_UNKNOWN:
1558           return PROB_UNKNOWN;
1559         }
1560       }
1561     }
1562     prob = PROB_STATIC_FREQUENT;     // Likely to take backwards branch
1563   }
1564 
1565   assert(prob != PROB_UNKNOWN, "must have some guess at this point");
1566   return prob;
1567 }
1568 
1569 // The magic constants are chosen so as to match the output of
1570 // branch_prediction() when the profile reports a zero taken count.
1571 // It is important to distinguish zero counts unambiguously, because
1572 // some branches (e.g., _213_javac.Assembler.eliminate) validly produce
1573 // very small but nonzero probabilities, which if confused with zero
1574 // counts would keep the program recompiling indefinitely.
1575 bool Parse::seems_never_taken(float prob) const {
1576   return prob < PROB_MIN;
1577 }
1578 
1579 // True if the comparison seems to be the kind that will not change its
1580 // statistics from true to false.  See comments in adjust_map_after_if.
1581 // This question is only asked along paths which are already
1582 // classifed as untaken (by seems_never_taken), so really,
1583 // if a path is never taken, its controlling comparison is
1584 // already acting in a stable fashion.  If the comparison
1585 // seems stable, we will put an expensive uncommon trap
1586 // on the untaken path.
1587 bool Parse::seems_stable_comparison() const {
1588   if (C->too_many_traps(method(), bci(), Deoptimization::Reason_unstable_if)) {
1589     return false;
1590   }
1591   return true;
1592 }
1593 
1594 //-------------------------------repush_if_args--------------------------------
1595 // Push arguments of an "if" bytecode back onto the stack by adjusting _sp.
1596 inline int Parse::repush_if_args() {
1597   if (PrintOpto && WizardMode) {
1598     tty->print("defending against excessive implicit null exceptions on %s @%d in ",
1599                Bytecodes::name(iter().cur_bc()), iter().cur_bci());
1600     method()->print_name(); tty->cr();
1601   }
1602   int bc_depth = - Bytecodes::depth(iter().cur_bc());
1603   assert(bc_depth == 1 || bc_depth == 2, "only two kinds of branches");
1604   DEBUG_ONLY(sync_jvms());   // argument(n) requires a synced jvms
1605   assert(argument(0) != NULL, "must exist");
1606   assert(bc_depth == 1 || argument(1) != NULL, "two must exist");
1607   inc_sp(bc_depth);
1608   return bc_depth;
1609 }
1610 
1611 //----------------------------------do_ifnull----------------------------------
1612 void Parse::do_ifnull(BoolTest::mask btest, Node *c) {
1613   int target_bci = iter().get_dest();
1614 
1615   Block* branch_block = successor_for_bci(target_bci);
1616   Block* next_block   = successor_for_bci(iter().next_bci());
1617 
1618   float cnt;
1619   float prob = branch_prediction(cnt, btest, target_bci, c);
1620   if (prob == PROB_UNKNOWN) {
1621     // (An earlier version of do_ifnull omitted this trap for OSR methods.)
1622     if (PrintOpto && Verbose) {
1623       tty->print_cr("Never-taken edge stops compilation at bci %d", bci());
1624     }
1625     repush_if_args(); // to gather stats on loop
1626     // We need to mark this branch as taken so that if we recompile we will
1627     // see that it is possible. In the tiered system the interpreter doesn't
1628     // do profiling and by the time we get to the lower tier from the interpreter
1629     // the path may be cold again. Make sure it doesn't look untaken
1630     profile_taken_branch(target_bci, !ProfileInterpreter);
1631     uncommon_trap(Deoptimization::Reason_unreached,
1632                   Deoptimization::Action_reinterpret,
1633                   NULL, "cold");
1634     if (C->eliminate_boxing()) {
1635       // Mark the successor blocks as parsed
1636       branch_block->next_path_num();
1637       next_block->next_path_num();
1638     }
1639     return;
1640   }
1641 
1642   NOT_PRODUCT(explicit_null_checks_inserted++);
1643 
1644   // Generate real control flow
1645   Node   *tst = _gvn.transform( new BoolNode( c, btest ) );
1646 
1647   // Sanity check the probability value
1648   assert(prob > 0.0f,"Bad probability in Parser");
1649  // Need xform to put node in hash table
1650   IfNode *iff = create_and_xform_if( control(), tst, prob, cnt );
1651   assert(iff->_prob > 0.0f,"Optimizer made bad probability in parser");
1652   // True branch
1653   { PreserveJVMState pjvms(this);
1654     Node* iftrue  = _gvn.transform( new IfTrueNode (iff) );
1655     set_control(iftrue);
1656 
1657     if (stopped()) {            // Path is dead?
1658       NOT_PRODUCT(explicit_null_checks_elided++);
1659       if (C->eliminate_boxing()) {
1660         // Mark the successor block as parsed
1661         branch_block->next_path_num();
1662       }
1663     } else {                    // Path is live.
1664       // Update method data
1665       profile_taken_branch(target_bci);
1666       adjust_map_after_if(btest, c, prob, branch_block);
1667       if (!stopped()) {
1668         merge(target_bci);
1669       }
1670     }
1671   }
1672 
1673   // False branch
1674   Node* iffalse = _gvn.transform( new IfFalseNode(iff) );
1675   set_control(iffalse);
1676 
1677   if (stopped()) {              // Path is dead?
1678     NOT_PRODUCT(explicit_null_checks_elided++);
1679     if (C->eliminate_boxing()) {
1680       // Mark the successor block as parsed
1681       next_block->next_path_num();
1682     }
1683   } else  {                     // Path is live.
1684     // Update method data
1685     profile_not_taken_branch();
1686     adjust_map_after_if(BoolTest(btest).negate(), c, 1.0-prob, next_block);
1687   }
1688 }
1689 
1690 //------------------------------------do_if------------------------------------
1691 void Parse::do_if(BoolTest::mask btest, Node* c, bool new_path, Node** ctrl_taken) {
1692   int target_bci = iter().get_dest();
1693 
1694   Block* branch_block = successor_for_bci(target_bci);
1695   Block* next_block   = successor_for_bci(iter().next_bci());
1696 
1697   float cnt;
1698   float prob = branch_prediction(cnt, btest, target_bci, c);
1699   float untaken_prob = 1.0 - prob;
1700 
1701   if (prob == PROB_UNKNOWN) {
1702     if (PrintOpto && Verbose) {
1703       tty->print_cr("Never-taken edge stops compilation at bci %d", bci());
1704     }
1705     repush_if_args(); // to gather stats on loop
1706     // We need to mark this branch as taken so that if we recompile we will
1707     // see that it is possible. In the tiered system the interpreter doesn't
1708     // do profiling and by the time we get to the lower tier from the interpreter
1709     // the path may be cold again. Make sure it doesn't look untaken
1710     profile_taken_branch(target_bci, !ProfileInterpreter);
1711     uncommon_trap(Deoptimization::Reason_unreached,
1712                   Deoptimization::Action_reinterpret,
1713                   NULL, "cold");
1714     if (C->eliminate_boxing()) {
1715       // Mark the successor blocks as parsed
1716       branch_block->next_path_num();
1717       next_block->next_path_num();
1718     }
1719     return;
1720   }
1721 
1722   // Sanity check the probability value
1723   assert(0.0f < prob && prob < 1.0f,"Bad probability in Parser");
1724 
1725   bool taken_if_true = true;
1726   // Convert BoolTest to canonical form:
1727   if (!BoolTest(btest).is_canonical()) {
1728     btest         = BoolTest(btest).negate();
1729     taken_if_true = false;
1730     // prob is NOT updated here; it remains the probability of the taken
1731     // path (as opposed to the prob of the path guarded by an 'IfTrueNode').
1732   }
1733   assert(btest != BoolTest::eq, "!= is the only canonical exact test");
1734 
1735   Node* tst0 = new BoolNode(c, btest);
1736   Node* tst = _gvn.transform(tst0);
1737   BoolTest::mask taken_btest   = BoolTest::illegal;
1738   BoolTest::mask untaken_btest = BoolTest::illegal;
1739 
1740   if (tst->is_Bool()) {
1741     // Refresh c from the transformed bool node, since it may be
1742     // simpler than the original c.  Also re-canonicalize btest.
1743     // This wins when (Bool ne (Conv2B p) 0) => (Bool ne (CmpP p NULL)).
1744     // That can arise from statements like: if (x instanceof C) ...
1745     if (tst != tst0) {
1746       // Canonicalize one more time since transform can change it.
1747       btest = tst->as_Bool()->_test._test;
1748       if (!BoolTest(btest).is_canonical()) {
1749         // Reverse edges one more time...
1750         tst   = _gvn.transform( tst->as_Bool()->negate(&_gvn) );
1751         btest = tst->as_Bool()->_test._test;
1752         assert(BoolTest(btest).is_canonical(), "sanity");
1753         taken_if_true = !taken_if_true;
1754       }
1755       c = tst->in(1);
1756     }
1757     BoolTest::mask neg_btest = BoolTest(btest).negate();
1758     taken_btest   = taken_if_true ?     btest : neg_btest;
1759     untaken_btest = taken_if_true ? neg_btest :     btest;
1760   }
1761 
1762   // Generate real control flow
1763   float true_prob = (taken_if_true ? prob : untaken_prob);
1764   IfNode* iff = create_and_map_if(control(), tst, true_prob, cnt);
1765   assert(iff->_prob > 0.0f,"Optimizer made bad probability in parser");
1766   Node* taken_branch   = new IfTrueNode(iff);
1767   Node* untaken_branch = new IfFalseNode(iff);
1768   if (!taken_if_true) {  // Finish conversion to canonical form
1769     Node* tmp      = taken_branch;
1770     taken_branch   = untaken_branch;
1771     untaken_branch = tmp;
1772   }
1773 
1774   // Branch is taken:
1775   { PreserveJVMState pjvms(this);
1776     taken_branch = _gvn.transform(taken_branch);
1777     set_control(taken_branch);
1778 
1779     if (stopped()) {
1780       if (C->eliminate_boxing() && !new_path) {
1781         // Mark the successor block as parsed (if we haven't created a new path)
1782         branch_block->next_path_num();
1783       }
1784     } else {
1785       // Update method data
1786       profile_taken_branch(target_bci);
1787       adjust_map_after_if(taken_btest, c, prob, branch_block);
1788       if (!stopped()) {
1789         if (new_path) {
1790           // Merge by using a new path
1791           merge_new_path(target_bci);
1792         } else if (ctrl_taken != NULL) {
1793           // Don't merge but save taken branch to be wired by caller
1794           *ctrl_taken = control();
1795         } else {
1796           merge(target_bci);
1797         }
1798       }
1799     }
1800   }
1801 
1802   untaken_branch = _gvn.transform(untaken_branch);
1803   set_control(untaken_branch);
1804 
1805   // Branch not taken.
1806   if (stopped() && ctrl_taken == NULL) {
1807     if (C->eliminate_boxing()) {
1808       // Mark the successor block as parsed (if caller does not re-wire control flow)
1809       next_block->next_path_num();
1810     }
1811   } else {
1812     // Update method data
1813     profile_not_taken_branch();
1814     adjust_map_after_if(untaken_btest, c, untaken_prob, next_block);
1815   }
1816 }
1817 
1818 void Parse::do_acmp(BoolTest::mask btest, Node* a, Node* b) {
1819   ciMethod* subst_method = ciEnv::current()->ValueBootstrapMethods_klass()->find_method(ciSymbol::isSubstitutable_name(), ciSymbol::object_object_boolean_signature());
1820   // If current method is ValueBootstrapMethods::isSubstitutable(),
1821   // compile the acmp as a regular pointer comparison otherwise we
1822   // could call ValueBootstrapMethods::isSubstitutable() back
1823   if (ACmpOnValues == 0 || !EnableValhalla || method() == subst_method) {
1824     Node* cmp = CmpP(a, b);
1825     cmp = optimize_cmp_with_klass(cmp);
1826     do_if(btest, cmp);
1827     return;
1828   }
1829 
1830   if (ACmpOnValues == 3) {
1831     // Substituability test
1832     if (a->is_ValueType()) {
1833       inc_sp(2);
1834       a = a->as_ValueType()->allocate(this, true)->get_oop();
1835       dec_sp(2);
1836     }
1837     if (b->is_ValueType()) {
1838       inc_sp(2);
1839       b = b->as_ValueType()->allocate(this, true)->get_oop();
1840       dec_sp(2);
1841     }
1842 
1843     const TypeOopPtr* ta = _gvn.type(a)->isa_oopptr();
1844     const TypeOopPtr* tb = _gvn.type(b)->isa_oopptr();
1845 
1846     if (ta == NULL || !ta->can_be_value_type() ||
1847         tb == NULL || !tb->can_be_value_type()) {
1848       Node* cmp = CmpP(a, b);
1849       cmp = optimize_cmp_with_klass(cmp);
1850       do_if(btest, cmp);
1851       return;
1852     }
1853     
1854     Node* cmp = CmpP(a, b);
1855     cmp = optimize_cmp_with_klass(cmp);
1856     Node* eq_region = NULL;
1857     if (btest == BoolTest::eq) {
1858       do_if(btest, cmp, true);
1859       if (stopped()) {
1860         return;
1861       }
1862     } else {
1863       assert(btest == BoolTest::ne, "only eq or ne");
1864       Node* is_not_equal = NULL;
1865       eq_region = new RegionNode(3);
1866       {
1867         PreserveJVMState pjvms(this);
1868         do_if(btest, cmp, false, &is_not_equal);
1869         if (!stopped()) {
1870           eq_region->init_req(1, control());
1871         }
1872       }
1873       if (is_not_equal == NULL || is_not_equal->is_top()) {
1874         record_for_igvn(eq_region);
1875         set_control(_gvn.transform(eq_region));
1876         return;
1877       }
1878       set_control(is_not_equal);
1879     }
1880     // Pointers not equal, check for values
1881     Node* ne_region = new RegionNode(6);
1882     inc_sp(2);
1883     Node* null_ctl = top();
1884     Node* not_null_a = null_check_oop(a, &null_ctl, !too_many_traps(Deoptimization::Reason_null_check), false, false);
1885     dec_sp(2);
1886     ne_region->init_req(1, null_ctl);
1887     if (stopped()) {
1888       record_for_igvn(ne_region);
1889       set_control(_gvn.transform(ne_region));
1890       if (btest == BoolTest::ne) {
1891         {
1892           PreserveJVMState pjvms(this);
1893           int target_bci = iter().get_dest();
1894           merge(target_bci);
1895         }
1896         record_for_igvn(eq_region);
1897         set_control(_gvn.transform(eq_region));
1898       }
1899       return;
1900     }
1901 
1902     Node* is_value = is_always_locked(not_null_a);
1903     Node* value_mask = _gvn.MakeConX(markOopDesc::always_locked_pattern);
1904     Node* is_value_cmp = _gvn.transform(new CmpXNode(is_value, value_mask));
1905     Node* is_value_bol = _gvn.transform(new BoolNode(is_value_cmp, BoolTest::ne));
1906     IfNode* is_value_iff = create_and_map_if(control(), is_value_bol, PROB_FAIR, COUNT_UNKNOWN);
1907     Node* not_value = _gvn.transform(new IfTrueNode(is_value_iff));
1908     set_control(_gvn.transform(new IfFalseNode(is_value_iff)));
1909     ne_region->init_req(2, not_value);
1910 
1911     // One of the 2 pointers refer to a value, check if both are of
1912     // the same class
1913     inc_sp(2);
1914     null_ctl = top();
1915     Node* not_null_b = null_check_oop(b, &null_ctl, !too_many_traps(Deoptimization::Reason_null_check), false, false);
1916     dec_sp(2);
1917     ne_region->init_req(3, null_ctl);
1918     if (stopped()) {
1919       record_for_igvn(ne_region);
1920       set_control(_gvn.transform(ne_region));
1921       if (btest == BoolTest::ne) {
1922         {
1923           PreserveJVMState pjvms(this);
1924           int target_bci = iter().get_dest();
1925           merge(target_bci);
1926         }
1927         record_for_igvn(eq_region);
1928         set_control(_gvn.transform(eq_region));
1929       }
1930       return;
1931     }
1932     Node* kls_a = load_object_klass(not_null_a);
1933     Node* kls_b = load_object_klass(not_null_b);
1934     Node* kls_cmp = CmpP(kls_a, kls_b);
1935     Node* kls_bol = _gvn.transform(new BoolNode(kls_cmp, BoolTest::ne));
1936     IfNode* kls_iff = create_and_map_if(control(), kls_bol, PROB_FAIR, COUNT_UNKNOWN);
1937     Node* kls_ne = _gvn.transform(new IfTrueNode(kls_iff));
1938     set_control(_gvn.transform(new IfFalseNode(kls_iff)));
1939     ne_region->init_req(4, kls_ne);
1940       
1941     if (stopped()) {
1942       record_for_igvn(ne_region);
1943       set_control(_gvn.transform(ne_region));
1944       if (btest == BoolTest::ne) {
1945         {
1946           PreserveJVMState pjvms(this);
1947           int target_bci = iter().get_dest();
1948           merge(target_bci);
1949         }
1950         record_for_igvn(eq_region);
1951         set_control(_gvn.transform(eq_region));
1952       }
1953       return;
1954     }
1955     // Both are values of the same class, we need to perform a
1956     // substituability test. Delegate to
1957     // ValueBootstrapMethods::isSubstitutable().
1958     
1959     Node* ne_io_phi = PhiNode::make(ne_region, i_o());
1960     Node* mem = reset_memory();
1961     Node* ne_mem_phi = PhiNode::make(ne_region, mem);
1962 
1963     Node* eq_io_phi = NULL;
1964     Node* eq_mem_phi = NULL;
1965     if (eq_region != NULL) {
1966       eq_io_phi = PhiNode::make(eq_region, i_o());
1967       eq_mem_phi = PhiNode::make(eq_region, mem);
1968     }
1969 
1970     set_all_memory(mem);
1971 
1972     kill_dead_locals();
1973     CallStaticJavaNode *call = new CallStaticJavaNode(C, TypeFunc::make(subst_method), SharedRuntime::get_resolve_static_call_stub(), subst_method, bci());
1974     call->set_override_symbolic_info(true);
1975     call->init_req(TypeFunc::Parms, not_null_a);
1976     call->init_req(TypeFunc::Parms+1, not_null_b);
1977     inc_sp(2);
1978     set_edges_for_java_call(call, false, false);
1979     Node* ret = set_results_for_java_call(call, false, true);
1980     dec_sp(2);
1981 
1982     // Test the return value of ValueBootstrapMethods::isSubstitutable()
1983     Node* subst_cmp = _gvn.transform(new CmpINode(ret, intcon(1)));
1984     if (btest == BoolTest::eq) {
1985       do_if(btest, subst_cmp);
1986     } else {
1987       assert(btest == BoolTest::ne, "only eq or ne");
1988       Node* is_not_equal = NULL;
1989       {
1990         PreserveJVMState pjvms(this);
1991         do_if(btest, subst_cmp, false, &is_not_equal);
1992         if (!stopped()) {
1993           eq_region->init_req(2, control());
1994           eq_io_phi->init_req(2, i_o());
1995           eq_mem_phi->init_req(2, reset_memory());
1996         }
1997       }
1998       set_control(is_not_equal);
1999     }
2000     ne_region->init_req(5, control());
2001     ne_io_phi->init_req(5, i_o());
2002     ne_mem_phi->init_req(5, reset_memory());
2003 
2004     record_for_igvn(ne_region);
2005     set_control(_gvn.transform(ne_region));
2006     set_i_o(_gvn.transform(ne_io_phi));
2007     set_all_memory(_gvn.transform(ne_mem_phi));
2008 
2009     if (btest == BoolTest::ne) {
2010       {
2011         PreserveJVMState pjvms(this);
2012         int target_bci = iter().get_dest();
2013         merge(target_bci);
2014       }
2015       
2016       record_for_igvn(eq_region);
2017       set_control(_gvn.transform(eq_region));
2018       set_i_o(_gvn.transform(eq_io_phi));
2019       set_all_memory(_gvn.transform(eq_mem_phi));
2020     }
2021     
2022     return;
2023   }
2024   // In the case were both operands might be value types, we need to
2025   // use the new acmp implementation. Otherwise, i.e. if one operand
2026   // is not a value type, we can use the old acmp implementation.
2027   Node* cmp = C->optimize_acmp(&_gvn, a, b);
2028   if (cmp != NULL) {
2029     // Use optimized/old acmp
2030     cmp = optimize_cmp_with_klass(_gvn.transform(cmp));
2031     do_if(btest, cmp);
2032     return;
2033   }
2034 
2035   Node* ctrl = NULL;
2036   bool safe_for_replace = true;
2037   if (ACmpOnValues != 1) {
2038     // Emit old acmp before new acmp for quick a != b check
2039     cmp = CmpP(a, b);
2040     cmp = optimize_cmp_with_klass(_gvn.transform(cmp));
2041     if (btest == BoolTest::ne) {
2042       do_if(btest, cmp, true);
2043       if (stopped()) {
2044         return; // Never equal
2045       }
2046     } else if (btest == BoolTest::eq) {
2047       Node* is_equal = NULL;
2048       {
2049         PreserveJVMState pjvms(this);
2050         do_if(btest, cmp, false, &is_equal);
2051         if (!stopped()) {
2052           // Not equal, skip valuetype check
2053           ctrl = new RegionNode(3);
2054           ctrl->init_req(1, control());
2055           _gvn.set_type(ctrl, Type::CONTROL);
2056           record_for_igvn(ctrl);
2057           safe_for_replace = false;
2058         }
2059       }
2060       if (is_equal == NULL) {
2061         assert(ctrl != NULL, "no control left");
2062         set_control(_gvn.transform(ctrl));
2063         return; // Never equal
2064       }
2065       set_control(is_equal);
2066     }
2067   }
2068 
2069   // Null check operand before loading the is_value bit
2070   bool speculate = false;
2071   if (!TypePtr::NULL_PTR->higher_equal(_gvn.type(b))) {
2072     // Operand 'b' is never null, swap operands to avoid null check
2073     swap(a, b);
2074   } else if (!too_many_traps(Deoptimization::Reason_speculate_null_check)) {
2075     // Speculate on non-nullness of one operand
2076     if (!_gvn.type(a)->speculative_maybe_null()) {
2077       speculate = true;
2078     } else if (!_gvn.type(b)->speculative_maybe_null()) {
2079       speculate = true;
2080       swap(a, b);
2081     }
2082   }
2083   inc_sp(2);
2084   Node* null_ctl = top();
2085   Node* not_null_a = null_check_oop(a, &null_ctl, speculate, safe_for_replace, speculate);
2086   assert(!stopped(), "operand is always null");
2087   dec_sp(2);
2088   Node* region = new RegionNode(2);
2089   Node* is_value = new PhiNode(region, TypeX_X);
2090   if (null_ctl != top()) {
2091     assert(!speculate, "should never be null");
2092     region->add_req(null_ctl);
2093     is_value->add_req(_gvn.MakeConX(0));
2094   }
2095 
2096   Node* value_mask = _gvn.MakeConX(markOopDesc::always_locked_pattern);
2097   if (ACmpOnValues == 1) {
2098     Node* mark_addr = basic_plus_adr(not_null_a, oopDesc::mark_offset_in_bytes());
2099     Node* mark = make_load(NULL, mark_addr, TypeX_X, TypeX_X->basic_type(), MemNode::unordered);
2100     Node* not_mark = _gvn.transform(new XorXNode(mark, _gvn.MakeConX(-1)));
2101     Node* andn = _gvn.transform(new AndXNode(not_mark, value_mask));
2102     Node* neg_if_value = _gvn.transform(new SubXNode(andn, _gvn.MakeConX(1)));
2103     is_value->init_req(1, _gvn.transform(new RShiftXNode(neg_if_value, _gvn.intcon(63))));
2104   } else {
2105     is_value->init_req(1, is_always_locked(not_null_a));
2106   }
2107   region->init_req(1, control());
2108 
2109   set_control(_gvn.transform(region));
2110   is_value = _gvn.transform(is_value);
2111 
2112   if (ACmpOnValues == 1) {
2113     // Perturbe oop if operand is a value type to make comparison fail
2114     Node* pert = _gvn.transform(new AddPNode(a, a, is_value));
2115     cmp = _gvn.transform(new CmpPNode(pert, b));
2116   } else {
2117     // Check for a value type because we already know that operands are equal
2118     cmp = _gvn.transform(new CmpXNode(is_value, value_mask));
2119     btest = (btest == BoolTest::eq) ? BoolTest::ne : BoolTest::eq;
2120   }
2121   cmp = optimize_cmp_with_klass(cmp);
2122   do_if(btest, cmp);
2123 
2124   if (ctrl != NULL) {
2125     ctrl->init_req(2, control());
2126     set_control(_gvn.transform(ctrl));
2127   }
2128 }
2129 
2130 bool Parse::path_is_suitable_for_uncommon_trap(float prob) const {
2131   // Don't want to speculate on uncommon traps when running with -Xcomp
2132   if (!UseInterpreter) {
2133     return false;
2134   }
2135   return (seems_never_taken(prob) && seems_stable_comparison());
2136 }
2137 
2138 void Parse::maybe_add_predicate_after_if(Block* path) {
2139   if (path->is_SEL_head() && path->preds_parsed() == 0) {
2140     // Add predicates at bci of if dominating the loop so traps can be
2141     // recorded on the if's profile data
2142     int bc_depth = repush_if_args();
2143     add_predicate();
2144     dec_sp(bc_depth);
2145     path->set_has_predicates();
2146   }
2147 }
2148 
2149 
2150 //----------------------------adjust_map_after_if------------------------------
2151 // Adjust the JVM state to reflect the result of taking this path.
2152 // Basically, it means inspecting the CmpNode controlling this
2153 // branch, seeing how it constrains a tested value, and then
2154 // deciding if it's worth our while to encode this constraint
2155 // as graph nodes in the current abstract interpretation map.
2156 void Parse::adjust_map_after_if(BoolTest::mask btest, Node* c, float prob, Block* path) {
2157   if (!c->is_Cmp()) {
2158     maybe_add_predicate_after_if(path);
2159     return;
2160   }
2161 
2162   if (stopped() || btest == BoolTest::illegal) {
2163     return;                             // nothing to do
2164   }
2165 
2166   bool is_fallthrough = (path == successor_for_bci(iter().next_bci()));
2167 
2168   if (path_is_suitable_for_uncommon_trap(prob)) {
2169     repush_if_args();
2170     uncommon_trap(Deoptimization::Reason_unstable_if,
2171                   Deoptimization::Action_reinterpret,
2172                   NULL,
2173                   (is_fallthrough ? "taken always" : "taken never"));
2174     return;
2175   }
2176 
2177   Node* val = c->in(1);
2178   Node* con = c->in(2);
2179   const Type* tcon = _gvn.type(con);
2180   const Type* tval = _gvn.type(val);
2181   bool have_con = tcon->singleton();
2182   if (tval->singleton()) {
2183     if (!have_con) {
2184       // Swap, so constant is in con.
2185       con  = val;
2186       tcon = tval;
2187       val  = c->in(2);
2188       tval = _gvn.type(val);
2189       btest = BoolTest(btest).commute();
2190       have_con = true;
2191     } else {
2192       // Do we have two constants?  Then leave well enough alone.
2193       have_con = false;
2194     }
2195   }
2196   if (!have_con) {                        // remaining adjustments need a con
2197     maybe_add_predicate_after_if(path);
2198     return;
2199   }
2200 
2201   sharpen_type_after_if(btest, con, tcon, val, tval);
2202   maybe_add_predicate_after_if(path);
2203 }
2204 
2205 
2206 static Node* extract_obj_from_klass_load(PhaseGVN* gvn, Node* n) {
2207   Node* ldk;
2208   if (n->is_DecodeNKlass()) {
2209     if (n->in(1)->Opcode() != Op_LoadNKlass) {
2210       return NULL;
2211     } else {
2212       ldk = n->in(1);
2213     }
2214   } else if (n->Opcode() != Op_LoadKlass) {
2215     return NULL;
2216   } else {
2217     ldk = n;
2218   }
2219   assert(ldk != NULL && ldk->is_Load(), "should have found a LoadKlass or LoadNKlass node");
2220 
2221   Node* adr = ldk->in(MemNode::Address);
2222   intptr_t off = 0;
2223   Node* obj = AddPNode::Ideal_base_and_offset(adr, gvn, off);
2224   if (obj == NULL || off != oopDesc::klass_offset_in_bytes()) // loading oopDesc::_klass?
2225     return NULL;
2226   const TypePtr* tp = gvn->type(obj)->is_ptr();
2227   if (tp == NULL || !(tp->isa_instptr() || tp->isa_aryptr())) // is obj a Java object ptr?
2228     return NULL;
2229 
2230   return obj;
2231 }
2232 
2233 void Parse::sharpen_type_after_if(BoolTest::mask btest,
2234                                   Node* con, const Type* tcon,
2235                                   Node* val, const Type* tval) {
2236   // Look for opportunities to sharpen the type of a node
2237   // whose klass is compared with a constant klass.
2238   if (btest == BoolTest::eq && tcon->isa_klassptr()) {
2239     Node* obj = extract_obj_from_klass_load(&_gvn, val);
2240     const TypeOopPtr* con_type = tcon->isa_klassptr()->as_instance_type();
2241     if (obj != NULL && (con_type->isa_instptr() || con_type->isa_aryptr())) {
2242        // Found:
2243        //   Bool(CmpP(LoadKlass(obj._klass), ConP(Foo.klass)), [eq])
2244        // or the narrowOop equivalent.
2245        const Type* obj_type = _gvn.type(obj);
2246        const TypeOopPtr* tboth = obj_type->join_speculative(con_type)->isa_oopptr();
2247        if (tboth != NULL && tboth->klass_is_exact() && tboth != obj_type &&
2248            tboth->higher_equal(obj_type)) {
2249           // obj has to be of the exact type Foo if the CmpP succeeds.
2250           int obj_in_map = map()->find_edge(obj);
2251           JVMState* jvms = this->jvms();
2252           if (obj_in_map >= 0 &&
2253               (jvms->is_loc(obj_in_map) || jvms->is_stk(obj_in_map))) {
2254             TypeNode* ccast = new CheckCastPPNode(control(), obj, tboth);
2255             const Type* tcc = ccast->as_Type()->type();
2256             assert(tcc != obj_type && tcc->higher_equal(obj_type), "must improve");
2257             // Delay transform() call to allow recovery of pre-cast value
2258             // at the control merge.
2259             _gvn.set_type_bottom(ccast);
2260             record_for_igvn(ccast);
2261             // Here's the payoff.
2262             replace_in_map(obj, ccast);
2263           }
2264        }
2265     }
2266   }
2267 
2268   int val_in_map = map()->find_edge(val);
2269   if (val_in_map < 0)  return;          // replace_in_map would be useless
2270   {
2271     JVMState* jvms = this->jvms();
2272     if (!(jvms->is_loc(val_in_map) ||
2273           jvms->is_stk(val_in_map)))
2274       return;                           // again, it would be useless
2275   }
2276 
2277   // Check for a comparison to a constant, and "know" that the compared
2278   // value is constrained on this path.
2279   assert(tcon->singleton(), "");
2280   ConstraintCastNode* ccast = NULL;
2281   Node* cast = NULL;
2282 
2283   switch (btest) {
2284   case BoolTest::eq:                    // Constant test?
2285     {
2286       const Type* tboth = tcon->join_speculative(tval);
2287       if (tboth == tval)  break;        // Nothing to gain.
2288       if (tcon->isa_int()) {
2289         ccast = new CastIINode(val, tboth);
2290       } else if (tcon == TypePtr::NULL_PTR) {
2291         // Cast to null, but keep the pointer identity temporarily live.
2292         ccast = new CastPPNode(val, tboth);
2293       } else {
2294         const TypeF* tf = tcon->isa_float_constant();
2295         const TypeD* td = tcon->isa_double_constant();
2296         // Exclude tests vs float/double 0 as these could be
2297         // either +0 or -0.  Just because you are equal to +0
2298         // doesn't mean you ARE +0!
2299         // Note, following code also replaces Long and Oop values.
2300         if ((!tf || tf->_f != 0.0) &&
2301             (!td || td->_d != 0.0))
2302           cast = con;                   // Replace non-constant val by con.
2303       }
2304     }
2305     break;
2306 
2307   case BoolTest::ne:
2308     if (tcon == TypePtr::NULL_PTR) {
2309       cast = cast_not_null(val, false);
2310     }
2311     break;
2312 
2313   default:
2314     // (At this point we could record int range types with CastII.)
2315     break;
2316   }
2317 
2318   if (ccast != NULL) {
2319     const Type* tcc = ccast->as_Type()->type();
2320     assert(tcc != tval && tcc->higher_equal(tval), "must improve");
2321     // Delay transform() call to allow recovery of pre-cast value
2322     // at the control merge.
2323     ccast->set_req(0, control());
2324     _gvn.set_type_bottom(ccast);
2325     record_for_igvn(ccast);
2326     cast = ccast;
2327   }
2328 
2329   if (cast != NULL) {                   // Here's the payoff.
2330     replace_in_map(val, cast);
2331   }
2332 }
2333 
2334 /**
2335  * Use speculative type to optimize CmpP node: if comparison is
2336  * against the low level class, cast the object to the speculative
2337  * type if any. CmpP should then go away.
2338  *
2339  * @param c  expected CmpP node
2340  * @return   result of CmpP on object casted to speculative type
2341  *
2342  */
2343 Node* Parse::optimize_cmp_with_klass(Node* c) {
2344   // If this is transformed by the _gvn to a comparison with the low
2345   // level klass then we may be able to use speculation
2346   if (c->Opcode() == Op_CmpP &&
2347       (c->in(1)->Opcode() == Op_LoadKlass || c->in(1)->Opcode() == Op_DecodeNKlass) &&
2348       c->in(2)->is_Con()) {
2349     Node* load_klass = NULL;
2350     Node* decode = NULL;
2351     if (c->in(1)->Opcode() == Op_DecodeNKlass) {
2352       decode = c->in(1);
2353       load_klass = c->in(1)->in(1);
2354     } else {
2355       load_klass = c->in(1);
2356     }
2357     if (load_klass->in(2)->is_AddP()) {
2358       Node* addp = load_klass->in(2);
2359       Node* obj = addp->in(AddPNode::Address);
2360       const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
2361       if (obj_type->speculative_type_not_null() != NULL) {
2362         ciKlass* k = obj_type->speculative_type();
2363         inc_sp(2);
2364         obj = maybe_cast_profiled_obj(obj, k);
2365         dec_sp(2);
2366         if (obj->is_ValueType()) {
2367           assert(obj->as_ValueType()->is_allocated(&_gvn), "must be allocated");
2368           obj = obj->as_ValueType()->get_oop();
2369         }
2370         // Make the CmpP use the casted obj
2371         addp = basic_plus_adr(obj, addp->in(AddPNode::Offset));
2372         load_klass = load_klass->clone();
2373         load_klass->set_req(2, addp);
2374         load_klass = _gvn.transform(load_klass);
2375         if (decode != NULL) {
2376           decode = decode->clone();
2377           decode->set_req(1, load_klass);
2378           load_klass = _gvn.transform(decode);
2379         }
2380         c = c->clone();
2381         c->set_req(1, load_klass);
2382         c = _gvn.transform(c);
2383       }
2384     }
2385   }
2386   return c;
2387 }
2388 
2389 //------------------------------do_one_bytecode--------------------------------
2390 // Parse this bytecode, and alter the Parsers JVM->Node mapping
2391 void Parse::do_one_bytecode() {
2392   Node *a, *b, *c, *d;          // Handy temps
2393   BoolTest::mask btest;
2394   int i;
2395 
2396   assert(!has_exceptions(), "bytecode entry state must be clear of throws");
2397 
2398   if (C->check_node_count(NodeLimitFudgeFactor * 5,
2399                           "out of nodes parsing method")) {
2400     return;
2401   }
2402 
2403 #ifdef ASSERT
2404   // for setting breakpoints
2405   if (TraceOptoParse) {
2406     tty->print(" @");
2407     dump_bci(bci());
2408     tty->cr();
2409   }
2410 #endif
2411 
2412   switch (bc()) {
2413   case Bytecodes::_nop:
2414     // do nothing
2415     break;
2416   case Bytecodes::_lconst_0:
2417     push_pair(longcon(0));
2418     break;
2419 
2420   case Bytecodes::_lconst_1:
2421     push_pair(longcon(1));
2422     break;
2423 
2424   case Bytecodes::_fconst_0:
2425     push(zerocon(T_FLOAT));
2426     break;
2427 
2428   case Bytecodes::_fconst_1:
2429     push(makecon(TypeF::ONE));
2430     break;
2431 
2432   case Bytecodes::_fconst_2:
2433     push(makecon(TypeF::make(2.0f)));
2434     break;
2435 
2436   case Bytecodes::_dconst_0:
2437     push_pair(zerocon(T_DOUBLE));
2438     break;
2439 
2440   case Bytecodes::_dconst_1:
2441     push_pair(makecon(TypeD::ONE));
2442     break;
2443 
2444   case Bytecodes::_iconst_m1:push(intcon(-1)); break;
2445   case Bytecodes::_iconst_0: push(intcon( 0)); break;
2446   case Bytecodes::_iconst_1: push(intcon( 1)); break;
2447   case Bytecodes::_iconst_2: push(intcon( 2)); break;
2448   case Bytecodes::_iconst_3: push(intcon( 3)); break;
2449   case Bytecodes::_iconst_4: push(intcon( 4)); break;
2450   case Bytecodes::_iconst_5: push(intcon( 5)); break;
2451   case Bytecodes::_bipush:   push(intcon(iter().get_constant_u1())); break;
2452   case Bytecodes::_sipush:   push(intcon(iter().get_constant_u2())); break;
2453   case Bytecodes::_aconst_null: push(null());  break;
2454   case Bytecodes::_ldc:
2455   case Bytecodes::_ldc_w:
2456   case Bytecodes::_ldc2_w:
2457     // If the constant is unresolved, run this BC once in the interpreter.
2458     {
2459       ciConstant constant = iter().get_constant();
2460       if (!constant.is_valid() ||
2461           (constant.basic_type() == T_OBJECT &&
2462            !constant.as_object()->is_loaded())) {
2463         int index = iter().get_constant_pool_index();
2464         constantTag tag = iter().get_constant_pool_tag(index);
2465         uncommon_trap(Deoptimization::make_trap_request
2466                       (Deoptimization::Reason_unloaded,
2467                        Deoptimization::Action_reinterpret,
2468                        index),
2469                       NULL, tag.internal_name());
2470         break;
2471       }
2472       assert(constant.basic_type() != T_OBJECT || constant.as_object()->is_instance(),
2473              "must be java_mirror of klass");
2474       const Type* con_type = Type::make_from_constant(constant);
2475       if (con_type != NULL) {
2476         push_node(con_type->basic_type(), makecon(con_type));
2477       }
2478     }
2479 
2480     break;
2481 
2482   case Bytecodes::_aload_0:
2483     push( local(0) );
2484     break;
2485   case Bytecodes::_aload_1:
2486     push( local(1) );
2487     break;
2488   case Bytecodes::_aload_2:
2489     push( local(2) );
2490     break;
2491   case Bytecodes::_aload_3:
2492     push( local(3) );
2493     break;
2494   case Bytecodes::_aload:
2495     push( local(iter().get_index()) );
2496     break;
2497 
2498   case Bytecodes::_fload_0:
2499   case Bytecodes::_iload_0:
2500     push( local(0) );
2501     break;
2502   case Bytecodes::_fload_1:
2503   case Bytecodes::_iload_1:
2504     push( local(1) );
2505     break;
2506   case Bytecodes::_fload_2:
2507   case Bytecodes::_iload_2:
2508     push( local(2) );
2509     break;
2510   case Bytecodes::_fload_3:
2511   case Bytecodes::_iload_3:
2512     push( local(3) );
2513     break;
2514   case Bytecodes::_fload:
2515   case Bytecodes::_iload:
2516     push( local(iter().get_index()) );
2517     break;
2518   case Bytecodes::_lload_0:
2519     push_pair_local( 0 );
2520     break;
2521   case Bytecodes::_lload_1:
2522     push_pair_local( 1 );
2523     break;
2524   case Bytecodes::_lload_2:
2525     push_pair_local( 2 );
2526     break;
2527   case Bytecodes::_lload_3:
2528     push_pair_local( 3 );
2529     break;
2530   case Bytecodes::_lload:
2531     push_pair_local( iter().get_index() );
2532     break;
2533 
2534   case Bytecodes::_dload_0:
2535     push_pair_local(0);
2536     break;
2537   case Bytecodes::_dload_1:
2538     push_pair_local(1);
2539     break;
2540   case Bytecodes::_dload_2:
2541     push_pair_local(2);
2542     break;
2543   case Bytecodes::_dload_3:
2544     push_pair_local(3);
2545     break;
2546   case Bytecodes::_dload:
2547     push_pair_local(iter().get_index());
2548     break;
2549   case Bytecodes::_fstore_0:
2550   case Bytecodes::_istore_0:
2551   case Bytecodes::_astore_0:
2552     set_local( 0, pop() );
2553     break;
2554   case Bytecodes::_fstore_1:
2555   case Bytecodes::_istore_1:
2556   case Bytecodes::_astore_1:
2557     set_local( 1, pop() );
2558     break;
2559   case Bytecodes::_fstore_2:
2560   case Bytecodes::_istore_2:
2561   case Bytecodes::_astore_2:
2562     set_local( 2, pop() );
2563     break;
2564   case Bytecodes::_fstore_3:
2565   case Bytecodes::_istore_3:
2566   case Bytecodes::_astore_3:
2567     set_local( 3, pop() );
2568     break;
2569   case Bytecodes::_fstore:
2570   case Bytecodes::_istore:
2571   case Bytecodes::_astore:
2572     set_local( iter().get_index(), pop() );
2573     break;
2574   // long stores
2575   case Bytecodes::_lstore_0:
2576     set_pair_local( 0, pop_pair() );
2577     break;
2578   case Bytecodes::_lstore_1:
2579     set_pair_local( 1, pop_pair() );
2580     break;
2581   case Bytecodes::_lstore_2:
2582     set_pair_local( 2, pop_pair() );
2583     break;
2584   case Bytecodes::_lstore_3:
2585     set_pair_local( 3, pop_pair() );
2586     break;
2587   case Bytecodes::_lstore:
2588     set_pair_local( iter().get_index(), pop_pair() );
2589     break;
2590 
2591   // double stores
2592   case Bytecodes::_dstore_0:
2593     set_pair_local( 0, dstore_rounding(pop_pair()) );
2594     break;
2595   case Bytecodes::_dstore_1:
2596     set_pair_local( 1, dstore_rounding(pop_pair()) );
2597     break;
2598   case Bytecodes::_dstore_2:
2599     set_pair_local( 2, dstore_rounding(pop_pair()) );
2600     break;
2601   case Bytecodes::_dstore_3:
2602     set_pair_local( 3, dstore_rounding(pop_pair()) );
2603     break;
2604   case Bytecodes::_dstore:
2605     set_pair_local( iter().get_index(), dstore_rounding(pop_pair()) );
2606     break;
2607 
2608   case Bytecodes::_pop:  dec_sp(1);   break;
2609   case Bytecodes::_pop2: dec_sp(2);   break;
2610   case Bytecodes::_swap:
2611     a = pop();
2612     b = pop();
2613     push(a);
2614     push(b);
2615     break;
2616   case Bytecodes::_dup:
2617     a = pop();
2618     push(a);
2619     push(a);
2620     break;
2621   case Bytecodes::_dup_x1:
2622     a = pop();
2623     b = pop();
2624     push( a );
2625     push( b );
2626     push( a );
2627     break;
2628   case Bytecodes::_dup_x2:
2629     a = pop();
2630     b = pop();
2631     c = pop();
2632     push( a );
2633     push( c );
2634     push( b );
2635     push( a );
2636     break;
2637   case Bytecodes::_dup2:
2638     a = pop();
2639     b = pop();
2640     push( b );
2641     push( a );
2642     push( b );
2643     push( a );
2644     break;
2645 
2646   case Bytecodes::_dup2_x1:
2647     // before: .. c, b, a
2648     // after:  .. b, a, c, b, a
2649     // not tested
2650     a = pop();
2651     b = pop();
2652     c = pop();
2653     push( b );
2654     push( a );
2655     push( c );
2656     push( b );
2657     push( a );
2658     break;
2659   case Bytecodes::_dup2_x2:
2660     // before: .. d, c, b, a
2661     // after:  .. b, a, d, c, b, a
2662     // not tested
2663     a = pop();
2664     b = pop();
2665     c = pop();
2666     d = pop();
2667     push( b );
2668     push( a );
2669     push( d );
2670     push( c );
2671     push( b );
2672     push( a );
2673     break;
2674 
2675   case Bytecodes::_arraylength: {
2676     // Must do null-check with value on expression stack
2677     Node *ary = null_check(peek(), T_ARRAY);
2678     // Compile-time detect of null-exception?
2679     if (stopped())  return;
2680     a = pop();
2681     push(load_array_length(a));
2682     break;
2683   }
2684 
2685   case Bytecodes::_baload:  array_load(T_BYTE);    break;
2686   case Bytecodes::_caload:  array_load(T_CHAR);    break;
2687   case Bytecodes::_iaload:  array_load(T_INT);     break;
2688   case Bytecodes::_saload:  array_load(T_SHORT);   break;
2689   case Bytecodes::_faload:  array_load(T_FLOAT);   break;
2690   case Bytecodes::_aaload:  array_load(T_OBJECT);  break;
2691   case Bytecodes::_laload:  array_load(T_LONG);    break;
2692   case Bytecodes::_daload:  array_load(T_DOUBLE);  break;
2693   case Bytecodes::_bastore: array_store(T_BYTE);   break;
2694   case Bytecodes::_castore: array_store(T_CHAR);   break;
2695   case Bytecodes::_iastore: array_store(T_INT);    break;
2696   case Bytecodes::_sastore: array_store(T_SHORT);  break;
2697   case Bytecodes::_fastore: array_store(T_FLOAT);  break;
2698   case Bytecodes::_aastore: array_store(T_OBJECT); break;
2699   case Bytecodes::_lastore: array_store(T_LONG);   break;
2700   case Bytecodes::_dastore: array_store(T_DOUBLE); break;
2701 
2702   case Bytecodes::_getfield:
2703     do_getfield();
2704     break;
2705 
2706   case Bytecodes::_getstatic:
2707     do_getstatic();
2708     break;
2709 
2710   case Bytecodes::_putfield:
2711     do_putfield();
2712     break;
2713 
2714   case Bytecodes::_putstatic:
2715     do_putstatic();
2716     break;
2717 
2718   case Bytecodes::_irem:
2719     do_irem();
2720     break;
2721   case Bytecodes::_idiv:
2722     // Must keep both values on the expression-stack during null-check
2723     zero_check_int(peek());
2724     // Compile-time detect of null-exception?
2725     if (stopped())  return;
2726     b = pop();
2727     a = pop();
2728     push( _gvn.transform( new DivINode(control(),a,b) ) );
2729     break;
2730   case Bytecodes::_imul:
2731     b = pop(); a = pop();
2732     push( _gvn.transform( new MulINode(a,b) ) );
2733     break;
2734   case Bytecodes::_iadd:
2735     b = pop(); a = pop();
2736     push( _gvn.transform( new AddINode(a,b) ) );
2737     break;
2738   case Bytecodes::_ineg:
2739     a = pop();
2740     push( _gvn.transform( new SubINode(_gvn.intcon(0),a)) );
2741     break;
2742   case Bytecodes::_isub:
2743     b = pop(); a = pop();
2744     push( _gvn.transform( new SubINode(a,b) ) );
2745     break;
2746   case Bytecodes::_iand:
2747     b = pop(); a = pop();
2748     push( _gvn.transform( new AndINode(a,b) ) );
2749     break;
2750   case Bytecodes::_ior:
2751     b = pop(); a = pop();
2752     push( _gvn.transform( new OrINode(a,b) ) );
2753     break;
2754   case Bytecodes::_ixor:
2755     b = pop(); a = pop();
2756     push( _gvn.transform( new XorINode(a,b) ) );
2757     break;
2758   case Bytecodes::_ishl:
2759     b = pop(); a = pop();
2760     push( _gvn.transform( new LShiftINode(a,b) ) );
2761     break;
2762   case Bytecodes::_ishr:
2763     b = pop(); a = pop();
2764     push( _gvn.transform( new RShiftINode(a,b) ) );
2765     break;
2766   case Bytecodes::_iushr:
2767     b = pop(); a = pop();
2768     push( _gvn.transform( new URShiftINode(a,b) ) );
2769     break;
2770 
2771   case Bytecodes::_fneg:
2772     a = pop();
2773     b = _gvn.transform(new NegFNode (a));
2774     push(b);
2775     break;
2776 
2777   case Bytecodes::_fsub:
2778     b = pop();
2779     a = pop();
2780     c = _gvn.transform( new SubFNode(a,b) );
2781     d = precision_rounding(c);
2782     push( d );
2783     break;
2784 
2785   case Bytecodes::_fadd:
2786     b = pop();
2787     a = pop();
2788     c = _gvn.transform( new AddFNode(a,b) );
2789     d = precision_rounding(c);
2790     push( d );
2791     break;
2792 
2793   case Bytecodes::_fmul:
2794     b = pop();
2795     a = pop();
2796     c = _gvn.transform( new MulFNode(a,b) );
2797     d = precision_rounding(c);
2798     push( d );
2799     break;
2800 
2801   case Bytecodes::_fdiv:
2802     b = pop();
2803     a = pop();
2804     c = _gvn.transform( new DivFNode(0,a,b) );
2805     d = precision_rounding(c);
2806     push( d );
2807     break;
2808 
2809   case Bytecodes::_frem:
2810     if (Matcher::has_match_rule(Op_ModF)) {
2811       // Generate a ModF node.
2812       b = pop();
2813       a = pop();
2814       c = _gvn.transform( new ModFNode(0,a,b) );
2815       d = precision_rounding(c);
2816       push( d );
2817     }
2818     else {
2819       // Generate a call.
2820       modf();
2821     }
2822     break;
2823 
2824   case Bytecodes::_fcmpl:
2825     b = pop();
2826     a = pop();
2827     c = _gvn.transform( new CmpF3Node( a, b));
2828     push(c);
2829     break;
2830   case Bytecodes::_fcmpg:
2831     b = pop();
2832     a = pop();
2833 
2834     // Same as fcmpl but need to flip the unordered case.  Swap the inputs,
2835     // which negates the result sign except for unordered.  Flip the unordered
2836     // as well by using CmpF3 which implements unordered-lesser instead of
2837     // unordered-greater semantics.  Finally, commute the result bits.  Result
2838     // is same as using a CmpF3Greater except we did it with CmpF3 alone.
2839     c = _gvn.transform( new CmpF3Node( b, a));
2840     c = _gvn.transform( new SubINode(_gvn.intcon(0),c) );
2841     push(c);
2842     break;
2843 
2844   case Bytecodes::_f2i:
2845     a = pop();
2846     push(_gvn.transform(new ConvF2INode(a)));
2847     break;
2848 
2849   case Bytecodes::_d2i:
2850     a = pop_pair();
2851     b = _gvn.transform(new ConvD2INode(a));
2852     push( b );
2853     break;
2854 
2855   case Bytecodes::_f2d:
2856     a = pop();
2857     b = _gvn.transform( new ConvF2DNode(a));
2858     push_pair( b );
2859     break;
2860 
2861   case Bytecodes::_d2f:
2862     a = pop_pair();
2863     b = _gvn.transform( new ConvD2FNode(a));
2864     // This breaks _227_mtrt (speed & correctness) and _222_mpegaudio (speed)
2865     //b = _gvn.transform(new RoundFloatNode(0, b) );
2866     push( b );
2867     break;
2868 
2869   case Bytecodes::_l2f:
2870     if (Matcher::convL2FSupported()) {
2871       a = pop_pair();
2872       b = _gvn.transform( new ConvL2FNode(a));
2873       // For i486.ad, FILD doesn't restrict precision to 24 or 53 bits.
2874       // Rather than storing the result into an FP register then pushing
2875       // out to memory to round, the machine instruction that implements
2876       // ConvL2D is responsible for rounding.
2877       // c = precision_rounding(b);
2878       c = _gvn.transform(b);
2879       push(c);
2880     } else {
2881       l2f();
2882     }
2883     break;
2884 
2885   case Bytecodes::_l2d:
2886     a = pop_pair();
2887     b = _gvn.transform( new ConvL2DNode(a));
2888     // For i486.ad, rounding is always necessary (see _l2f above).
2889     // c = dprecision_rounding(b);
2890     c = _gvn.transform(b);
2891     push_pair(c);
2892     break;
2893 
2894   case Bytecodes::_f2l:
2895     a = pop();
2896     b = _gvn.transform( new ConvF2LNode(a));
2897     push_pair(b);
2898     break;
2899 
2900   case Bytecodes::_d2l:
2901     a = pop_pair();
2902     b = _gvn.transform( new ConvD2LNode(a));
2903     push_pair(b);
2904     break;
2905 
2906   case Bytecodes::_dsub:
2907     b = pop_pair();
2908     a = pop_pair();
2909     c = _gvn.transform( new SubDNode(a,b) );
2910     d = dprecision_rounding(c);
2911     push_pair( d );
2912     break;
2913 
2914   case Bytecodes::_dadd:
2915     b = pop_pair();
2916     a = pop_pair();
2917     c = _gvn.transform( new AddDNode(a,b) );
2918     d = dprecision_rounding(c);
2919     push_pair( d );
2920     break;
2921 
2922   case Bytecodes::_dmul:
2923     b = pop_pair();
2924     a = pop_pair();
2925     c = _gvn.transform( new MulDNode(a,b) );
2926     d = dprecision_rounding(c);
2927     push_pair( d );
2928     break;
2929 
2930   case Bytecodes::_ddiv:
2931     b = pop_pair();
2932     a = pop_pair();
2933     c = _gvn.transform( new DivDNode(0,a,b) );
2934     d = dprecision_rounding(c);
2935     push_pair( d );
2936     break;
2937 
2938   case Bytecodes::_dneg:
2939     a = pop_pair();
2940     b = _gvn.transform(new NegDNode (a));
2941     push_pair(b);
2942     break;
2943 
2944   case Bytecodes::_drem:
2945     if (Matcher::has_match_rule(Op_ModD)) {
2946       // Generate a ModD node.
2947       b = pop_pair();
2948       a = pop_pair();
2949       // a % b
2950 
2951       c = _gvn.transform( new ModDNode(0,a,b) );
2952       d = dprecision_rounding(c);
2953       push_pair( d );
2954     }
2955     else {
2956       // Generate a call.
2957       modd();
2958     }
2959     break;
2960 
2961   case Bytecodes::_dcmpl:
2962     b = pop_pair();
2963     a = pop_pair();
2964     c = _gvn.transform( new CmpD3Node( a, b));
2965     push(c);
2966     break;
2967 
2968   case Bytecodes::_dcmpg:
2969     b = pop_pair();
2970     a = pop_pair();
2971     // Same as dcmpl but need to flip the unordered case.
2972     // Commute the inputs, which negates the result sign except for unordered.
2973     // Flip the unordered as well by using CmpD3 which implements
2974     // unordered-lesser instead of unordered-greater semantics.
2975     // Finally, negate the result bits.  Result is same as using a
2976     // CmpD3Greater except we did it with CmpD3 alone.
2977     c = _gvn.transform( new CmpD3Node( b, a));
2978     c = _gvn.transform( new SubINode(_gvn.intcon(0),c) );
2979     push(c);
2980     break;
2981 
2982 
2983     // Note for longs -> lo word is on TOS, hi word is on TOS - 1
2984   case Bytecodes::_land:
2985     b = pop_pair();
2986     a = pop_pair();
2987     c = _gvn.transform( new AndLNode(a,b) );
2988     push_pair(c);
2989     break;
2990   case Bytecodes::_lor:
2991     b = pop_pair();
2992     a = pop_pair();
2993     c = _gvn.transform( new OrLNode(a,b) );
2994     push_pair(c);
2995     break;
2996   case Bytecodes::_lxor:
2997     b = pop_pair();
2998     a = pop_pair();
2999     c = _gvn.transform( new XorLNode(a,b) );
3000     push_pair(c);
3001     break;
3002 
3003   case Bytecodes::_lshl:
3004     b = pop();                  // the shift count
3005     a = pop_pair();             // value to be shifted
3006     c = _gvn.transform( new LShiftLNode(a,b) );
3007     push_pair(c);
3008     break;
3009   case Bytecodes::_lshr:
3010     b = pop();                  // the shift count
3011     a = pop_pair();             // value to be shifted
3012     c = _gvn.transform( new RShiftLNode(a,b) );
3013     push_pair(c);
3014     break;
3015   case Bytecodes::_lushr:
3016     b = pop();                  // the shift count
3017     a = pop_pair();             // value to be shifted
3018     c = _gvn.transform( new URShiftLNode(a,b) );
3019     push_pair(c);
3020     break;
3021   case Bytecodes::_lmul:
3022     b = pop_pair();
3023     a = pop_pair();
3024     c = _gvn.transform( new MulLNode(a,b) );
3025     push_pair(c);
3026     break;
3027 
3028   case Bytecodes::_lrem:
3029     // Must keep both values on the expression-stack during null-check
3030     assert(peek(0) == top(), "long word order");
3031     zero_check_long(peek(1));
3032     // Compile-time detect of null-exception?
3033     if (stopped())  return;
3034     b = pop_pair();
3035     a = pop_pair();
3036     c = _gvn.transform( new ModLNode(control(),a,b) );
3037     push_pair(c);
3038     break;
3039 
3040   case Bytecodes::_ldiv:
3041     // Must keep both values on the expression-stack during null-check
3042     assert(peek(0) == top(), "long word order");
3043     zero_check_long(peek(1));
3044     // Compile-time detect of null-exception?
3045     if (stopped())  return;
3046     b = pop_pair();
3047     a = pop_pair();
3048     c = _gvn.transform( new DivLNode(control(),a,b) );
3049     push_pair(c);
3050     break;
3051 
3052   case Bytecodes::_ladd:
3053     b = pop_pair();
3054     a = pop_pair();
3055     c = _gvn.transform( new AddLNode(a,b) );
3056     push_pair(c);
3057     break;
3058   case Bytecodes::_lsub:
3059     b = pop_pair();
3060     a = pop_pair();
3061     c = _gvn.transform( new SubLNode(a,b) );
3062     push_pair(c);
3063     break;
3064   case Bytecodes::_lcmp:
3065     // Safepoints are now inserted _before_ branches.  The long-compare
3066     // bytecode painfully produces a 3-way value (-1,0,+1) which requires a
3067     // slew of control flow.  These are usually followed by a CmpI vs zero and
3068     // a branch; this pattern then optimizes to the obvious long-compare and
3069     // branch.  However, if the branch is backwards there's a Safepoint
3070     // inserted.  The inserted Safepoint captures the JVM state at the
3071     // pre-branch point, i.e. it captures the 3-way value.  Thus if a
3072     // long-compare is used to control a loop the debug info will force
3073     // computation of the 3-way value, even though the generated code uses a
3074     // long-compare and branch.  We try to rectify the situation by inserting
3075     // a SafePoint here and have it dominate and kill the safepoint added at a
3076     // following backwards branch.  At this point the JVM state merely holds 2
3077     // longs but not the 3-way value.
3078     if( UseLoopSafepoints ) {
3079       switch( iter().next_bc() ) {
3080       case Bytecodes::_ifgt:
3081       case Bytecodes::_iflt:
3082       case Bytecodes::_ifge:
3083       case Bytecodes::_ifle:
3084       case Bytecodes::_ifne:
3085       case Bytecodes::_ifeq:
3086         // If this is a backwards branch in the bytecodes, add Safepoint
3087         maybe_add_safepoint(iter().next_get_dest());
3088       default:
3089         break;
3090       }
3091     }
3092     b = pop_pair();
3093     a = pop_pair();
3094     c = _gvn.transform( new CmpL3Node( a, b ));
3095     push(c);
3096     break;
3097 
3098   case Bytecodes::_lneg:
3099     a = pop_pair();
3100     b = _gvn.transform( new SubLNode(longcon(0),a));
3101     push_pair(b);
3102     break;
3103   case Bytecodes::_l2i:
3104     a = pop_pair();
3105     push( _gvn.transform( new ConvL2INode(a)));
3106     break;
3107   case Bytecodes::_i2l:
3108     a = pop();
3109     b = _gvn.transform( new ConvI2LNode(a));
3110     push_pair(b);
3111     break;
3112   case Bytecodes::_i2b:
3113     // Sign extend
3114     a = pop();
3115     a = _gvn.transform( new LShiftINode(a,_gvn.intcon(24)) );
3116     a = _gvn.transform( new RShiftINode(a,_gvn.intcon(24)) );
3117     push( a );
3118     break;
3119   case Bytecodes::_i2s:
3120     a = pop();
3121     a = _gvn.transform( new LShiftINode(a,_gvn.intcon(16)) );
3122     a = _gvn.transform( new RShiftINode(a,_gvn.intcon(16)) );
3123     push( a );
3124     break;
3125   case Bytecodes::_i2c:
3126     a = pop();
3127     push( _gvn.transform( new AndINode(a,_gvn.intcon(0xFFFF)) ) );
3128     break;
3129 
3130   case Bytecodes::_i2f:
3131     a = pop();
3132     b = _gvn.transform( new ConvI2FNode(a) ) ;
3133     c = precision_rounding(b);
3134     push (b);
3135     break;
3136 
3137   case Bytecodes::_i2d:
3138     a = pop();
3139     b = _gvn.transform( new ConvI2DNode(a));
3140     push_pair(b);
3141     break;
3142 
3143   case Bytecodes::_iinc:        // Increment local
3144     i = iter().get_index();     // Get local index
3145     set_local( i, _gvn.transform( new AddINode( _gvn.intcon(iter().get_iinc_con()), local(i) ) ) );
3146     break;
3147 
3148   // Exit points of synchronized methods must have an unlock node
3149   case Bytecodes::_return:
3150     return_current(NULL);
3151     break;
3152 
3153   case Bytecodes::_ireturn:
3154   case Bytecodes::_areturn:
3155   case Bytecodes::_freturn:
3156     return_current(pop());
3157     break;
3158   case Bytecodes::_lreturn:
3159     return_current(pop_pair());
3160     break;
3161   case Bytecodes::_dreturn:
3162     return_current(pop_pair());
3163     break;
3164 
3165   case Bytecodes::_athrow:
3166     // null exception oop throws NULL pointer exception
3167     null_check(peek());
3168     if (stopped())  return;
3169     // Hook the thrown exception directly to subsequent handlers.
3170     if (BailoutToInterpreterForThrows) {
3171       // Keep method interpreted from now on.
3172       uncommon_trap(Deoptimization::Reason_unhandled,
3173                     Deoptimization::Action_make_not_compilable);
3174       return;
3175     }
3176     if (env()->jvmti_can_post_on_exceptions()) {
3177       // check if we must post exception events, take uncommon trap if so (with must_throw = false)
3178       uncommon_trap_if_should_post_on_exceptions(Deoptimization::Reason_unhandled, false);
3179     }
3180     // Here if either can_post_on_exceptions or should_post_on_exceptions is false
3181     add_exception_state(make_exception_state(peek()));
3182     break;
3183 
3184   case Bytecodes::_goto:   // fall through
3185   case Bytecodes::_goto_w: {
3186     int target_bci = (bc() == Bytecodes::_goto) ? iter().get_dest() : iter().get_far_dest();
3187 
3188     // If this is a backwards branch in the bytecodes, add Safepoint
3189     maybe_add_safepoint(target_bci);
3190 
3191     // Update method data
3192     profile_taken_branch(target_bci);
3193 
3194     // Merge the current control into the target basic block
3195     merge(target_bci);
3196 
3197     // See if we can get some profile data and hand it off to the next block
3198     Block *target_block = block()->successor_for_bci(target_bci);
3199     if (target_block->pred_count() != 1)  break;
3200     ciMethodData* methodData = method()->method_data();
3201     if (!methodData->is_mature())  break;
3202     ciProfileData* data = methodData->bci_to_data(bci());
3203     assert(data != NULL && data->is_JumpData(), "need JumpData for taken branch");
3204     int taken = ((ciJumpData*)data)->taken();
3205     taken = method()->scale_count(taken);
3206     target_block->set_count(taken);
3207     break;
3208   }
3209 
3210   case Bytecodes::_ifnull:    btest = BoolTest::eq; goto handle_if_null;
3211   case Bytecodes::_ifnonnull: btest = BoolTest::ne; goto handle_if_null;
3212   handle_if_null:
3213     // If this is a backwards branch in the bytecodes, add Safepoint
3214     maybe_add_safepoint(iter().get_dest());
3215     a = null();
3216     b = pop();
3217     if (b->is_ValueType()) {
3218       // Return constant false because 'b' is always non-null
3219       c = _gvn.makecon(TypeInt::CC_GT);
3220     } else {
3221       if (!_gvn.type(b)->speculative_maybe_null() &&
3222           !too_many_traps(Deoptimization::Reason_speculate_null_check)) {
3223         inc_sp(1);
3224         Node* null_ctl = top();
3225         b = null_check_oop(b, &null_ctl, true, true, true);
3226         assert(null_ctl->is_top(), "no null control here");
3227         dec_sp(1);
3228       } else if (_gvn.type(b)->speculative_always_null() &&
3229                  !too_many_traps(Deoptimization::Reason_speculate_null_assert)) {
3230         inc_sp(1);
3231         b = null_assert(b);
3232         dec_sp(1);
3233       }
3234       c = _gvn.transform( new CmpPNode(b, a) );
3235     }
3236     do_ifnull(btest, c);
3237     break;
3238 
3239   case Bytecodes::_if_acmpeq: btest = BoolTest::eq; goto handle_if_acmp;
3240   case Bytecodes::_if_acmpne: btest = BoolTest::ne; goto handle_if_acmp;
3241   handle_if_acmp:
3242     // If this is a backwards branch in the bytecodes, add Safepoint
3243     maybe_add_safepoint(iter().get_dest());
3244     a = access_resolve(pop(), 0);
3245     b = access_resolve(pop(), 0);
3246     do_acmp(btest, a, b);
3247     break;
3248 
3249   case Bytecodes::_ifeq: btest = BoolTest::eq; goto handle_ifxx;
3250   case Bytecodes::_ifne: btest = BoolTest::ne; goto handle_ifxx;
3251   case Bytecodes::_iflt: btest = BoolTest::lt; goto handle_ifxx;
3252   case Bytecodes::_ifle: btest = BoolTest::le; goto handle_ifxx;
3253   case Bytecodes::_ifgt: btest = BoolTest::gt; goto handle_ifxx;
3254   case Bytecodes::_ifge: btest = BoolTest::ge; goto handle_ifxx;
3255   handle_ifxx:
3256     // If this is a backwards branch in the bytecodes, add Safepoint
3257     maybe_add_safepoint(iter().get_dest());
3258     a = _gvn.intcon(0);
3259     b = pop();
3260     c = _gvn.transform( new CmpINode(b, a) );
3261     do_if(btest, c);
3262     break;
3263 
3264   case Bytecodes::_if_icmpeq: btest = BoolTest::eq; goto handle_if_icmp;
3265   case Bytecodes::_if_icmpne: btest = BoolTest::ne; goto handle_if_icmp;
3266   case Bytecodes::_if_icmplt: btest = BoolTest::lt; goto handle_if_icmp;
3267   case Bytecodes::_if_icmple: btest = BoolTest::le; goto handle_if_icmp;
3268   case Bytecodes::_if_icmpgt: btest = BoolTest::gt; goto handle_if_icmp;
3269   case Bytecodes::_if_icmpge: btest = BoolTest::ge; goto handle_if_icmp;
3270   handle_if_icmp:
3271     // If this is a backwards branch in the bytecodes, add Safepoint
3272     maybe_add_safepoint(iter().get_dest());
3273     a = pop();
3274     b = pop();
3275     c = _gvn.transform( new CmpINode( b, a ) );
3276     do_if(btest, c);
3277     break;
3278 
3279   case Bytecodes::_tableswitch:
3280     do_tableswitch();
3281     break;
3282 
3283   case Bytecodes::_lookupswitch:
3284     do_lookupswitch();
3285     break;
3286 
3287   case Bytecodes::_invokestatic:
3288   case Bytecodes::_invokedynamic:
3289   case Bytecodes::_invokespecial:
3290   case Bytecodes::_invokevirtual:
3291   case Bytecodes::_invokeinterface:
3292     do_call();
3293     break;
3294   case Bytecodes::_checkcast:
3295     do_checkcast();
3296     break;
3297   case Bytecodes::_instanceof:
3298     do_instanceof();
3299     break;
3300   case Bytecodes::_anewarray:
3301     do_newarray();
3302     break;
3303   case Bytecodes::_newarray:
3304     do_newarray((BasicType)iter().get_index());
3305     break;
3306   case Bytecodes::_multianewarray:
3307     do_multianewarray();
3308     break;
3309   case Bytecodes::_new:
3310     do_new();
3311     break;
3312   case Bytecodes::_defaultvalue:
3313     do_defaultvalue();
3314     break;
3315   case Bytecodes::_withfield:
3316     do_withfield();
3317     break;
3318 
3319   case Bytecodes::_jsr:
3320   case Bytecodes::_jsr_w:
3321     do_jsr();
3322     break;
3323 
3324   case Bytecodes::_ret:
3325     do_ret();
3326     break;
3327 
3328 
3329   case Bytecodes::_monitorenter:
3330     do_monitor_enter();
3331     break;
3332 
3333   case Bytecodes::_monitorexit:
3334     do_monitor_exit();
3335     break;
3336 
3337   case Bytecodes::_breakpoint:
3338     // Breakpoint set concurrently to compile
3339     // %%% use an uncommon trap?
3340     C->record_failure("breakpoint in method");
3341     return;
3342 
3343   default:
3344 #ifndef PRODUCT
3345     map()->dump(99);
3346 #endif
3347     tty->print("\nUnhandled bytecode %s\n", Bytecodes::name(bc()) );
3348     ShouldNotReachHere();
3349   }
3350 
3351 #ifndef PRODUCT
3352   IdealGraphPrinter *printer = C->printer();
3353   if (printer && printer->should_print(1)) {
3354     char buffer[256];
3355     jio_snprintf(buffer, sizeof(buffer), "Bytecode %d: %s", bci(), Bytecodes::name(bc()));
3356     bool old = printer->traverse_outs();
3357     printer->set_traverse_outs(true);
3358     printer->print_method(buffer, 4);
3359     printer->set_traverse_outs(old);
3360   }
3361 #endif
3362 }
--- EOF ---