1 /*
   2  * Copyright (c) 1998, 2026, 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 "ci/ciMethodData.hpp"
  26 #include "classfile/vmSymbols.hpp"
  27 #include "compiler/compileLog.hpp"
  28 #include "interpreter/linkResolver.hpp"
  29 #include "jvm_io.h"
  30 #include "memory/resourceArea.hpp"
  31 #include "memory/universe.hpp"
  32 #include "oops/oop.inline.hpp"
  33 #include "opto/addnode.hpp"
  34 #include "opto/castnode.hpp"
  35 #include "opto/convertnode.hpp"
  36 #include "opto/divnode.hpp"
  37 #include "opto/idealGraphPrinter.hpp"
  38 #include "opto/matcher.hpp"
  39 #include "opto/memnode.hpp"
  40 #include "opto/mulnode.hpp"
  41 #include "opto/opaquenode.hpp"
  42 #include "opto/parse.hpp"
  43 #include "opto/runtime.hpp"
  44 #include "opto/subtypenode.hpp"
  45 #include "runtime/deoptimization.hpp"
  46 #include "runtime/sharedRuntime.hpp"
  47 
  48 #ifndef PRODUCT
  49 extern uint explicit_null_checks_inserted,
  50             explicit_null_checks_elided;
  51 #endif
  52 
  53 //---------------------------------array_load----------------------------------
  54 void Parse::array_load(BasicType bt) {
  55   const Type* elemtype = Type::TOP;
  56   bool big_val = bt == T_DOUBLE || bt == T_LONG;
  57   Node* adr = array_addressing(bt, 0, elemtype);
  58   if (stopped())  return;     // guaranteed null or range check
  59 
  60   pop();                      // index (already used)
  61   Node* array = pop();        // the array itself
  62 
  63   if (elemtype == TypeInt::BOOL) {
  64     bt = T_BOOLEAN;
  65   }
  66   const TypeAryPtr* adr_type = TypeAryPtr::get_array_body_type(bt);
  67 
  68   Node* ld = access_load_at(array, adr, adr_type, elemtype, bt,
  69                             IN_HEAP | IS_ARRAY | C2_CONTROL_DEPENDENT_LOAD);
  70   if (big_val) {
  71     push_pair(ld);
  72   } else {
  73     push(ld);
  74   }
  75 }
  76 
  77 
  78 //--------------------------------array_store----------------------------------
  79 void Parse::array_store(BasicType bt) {
  80   const Type* elemtype = Type::TOP;
  81   bool big_val = bt == T_DOUBLE || bt == T_LONG;
  82   Node* adr = array_addressing(bt, big_val ? 2 : 1, elemtype);
  83   if (stopped())  return;     // guaranteed null or range check
  84   if (bt == T_OBJECT) {
  85     array_store_check();
  86     if (stopped()) {
  87       return;
  88     }
  89   }
  90   Node* val;                  // Oop to store
  91   if (big_val) {
  92     val = pop_pair();
  93   } else {
  94     val = pop();
  95   }
  96   pop();                      // index (already used)
  97   Node* array = pop();        // the array itself
  98 
  99   if (elemtype == TypeInt::BOOL) {
 100     bt = T_BOOLEAN;
 101   }
 102   const TypeAryPtr* adr_type = TypeAryPtr::get_array_body_type(bt);
 103 
 104   access_store_at(array, adr, adr_type, val, elemtype, bt, MO_UNORDERED | IN_HEAP | IS_ARRAY);
 105 }
 106 
 107 
 108 //------------------------------array_addressing-------------------------------
 109 // Pull array and index from the stack.  Compute pointer-to-element.
 110 Node* Parse::array_addressing(BasicType type, int vals, const Type*& elemtype) {
 111   Node *idx   = peek(0+vals);   // Get from stack without popping
 112   Node *ary   = peek(1+vals);   // in case of exception
 113 
 114   // Null check the array base, with correct stack contents
 115   ary = null_check(ary, T_ARRAY);
 116   // Compile-time detect of null-exception?
 117   if (stopped())  return top();
 118 
 119   const TypeAryPtr* arytype  = _gvn.type(ary)->is_aryptr();
 120   const TypeInt*    sizetype = arytype->size();
 121   elemtype = arytype->elem();
 122 
 123   if (UseUniqueSubclasses) {
 124     const Type* el = elemtype->make_ptr();
 125     if (el && el->isa_instptr()) {
 126       const TypeInstPtr* toop = el->is_instptr();
 127       if (toop->instance_klass()->unique_concrete_subklass()) {
 128         // If we load from "AbstractClass[]" we must see "ConcreteSubClass".
 129         const Type* subklass = Type::get_const_type(toop->instance_klass());
 130         elemtype = subklass->join_speculative(el);
 131       }
 132     }
 133   }
 134 
 135   // Check for big class initializers with all constant offsets
 136   // feeding into a known-size array.
 137   const TypeInt* idxtype = _gvn.type(idx)->is_int();
 138   // See if the highest idx value is less than the lowest array bound,
 139   // and if the idx value cannot be negative:
 140   bool need_range_check = true;
 141   if (idxtype->_hi < sizetype->_lo && idxtype->_lo >= 0) {
 142     need_range_check = false;
 143     if (C->log() != nullptr)   C->log()->elem("observe that='!need_range_check'");
 144   }
 145 
 146   if (!arytype->is_loaded()) {
 147     // Only fails for some -Xcomp runs
 148     // The class is unloaded.  We have to run this bytecode in the interpreter.
 149     ciKlass* klass = arytype->unloaded_klass();
 150 
 151     uncommon_trap(Deoptimization::Reason_unloaded,
 152                   Deoptimization::Action_reinterpret,
 153                   klass, "!loaded array");
 154     return top();
 155   }
 156 
 157   // Do the range check
 158   if (need_range_check) {
 159     Node* tst;
 160     if (sizetype->_hi <= 0) {
 161       // The greatest array bound is negative, so we can conclude that we're
 162       // compiling unreachable code, but the unsigned compare trick used below
 163       // only works with non-negative lengths.  Instead, hack "tst" to be zero so
 164       // the uncommon_trap path will always be taken.
 165       tst = _gvn.intcon(0);
 166     } else {
 167       // Range is constant in array-oop, so we can use the original state of mem
 168       Node* len = load_array_length(ary);
 169 
 170       // Test length vs index (standard trick using unsigned compare)
 171       Node* chk = _gvn.transform( new CmpUNode(idx, len) );
 172       BoolTest::mask btest = BoolTest::lt;
 173       tst = _gvn.transform( new BoolNode(chk, btest) );
 174     }
 175     RangeCheckNode* rc = new RangeCheckNode(control(), tst, PROB_MAX, COUNT_UNKNOWN);
 176     _gvn.set_type(rc, rc->Value(&_gvn));
 177     if (!tst->is_Con()) {
 178       record_for_igvn(rc);
 179     }
 180     set_control(_gvn.transform(new IfTrueNode(rc)));
 181     // Branch to failure if out of bounds
 182     {
 183       PreserveJVMState pjvms(this);
 184       set_control(_gvn.transform(new IfFalseNode(rc)));
 185       if (C->allow_range_check_smearing()) {
 186         // Do not use builtin_throw, since range checks are sometimes
 187         // made more stringent by an optimistic transformation.
 188         // This creates "tentative" range checks at this point,
 189         // which are not guaranteed to throw exceptions.
 190         // See IfNode::Ideal, is_range_check, adjust_check.
 191         uncommon_trap(Deoptimization::Reason_range_check,
 192                       Deoptimization::Action_make_not_entrant,
 193                       nullptr, "range_check");
 194       } else {
 195         // If we have already recompiled with the range-check-widening
 196         // heroic optimization turned off, then we must really be throwing
 197         // range check exceptions.
 198         builtin_throw(Deoptimization::Reason_range_check);
 199       }
 200     }
 201   }
 202   // Check for always knowing you are throwing a range-check exception
 203   if (stopped())  return top();
 204 
 205   // Make array address computation control dependent to prevent it
 206   // from floating above the range check during loop optimizations.
 207   Node* ptr = array_element_address(ary, idx, type, sizetype, control());
 208   assert(ptr != top(), "top should go hand-in-hand with stopped");
 209 
 210   return ptr;
 211 }
 212 
 213 
 214 // returns IfNode
 215 IfNode* Parse::jump_if_fork_int(Node* a, Node* b, BoolTest::mask mask, float prob, float cnt) {
 216   Node   *cmp = _gvn.transform(new CmpINode(a, b)); // two cases: shiftcount > 32 and shiftcount <= 32
 217   Node   *tst = _gvn.transform(new BoolNode(cmp, mask));
 218   IfNode *iff = create_and_map_if(control(), tst, prob, cnt);
 219   return iff;
 220 }
 221 
 222 
 223 // sentinel value for the target bci to mark never taken branches
 224 // (according to profiling)
 225 static const int never_reached = INT_MAX;
 226 
 227 //------------------------------helper for tableswitch-------------------------
 228 void Parse::jump_if_true_fork(IfNode *iff, int dest_bci_if_true, bool unc) {
 229   // True branch, use existing map info
 230   { PreserveJVMState pjvms(this);
 231     Node *iftrue  = _gvn.transform( new IfTrueNode (iff) );
 232     set_control( iftrue );
 233     if (unc) {
 234       repush_if_args();
 235       uncommon_trap(Deoptimization::Reason_unstable_if,
 236                     Deoptimization::Action_reinterpret,
 237                     nullptr,
 238                     "taken always");
 239     } else {
 240       assert(dest_bci_if_true != never_reached, "inconsistent dest");
 241       merge_new_path(dest_bci_if_true);
 242     }
 243   }
 244 
 245   // False branch
 246   Node *iffalse = _gvn.transform( new IfFalseNode(iff) );
 247   set_control( iffalse );
 248 }
 249 
 250 void Parse::jump_if_false_fork(IfNode *iff, int dest_bci_if_true, bool unc) {
 251   // True branch, use existing map info
 252   { PreserveJVMState pjvms(this);
 253     Node *iffalse  = _gvn.transform( new IfFalseNode (iff) );
 254     set_control( iffalse );
 255     if (unc) {
 256       repush_if_args();
 257       uncommon_trap(Deoptimization::Reason_unstable_if,
 258                     Deoptimization::Action_reinterpret,
 259                     nullptr,
 260                     "taken never");
 261     } else {
 262       assert(dest_bci_if_true != never_reached, "inconsistent dest");
 263       merge_new_path(dest_bci_if_true);
 264     }
 265   }
 266 
 267   // False branch
 268   Node *iftrue = _gvn.transform( new IfTrueNode(iff) );
 269   set_control( iftrue );
 270 }
 271 
 272 void Parse::jump_if_always_fork(int dest_bci, bool unc) {
 273   // False branch, use existing map and control()
 274   if (unc) {
 275     repush_if_args();
 276     uncommon_trap(Deoptimization::Reason_unstable_if,
 277                   Deoptimization::Action_reinterpret,
 278                   nullptr,
 279                   "taken never");
 280   } else {
 281     assert(dest_bci != never_reached, "inconsistent dest");
 282     merge_new_path(dest_bci);
 283   }
 284 }
 285 
 286 
 287 extern "C" {
 288   static int jint_cmp(const void *i, const void *j) {
 289     int a = *(jint *)i;
 290     int b = *(jint *)j;
 291     return a > b ? 1 : a < b ? -1 : 0;
 292   }
 293 }
 294 
 295 
 296 class SwitchRange : public StackObj {
 297   // a range of integers coupled with a bci destination
 298   jint _lo;                     // inclusive lower limit
 299   jint _hi;                     // inclusive upper limit
 300   int _dest;
 301   float _cnt;                   // how many times this range was hit according to profiling
 302 
 303 public:
 304   jint lo() const              { return _lo;   }
 305   jint hi() const              { return _hi;   }
 306   int  dest() const            { return _dest; }
 307   bool is_singleton() const    { return _lo == _hi; }
 308   float cnt() const            { return _cnt; }
 309 
 310   void setRange(jint lo, jint hi, int dest, float cnt) {
 311     assert(lo <= hi, "must be a non-empty range");
 312     _lo = lo, _hi = hi; _dest = dest; _cnt = cnt;
 313     assert(_cnt >= 0, "");
 314   }
 315   bool adjoinRange(jint lo, jint hi, int dest, float cnt, bool trim_ranges) {
 316     assert(lo <= hi, "must be a non-empty range");
 317     if (lo == _hi+1) {
 318       // see merge_ranges() comment below
 319       if (trim_ranges) {
 320         if (cnt == 0) {
 321           if (_cnt != 0) {
 322             return false;
 323           }
 324           if (dest != _dest) {
 325             _dest = never_reached;
 326           }
 327         } else {
 328           if (_cnt == 0) {
 329             return false;
 330           }
 331           if (dest != _dest) {
 332             return false;
 333           }
 334         }
 335       } else {
 336         if (dest != _dest) {
 337           return false;
 338         }
 339       }
 340       _hi = hi;
 341       _cnt += cnt;
 342       return true;
 343     }
 344     return false;
 345   }
 346 
 347   void set (jint value, int dest, float cnt) {
 348     setRange(value, value, dest, cnt);
 349   }
 350   bool adjoin(jint value, int dest, float cnt, bool trim_ranges) {
 351     return adjoinRange(value, value, dest, cnt, trim_ranges);
 352   }
 353   bool adjoin(SwitchRange& other) {
 354     return adjoinRange(other._lo, other._hi, other._dest, other._cnt, false);
 355   }
 356 
 357   void print() {
 358     if (is_singleton())
 359       tty->print(" {%d}=>%d (cnt=%f)", lo(), dest(), cnt());
 360     else if (lo() == min_jint)
 361       tty->print(" {..%d}=>%d (cnt=%f)", hi(), dest(), cnt());
 362     else if (hi() == max_jint)
 363       tty->print(" {%d..}=>%d (cnt=%f)", lo(), dest(), cnt());
 364     else
 365       tty->print(" {%d..%d}=>%d (cnt=%f)", lo(), hi(), dest(), cnt());
 366   }
 367 };
 368 
 369 // We try to minimize the number of ranges and the size of the taken
 370 // ones using profiling data. When ranges are created,
 371 // SwitchRange::adjoinRange() only allows 2 adjoining ranges to merge
 372 // if both were never hit or both were hit to build longer unreached
 373 // ranges. Here, we now merge adjoining ranges with the same
 374 // destination and finally set destination of unreached ranges to the
 375 // special value never_reached because it can help minimize the number
 376 // of tests that are necessary.
 377 //
 378 // For instance:
 379 // [0, 1] to target1 sometimes taken
 380 // [1, 2] to target1 never taken
 381 // [2, 3] to target2 never taken
 382 // would lead to:
 383 // [0, 1] to target1 sometimes taken
 384 // [1, 3] never taken
 385 //
 386 // (first 2 ranges to target1 are not merged)
 387 static void merge_ranges(SwitchRange* ranges, int& rp) {
 388   if (rp == 0) {
 389     return;
 390   }
 391   int shift = 0;
 392   for (int j = 0; j < rp; j++) {
 393     SwitchRange& r1 = ranges[j-shift];
 394     SwitchRange& r2 = ranges[j+1];
 395     if (r1.adjoin(r2)) {
 396       shift++;
 397     } else if (shift > 0) {
 398       ranges[j+1-shift] = r2;
 399     }
 400   }
 401   rp -= shift;
 402   for (int j = 0; j <= rp; j++) {
 403     SwitchRange& r = ranges[j];
 404     if (r.cnt() == 0 && r.dest() != never_reached) {
 405       r.setRange(r.lo(), r.hi(), never_reached, r.cnt());
 406     }
 407   }
 408 }
 409 
 410 //-------------------------------do_tableswitch--------------------------------
 411 void Parse::do_tableswitch() {
 412   // Get information about tableswitch
 413   int default_dest = iter().get_dest_table(0);
 414   jint lo_index    = iter().get_int_table(1);
 415   jint hi_index    = iter().get_int_table(2);
 416   int len          = hi_index - lo_index + 1;
 417 
 418   if (len < 1) {
 419     // If this is a backward branch, add safepoint
 420     maybe_add_safepoint(default_dest);
 421     pop(); // the effect of the instruction execution on the operand stack
 422     merge(default_dest);
 423     return;
 424   }
 425 
 426   ciMethodData* methodData = method()->method_data();
 427   ciMultiBranchData* profile = nullptr;
 428   if (methodData->is_mature() && UseSwitchProfiling) {
 429     ciProfileData* data = methodData->bci_to_data(bci());
 430     if (data != nullptr && data->is_MultiBranchData()) {
 431       profile = (ciMultiBranchData*)data;
 432     }
 433   }
 434   bool trim_ranges = !C->too_many_traps(method(), bci(), Deoptimization::Reason_unstable_if);
 435 
 436   // generate decision tree, using trichotomy when possible
 437   int rnum = len+2;
 438   bool makes_backward_branch = (default_dest <= bci());
 439   SwitchRange* ranges = NEW_RESOURCE_ARRAY(SwitchRange, rnum);
 440   int rp = -1;
 441   if (lo_index != min_jint) {
 442     float cnt = 1.0F;
 443     if (profile != nullptr) {
 444       cnt = (float)profile->default_count() / (hi_index != max_jint ? 2.0F : 1.0F);
 445     }
 446     ranges[++rp].setRange(min_jint, lo_index-1, default_dest, cnt);
 447   }
 448   for (int j = 0; j < len; j++) {
 449     jint match_int = lo_index+j;
 450     int  dest      = iter().get_dest_table(j+3);
 451     makes_backward_branch |= (dest <= bci());
 452     float cnt = 1.0F;
 453     if (profile != nullptr) {
 454       cnt = (float)profile->count_at(j);
 455     }
 456     if (rp < 0 || !ranges[rp].adjoin(match_int, dest, cnt, trim_ranges)) {
 457       ranges[++rp].set(match_int, dest, cnt);
 458     }
 459   }
 460   jint highest = lo_index+(len-1);
 461   assert(ranges[rp].hi() == highest, "");
 462   if (highest != max_jint) {
 463     float cnt = 1.0F;
 464     if (profile != nullptr) {
 465       cnt = (float)profile->default_count() / (lo_index != min_jint ? 2.0F : 1.0F);
 466     }
 467     if (!ranges[rp].adjoinRange(highest+1, max_jint, default_dest, cnt, trim_ranges)) {
 468       ranges[++rp].setRange(highest+1, max_jint, default_dest, cnt);
 469     }
 470   }
 471   assert(rp < len+2, "not too many ranges");
 472 
 473   if (trim_ranges) {
 474     merge_ranges(ranges, rp);
 475   }
 476 
 477   // Safepoint in case if backward branch observed
 478   if (makes_backward_branch) {
 479     add_safepoint();
 480   }
 481 
 482   Node* lookup = pop(); // lookup value
 483   jump_switch_ranges(lookup, &ranges[0], &ranges[rp]);
 484 }
 485 
 486 
 487 //------------------------------do_lookupswitch--------------------------------
 488 void Parse::do_lookupswitch() {
 489   // Get information about lookupswitch
 490   int default_dest = iter().get_dest_table(0);
 491   jint len          = iter().get_int_table(1);
 492 
 493   if (len < 1) {    // If this is a backward branch, add safepoint
 494     maybe_add_safepoint(default_dest);
 495     pop(); // the effect of the instruction execution on the operand stack
 496     merge(default_dest);
 497     return;
 498   }
 499 
 500   ciMethodData* methodData = method()->method_data();
 501   ciMultiBranchData* profile = nullptr;
 502   if (methodData->is_mature() && UseSwitchProfiling) {
 503     ciProfileData* data = methodData->bci_to_data(bci());
 504     if (data != nullptr && data->is_MultiBranchData()) {
 505       profile = (ciMultiBranchData*)data;
 506     }
 507   }
 508   bool trim_ranges = !C->too_many_traps(method(), bci(), Deoptimization::Reason_unstable_if);
 509 
 510   // generate decision tree, using trichotomy when possible
 511   jint* table = NEW_RESOURCE_ARRAY(jint, len*3);
 512   {
 513     for (int j = 0; j < len; j++) {
 514       table[3*j+0] = iter().get_int_table(2+2*j);
 515       table[3*j+1] = iter().get_dest_table(2+2*j+1);
 516       // Handle overflow when converting from uint to jint
 517       table[3*j+2] = (profile == nullptr) ? 1 : (jint)MIN2<uint>((uint)max_jint, profile->count_at(j));
 518     }
 519     qsort(table, len, 3*sizeof(table[0]), jint_cmp);
 520   }
 521 
 522   float default_cnt = 1.0F;
 523   if (profile != nullptr) {
 524     juint defaults = max_juint - len;
 525     default_cnt = (float)profile->default_count()/(float)defaults;
 526   }
 527 
 528   int rnum = len*2+1;
 529   bool makes_backward_branch = (default_dest <= bci());
 530   SwitchRange* ranges = NEW_RESOURCE_ARRAY(SwitchRange, rnum);
 531   int rp = -1;
 532   for (int j = 0; j < len; j++) {
 533     jint match_int   = table[3*j+0];
 534     jint  dest        = table[3*j+1];
 535     jint  cnt         = table[3*j+2];
 536     jint  next_lo     = rp < 0 ? min_jint : ranges[rp].hi()+1;
 537     makes_backward_branch |= (dest <= bci());
 538     float c = default_cnt * ((float)match_int - (float)next_lo);
 539     if (match_int != next_lo && (rp < 0 || !ranges[rp].adjoinRange(next_lo, match_int-1, default_dest, c, trim_ranges))) {
 540       assert(default_dest != never_reached, "sentinel value for dead destinations");
 541       ranges[++rp].setRange(next_lo, match_int-1, default_dest, c);
 542     }
 543     if (rp < 0 || !ranges[rp].adjoin(match_int, dest, (float)cnt, trim_ranges)) {
 544       assert(dest != never_reached, "sentinel value for dead destinations");
 545       ranges[++rp].set(match_int, dest,  (float)cnt);
 546     }
 547   }
 548   jint highest = table[3*(len-1)];
 549   assert(ranges[rp].hi() == highest, "");
 550   if (highest != max_jint &&
 551       !ranges[rp].adjoinRange(highest+1, max_jint, default_dest, default_cnt * ((float)max_jint - (float)highest), trim_ranges)) {
 552     ranges[++rp].setRange(highest+1, max_jint, default_dest, default_cnt * ((float)max_jint - (float)highest));
 553   }
 554   assert(rp < rnum, "not too many ranges");
 555 
 556   if (trim_ranges) {
 557     merge_ranges(ranges, rp);
 558   }
 559 
 560   // Safepoint in case backward branch observed
 561   if (makes_backward_branch) {
 562     add_safepoint();
 563   }
 564 
 565   Node *lookup = pop(); // lookup value
 566   jump_switch_ranges(lookup, &ranges[0], &ranges[rp]);
 567 }
 568 
 569 static float if_prob(float taken_cnt, float total_cnt) {
 570   assert(taken_cnt <= total_cnt, "");
 571   if (total_cnt == 0) {
 572     return PROB_FAIR;
 573   }
 574   float p = taken_cnt / total_cnt;
 575   return clamp(p, PROB_MIN, PROB_MAX);
 576 }
 577 
 578 static float if_cnt(float cnt) {
 579   if (cnt == 0) {
 580     return COUNT_UNKNOWN;
 581   }
 582   return cnt;
 583 }
 584 
 585 static float sum_of_cnts(SwitchRange *lo, SwitchRange *hi) {
 586   float total_cnt = 0;
 587   for (SwitchRange* sr = lo; sr <= hi; sr++) {
 588     total_cnt += sr->cnt();
 589   }
 590   return total_cnt;
 591 }
 592 
 593 class SwitchRanges : public ResourceObj {
 594 public:
 595   SwitchRange* _lo;
 596   SwitchRange* _hi;
 597   SwitchRange* _mid;
 598   float _cost;
 599 
 600   enum {
 601     Start,
 602     LeftDone,
 603     RightDone,
 604     Done
 605   } _state;
 606 
 607   SwitchRanges(SwitchRange *lo, SwitchRange *hi)
 608     : _lo(lo), _hi(hi), _mid(nullptr),
 609       _cost(0), _state(Start) {
 610   }
 611 
 612   SwitchRanges()
 613     : _lo(nullptr), _hi(nullptr), _mid(nullptr),
 614       _cost(0), _state(Start) {}
 615 };
 616 
 617 // Estimate cost of performing a binary search on lo..hi
 618 static float compute_tree_cost(SwitchRange *lo, SwitchRange *hi, float total_cnt) {
 619   GrowableArray<SwitchRanges> tree;
 620   SwitchRanges root(lo, hi);
 621   tree.push(root);
 622 
 623   float cost = 0;
 624   do {
 625     SwitchRanges& r = *tree.adr_at(tree.length()-1);
 626     if (r._hi != r._lo) {
 627       if (r._mid == nullptr) {
 628         float r_cnt = sum_of_cnts(r._lo, r._hi);
 629 
 630         if (r_cnt == 0) {
 631           tree.pop();
 632           cost = 0;
 633           continue;
 634         }
 635 
 636         SwitchRange* mid = nullptr;
 637         mid = r._lo;
 638         for (float cnt = 0; ; ) {
 639           assert(mid <= r._hi, "out of bounds");
 640           cnt += mid->cnt();
 641           if (cnt > r_cnt / 2) {
 642             break;
 643           }
 644           mid++;
 645         }
 646         assert(mid <= r._hi, "out of bounds");
 647         r._mid = mid;
 648         r._cost = r_cnt / total_cnt;
 649       }
 650       r._cost += cost;
 651       if (r._state < SwitchRanges::LeftDone && r._mid > r._lo) {
 652         cost = 0;
 653         r._state = SwitchRanges::LeftDone;
 654         tree.push(SwitchRanges(r._lo, r._mid-1));
 655       } else if (r._state < SwitchRanges::RightDone) {
 656         cost = 0;
 657         r._state = SwitchRanges::RightDone;
 658         tree.push(SwitchRanges(r._mid == r._lo ? r._mid+1 : r._mid, r._hi));
 659       } else {
 660         tree.pop();
 661         cost = r._cost;
 662       }
 663     } else {
 664       tree.pop();
 665       cost = r._cost;
 666     }
 667   } while (tree.length() > 0);
 668 
 669 
 670   return cost;
 671 }
 672 
 673 // It sometimes pays off to test most common ranges before the binary search
 674 void Parse::linear_search_switch_ranges(Node* key_val, SwitchRange*& lo, SwitchRange*& hi) {
 675   uint nr = hi - lo + 1;
 676   float total_cnt = sum_of_cnts(lo, hi);
 677 
 678   float min = compute_tree_cost(lo, hi, total_cnt);
 679   float extra = 1;
 680   float sub = 0;
 681 
 682   SwitchRange* array1 = lo;
 683   SwitchRange* array2 = NEW_RESOURCE_ARRAY(SwitchRange, nr);
 684 
 685   SwitchRange* ranges = nullptr;
 686 
 687   while (nr >= 2) {
 688     assert(lo == array1 || lo == array2, "one the 2 already allocated arrays");
 689     ranges = (lo == array1) ? array2 : array1;
 690 
 691     // Find highest frequency range
 692     SwitchRange* candidate = lo;
 693     for (SwitchRange* sr = lo+1; sr <= hi; sr++) {
 694       if (sr->cnt() > candidate->cnt()) {
 695         candidate = sr;
 696       }
 697     }
 698     SwitchRange most_freq = *candidate;
 699     if (most_freq.cnt() == 0) {
 700       break;
 701     }
 702 
 703     // Copy remaining ranges into another array
 704     int shift = 0;
 705     for (uint i = 0; i < nr; i++) {
 706       SwitchRange* sr = &lo[i];
 707       if (sr != candidate) {
 708         ranges[i-shift] = *sr;
 709       } else {
 710         shift++;
 711         if (i > 0 && i < nr-1) {
 712           SwitchRange prev = lo[i-1];
 713           prev.setRange(prev.lo(), sr->hi(), prev.dest(), prev.cnt());
 714           if (prev.adjoin(lo[i+1])) {
 715             shift++;
 716             i++;
 717           }
 718           ranges[i-shift] = prev;
 719         }
 720       }
 721     }
 722     nr -= shift;
 723 
 724     // Evaluate cost of testing the most common range and performing a
 725     // binary search on the other ranges
 726     float cost = extra + compute_tree_cost(&ranges[0], &ranges[nr-1], total_cnt);
 727     if (cost >= min) {
 728       break;
 729     }
 730     // swap arrays
 731     lo = &ranges[0];
 732     hi = &ranges[nr-1];
 733 
 734     // It pays off: emit the test for the most common range
 735     assert(most_freq.cnt() > 0, "must be taken");
 736     Node* val = _gvn.transform(new SubINode(key_val, _gvn.intcon(most_freq.lo())));
 737     Node* cmp = _gvn.transform(new CmpUNode(val, _gvn.intcon(java_subtract(most_freq.hi(), most_freq.lo()))));
 738     Node* tst = _gvn.transform(new BoolNode(cmp, BoolTest::le));
 739     IfNode* iff = create_and_map_if(control(), tst, if_prob(most_freq.cnt(), total_cnt), if_cnt(most_freq.cnt()));
 740     jump_if_true_fork(iff, most_freq.dest(), false);
 741 
 742     sub += most_freq.cnt() / total_cnt;
 743     extra += 1 - sub;
 744     min = cost;
 745   }
 746 }
 747 
 748 //----------------------------create_jump_tables-------------------------------
 749 bool Parse::create_jump_tables(Node* key_val, SwitchRange* lo, SwitchRange* hi) {
 750   // Are jumptables enabled
 751   if (!UseJumpTables)  return false;
 752 
 753   // Are jumptables supported
 754   if (!Matcher::has_match_rule(Op_Jump))  return false;
 755 
 756   bool trim_ranges = !C->too_many_traps(method(), bci(), Deoptimization::Reason_unstable_if);
 757 
 758   // Decide if a guard is needed to lop off big ranges at either (or
 759   // both) end(s) of the input set. We'll call this the default target
 760   // even though we can't be sure that it is the true "default".
 761 
 762   bool needs_guard = false;
 763   int default_dest;
 764   int64_t total_outlier_size = 0;
 765   int64_t hi_size = ((int64_t)hi->hi()) - ((int64_t)hi->lo()) + 1;
 766   int64_t lo_size = ((int64_t)lo->hi()) - ((int64_t)lo->lo()) + 1;
 767 
 768   if (lo->dest() == hi->dest()) {
 769     total_outlier_size = hi_size + lo_size;
 770     default_dest = lo->dest();
 771   } else if (lo_size > hi_size) {
 772     total_outlier_size = lo_size;
 773     default_dest = lo->dest();
 774   } else {
 775     total_outlier_size = hi_size;
 776     default_dest = hi->dest();
 777   }
 778 
 779   float total = sum_of_cnts(lo, hi);
 780   float cost = compute_tree_cost(lo, hi, total);
 781 
 782   // If a guard test will eliminate very sparse end ranges, then
 783   // it is worth the cost of an extra jump.
 784   float trimmed_cnt = 0;
 785   if (total_outlier_size > (MaxJumpTableSparseness * 4)) {
 786     needs_guard = true;
 787     if (default_dest == lo->dest()) {
 788       trimmed_cnt += lo->cnt();
 789       lo++;
 790     }
 791     if (default_dest == hi->dest()) {
 792       trimmed_cnt += hi->cnt();
 793       hi--;
 794     }
 795   }
 796 
 797   // Find the total number of cases and ranges
 798   int64_t num_cases = ((int64_t)hi->hi()) - ((int64_t)lo->lo()) + 1;
 799   int num_range = hi - lo + 1;
 800 
 801   // Don't create table if: too large, too small, or too sparse.
 802   if (num_cases > MaxJumpTableSize)
 803     return false;
 804   if (UseSwitchProfiling) {
 805     // MinJumpTableSize is set so with a well balanced binary tree,
 806     // when the number of ranges is MinJumpTableSize, it's cheaper to
 807     // go through a JumpNode that a tree of IfNodes. Average cost of a
 808     // tree of IfNodes with MinJumpTableSize is
 809     // log2f(MinJumpTableSize) comparisons. So if the cost computed
 810     // from profile data is less than log2f(MinJumpTableSize) then
 811     // going with the binary search is cheaper.
 812     if (cost < log2f(MinJumpTableSize)) {
 813       return false;
 814     }
 815   } else {
 816     if (num_cases < MinJumpTableSize)
 817       return false;
 818   }
 819   if (num_cases > (MaxJumpTableSparseness * num_range))
 820     return false;
 821 
 822   // Normalize table lookups to zero
 823   int lowval = lo->lo();
 824   key_val = _gvn.transform( new SubINode(key_val, _gvn.intcon(lowval)) );
 825 
 826   // Generate a guard to protect against input keyvals that aren't
 827   // in the switch domain.
 828   if (needs_guard) {
 829     Node*   size = _gvn.intcon(num_cases);
 830     Node*   cmp = _gvn.transform(new CmpUNode(key_val, size));
 831     Node*   tst = _gvn.transform(new BoolNode(cmp, BoolTest::ge));
 832     IfNode* iff = create_and_map_if(control(), tst, if_prob(trimmed_cnt, total), if_cnt(trimmed_cnt));
 833     jump_if_true_fork(iff, default_dest, trim_ranges && trimmed_cnt == 0);
 834 
 835     total -= trimmed_cnt;
 836   }
 837 
 838   // Create an ideal node JumpTable that has projections
 839   // of all possible ranges for a switch statement
 840   // The key_val input must be converted to a pointer offset and scaled.
 841   // Compare Parse::array_addressing above.
 842 
 843   // Clean the 32-bit int into a real 64-bit offset.
 844   // Otherwise, the jint value 0 might turn into an offset of 0x0800000000.
 845   // Make I2L conversion control dependent to prevent it from
 846   // floating above the range check during loop optimizations.
 847   // Do not use a narrow int type here to prevent the data path from dying
 848   // while the control path is not removed. This can happen if the type of key_val
 849   // is later known to be out of bounds of [0, num_cases] and therefore a narrow cast
 850   // would be replaced by TOP while C2 is not able to fold the corresponding range checks.
 851   // Set _carry_dependency for the cast to avoid being removed by IGVN.
 852 #ifdef _LP64
 853   key_val = C->constrained_convI2L(&_gvn, key_val, TypeInt::INT, control(), true /* carry_dependency */);
 854 #endif
 855 
 856   // Shift the value by wordsize so we have an index into the table, rather
 857   // than a switch value
 858   Node *shiftWord = _gvn.MakeConX(wordSize);
 859   key_val = _gvn.transform( new MulXNode( key_val, shiftWord));
 860 
 861   // Create the JumpNode
 862   Arena* arena = C->comp_arena();
 863   float* probs = (float*)arena->Amalloc(sizeof(float)*num_cases);
 864   int i = 0;
 865   if (total == 0) {
 866     for (SwitchRange* r = lo; r <= hi; r++) {
 867       for (int64_t j = r->lo(); j <= r->hi(); j++, i++) {
 868         probs[i] = 1.0F / num_cases;
 869       }
 870     }
 871   } else {
 872     for (SwitchRange* r = lo; r <= hi; r++) {
 873       float prob = r->cnt()/total;
 874       for (int64_t j = r->lo(); j <= r->hi(); j++, i++) {
 875         probs[i] = prob / (r->hi() - r->lo() + 1);
 876       }
 877     }
 878   }
 879 
 880   ciMethodData* methodData = method()->method_data();
 881   ciMultiBranchData* profile = nullptr;
 882   if (methodData->is_mature()) {
 883     ciProfileData* data = methodData->bci_to_data(bci());
 884     if (data != nullptr && data->is_MultiBranchData()) {
 885       profile = (ciMultiBranchData*)data;
 886     }
 887   }
 888 
 889   Node* jtn = _gvn.transform(new JumpNode(control(), key_val, num_cases, probs, profile == nullptr ? COUNT_UNKNOWN : total));
 890 
 891   // These are the switch destinations hanging off the jumpnode
 892   i = 0;
 893   for (SwitchRange* r = lo; r <= hi; r++) {
 894     for (int64_t j = r->lo(); j <= r->hi(); j++, i++) {
 895       Node* input = _gvn.transform(new JumpProjNode(jtn, i, r->dest(), (int)(j - lowval)));
 896       {
 897         PreserveJVMState pjvms(this);
 898         set_control(input);
 899         jump_if_always_fork(r->dest(), trim_ranges && r->cnt() == 0);
 900       }
 901     }
 902   }
 903   assert(i == num_cases, "miscount of cases");
 904   stop_and_kill_map();  // no more uses for this JVMS
 905   return true;
 906 }
 907 
 908 //----------------------------jump_switch_ranges-------------------------------
 909 void Parse::jump_switch_ranges(Node* key_val, SwitchRange *lo, SwitchRange *hi, int switch_depth) {
 910   Block* switch_block = block();
 911   bool trim_ranges = !C->too_many_traps(method(), bci(), Deoptimization::Reason_unstable_if);
 912 
 913   if (switch_depth == 0) {
 914     // Do special processing for the top-level call.
 915     assert(lo->lo() == min_jint, "initial range must exhaust Type::INT");
 916     assert(hi->hi() == max_jint, "initial range must exhaust Type::INT");
 917 
 918     // Decrement pred-numbers for the unique set of nodes.
 919 #ifdef ASSERT
 920     if (!trim_ranges) {
 921       // Ensure that the block's successors are a (duplicate-free) set.
 922       int successors_counted = 0;  // block occurrences in [hi..lo]
 923       int unique_successors = switch_block->num_successors();
 924       for (int i = 0; i < unique_successors; i++) {
 925         Block* target = switch_block->successor_at(i);
 926 
 927         // Check that the set of successors is the same in both places.
 928         int successors_found = 0;
 929         for (SwitchRange* p = lo; p <= hi; p++) {
 930           if (p->dest() == target->start())  successors_found++;
 931         }
 932         assert(successors_found > 0, "successor must be known");
 933         successors_counted += successors_found;
 934       }
 935       assert(successors_counted == (hi-lo)+1, "no unexpected successors");
 936     }
 937 #endif
 938 
 939     // Maybe prune the inputs, based on the type of key_val.
 940     jint min_val = min_jint;
 941     jint max_val = max_jint;
 942     const TypeInt* ti = key_val->bottom_type()->isa_int();
 943     if (ti != nullptr) {
 944       min_val = ti->_lo;
 945       max_val = ti->_hi;
 946       assert(min_val <= max_val, "invalid int type");
 947     }
 948     while (lo->hi() < min_val) {
 949       lo++;
 950     }
 951     if (lo->lo() < min_val)  {
 952       lo->setRange(min_val, lo->hi(), lo->dest(), lo->cnt());
 953     }
 954     while (hi->lo() > max_val) {
 955       hi--;
 956     }
 957     if (hi->hi() > max_val) {
 958       hi->setRange(hi->lo(), max_val, hi->dest(), hi->cnt());
 959     }
 960 
 961     linear_search_switch_ranges(key_val, lo, hi);
 962   }
 963 
 964 #ifndef PRODUCT
 965   if (switch_depth == 0) {
 966     _max_switch_depth = 0;
 967     _est_switch_depth = log2i_graceful((hi - lo + 1) - 1) + 1;
 968   }
 969   SwitchRange* orig_lo = lo;
 970   SwitchRange* orig_hi = hi;
 971 #endif
 972 
 973   // The lower-range processing is done iteratively to avoid O(N) stack depth
 974   // when the profiling-based pivot repeatedly selects mid==lo (JDK-8366138).
 975   // The upper-range processing remains recursive but is only reached for
 976   // balanced splits, bounding its depth to O(log N).
 977   // Termination: every iteration either exits or strictly decreases hi-lo:
 978   //   lo == mid && mid < hi, increments lo
 979   //   lo < mid <= hi, sets hi = mid - 1.
 980   for (int depth = switch_depth;; depth++) {
 981 #ifndef PRODUCT
 982     _max_switch_depth = MAX2(depth, _max_switch_depth);
 983 #endif
 984 
 985     assert(lo <= hi, "must be a non-empty set of ranges");
 986     if (lo == hi) {
 987       jump_if_always_fork(lo->dest(), trim_ranges && lo->cnt() == 0);
 988       break;
 989     }
 990 
 991     assert(lo->hi() == (lo+1)->lo()-1, "contiguous ranges");
 992     assert(hi->lo() == (hi-1)->hi()+1, "contiguous ranges");
 993 
 994     if (create_jump_tables(key_val, lo, hi)) return;
 995 
 996     SwitchRange* mid = nullptr;
 997     float total_cnt = sum_of_cnts(lo, hi);
 998 
 999     int nr = hi - lo + 1;
1000     // With total_cnt==0 the profiling pivot degenerates to mid==lo
1001     // (0 >= 0/2), producing a linear chain of If nodes instead of a
1002     // balanced tree. A balanced tree is strictly better here: all paths
1003     // are cold, so a balanced split gives fewer comparisons at runtime
1004     // and avoids pathological memory usage in the optimizer.
1005     if (UseSwitchProfiling && total_cnt > 0) {
1006       // Don't keep the binary search tree balanced: pick up mid point
1007       // that split frequencies in half.
1008       float cnt = 0;
1009       for (SwitchRange* sr = lo; sr <= hi; sr++) {
1010         cnt += sr->cnt();
1011         if (cnt >= total_cnt / 2) {
1012           mid = sr;
1013           break;
1014         }
1015       }
1016     } else {
1017       mid = lo + nr/2;
1018 
1019       // if there is an easy choice, pivot at a singleton:
1020       if (nr > 3 && !mid->is_singleton() && (mid-1)->is_singleton())  mid--;
1021 
1022       assert(lo < mid && mid <= hi, "good pivot choice");
1023       assert(nr != 2 || mid == hi,   "should pick higher of 2");
1024       assert(nr != 3 || mid == hi-1, "should pick middle of 3");
1025     }
1026     assert(mid != nullptr, "mid must be set");
1027 
1028     Node *test_val = _gvn.intcon(mid == lo ? mid->hi() : mid->lo());
1029 
1030     if (mid->is_singleton()) {
1031       IfNode *iff_ne = jump_if_fork_int(key_val, test_val, BoolTest::ne, 1-if_prob(mid->cnt(), total_cnt), if_cnt(mid->cnt()));
1032       jump_if_false_fork(iff_ne, mid->dest(), trim_ranges && mid->cnt() == 0);
1033 
1034       // Special Case:  If there are exactly three ranges, and the high
1035       // and low range each go to the same place, omit the "gt" test,
1036       // since it will not discriminate anything.
1037       bool eq_test_only = (hi == lo+2 && hi->dest() == lo->dest() && mid == hi-1) || mid == lo;
1038 
1039       // if there is a higher range, test for it and process it:
1040       if (mid < hi && !eq_test_only) {
1041         // two comparisons of same values--should enable 1 test for 2 branches
1042         // Use BoolTest::lt instead of BoolTest::gt
1043         float cnt = sum_of_cnts(lo, mid-1);
1044         IfNode *iff_lt  = jump_if_fork_int(key_val, test_val, BoolTest::lt, if_prob(cnt, total_cnt), if_cnt(cnt));
1045         Node   *iftrue  = _gvn.transform( new IfTrueNode(iff_lt) );
1046         Node   *iffalse = _gvn.transform( new IfFalseNode(iff_lt) );
1047         { PreserveJVMState pjvms(this);
1048           set_control(iffalse);
1049           jump_switch_ranges(key_val, mid+1, hi, depth+1);
1050         }
1051         set_control(iftrue);
1052       }
1053 
1054     } else {
1055       // mid is a range, not a singleton, so treat mid..hi as a unit
1056       float cnt = sum_of_cnts(mid == lo ? mid+1 : mid, hi);
1057       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));
1058 
1059       // if there is a higher range, test for it and process it:
1060       if (mid == hi) {
1061         jump_if_true_fork(iff_ge, mid->dest(), trim_ranges && cnt == 0);
1062       } else {
1063         Node *iftrue  = _gvn.transform( new IfTrueNode(iff_ge) );
1064         Node *iffalse = _gvn.transform( new IfFalseNode(iff_ge) );
1065         { PreserveJVMState pjvms(this);
1066           set_control(iftrue);
1067           jump_switch_ranges(key_val, mid == lo ? mid+1 : mid, hi, depth+1);
1068         }
1069         set_control(iffalse);
1070       }
1071     }
1072 
1073     // Process the lower range: iterate instead of recursing.
1074     if (mid == lo) {
1075       if (mid->is_singleton()) {
1076         lo++;
1077       } else {
1078         jump_if_always_fork(lo->dest(), trim_ranges && lo->cnt() == 0);
1079         break;
1080       }
1081     } else {
1082       hi = mid - 1;
1083     }
1084   }
1085 
1086   // Decrease pred_count for each successor after all is done.
1087   if (switch_depth == 0) {
1088     int unique_successors = switch_block->num_successors();
1089     for (int i = 0; i < unique_successors; i++) {
1090       Block* target = switch_block->successor_at(i);
1091       // Throw away the pre-allocated path for each unique successor.
1092       target->next_path_num();
1093     }
1094   }
1095 
1096 #ifndef PRODUCT
1097   if (TraceOptoParse && Verbose && WizardMode && switch_depth == 0) {
1098     SwitchRange* r;
1099     int nsing = 0;
1100     for (r = orig_lo; r <= orig_hi; r++) {
1101       if( r->is_singleton() )  nsing++;
1102     }
1103     tty->print(">>> ");
1104     _method->print_short_name();
1105     tty->print_cr(" switch decision tree");
1106     tty->print_cr("    %d ranges (%d singletons), max_depth=%d, est_depth=%d",
1107                   (int) (orig_hi-orig_lo+1), nsing, _max_switch_depth, _est_switch_depth);
1108     if (_max_switch_depth > _est_switch_depth) {
1109       tty->print_cr("******** BAD SWITCH DEPTH ********");
1110     }
1111     tty->print("   ");
1112     for (r = orig_lo; r <= orig_hi; r++) {
1113       r->print();
1114     }
1115     tty->cr();
1116   }
1117 #endif
1118 }
1119 
1120 Node* Parse::floating_point_mod(Node* a, Node* b, BasicType type) {
1121   assert(type == BasicType::T_FLOAT || type == BasicType::T_DOUBLE, "only float and double are floating points");
1122   CallLeafPureNode* mod = type == BasicType::T_DOUBLE ? static_cast<CallLeafPureNode*>(new ModDNode(C, a, b)) : new ModFNode(C, a, b);
1123 
1124   set_predefined_input_for_runtime_call(mod);
1125   mod = _gvn.transform(mod)->as_CallLeafPure();
1126   set_predefined_output_for_runtime_call(mod);
1127   Node* result = _gvn.transform(new ProjNode(mod, TypeFunc::Parms + 0));
1128   record_for_igvn(mod);
1129   return result;
1130 }
1131 
1132 void Parse::l2f() {
1133   Node* f2 = pop();
1134   Node* f1 = pop();
1135   Node* c = make_runtime_call(RC_LEAF, OptoRuntime::l2f_Type(),
1136                               CAST_FROM_FN_PTR(address, SharedRuntime::l2f),
1137                               "l2f", nullptr, //no memory effects
1138                               f1, f2);
1139   Node* res = _gvn.transform(new ProjNode(c, TypeFunc::Parms + 0));
1140 
1141   push(res);
1142 }
1143 
1144 // Handle jsr and jsr_w bytecode
1145 void Parse::do_jsr() {
1146   assert(bc() == Bytecodes::_jsr || bc() == Bytecodes::_jsr_w, "wrong bytecode");
1147 
1148   // Store information about current state, tagged with new _jsr_bci
1149   int return_bci = iter().next_bci();
1150   int jsr_bci    = (bc() == Bytecodes::_jsr) ? iter().get_dest() : iter().get_far_dest();
1151 
1152   // The way we do things now, there is only one successor block
1153   // for the jsr, because the target code is cloned by ciTypeFlow.
1154   Block* target = successor_for_bci(jsr_bci);
1155 
1156   // What got pushed?
1157   const Type* ret_addr = target->peek();
1158   assert(ret_addr->singleton(), "must be a constant (cloned jsr body)");
1159 
1160   // Effect on jsr on stack
1161   push(_gvn.makecon(ret_addr));
1162 
1163   // Flow to the jsr.
1164   merge(jsr_bci);
1165 }
1166 
1167 // Handle ret bytecode
1168 void Parse::do_ret() {
1169   // Find to whom we return.
1170   assert(block()->num_successors() == 1, "a ret can only go one place now");
1171   Block* target = block()->successor_at(0);
1172   assert(!target->is_ready(), "our arrival must be expected");
1173   int pnum = target->next_path_num();
1174   merge_common(target, pnum);
1175 }
1176 
1177 static bool has_injected_profile(BoolTest::mask btest, Node* test, int& taken, int& not_taken) {
1178   if (btest != BoolTest::eq && btest != BoolTest::ne) {
1179     // Only ::eq and ::ne are supported for profile injection.
1180     return false;
1181   }
1182   if (test->is_Cmp() &&
1183       test->in(1)->Opcode() == Op_ProfileBoolean) {
1184     ProfileBooleanNode* profile = (ProfileBooleanNode*)test->in(1);
1185     int false_cnt = profile->false_count();
1186     int  true_cnt = profile->true_count();
1187 
1188     // Counts matching depends on the actual test operation (::eq or ::ne).
1189     // No need to scale the counts because profile injection was designed
1190     // to feed exact counts into VM.
1191     taken     = (btest == BoolTest::eq) ? false_cnt :  true_cnt;
1192     not_taken = (btest == BoolTest::eq) ?  true_cnt : false_cnt;
1193 
1194     profile->consume();
1195     return true;
1196   }
1197   return false;
1198 }
1199 
1200 // Give up if too few (or too many, in which case the sum will overflow) counts to be meaningful.
1201 // We also check that individual counters are positive first, otherwise the sum can become positive.
1202 // (check for saturation, integer overflow, and immature counts)
1203 static bool counters_are_meaningful(int counter1, int counter2, int min) {
1204   // check for saturation, including "uint" values too big to fit in "int"
1205   if (counter1 < 0 || counter2 < 0) {
1206     return false;
1207   }
1208   // check for integer overflow of the sum
1209   int64_t sum = (int64_t)counter1 + (int64_t)counter2;
1210   STATIC_ASSERT(sizeof(counter1) < sizeof(sum));
1211   if (sum > INT_MAX) {
1212     return false;
1213   }
1214   // check if mature
1215   return (counter1 + counter2) >= min;
1216 }
1217 
1218 //--------------------------dynamic_branch_prediction--------------------------
1219 // Try to gather dynamic branch prediction behavior.  Return a probability
1220 // of the branch being taken and set the "cnt" field.  Returns a -1.0
1221 // if we need to use static prediction for some reason.
1222 float Parse::dynamic_branch_prediction(float &cnt, BoolTest::mask btest, Node* test) {
1223   ResourceMark rm;
1224 
1225   cnt  = COUNT_UNKNOWN;
1226 
1227   int     taken = 0;
1228   int not_taken = 0;
1229 
1230   bool use_mdo = !has_injected_profile(btest, test, taken, not_taken);
1231 
1232   if (use_mdo) {
1233     // Use MethodData information if it is available
1234     // FIXME: free the ProfileData structure
1235     ciMethodData* methodData = method()->method_data();
1236     if (!methodData->is_mature())  return PROB_UNKNOWN;
1237     ciProfileData* data = methodData->bci_to_data(bci());
1238     if (data == nullptr) {
1239       return PROB_UNKNOWN;
1240     }
1241     if (!data->is_JumpData())  return PROB_UNKNOWN;
1242 
1243     // get taken and not taken values
1244     // NOTE: saturated UINT_MAX values become negative,
1245     // as do counts above INT_MAX.
1246     taken = data->as_JumpData()->taken();
1247     not_taken = 0;
1248     if (data->is_BranchData()) {
1249       not_taken = data->as_BranchData()->not_taken();
1250     }
1251 
1252     // scale the counts to be commensurate with invocation counts:
1253     // NOTE: overflow for positive values is clamped at INT_MAX
1254     taken = method()->scale_count(taken);
1255     not_taken = method()->scale_count(not_taken);
1256   }
1257   // At this point, saturation or overflow is indicated by INT_MAX
1258   // or a negative value.
1259 
1260   // Give up if too few (or too many, in which case the sum will overflow) counts to be meaningful.
1261   // We also check that individual counters are positive first, otherwise the sum can become positive.
1262   if (!counters_are_meaningful(taken, not_taken, 40)) {
1263     if (C->log() != nullptr) {
1264       C->log()->elem("branch target_bci='%d' taken='%d' not_taken='%d'", iter().get_dest(), taken, not_taken);
1265     }
1266     return PROB_UNKNOWN;
1267   }
1268 
1269   // Compute frequency that we arrive here
1270   float sum = taken + not_taken;
1271   // Adjust, if this block is a cloned private block but the
1272   // Jump counts are shared.  Taken the private counts for
1273   // just this path instead of the shared counts.
1274   if( block()->count() > 0 )
1275     sum = block()->count();
1276   cnt = sum / FreqCountInvocations;
1277 
1278   // Pin probability to sane limits
1279   float prob;
1280   if( !taken )
1281     prob = (0+PROB_MIN) / 2;
1282   else if( !not_taken )
1283     prob = (1+PROB_MAX) / 2;
1284   else {                         // Compute probability of true path
1285     prob = (float)taken / (float)(taken + not_taken);
1286     if (prob > PROB_MAX)  prob = PROB_MAX;
1287     if (prob < PROB_MIN)   prob = PROB_MIN;
1288   }
1289 
1290   assert((cnt > 0.0f) && (prob > 0.0f),
1291          "Bad frequency assignment in if cnt=%g prob=%g taken=%d not_taken=%d", cnt, prob, taken, not_taken);
1292 
1293   if (C->log() != nullptr) {
1294     const char* prob_str = nullptr;
1295     if (prob >= PROB_MAX)  prob_str = (prob == PROB_MAX) ? "max" : "always";
1296     if (prob <= PROB_MIN)  prob_str = (prob == PROB_MIN) ? "min" : "never";
1297     char prob_str_buf[30];
1298     if (prob_str == nullptr) {
1299       jio_snprintf(prob_str_buf, sizeof(prob_str_buf), "%20.2f", prob);
1300       prob_str = prob_str_buf;
1301     }
1302     C->log()->elem("branch target_bci='%d' taken='%d' not_taken='%d' cnt='%f' prob='%s'",
1303                    iter().get_dest(), taken, not_taken, cnt, prob_str);
1304   }
1305   return prob;
1306 }
1307 
1308 //-----------------------------branch_prediction-------------------------------
1309 float Parse::branch_prediction(float& cnt,
1310                                BoolTest::mask btest,
1311                                int target_bci,
1312                                Node* test) {
1313   float prob = dynamic_branch_prediction(cnt, btest, test);
1314   // If prob is unknown, switch to static prediction
1315   if (prob != PROB_UNKNOWN)  return prob;
1316 
1317   prob = PROB_FAIR;                   // Set default value
1318   if (btest == BoolTest::eq)          // Exactly equal test?
1319     prob = PROB_STATIC_INFREQUENT;    // Assume its relatively infrequent
1320   else if (btest == BoolTest::ne)
1321     prob = PROB_STATIC_FREQUENT;      // Assume its relatively frequent
1322 
1323   // If this is a conditional test guarding a backwards branch,
1324   // assume its a loop-back edge.  Make it a likely taken branch.
1325   if (target_bci < bci()) {
1326     if (is_osr_parse()) {    // Could be a hot OSR'd loop; force deopt
1327       // Since it's an OSR, we probably have profile data, but since
1328       // branch_prediction returned PROB_UNKNOWN, the counts are too small.
1329       // Let's make a special check here for completely zero counts.
1330       ciMethodData* methodData = method()->method_data();
1331       if (!methodData->is_empty()) {
1332         ciProfileData* data = methodData->bci_to_data(bci());
1333         // Only stop for truly zero counts, which mean an unknown part
1334         // of the OSR-ed method, and we want to deopt to gather more stats.
1335         // If you have ANY counts, then this loop is simply 'cold' relative
1336         // to the OSR loop.
1337         if (data == nullptr ||
1338             (data->as_BranchData()->taken() +  data->as_BranchData()->not_taken() == 0)) {
1339           // This is the only way to return PROB_UNKNOWN:
1340           return PROB_UNKNOWN;
1341         }
1342       }
1343     }
1344     prob = PROB_STATIC_FREQUENT;     // Likely to take backwards branch
1345   }
1346 
1347   assert(prob != PROB_UNKNOWN, "must have some guess at this point");
1348   return prob;
1349 }
1350 
1351 // The magic constants are chosen so as to match the output of
1352 // branch_prediction() when the profile reports a zero taken count.
1353 // It is important to distinguish zero counts unambiguously, because
1354 // some branches (e.g., _213_javac.Assembler.eliminate) validly produce
1355 // very small but nonzero probabilities, which if confused with zero
1356 // counts would keep the program recompiling indefinitely.
1357 bool Parse::seems_never_taken(float prob) const {
1358   return prob < PROB_MIN;
1359 }
1360 
1361 //-------------------------------repush_if_args--------------------------------
1362 // Push arguments of an "if" bytecode back onto the stack by adjusting _sp.
1363 inline int Parse::repush_if_args() {
1364   if (PrintOpto && WizardMode) {
1365     tty->print("defending against excessive implicit null exceptions on %s @%d in ",
1366                Bytecodes::name(iter().cur_bc()), iter().cur_bci());
1367     method()->print_name(); tty->cr();
1368   }
1369   int bc_depth = - Bytecodes::depth(iter().cur_bc());
1370   assert(bc_depth == 1 || bc_depth == 2, "only two kinds of branches");
1371   DEBUG_ONLY(sync_jvms());   // argument(n) requires a synced jvms
1372   assert(argument(0) != nullptr, "must exist");
1373   assert(bc_depth == 1 || argument(1) != nullptr, "two must exist");
1374   inc_sp(bc_depth);
1375   return bc_depth;
1376 }
1377 
1378 // Used by StressUnstableIfTraps
1379 static volatile int _trap_stress_counter = 0;
1380 
1381 void Parse::increment_trap_stress_counter(Node*& counter, Node*& incr_store) {
1382   Node* counter_addr = makecon(TypeRawPtr::make((address)&_trap_stress_counter));
1383   counter = make_load(control(), counter_addr, TypeInt::INT, T_INT, MemNode::unordered);
1384   counter = _gvn.transform(new AddINode(counter, intcon(1)));
1385   incr_store = store_to_memory(control(), counter_addr, counter, T_INT, MemNode::unordered);
1386 }
1387 
1388 //----------------------------------do_ifnull----------------------------------
1389 void Parse::do_ifnull(BoolTest::mask btest, Node *c) {
1390   int target_bci = iter().get_dest();
1391 
1392   Node* counter = nullptr;
1393   Node* incr_store = nullptr;
1394   bool do_stress_trap = StressUnstableIfTraps && ((C->random() % 2) == 0);
1395   if (do_stress_trap) {
1396     increment_trap_stress_counter(counter, incr_store);
1397   }
1398 
1399   Block* branch_block = successor_for_bci(target_bci);
1400   Block* next_block   = successor_for_bci(iter().next_bci());
1401 
1402   float cnt;
1403   float prob = branch_prediction(cnt, btest, target_bci, c);
1404   if (prob == PROB_UNKNOWN) {
1405     // (An earlier version of do_ifnull omitted this trap for OSR methods.)
1406     if (PrintOpto && Verbose) {
1407       tty->print_cr("Never-taken edge stops compilation at bci %d", bci());
1408     }
1409     repush_if_args(); // to gather stats on loop
1410     uncommon_trap(Deoptimization::Reason_unreached,
1411                   Deoptimization::Action_reinterpret,
1412                   nullptr, "cold");
1413     if (C->eliminate_boxing()) {
1414       // Mark the successor blocks as parsed
1415       branch_block->next_path_num();
1416       next_block->next_path_num();
1417     }
1418     return;
1419   }
1420 
1421   NOT_PRODUCT(explicit_null_checks_inserted++);
1422 
1423   // Generate real control flow
1424   Node   *tst = _gvn.transform( new BoolNode( c, btest ) );
1425 
1426   // Sanity check the probability value
1427   assert(prob > 0.0f,"Bad probability in Parser");
1428  // Need xform to put node in hash table
1429   IfNode *iff = create_and_xform_if( control(), tst, prob, cnt );
1430   assert(iff->_prob > 0.0f,"Optimizer made bad probability in parser");
1431   // True branch
1432   { PreserveJVMState pjvms(this);
1433     Node* iftrue  = _gvn.transform( new IfTrueNode (iff) );
1434     set_control(iftrue);
1435 
1436     if (stopped()) {            // Path is dead?
1437       NOT_PRODUCT(explicit_null_checks_elided++);
1438       if (C->eliminate_boxing()) {
1439         // Mark the successor block as parsed
1440         branch_block->next_path_num();
1441       }
1442     } else {                    // Path is live.
1443       adjust_map_after_if(btest, c, prob, branch_block);
1444       if (!stopped()) {
1445         merge(target_bci);
1446       }
1447     }
1448   }
1449 
1450   // False branch
1451   Node* iffalse = _gvn.transform( new IfFalseNode(iff) );
1452   set_control(iffalse);
1453 
1454   if (stopped()) {              // Path is dead?
1455     NOT_PRODUCT(explicit_null_checks_elided++);
1456     if (C->eliminate_boxing()) {
1457       // Mark the successor block as parsed
1458       next_block->next_path_num();
1459     }
1460   } else  {                     // Path is live.
1461     adjust_map_after_if(BoolTest(btest).negate(), c, 1.0-prob, next_block);
1462   }
1463 
1464   if (do_stress_trap) {
1465     stress_trap(iff, counter, incr_store);
1466   }
1467 }
1468 
1469 //------------------------------------do_if------------------------------------
1470 void Parse::do_if(BoolTest::mask btest, Node* c) {
1471   int target_bci = iter().get_dest();
1472 
1473   Block* branch_block = successor_for_bci(target_bci);
1474   Block* next_block   = successor_for_bci(iter().next_bci());
1475 
1476   float cnt;
1477   float prob = branch_prediction(cnt, btest, target_bci, c);
1478   float untaken_prob = 1.0 - prob;
1479 
1480   if (prob == PROB_UNKNOWN) {
1481     if (PrintOpto && Verbose) {
1482       tty->print_cr("Never-taken edge stops compilation at bci %d", bci());
1483     }
1484     repush_if_args(); // to gather stats on loop
1485     uncommon_trap(Deoptimization::Reason_unreached,
1486                   Deoptimization::Action_reinterpret,
1487                   nullptr, "cold");
1488     if (C->eliminate_boxing()) {
1489       // Mark the successor blocks as parsed
1490       branch_block->next_path_num();
1491       next_block->next_path_num();
1492     }
1493     return;
1494   }
1495 
1496   Node* counter = nullptr;
1497   Node* incr_store = nullptr;
1498   bool do_stress_trap = StressUnstableIfTraps && ((C->random() % 2) == 0);
1499   if (do_stress_trap) {
1500     increment_trap_stress_counter(counter, incr_store);
1501   }
1502 
1503   // Sanity check the probability value
1504   assert(0.0f < prob && prob < 1.0f,"Bad probability in Parser");
1505 
1506   bool taken_if_true = true;
1507   // Convert BoolTest to canonical form:
1508   if (!BoolTest(btest).is_canonical()) {
1509     btest         = BoolTest(btest).negate();
1510     taken_if_true = false;
1511     // prob is NOT updated here; it remains the probability of the taken
1512     // path (as opposed to the prob of the path guarded by an 'IfTrueNode').
1513   }
1514   assert(btest != BoolTest::eq, "!= is the only canonical exact test");
1515 
1516   Node* tst0 = new BoolNode(c, btest);
1517   Node* tst = _gvn.transform(tst0);
1518   BoolTest::mask taken_btest   = BoolTest::illegal;
1519   BoolTest::mask untaken_btest = BoolTest::illegal;
1520 
1521   if (tst->is_Bool()) {
1522     // Refresh c from the transformed bool node, since it may be
1523     // simpler than the original c.  Also re-canonicalize btest.
1524     // This wins when (Bool ne (Conv2B p) 0) => (Bool ne (CmpP p null)).
1525     // That can arise from statements like: if (x instanceof C) ...
1526     if (tst != tst0) {
1527       // Canonicalize one more time since transform can change it.
1528       btest = tst->as_Bool()->_test._test;
1529       if (!BoolTest(btest).is_canonical()) {
1530         // Reverse edges one more time...
1531         tst   = _gvn.transform( tst->as_Bool()->negate(&_gvn) );
1532         btest = tst->as_Bool()->_test._test;
1533         assert(BoolTest(btest).is_canonical(), "sanity");
1534         taken_if_true = !taken_if_true;
1535       }
1536       c = tst->in(1);
1537     }
1538     BoolTest::mask neg_btest = BoolTest(btest).negate();
1539     taken_btest   = taken_if_true ?     btest : neg_btest;
1540     untaken_btest = taken_if_true ? neg_btest :     btest;
1541   }
1542 
1543   // Generate real control flow
1544   float true_prob = (taken_if_true ? prob : untaken_prob);
1545   IfNode* iff = create_and_map_if(control(), tst, true_prob, cnt);
1546   assert(iff->_prob > 0.0f,"Optimizer made bad probability in parser");
1547   Node* taken_branch   = new IfTrueNode(iff);
1548   Node* untaken_branch = new IfFalseNode(iff);
1549   if (!taken_if_true) {  // Finish conversion to canonical form
1550     Node* tmp      = taken_branch;
1551     taken_branch   = untaken_branch;
1552     untaken_branch = tmp;
1553   }
1554 
1555   // Branch is taken:
1556   { PreserveJVMState pjvms(this);
1557     taken_branch = _gvn.transform(taken_branch);
1558     set_control(taken_branch);
1559 
1560     if (stopped()) {
1561       if (C->eliminate_boxing()) {
1562         // Mark the successor block as parsed
1563         branch_block->next_path_num();
1564       }
1565     } else {
1566       adjust_map_after_if(taken_btest, c, prob, branch_block);
1567       if (!stopped()) {
1568         merge(target_bci);
1569       }
1570     }
1571   }
1572 
1573   untaken_branch = _gvn.transform(untaken_branch);
1574   set_control(untaken_branch);
1575 
1576   // Branch not taken.
1577   if (stopped()) {
1578     if (C->eliminate_boxing()) {
1579       // Mark the successor block as parsed
1580       next_block->next_path_num();
1581     }
1582   } else {
1583     adjust_map_after_if(untaken_btest, c, untaken_prob, next_block);
1584   }
1585 
1586   if (do_stress_trap) {
1587     stress_trap(iff, counter, incr_store);
1588   }
1589 }
1590 
1591 // Force unstable if traps to be taken randomly to trigger intermittent bugs such as incorrect debug information.
1592 // Add another if before the unstable if that checks a "random" condition at runtime (a simple shared counter) and
1593 // then either takes the trap or executes the original, unstable if.
1594 void Parse::stress_trap(IfNode* orig_iff, Node* counter, Node* incr_store) {
1595   // Search for an unstable if trap
1596   CallStaticJavaNode* trap = nullptr;
1597   assert(orig_iff->Opcode() == Op_If && orig_iff->outcnt() == 2, "malformed if");
1598   ProjNode* trap_proj = orig_iff->uncommon_trap_proj(trap, Deoptimization::Reason_unstable_if);
1599   if (trap == nullptr || !trap->jvms()->should_reexecute()) {
1600     // No suitable trap found. Remove unused counter load and increment.
1601     C->gvn_replace_by(incr_store, incr_store->in(MemNode::Memory));
1602     return;
1603   }
1604 
1605   // Remove trap from optimization list since we add another path to the trap.
1606   bool success = C->remove_unstable_if_trap(trap, true);
1607   assert(success, "Trap already modified");
1608 
1609   // Add a check before the original if that will trap with a certain frequency and execute the original if otherwise
1610   int freq_log = (C->random() % 31) + 1; // Random logarithmic frequency in [1, 31]
1611   Node* mask = intcon(right_n_bits(freq_log));
1612   counter = _gvn.transform(new AndINode(counter, mask));
1613   Node* cmp = _gvn.transform(new CmpINode(counter, intcon(0)));
1614   Node* bol = _gvn.transform(new BoolNode(cmp, BoolTest::mask::eq));
1615   IfNode* iff = _gvn.transform(new IfNode(orig_iff->in(0), bol, orig_iff->_prob, orig_iff->_fcnt))->as_If();
1616   Node* if_true = _gvn.transform(new IfTrueNode(iff));
1617   Node* if_false = _gvn.transform(new IfFalseNode(iff));
1618   assert(!if_true->is_top() && !if_false->is_top(), "trap always / never taken");
1619 
1620   // Trap
1621   assert(trap_proj->outcnt() == 1, "some other nodes are dependent on the trap projection");
1622 
1623   Node* trap_region = new RegionNode(3);
1624   trap_region->set_req(1, trap_proj);
1625   trap_region->set_req(2, if_true);
1626   trap->set_req(0, _gvn.transform(trap_region));
1627 
1628   // Don't trap, execute original if
1629   orig_iff->set_req(0, if_false);
1630 }
1631 
1632 bool Parse::path_is_suitable_for_uncommon_trap(float prob) const {
1633   // Randomly skip emitting an uncommon trap
1634   if (StressUnstableIfTraps && ((C->random() % 2) == 0)) {
1635     return false;
1636   }
1637   // Don't want to speculate on uncommon traps when running with -Xcomp
1638   if (!UseInterpreter) {
1639     return false;
1640   }
1641   return seems_never_taken(prob) &&
1642          !C->too_many_traps(method(), bci(), Deoptimization::Reason_unstable_if);
1643 }
1644 
1645 void Parse::maybe_add_predicate_after_if(Block* path) {
1646   if (path->is_SEL_head() && path->preds_parsed() == 0) {
1647     // Add predicates at bci of if dominating the loop so traps can be
1648     // recorded on the if's profile data
1649     int bc_depth = repush_if_args();
1650     add_parse_predicates();
1651     dec_sp(bc_depth);
1652     path->set_has_predicates();
1653   }
1654 }
1655 
1656 
1657 //----------------------------adjust_map_after_if------------------------------
1658 // Adjust the JVM state to reflect the result of taking this path.
1659 // Basically, it means inspecting the CmpNode controlling this
1660 // branch, seeing how it constrains a tested value, and then
1661 // deciding if it's worth our while to encode this constraint
1662 // as graph nodes in the current abstract interpretation map.
1663 void Parse::adjust_map_after_if(BoolTest::mask btest, Node* c, float prob, Block* path) {
1664   if (!c->is_Cmp()) {
1665     maybe_add_predicate_after_if(path);
1666     return;
1667   }
1668 
1669   if (stopped() || btest == BoolTest::illegal) {
1670     return;                             // nothing to do
1671   }
1672 
1673   bool is_fallthrough = (path == successor_for_bci(iter().next_bci()));
1674 
1675   if (path_is_suitable_for_uncommon_trap(prob)) {
1676     repush_if_args();
1677     Node* call = uncommon_trap(Deoptimization::Reason_unstable_if,
1678                   Deoptimization::Action_reinterpret,
1679                   nullptr,
1680                   (is_fallthrough ? "taken always" : "taken never"));
1681 
1682     if (call != nullptr) {
1683       C->record_unstable_if_trap(new UnstableIfTrap(call->as_CallStaticJava(), path));
1684     }
1685     return;
1686   }
1687 
1688   Node* val = c->in(1);
1689   Node* con = c->in(2);
1690   const Type* tcon = _gvn.type(con);
1691   const Type* tval = _gvn.type(val);
1692   bool have_con = tcon->singleton();
1693   if (tval->singleton()) {
1694     if (!have_con) {
1695       // Swap, so constant is in con.
1696       con  = val;
1697       tcon = tval;
1698       val  = c->in(2);
1699       tval = _gvn.type(val);
1700       btest = BoolTest(btest).commute();
1701       have_con = true;
1702     } else {
1703       // Do we have two constants?  Then leave well enough alone.
1704       have_con = false;
1705     }
1706   }
1707   if (!have_con) {                        // remaining adjustments need a con
1708     maybe_add_predicate_after_if(path);
1709     return;
1710   }
1711 
1712   sharpen_type_after_if(btest, con, tcon, val, tval);
1713   maybe_add_predicate_after_if(path);
1714 }
1715 
1716 
1717 static Node* extract_obj_from_klass_load(PhaseGVN* gvn, Node* n) {
1718   Node* ldk;
1719   if (n->is_DecodeNKlass()) {
1720     if (n->in(1)->Opcode() != Op_LoadNKlass) {
1721       return nullptr;
1722     } else {
1723       ldk = n->in(1);
1724     }
1725   } else if (n->Opcode() != Op_LoadKlass) {
1726     return nullptr;
1727   } else {
1728     ldk = n;
1729   }
1730   assert(ldk != nullptr && ldk->is_Load(), "should have found a LoadKlass or LoadNKlass node");
1731 
1732   Node* adr = ldk->in(MemNode::Address);
1733   intptr_t off = 0;
1734   Node* obj = AddPNode::Ideal_base_and_offset(adr, gvn, off);
1735   if (obj == nullptr || off != oopDesc::klass_offset_in_bytes()) // loading oopDesc::_klass?
1736     return nullptr;
1737   const TypePtr* tp = gvn->type(obj)->is_ptr();
1738   if (tp == nullptr || !(tp->isa_instptr() || tp->isa_aryptr())) // is obj a Java object ptr?
1739     return nullptr;
1740 
1741   return obj;
1742 }
1743 
1744 // Matches exact and inexact type check IR shapes during parsing.
1745 // On successful match, returns type checked object node and its type after successful check
1746 // as out parameters.
1747 static bool match_type_check(PhaseGVN& gvn,
1748                              BoolTest::mask btest,
1749                              Node* con, const Type* tcon,
1750                              Node* val, const Type* tval,
1751                              Node** obj, const TypeOopPtr** cast_type) { // out-parameters
1752   // Look for opportunities to sharpen the type of a node whose klass is compared with a constant klass.
1753   // The constant klass being tested against can come from many bytecode instructions (implicitly or explicitly),
1754   // and also from profile data used by speculative casts.
1755   if (btest == BoolTest::eq && tcon->isa_klassptr()) {
1756     // Found:
1757     //   Bool(CmpP(LoadKlass(obj._klass), ConP(Foo.klass)), [eq])
1758     // or the narrowOop equivalent.
1759     (*obj) = extract_obj_from_klass_load(&gvn, val);
1760     (*cast_type) = tcon->isa_klassptr()->as_instance_type();
1761     return true; // found
1762   }
1763 
1764   // Match an instanceof check.
1765   // During parsing its IR shape is not canonicalized yet.
1766   //
1767   //             obj superklass
1768   //              |    |
1769   //           SubTypeCheck
1770   //                |
1771   //               Bool [eq] / [ne]
1772   //                |
1773   //                If
1774   //               / \
1775   //              T   F
1776   //               \ /
1777   //              Region
1778   //                 \  ConI ConI
1779   //                  \  |  /
1780   //          val ->    Phi  ConI  <- con
1781   //                     \  /
1782   //                     CmpI
1783   //                      |
1784   //                    Bool [btest]
1785   //                      |
1786   //
1787   if (tval->isa_int() && val->is_Phi() && val->in(0)->as_Region()->is_diamond()) {
1788     RegionNode* diamond = val->in(0)->as_Region();
1789     IfNode* if1 = diamond->in(1)->in(0)->as_If();
1790     BoolNode* b1 = if1->in(1)->isa_Bool();
1791     if (b1 != nullptr && b1->in(1)->isa_SubTypeCheck()) {
1792       assert(b1->_test._test == BoolTest::eq ||
1793              b1->_test._test == BoolTest::ne, "%d", b1->_test._test);
1794 
1795       ProjNode* success_proj = if1->proj_out(b1->_test._test == BoolTest::eq ? 1 : 0);
1796       int idx = diamond->find_edge(success_proj);
1797       assert(idx == 1 || idx == 2, "");
1798       Node* vcon = val->in(idx);
1799 
1800       assert(val->find_edge(con) > 0, "");
1801       if ((btest == BoolTest::eq && vcon == con) || (btest == BoolTest::ne && vcon != con)) {
1802         SubTypeCheckNode* sub = b1->in(1)->as_SubTypeCheck();
1803         Node* obj_or_subklass = sub->in(SubTypeCheckNode::ObjOrSubKlass);
1804         Node* superklass = sub->in(SubTypeCheckNode::SuperKlass);
1805 
1806         if (gvn.type(obj_or_subklass)->isa_oopptr()) {
1807           const TypeKlassPtr* klass_ptr_type = gvn.type(superklass)->is_klassptr();
1808           const TypeKlassPtr* improved_klass_ptr_type = klass_ptr_type->try_improve();
1809 
1810           (*obj) = obj_or_subklass;
1811           (*cast_type) = improved_klass_ptr_type->cast_to_exactness(false)->as_instance_type();
1812           return true; // found
1813         }
1814       }
1815     }
1816   }
1817   return false; // not found
1818 }
1819 
1820 void Parse::sharpen_type_after_if(BoolTest::mask btest,
1821                                   Node* con, const Type* tcon,
1822                                   Node* val, const Type* tval) {
1823   Node* obj = nullptr;
1824   const TypeOopPtr* cast_type = nullptr;
1825   // Insert a cast node with a narrowed type after a successful type check.
1826   if (match_type_check(_gvn, btest, con, tcon, val, tval,
1827                        &obj, &cast_type)) {
1828     assert(obj != nullptr && cast_type != nullptr, "missing type check info");
1829     const Type* obj_type = _gvn.type(obj);
1830     const TypeOopPtr* tboth = obj_type->join_speculative(cast_type)->isa_oopptr();
1831     if (tboth != nullptr && tboth != obj_type && tboth->higher_equal(obj_type)) {
1832       int obj_in_map = map()->find_edge(obj);
1833       JVMState* jvms = this->jvms();
1834       if (obj_in_map >= 0 &&
1835           (jvms->is_loc(obj_in_map) || jvms->is_stk(obj_in_map))) {
1836         TypeNode* ccast = new CheckCastPPNode(control(), obj, tboth);
1837         const Type* tcc = ccast->as_Type()->type();
1838         assert(tcc != obj_type && tcc->higher_equal(obj_type), "must improve");
1839         // Delay transform() call to allow recovery of pre-cast value
1840         // at the control merge.
1841         _gvn.set_type_bottom(ccast);
1842         record_for_igvn(ccast);
1843         // Here's the payoff.
1844         replace_in_map(obj, ccast);
1845       }
1846     }
1847   }
1848 
1849   int val_in_map = map()->find_edge(val);
1850   if (val_in_map < 0)  return;          // replace_in_map would be useless
1851   {
1852     JVMState* jvms = this->jvms();
1853     if (!(jvms->is_loc(val_in_map) ||
1854           jvms->is_stk(val_in_map)))
1855       return;                           // again, it would be useless
1856   }
1857 
1858   // Check for a comparison to a constant, and "know" that the compared
1859   // value is constrained on this path.
1860   assert(tcon->singleton(), "");
1861   ConstraintCastNode* ccast = nullptr;
1862   Node* cast = nullptr;
1863 
1864   switch (btest) {
1865   case BoolTest::eq:                    // Constant test?
1866     {
1867       const Type* tboth = tcon->join_speculative(tval);
1868       if (tboth == tval)  break;        // Nothing to gain.
1869       if (tcon->isa_int()) {
1870         ccast = new CastIINode(control(), val, tboth);
1871       } else if (tcon == TypePtr::NULL_PTR) {
1872         // Cast to null, but keep the pointer identity temporarily live.
1873         ccast = new CastPPNode(control(), val, tboth);
1874       } else {
1875         const TypeF* tf = tcon->isa_float_constant();
1876         const TypeD* td = tcon->isa_double_constant();
1877         // Exclude tests vs float/double 0 as these could be
1878         // either +0 or -0.  Just because you are equal to +0
1879         // doesn't mean you ARE +0!
1880         // Note, following code also replaces Long and Oop values.
1881         if ((!tf || tf->_f != 0.0) &&
1882             (!td || td->_d != 0.0))
1883           cast = con;                   // Replace non-constant val by con.
1884       }
1885     }
1886     break;
1887 
1888   case BoolTest::ne:
1889     if (tcon == TypePtr::NULL_PTR) {
1890       cast = cast_not_null(val, false);
1891     }
1892     break;
1893 
1894   default:
1895     // (At this point we could record int range types with CastII.)
1896     break;
1897   }
1898 
1899   if (ccast != nullptr) {
1900     const Type* tcc = ccast->as_Type()->type();
1901     assert(tcc != tval && tcc->higher_equal(tval), "must improve");
1902     // Delay transform() call to allow recovery of pre-cast value
1903     // at the control merge.
1904     _gvn.set_type_bottom(ccast);
1905     record_for_igvn(ccast);
1906     cast = ccast;
1907   }
1908 
1909   if (cast != nullptr) {                   // Here's the payoff.
1910     replace_in_map(val, cast);
1911   }
1912 }
1913 
1914 /**
1915  * Use speculative type to optimize CmpP node: if comparison is
1916  * against the low level class, cast the object to the speculative
1917  * type if any. CmpP should then go away.
1918  *
1919  * @param c  expected CmpP node
1920  * @return   result of CmpP on object casted to speculative type
1921  *
1922  */
1923 Node* Parse::optimize_cmp_with_klass(Node* c) {
1924   // If this is transformed by the _gvn to a comparison with the low
1925   // level klass then we may be able to use speculation
1926   if (c->Opcode() == Op_CmpP &&
1927       (c->in(1)->Opcode() == Op_LoadKlass || c->in(1)->Opcode() == Op_DecodeNKlass) &&
1928       c->in(2)->is_Con()) {
1929     Node* load_klass = nullptr;
1930     Node* decode = nullptr;
1931     if (c->in(1)->Opcode() == Op_DecodeNKlass) {
1932       decode = c->in(1);
1933       load_klass = c->in(1)->in(1);
1934     } else {
1935       load_klass = c->in(1);
1936     }
1937     if (load_klass->in(2)->is_AddP()) {
1938       Node* addp = load_klass->in(2);
1939       Node* obj = addp->in(AddPNode::Address);
1940       const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
1941       if (obj_type->speculative_type_not_null() != nullptr) {
1942         ciKlass* k = obj_type->speculative_type();
1943         inc_sp(2);
1944         obj = maybe_cast_profiled_obj(obj, k);
1945         dec_sp(2);
1946         // Make the CmpP use the casted obj
1947         addp = basic_plus_adr(obj, addp->in(AddPNode::Offset));
1948         load_klass = load_klass->clone();
1949         load_klass->set_req(2, addp);
1950         load_klass = _gvn.transform(load_klass);
1951         if (decode != nullptr) {
1952           decode = decode->clone();
1953           decode->set_req(1, load_klass);
1954           load_klass = _gvn.transform(decode);
1955         }
1956         c = c->clone();
1957         c->set_req(1, load_klass);
1958         c = _gvn.transform(c);
1959       }
1960     }
1961   }
1962   return c;
1963 }
1964 
1965 //------------------------------do_one_bytecode--------------------------------
1966 // Parse this bytecode, and alter the Parsers JVM->Node mapping
1967 void Parse::do_one_bytecode() {
1968   Node *a, *b, *c, *d;          // Handy temps
1969   BoolTest::mask btest;
1970   int i;
1971 
1972   assert(!has_exceptions(), "bytecode entry state must be clear of throws");
1973 
1974   if (C->check_node_count(NodeLimitFudgeFactor * 5,
1975                           "out of nodes parsing method")) {
1976     return;
1977   }
1978 
1979 #ifdef ASSERT
1980   // for setting breakpoints
1981   if (TraceOptoParse) {
1982     tty->print(" @");
1983     dump_bci(bci());
1984     tty->print(" %s", Bytecodes::name(bc()));
1985     tty->cr();
1986   }
1987 #endif
1988 
1989   switch (bc()) {
1990   case Bytecodes::_nop:
1991     // do nothing
1992     break;
1993   case Bytecodes::_lconst_0:
1994     push_pair(longcon(0));
1995     break;
1996 
1997   case Bytecodes::_lconst_1:
1998     push_pair(longcon(1));
1999     break;
2000 
2001   case Bytecodes::_fconst_0:
2002     push(zerocon(T_FLOAT));
2003     break;
2004 
2005   case Bytecodes::_fconst_1:
2006     push(makecon(TypeF::ONE));
2007     break;
2008 
2009   case Bytecodes::_fconst_2:
2010     push(makecon(TypeF::make(2.0f)));
2011     break;
2012 
2013   case Bytecodes::_dconst_0:
2014     push_pair(zerocon(T_DOUBLE));
2015     break;
2016 
2017   case Bytecodes::_dconst_1:
2018     push_pair(makecon(TypeD::ONE));
2019     break;
2020 
2021   case Bytecodes::_iconst_m1:push(intcon(-1)); break;
2022   case Bytecodes::_iconst_0: push(intcon( 0)); break;
2023   case Bytecodes::_iconst_1: push(intcon( 1)); break;
2024   case Bytecodes::_iconst_2: push(intcon( 2)); break;
2025   case Bytecodes::_iconst_3: push(intcon( 3)); break;
2026   case Bytecodes::_iconst_4: push(intcon( 4)); break;
2027   case Bytecodes::_iconst_5: push(intcon( 5)); break;
2028   case Bytecodes::_bipush:   push(intcon(iter().get_constant_u1())); break;
2029   case Bytecodes::_sipush:   push(intcon(iter().get_constant_u2())); break;
2030   case Bytecodes::_aconst_null: push(null());  break;
2031 
2032   case Bytecodes::_ldc:
2033   case Bytecodes::_ldc_w:
2034   case Bytecodes::_ldc2_w: {
2035     // ciTypeFlow should trap if the ldc is in error state or if the constant is not loaded
2036     assert(!iter().is_in_error(), "ldc is in error state");
2037     ciConstant constant = iter().get_constant();
2038     assert(constant.is_loaded(), "constant is not loaded");
2039     const Type* con_type = Type::make_from_constant(constant);
2040     if (con_type != nullptr) {
2041       push_node(con_type->basic_type(), makecon(con_type));
2042     }
2043     break;
2044   }
2045 
2046   case Bytecodes::_aload_0:
2047     push( local(0) );
2048     break;
2049   case Bytecodes::_aload_1:
2050     push( local(1) );
2051     break;
2052   case Bytecodes::_aload_2:
2053     push( local(2) );
2054     break;
2055   case Bytecodes::_aload_3:
2056     push( local(3) );
2057     break;
2058   case Bytecodes::_aload:
2059     push( local(iter().get_index()) );
2060     break;
2061 
2062   case Bytecodes::_fload_0:
2063   case Bytecodes::_iload_0:
2064     push( local(0) );
2065     break;
2066   case Bytecodes::_fload_1:
2067   case Bytecodes::_iload_1:
2068     push( local(1) );
2069     break;
2070   case Bytecodes::_fload_2:
2071   case Bytecodes::_iload_2:
2072     push( local(2) );
2073     break;
2074   case Bytecodes::_fload_3:
2075   case Bytecodes::_iload_3:
2076     push( local(3) );
2077     break;
2078   case Bytecodes::_fload:
2079   case Bytecodes::_iload:
2080     push( local(iter().get_index()) );
2081     break;
2082   case Bytecodes::_lload_0:
2083     push_pair_local( 0 );
2084     break;
2085   case Bytecodes::_lload_1:
2086     push_pair_local( 1 );
2087     break;
2088   case Bytecodes::_lload_2:
2089     push_pair_local( 2 );
2090     break;
2091   case Bytecodes::_lload_3:
2092     push_pair_local( 3 );
2093     break;
2094   case Bytecodes::_lload:
2095     push_pair_local( iter().get_index() );
2096     break;
2097 
2098   case Bytecodes::_dload_0:
2099     push_pair_local(0);
2100     break;
2101   case Bytecodes::_dload_1:
2102     push_pair_local(1);
2103     break;
2104   case Bytecodes::_dload_2:
2105     push_pair_local(2);
2106     break;
2107   case Bytecodes::_dload_3:
2108     push_pair_local(3);
2109     break;
2110   case Bytecodes::_dload:
2111     push_pair_local(iter().get_index());
2112     break;
2113   case Bytecodes::_fstore_0:
2114   case Bytecodes::_istore_0:
2115   case Bytecodes::_astore_0:
2116     set_local( 0, pop() );
2117     break;
2118   case Bytecodes::_fstore_1:
2119   case Bytecodes::_istore_1:
2120   case Bytecodes::_astore_1:
2121     set_local( 1, pop() );
2122     break;
2123   case Bytecodes::_fstore_2:
2124   case Bytecodes::_istore_2:
2125   case Bytecodes::_astore_2:
2126     set_local( 2, pop() );
2127     break;
2128   case Bytecodes::_fstore_3:
2129   case Bytecodes::_istore_3:
2130   case Bytecodes::_astore_3:
2131     set_local( 3, pop() );
2132     break;
2133   case Bytecodes::_fstore:
2134   case Bytecodes::_istore:
2135   case Bytecodes::_astore:
2136     set_local( iter().get_index(), pop() );
2137     break;
2138   // long stores
2139   case Bytecodes::_lstore_0:
2140     set_pair_local( 0, pop_pair() );
2141     break;
2142   case Bytecodes::_lstore_1:
2143     set_pair_local( 1, pop_pair() );
2144     break;
2145   case Bytecodes::_lstore_2:
2146     set_pair_local( 2, pop_pair() );
2147     break;
2148   case Bytecodes::_lstore_3:
2149     set_pair_local( 3, pop_pair() );
2150     break;
2151   case Bytecodes::_lstore:
2152     set_pair_local( iter().get_index(), pop_pair() );
2153     break;
2154 
2155   // double stores
2156   case Bytecodes::_dstore_0:
2157     set_pair_local( 0, pop_pair() );
2158     break;
2159   case Bytecodes::_dstore_1:
2160     set_pair_local( 1, pop_pair() );
2161     break;
2162   case Bytecodes::_dstore_2:
2163     set_pair_local( 2, pop_pair() );
2164     break;
2165   case Bytecodes::_dstore_3:
2166     set_pair_local( 3, pop_pair() );
2167     break;
2168   case Bytecodes::_dstore:
2169     set_pair_local( iter().get_index(), pop_pair() );
2170     break;
2171 
2172   case Bytecodes::_pop:  dec_sp(1);   break;
2173   case Bytecodes::_pop2: dec_sp(2);   break;
2174   case Bytecodes::_swap:
2175     a = pop();
2176     b = pop();
2177     push(a);
2178     push(b);
2179     break;
2180   case Bytecodes::_dup:
2181     a = pop();
2182     push(a);
2183     push(a);
2184     break;
2185   case Bytecodes::_dup_x1:
2186     a = pop();
2187     b = pop();
2188     push( a );
2189     push( b );
2190     push( a );
2191     break;
2192   case Bytecodes::_dup_x2:
2193     a = pop();
2194     b = pop();
2195     c = pop();
2196     push( a );
2197     push( c );
2198     push( b );
2199     push( a );
2200     break;
2201   case Bytecodes::_dup2:
2202     a = pop();
2203     b = pop();
2204     push( b );
2205     push( a );
2206     push( b );
2207     push( a );
2208     break;
2209 
2210   case Bytecodes::_dup2_x1:
2211     // before: .. c, b, a
2212     // after:  .. b, a, c, b, a
2213     // not tested
2214     a = pop();
2215     b = pop();
2216     c = pop();
2217     push( b );
2218     push( a );
2219     push( c );
2220     push( b );
2221     push( a );
2222     break;
2223   case Bytecodes::_dup2_x2:
2224     // before: .. d, c, b, a
2225     // after:  .. b, a, d, c, b, a
2226     // not tested
2227     a = pop();
2228     b = pop();
2229     c = pop();
2230     d = pop();
2231     push( b );
2232     push( a );
2233     push( d );
2234     push( c );
2235     push( b );
2236     push( a );
2237     break;
2238 
2239   case Bytecodes::_arraylength: {
2240     // Must do null-check with value on expression stack
2241     Node *ary = null_check(peek(), T_ARRAY);
2242     // Compile-time detect of null-exception?
2243     if (stopped())  return;
2244     a = pop();
2245     push(load_array_length(a));
2246     break;
2247   }
2248 
2249   case Bytecodes::_baload:  array_load(T_BYTE);    break;
2250   case Bytecodes::_caload:  array_load(T_CHAR);    break;
2251   case Bytecodes::_iaload:  array_load(T_INT);     break;
2252   case Bytecodes::_saload:  array_load(T_SHORT);   break;
2253   case Bytecodes::_faload:  array_load(T_FLOAT);   break;
2254   case Bytecodes::_aaload:  array_load(T_OBJECT);  break;
2255   case Bytecodes::_laload:  array_load(T_LONG);    break;
2256   case Bytecodes::_daload:  array_load(T_DOUBLE);  break;
2257   case Bytecodes::_bastore: array_store(T_BYTE);   break;
2258   case Bytecodes::_castore: array_store(T_CHAR);   break;
2259   case Bytecodes::_iastore: array_store(T_INT);    break;
2260   case Bytecodes::_sastore: array_store(T_SHORT);  break;
2261   case Bytecodes::_fastore: array_store(T_FLOAT);  break;
2262   case Bytecodes::_aastore: array_store(T_OBJECT); break;
2263   case Bytecodes::_lastore: array_store(T_LONG);   break;
2264   case Bytecodes::_dastore: array_store(T_DOUBLE); break;
2265 
2266   case Bytecodes::_getfield:
2267     do_getfield();
2268     break;
2269 
2270   case Bytecodes::_getstatic:
2271     do_getstatic();
2272     break;
2273 
2274   case Bytecodes::_putfield:
2275     do_putfield();
2276     break;
2277 
2278   case Bytecodes::_putstatic:
2279     do_putstatic();
2280     break;
2281 
2282   case Bytecodes::_irem:
2283     // Must keep both values on the expression-stack during null-check
2284     zero_check_int(peek());
2285     // Compile-time detect of null-exception?
2286     if (stopped())  return;
2287     b = pop();
2288     a = pop();
2289     push(_gvn.transform(new ModINode(control(), a, b)));
2290     break;
2291   case Bytecodes::_idiv:
2292     // Must keep both values on the expression-stack during null-check
2293     zero_check_int(peek());
2294     // Compile-time detect of null-exception?
2295     if (stopped())  return;
2296     b = pop();
2297     a = pop();
2298     push( _gvn.transform( new DivINode(control(),a,b) ) );
2299     break;
2300   case Bytecodes::_imul:
2301     b = pop(); a = pop();
2302     push( _gvn.transform( new MulINode(a,b) ) );
2303     break;
2304   case Bytecodes::_iadd:
2305     b = pop(); a = pop();
2306     push( _gvn.transform( new AddINode(a,b) ) );
2307     break;
2308   case Bytecodes::_ineg:
2309     a = pop();
2310     push( _gvn.transform( new SubINode(_gvn.intcon(0),a)) );
2311     break;
2312   case Bytecodes::_isub:
2313     b = pop(); a = pop();
2314     push( _gvn.transform( new SubINode(a,b) ) );
2315     break;
2316   case Bytecodes::_iand:
2317     b = pop(); a = pop();
2318     push( _gvn.transform( new AndINode(a,b) ) );
2319     break;
2320   case Bytecodes::_ior:
2321     b = pop(); a = pop();
2322     push( _gvn.transform( new OrINode(a,b) ) );
2323     break;
2324   case Bytecodes::_ixor:
2325     b = pop(); a = pop();
2326     push( _gvn.transform( new XorINode(a,b) ) );
2327     break;
2328   case Bytecodes::_ishl:
2329     b = pop(); a = pop();
2330     push( _gvn.transform( new LShiftINode(a,b) ) );
2331     break;
2332   case Bytecodes::_ishr:
2333     b = pop(); a = pop();
2334     push( _gvn.transform( new RShiftINode(a,b) ) );
2335     break;
2336   case Bytecodes::_iushr:
2337     b = pop(); a = pop();
2338     push( _gvn.transform( new URShiftINode(a,b) ) );
2339     break;
2340 
2341   case Bytecodes::_fneg:
2342     a = pop();
2343     b = _gvn.transform(new NegFNode (a));
2344     push(b);
2345     break;
2346 
2347   case Bytecodes::_fsub:
2348     b = pop();
2349     a = pop();
2350     c = _gvn.transform( new SubFNode(a,b) );
2351     push(c);
2352     break;
2353 
2354   case Bytecodes::_fadd:
2355     b = pop();
2356     a = pop();
2357     c = _gvn.transform( new AddFNode(a,b) );
2358     push(c);
2359     break;
2360 
2361   case Bytecodes::_fmul:
2362     b = pop();
2363     a = pop();
2364     c = _gvn.transform( new MulFNode(a,b) );
2365     push(c);
2366     break;
2367 
2368   case Bytecodes::_fdiv:
2369     b = pop();
2370     a = pop();
2371     c = _gvn.transform( new DivFNode(nullptr,a,b) );
2372     push(c);
2373     break;
2374 
2375   case Bytecodes::_frem:
2376     // Generate a ModF node.
2377     b = pop();
2378     a = pop();
2379     push(floating_point_mod(a, b, BasicType::T_FLOAT));
2380     break;
2381 
2382   case Bytecodes::_fcmpl:
2383     b = pop();
2384     a = pop();
2385     c = _gvn.transform( new CmpF3Node( a, b));
2386     push(c);
2387     break;
2388   case Bytecodes::_fcmpg:
2389     b = pop();
2390     a = pop();
2391 
2392     // Same as fcmpl but need to flip the unordered case.  Swap the inputs,
2393     // which negates the result sign except for unordered.  Flip the unordered
2394     // as well by using CmpF3 which implements unordered-lesser instead of
2395     // unordered-greater semantics.  Finally, commute the result bits.  Result
2396     // is same as using a CmpF3Greater except we did it with CmpF3 alone.
2397     c = _gvn.transform( new CmpF3Node( b, a));
2398     c = _gvn.transform( new SubINode(_gvn.intcon(0),c) );
2399     push(c);
2400     break;
2401 
2402   case Bytecodes::_f2i:
2403     a = pop();
2404     push(_gvn.transform(new ConvF2INode(a)));
2405     break;
2406 
2407   case Bytecodes::_d2i:
2408     a = pop_pair();
2409     b = _gvn.transform(new ConvD2INode(a));
2410     push( b );
2411     break;
2412 
2413   case Bytecodes::_f2d:
2414     a = pop();
2415     b = _gvn.transform( new ConvF2DNode(a));
2416     push_pair( b );
2417     break;
2418 
2419   case Bytecodes::_d2f:
2420     a = pop_pair();
2421     b = _gvn.transform( new ConvD2FNode(a));
2422     push( b );
2423     break;
2424 
2425   case Bytecodes::_l2f:
2426     if (Matcher::convL2FSupported()) {
2427       a = pop_pair();
2428       b = _gvn.transform( new ConvL2FNode(a));
2429       push(b);
2430     } else {
2431       l2f();
2432     }
2433     break;
2434 
2435   case Bytecodes::_l2d:
2436     a = pop_pair();
2437     b = _gvn.transform( new ConvL2DNode(a));
2438     push_pair(b);
2439     break;
2440 
2441   case Bytecodes::_f2l:
2442     a = pop();
2443     b = _gvn.transform( new ConvF2LNode(a));
2444     push_pair(b);
2445     break;
2446 
2447   case Bytecodes::_d2l:
2448     a = pop_pair();
2449     b = _gvn.transform( new ConvD2LNode(a));
2450     push_pair(b);
2451     break;
2452 
2453   case Bytecodes::_dsub:
2454     b = pop_pair();
2455     a = pop_pair();
2456     c = _gvn.transform( new SubDNode(a,b) );
2457     push_pair(c);
2458     break;
2459 
2460   case Bytecodes::_dadd:
2461     b = pop_pair();
2462     a = pop_pair();
2463     c = _gvn.transform( new AddDNode(a,b) );
2464     push_pair(c);
2465     break;
2466 
2467   case Bytecodes::_dmul:
2468     b = pop_pair();
2469     a = pop_pair();
2470     c = _gvn.transform( new MulDNode(a,b) );
2471     push_pair(c);
2472     break;
2473 
2474   case Bytecodes::_ddiv:
2475     b = pop_pair();
2476     a = pop_pair();
2477     c = _gvn.transform( new DivDNode(nullptr,a,b) );
2478     push_pair(c);
2479     break;
2480 
2481   case Bytecodes::_dneg:
2482     a = pop_pair();
2483     b = _gvn.transform(new NegDNode (a));
2484     push_pair(b);
2485     break;
2486 
2487   case Bytecodes::_drem:
2488     // Generate a ModD node.
2489     b = pop_pair();
2490     a = pop_pair();
2491     push_pair(floating_point_mod(a, b, BasicType::T_DOUBLE));
2492     break;
2493 
2494   case Bytecodes::_dcmpl:
2495     b = pop_pair();
2496     a = pop_pair();
2497     c = _gvn.transform( new CmpD3Node( a, b));
2498     push(c);
2499     break;
2500 
2501   case Bytecodes::_dcmpg:
2502     b = pop_pair();
2503     a = pop_pair();
2504     // Same as dcmpl but need to flip the unordered case.
2505     // Commute the inputs, which negates the result sign except for unordered.
2506     // Flip the unordered as well by using CmpD3 which implements
2507     // unordered-lesser instead of unordered-greater semantics.
2508     // Finally, negate the result bits.  Result is same as using a
2509     // CmpD3Greater except we did it with CmpD3 alone.
2510     c = _gvn.transform( new CmpD3Node( b, a));
2511     c = _gvn.transform( new SubINode(_gvn.intcon(0),c) );
2512     push(c);
2513     break;
2514 
2515 
2516     // Note for longs -> lo word is on TOS, hi word is on TOS - 1
2517   case Bytecodes::_land:
2518     b = pop_pair();
2519     a = pop_pair();
2520     c = _gvn.transform( new AndLNode(a,b) );
2521     push_pair(c);
2522     break;
2523   case Bytecodes::_lor:
2524     b = pop_pair();
2525     a = pop_pair();
2526     c = _gvn.transform( new OrLNode(a,b) );
2527     push_pair(c);
2528     break;
2529   case Bytecodes::_lxor:
2530     b = pop_pair();
2531     a = pop_pair();
2532     c = _gvn.transform( new XorLNode(a,b) );
2533     push_pair(c);
2534     break;
2535 
2536   case Bytecodes::_lshl:
2537     b = pop();                  // the shift count
2538     a = pop_pair();             // value to be shifted
2539     c = _gvn.transform( new LShiftLNode(a,b) );
2540     push_pair(c);
2541     break;
2542   case Bytecodes::_lshr:
2543     b = pop();                  // the shift count
2544     a = pop_pair();             // value to be shifted
2545     c = _gvn.transform( new RShiftLNode(a,b) );
2546     push_pair(c);
2547     break;
2548   case Bytecodes::_lushr:
2549     b = pop();                  // the shift count
2550     a = pop_pair();             // value to be shifted
2551     c = _gvn.transform( new URShiftLNode(a,b) );
2552     push_pair(c);
2553     break;
2554   case Bytecodes::_lmul:
2555     b = pop_pair();
2556     a = pop_pair();
2557     c = _gvn.transform( new MulLNode(a,b) );
2558     push_pair(c);
2559     break;
2560 
2561   case Bytecodes::_lrem:
2562     // Must keep both values on the expression-stack during null-check
2563     assert(peek(0) == top(), "long word order");
2564     zero_check_long(peek(1));
2565     // Compile-time detect of null-exception?
2566     if (stopped())  return;
2567     b = pop_pair();
2568     a = pop_pair();
2569     c = _gvn.transform( new ModLNode(control(),a,b) );
2570     push_pair(c);
2571     break;
2572 
2573   case Bytecodes::_ldiv:
2574     // Must keep both values on the expression-stack during null-check
2575     assert(peek(0) == top(), "long word order");
2576     zero_check_long(peek(1));
2577     // Compile-time detect of null-exception?
2578     if (stopped())  return;
2579     b = pop_pair();
2580     a = pop_pair();
2581     c = _gvn.transform( new DivLNode(control(),a,b) );
2582     push_pair(c);
2583     break;
2584 
2585   case Bytecodes::_ladd:
2586     b = pop_pair();
2587     a = pop_pair();
2588     c = _gvn.transform( new AddLNode(a,b) );
2589     push_pair(c);
2590     break;
2591   case Bytecodes::_lsub:
2592     b = pop_pair();
2593     a = pop_pair();
2594     c = _gvn.transform( new SubLNode(a,b) );
2595     push_pair(c);
2596     break;
2597   case Bytecodes::_lcmp:
2598     // Safepoints are now inserted _before_ branches.  The long-compare
2599     // bytecode painfully produces a 3-way value (-1,0,+1) which requires a
2600     // slew of control flow.  These are usually followed by a CmpI vs zero and
2601     // a branch; this pattern then optimizes to the obvious long-compare and
2602     // branch.  However, if the branch is backwards there's a Safepoint
2603     // inserted.  The inserted Safepoint captures the JVM state at the
2604     // pre-branch point, i.e. it captures the 3-way value.  Thus if a
2605     // long-compare is used to control a loop the debug info will force
2606     // computation of the 3-way value, even though the generated code uses a
2607     // long-compare and branch.  We try to rectify the situation by inserting
2608     // a SafePoint here and have it dominate and kill the safepoint added at a
2609     // following backwards branch.  At this point the JVM state merely holds 2
2610     // longs but not the 3-way value.
2611     switch (iter().next_bc()) {
2612       case Bytecodes::_ifgt:
2613       case Bytecodes::_iflt:
2614       case Bytecodes::_ifge:
2615       case Bytecodes::_ifle:
2616       case Bytecodes::_ifne:
2617       case Bytecodes::_ifeq:
2618         // If this is a backwards branch in the bytecodes, add Safepoint
2619         maybe_add_safepoint(iter().next_get_dest());
2620       default:
2621         break;
2622     }
2623     b = pop_pair();
2624     a = pop_pair();
2625     c = _gvn.transform( new CmpL3Node( a, b ));
2626     push(c);
2627     break;
2628 
2629   case Bytecodes::_lneg:
2630     a = pop_pair();
2631     b = _gvn.transform( new SubLNode(longcon(0),a));
2632     push_pair(b);
2633     break;
2634   case Bytecodes::_l2i:
2635     a = pop_pair();
2636     push( _gvn.transform( new ConvL2INode(a)));
2637     break;
2638   case Bytecodes::_i2l:
2639     a = pop();
2640     b = _gvn.transform( new ConvI2LNode(a));
2641     push_pair(b);
2642     break;
2643   case Bytecodes::_i2b:
2644     // Sign extend
2645     a = pop();
2646     a = Compile::narrow_value(T_BYTE, a, nullptr, &_gvn, true);
2647     push(a);
2648     break;
2649   case Bytecodes::_i2s:
2650     a = pop();
2651     a = Compile::narrow_value(T_SHORT, a, nullptr, &_gvn, true);
2652     push(a);
2653     break;
2654   case Bytecodes::_i2c:
2655     a = pop();
2656     a = Compile::narrow_value(T_CHAR, a, nullptr, &_gvn, true);
2657     push(a);
2658     break;
2659 
2660   case Bytecodes::_i2f:
2661     a = pop();
2662     b = _gvn.transform( new ConvI2FNode(a) ) ;
2663     push(b);
2664     break;
2665 
2666   case Bytecodes::_i2d:
2667     a = pop();
2668     b = _gvn.transform( new ConvI2DNode(a));
2669     push_pair(b);
2670     break;
2671 
2672   case Bytecodes::_iinc:        // Increment local
2673     i = iter().get_index();     // Get local index
2674     set_local( i, _gvn.transform( new AddINode( _gvn.intcon(iter().get_iinc_con()), local(i) ) ) );
2675     break;
2676 
2677   // Exit points of synchronized methods must have an unlock node
2678   case Bytecodes::_return:
2679     return_current(nullptr);
2680     break;
2681 
2682   case Bytecodes::_ireturn:
2683   case Bytecodes::_areturn:
2684   case Bytecodes::_freturn:
2685     return_current(pop());
2686     break;
2687   case Bytecodes::_lreturn:
2688     return_current(pop_pair());
2689     break;
2690   case Bytecodes::_dreturn:
2691     return_current(pop_pair());
2692     break;
2693 
2694   case Bytecodes::_athrow:
2695     // null exception oop throws null pointer exception
2696     null_check(peek());
2697     if (stopped())  return;
2698     // Hook the thrown exception directly to subsequent handlers.
2699     if (BailoutToInterpreterForThrows) {
2700       // Keep method interpreted from now on.
2701       uncommon_trap(Deoptimization::Reason_unhandled,
2702                     Deoptimization::Action_make_not_compilable);
2703       return;
2704     }
2705     if (env()->jvmti_can_post_on_exceptions()) {
2706       // check if we must post exception events, take uncommon trap if so (with must_throw = false)
2707       uncommon_trap_if_should_post_on_exceptions(Deoptimization::Reason_unhandled, false);
2708     }
2709     // Here if either can_post_on_exceptions or should_post_on_exceptions is false
2710     add_exception_state(make_exception_state(peek()));
2711     break;
2712 
2713   case Bytecodes::_goto:   // fall through
2714   case Bytecodes::_goto_w: {
2715     int target_bci = (bc() == Bytecodes::_goto) ? iter().get_dest() : iter().get_far_dest();
2716 
2717     // If this is a backwards branch in the bytecodes, add Safepoint
2718     maybe_add_safepoint(target_bci);
2719 
2720     // Merge the current control into the target basic block
2721     merge(target_bci);
2722 
2723     // See if we can get some profile data and hand it off to the next block
2724     Block *target_block = block()->successor_for_bci(target_bci);
2725     if (target_block->pred_count() != 1)  break;
2726     ciMethodData* methodData = method()->method_data();
2727     if (!methodData->is_mature())  break;
2728     ciProfileData* data = methodData->bci_to_data(bci());
2729     assert(data != nullptr && data->is_JumpData(), "need JumpData for taken branch");
2730     int taken = ((ciJumpData*)data)->taken();
2731     taken = method()->scale_count(taken);
2732     target_block->set_count(taken);
2733     break;
2734   }
2735 
2736   case Bytecodes::_ifnull:    btest = BoolTest::eq; goto handle_if_null;
2737   case Bytecodes::_ifnonnull: btest = BoolTest::ne; goto handle_if_null;
2738   handle_if_null:
2739     // If this is a backwards branch in the bytecodes, add Safepoint
2740     maybe_add_safepoint(iter().get_dest());
2741     a = null();
2742     b = pop();
2743     if (!_gvn.type(b)->speculative_maybe_null() &&
2744         !too_many_traps(Deoptimization::Reason_speculate_null_check)) {
2745       inc_sp(1);
2746       Node* null_ctl = top();
2747       b = null_check_oop(b, &null_ctl, true, true, true);
2748       assert(null_ctl->is_top(), "no null control here");
2749       dec_sp(1);
2750     } else if (_gvn.type(b)->speculative_always_null() &&
2751                !too_many_traps(Deoptimization::Reason_speculate_null_assert)) {
2752       inc_sp(1);
2753       b = null_assert(b);
2754       dec_sp(1);
2755     }
2756     c = _gvn.transform( new CmpPNode(b, a) );
2757     do_ifnull(btest, c);
2758     break;
2759 
2760   case Bytecodes::_if_acmpeq: btest = BoolTest::eq; goto handle_if_acmp;
2761   case Bytecodes::_if_acmpne: btest = BoolTest::ne; goto handle_if_acmp;
2762   handle_if_acmp:
2763     // If this is a backwards branch in the bytecodes, add Safepoint
2764     maybe_add_safepoint(iter().get_dest());
2765     a = pop();
2766     b = pop();
2767     c = _gvn.transform( new CmpPNode(b, a) );
2768     c = optimize_cmp_with_klass(c);
2769     do_if(btest, c);
2770     break;
2771 
2772   case Bytecodes::_ifeq: btest = BoolTest::eq; goto handle_ifxx;
2773   case Bytecodes::_ifne: btest = BoolTest::ne; goto handle_ifxx;
2774   case Bytecodes::_iflt: btest = BoolTest::lt; goto handle_ifxx;
2775   case Bytecodes::_ifle: btest = BoolTest::le; goto handle_ifxx;
2776   case Bytecodes::_ifgt: btest = BoolTest::gt; goto handle_ifxx;
2777   case Bytecodes::_ifge: btest = BoolTest::ge; goto handle_ifxx;
2778   handle_ifxx:
2779     // If this is a backwards branch in the bytecodes, add Safepoint
2780     maybe_add_safepoint(iter().get_dest());
2781     a = _gvn.intcon(0);
2782     b = pop();
2783     c = _gvn.transform( new CmpINode(b, a) );
2784     do_if(btest, c);
2785     break;
2786 
2787   case Bytecodes::_if_icmpeq: btest = BoolTest::eq; goto handle_if_icmp;
2788   case Bytecodes::_if_icmpne: btest = BoolTest::ne; goto handle_if_icmp;
2789   case Bytecodes::_if_icmplt: btest = BoolTest::lt; goto handle_if_icmp;
2790   case Bytecodes::_if_icmple: btest = BoolTest::le; goto handle_if_icmp;
2791   case Bytecodes::_if_icmpgt: btest = BoolTest::gt; goto handle_if_icmp;
2792   case Bytecodes::_if_icmpge: btest = BoolTest::ge; goto handle_if_icmp;
2793   handle_if_icmp:
2794     // If this is a backwards branch in the bytecodes, add Safepoint
2795     maybe_add_safepoint(iter().get_dest());
2796     a = pop();
2797     b = pop();
2798     c = _gvn.transform( new CmpINode( b, a ) );
2799     do_if(btest, c);
2800     break;
2801 
2802   case Bytecodes::_tableswitch:
2803     do_tableswitch();
2804     break;
2805 
2806   case Bytecodes::_lookupswitch:
2807     do_lookupswitch();
2808     break;
2809 
2810   case Bytecodes::_invokestatic:
2811   case Bytecodes::_invokedynamic:
2812   case Bytecodes::_invokespecial:
2813   case Bytecodes::_invokevirtual:
2814   case Bytecodes::_invokeinterface:
2815     do_call();
2816     break;
2817   case Bytecodes::_checkcast:
2818     do_checkcast();
2819     break;
2820   case Bytecodes::_instanceof:
2821     do_instanceof();
2822     break;
2823   case Bytecodes::_anewarray:
2824     do_anewarray();
2825     break;
2826   case Bytecodes::_newarray:
2827     do_newarray((BasicType)iter().get_index());
2828     break;
2829   case Bytecodes::_multianewarray:
2830     do_multianewarray();
2831     break;
2832   case Bytecodes::_new:
2833     do_new();
2834     break;
2835 
2836   case Bytecodes::_jsr:
2837   case Bytecodes::_jsr_w:
2838     do_jsr();
2839     break;
2840 
2841   case Bytecodes::_ret:
2842     do_ret();
2843     break;
2844 
2845 
2846   case Bytecodes::_monitorenter:
2847     do_monitor_enter();
2848     break;
2849 
2850   case Bytecodes::_monitorexit:
2851     do_monitor_exit();
2852     break;
2853 
2854   case Bytecodes::_breakpoint:
2855     // Breakpoint set concurrently to compile
2856     // %%% use an uncommon trap?
2857     C->record_failure("breakpoint in method");
2858     return;
2859 
2860   default:
2861 #ifndef PRODUCT
2862     map()->dump(99);
2863 #endif
2864     tty->print("\nUnhandled bytecode %s\n", Bytecodes::name(bc()) );
2865     ShouldNotReachHere();
2866   }
2867 
2868 #ifndef PRODUCT
2869   if (failing()) { return; }
2870   constexpr int perBytecode = 6;
2871   if (C->should_print_igv(perBytecode)) {
2872     IdealGraphPrinter* printer = C->igv_printer();
2873     char buffer[256];
2874     jio_snprintf(buffer, sizeof(buffer), "Bytecode %d: %s", bci(), Bytecodes::name(bc()));
2875     bool old = printer->traverse_outs();
2876     printer->set_traverse_outs(true);
2877     printer->set_parse(this);
2878     printer->print_graph(buffer);
2879     printer->set_traverse_outs(old);
2880     printer->set_parse(nullptr);
2881   }
2882 #endif
2883 }