1 /*
   2  * Copyright (c) 1998, 2025, 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 #endif
 970 
 971   assert(lo <= hi, "must be a non-empty set of ranges");
 972   if (lo == hi) {
 973     jump_if_always_fork(lo->dest(), trim_ranges && lo->cnt() == 0);
 974   } else {
 975     assert(lo->hi() == (lo+1)->lo()-1, "contiguous ranges");
 976     assert(hi->lo() == (hi-1)->hi()+1, "contiguous ranges");
 977 
 978     if (create_jump_tables(key_val, lo, hi)) return;
 979 
 980     SwitchRange* mid = nullptr;
 981     float total_cnt = sum_of_cnts(lo, hi);
 982 
 983     int nr = hi - lo + 1;
 984     if (UseSwitchProfiling) {
 985       // Don't keep the binary search tree balanced: pick up mid point
 986       // that split frequencies in half.
 987       float cnt = 0;
 988       for (SwitchRange* sr = lo; sr <= hi; sr++) {
 989         cnt += sr->cnt();
 990         if (cnt >= total_cnt / 2) {
 991           mid = sr;
 992           break;
 993         }
 994       }
 995     } else {
 996       mid = lo + nr/2;
 997 
 998       // if there is an easy choice, pivot at a singleton:
 999       if (nr > 3 && !mid->is_singleton() && (mid-1)->is_singleton())  mid--;
1000 
1001       assert(lo < mid && mid <= hi, "good pivot choice");
1002       assert(nr != 2 || mid == hi,   "should pick higher of 2");
1003       assert(nr != 3 || mid == hi-1, "should pick middle of 3");
1004     }
1005 
1006 
1007     Node *test_val = _gvn.intcon(mid == lo ? mid->hi() : mid->lo());
1008 
1009     if (mid->is_singleton()) {
1010       IfNode *iff_ne = jump_if_fork_int(key_val, test_val, BoolTest::ne, 1-if_prob(mid->cnt(), total_cnt), if_cnt(mid->cnt()));
1011       jump_if_false_fork(iff_ne, mid->dest(), trim_ranges && mid->cnt() == 0);
1012 
1013       // Special Case:  If there are exactly three ranges, and the high
1014       // and low range each go to the same place, omit the "gt" test,
1015       // since it will not discriminate anything.
1016       bool eq_test_only = (hi == lo+2 && hi->dest() == lo->dest() && mid == hi-1) || mid == lo;
1017 
1018       // if there is a higher range, test for it and process it:
1019       if (mid < hi && !eq_test_only) {
1020         // two comparisons of same values--should enable 1 test for 2 branches
1021         // Use BoolTest::lt instead of BoolTest::gt
1022         float cnt = sum_of_cnts(lo, mid-1);
1023         IfNode *iff_lt  = jump_if_fork_int(key_val, test_val, BoolTest::lt, if_prob(cnt, total_cnt), if_cnt(cnt));
1024         Node   *iftrue  = _gvn.transform( new IfTrueNode(iff_lt) );
1025         Node   *iffalse = _gvn.transform( new IfFalseNode(iff_lt) );
1026         { PreserveJVMState pjvms(this);
1027           set_control(iffalse);
1028           jump_switch_ranges(key_val, mid+1, hi, switch_depth+1);
1029         }
1030         set_control(iftrue);
1031       }
1032 
1033     } else {
1034       // mid is a range, not a singleton, so treat mid..hi as a unit
1035       float cnt = sum_of_cnts(mid == lo ? mid+1 : mid, hi);
1036       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));
1037 
1038       // if there is a higher range, test for it and process it:
1039       if (mid == hi) {
1040         jump_if_true_fork(iff_ge, mid->dest(), trim_ranges && cnt == 0);
1041       } else {
1042         Node *iftrue  = _gvn.transform( new IfTrueNode(iff_ge) );
1043         Node *iffalse = _gvn.transform( new IfFalseNode(iff_ge) );
1044         { PreserveJVMState pjvms(this);
1045           set_control(iftrue);
1046           jump_switch_ranges(key_val, mid == lo ? mid+1 : mid, hi, switch_depth+1);
1047         }
1048         set_control(iffalse);
1049       }
1050     }
1051 
1052     // in any case, process the lower range
1053     if (mid == lo) {
1054       if (mid->is_singleton()) {
1055         jump_switch_ranges(key_val, lo+1, hi, switch_depth+1);
1056       } else {
1057         jump_if_always_fork(lo->dest(), trim_ranges && lo->cnt() == 0);
1058       }
1059     } else {
1060       jump_switch_ranges(key_val, lo, mid-1, switch_depth+1);
1061     }
1062   }
1063 
1064   // Decrease pred_count for each successor after all is done.
1065   if (switch_depth == 0) {
1066     int unique_successors = switch_block->num_successors();
1067     for (int i = 0; i < unique_successors; i++) {
1068       Block* target = switch_block->successor_at(i);
1069       // Throw away the pre-allocated path for each unique successor.
1070       target->next_path_num();
1071     }
1072   }
1073 
1074 #ifndef PRODUCT
1075   _max_switch_depth = MAX2(switch_depth, _max_switch_depth);
1076   if (TraceOptoParse && Verbose && WizardMode && switch_depth == 0) {
1077     SwitchRange* r;
1078     int nsing = 0;
1079     for( r = lo; r <= hi; r++ ) {
1080       if( r->is_singleton() )  nsing++;
1081     }
1082     tty->print(">>> ");
1083     _method->print_short_name();
1084     tty->print_cr(" switch decision tree");
1085     tty->print_cr("    %d ranges (%d singletons), max_depth=%d, est_depth=%d",
1086                   (int) (hi-lo+1), nsing, _max_switch_depth, _est_switch_depth);
1087     if (_max_switch_depth > _est_switch_depth) {
1088       tty->print_cr("******** BAD SWITCH DEPTH ********");
1089     }
1090     tty->print("   ");
1091     for( r = lo; r <= hi; r++ ) {
1092       r->print();
1093     }
1094     tty->cr();
1095   }
1096 #endif
1097 }
1098 
1099 Node* Parse::floating_point_mod(Node* a, Node* b, BasicType type) {
1100   assert(type == BasicType::T_FLOAT || type == BasicType::T_DOUBLE, "only float and double are floating points");
1101   CallLeafPureNode* mod = type == BasicType::T_DOUBLE ? static_cast<CallLeafPureNode*>(new ModDNode(C, a, b)) : new ModFNode(C, a, b);
1102 
1103   set_predefined_input_for_runtime_call(mod);
1104   mod = _gvn.transform(mod)->as_CallLeafPure();
1105   set_predefined_output_for_runtime_call(mod);
1106   Node* result = _gvn.transform(new ProjNode(mod, TypeFunc::Parms + 0));
1107   record_for_igvn(mod);
1108   return result;
1109 }
1110 
1111 void Parse::l2f() {
1112   Node* f2 = pop();
1113   Node* f1 = pop();
1114   Node* c = make_runtime_call(RC_LEAF, OptoRuntime::l2f_Type(),
1115                               CAST_FROM_FN_PTR(address, SharedRuntime::l2f),
1116                               "l2f", nullptr, //no memory effects
1117                               f1, f2);
1118   Node* res = _gvn.transform(new ProjNode(c, TypeFunc::Parms + 0));
1119 
1120   push(res);
1121 }
1122 
1123 // Handle jsr and jsr_w bytecode
1124 void Parse::do_jsr() {
1125   assert(bc() == Bytecodes::_jsr || bc() == Bytecodes::_jsr_w, "wrong bytecode");
1126 
1127   // Store information about current state, tagged with new _jsr_bci
1128   int return_bci = iter().next_bci();
1129   int jsr_bci    = (bc() == Bytecodes::_jsr) ? iter().get_dest() : iter().get_far_dest();
1130 
1131   // The way we do things now, there is only one successor block
1132   // for the jsr, because the target code is cloned by ciTypeFlow.
1133   Block* target = successor_for_bci(jsr_bci);
1134 
1135   // What got pushed?
1136   const Type* ret_addr = target->peek();
1137   assert(ret_addr->singleton(), "must be a constant (cloned jsr body)");
1138 
1139   // Effect on jsr on stack
1140   push(_gvn.makecon(ret_addr));
1141 
1142   // Flow to the jsr.
1143   merge(jsr_bci);
1144 }
1145 
1146 // Handle ret bytecode
1147 void Parse::do_ret() {
1148   // Find to whom we return.
1149   assert(block()->num_successors() == 1, "a ret can only go one place now");
1150   Block* target = block()->successor_at(0);
1151   assert(!target->is_ready(), "our arrival must be expected");
1152   int pnum = target->next_path_num();
1153   merge_common(target, pnum);
1154 }
1155 
1156 static bool has_injected_profile(BoolTest::mask btest, Node* test, int& taken, int& not_taken) {
1157   if (btest != BoolTest::eq && btest != BoolTest::ne) {
1158     // Only ::eq and ::ne are supported for profile injection.
1159     return false;
1160   }
1161   if (test->is_Cmp() &&
1162       test->in(1)->Opcode() == Op_ProfileBoolean) {
1163     ProfileBooleanNode* profile = (ProfileBooleanNode*)test->in(1);
1164     int false_cnt = profile->false_count();
1165     int  true_cnt = profile->true_count();
1166 
1167     // Counts matching depends on the actual test operation (::eq or ::ne).
1168     // No need to scale the counts because profile injection was designed
1169     // to feed exact counts into VM.
1170     taken     = (btest == BoolTest::eq) ? false_cnt :  true_cnt;
1171     not_taken = (btest == BoolTest::eq) ?  true_cnt : false_cnt;
1172 
1173     profile->consume();
1174     return true;
1175   }
1176   return false;
1177 }
1178 
1179 // Give up if too few (or too many, in which case the sum will overflow) counts to be meaningful.
1180 // We also check that individual counters are positive first, otherwise the sum can become positive.
1181 // (check for saturation, integer overflow, and immature counts)
1182 static bool counters_are_meaningful(int counter1, int counter2, int min) {
1183   // check for saturation, including "uint" values too big to fit in "int"
1184   if (counter1 < 0 || counter2 < 0) {
1185     return false;
1186   }
1187   // check for integer overflow of the sum
1188   int64_t sum = (int64_t)counter1 + (int64_t)counter2;
1189   STATIC_ASSERT(sizeof(counter1) < sizeof(sum));
1190   if (sum > INT_MAX) {
1191     return false;
1192   }
1193   // check if mature
1194   return (counter1 + counter2) >= min;
1195 }
1196 
1197 //--------------------------dynamic_branch_prediction--------------------------
1198 // Try to gather dynamic branch prediction behavior.  Return a probability
1199 // of the branch being taken and set the "cnt" field.  Returns a -1.0
1200 // if we need to use static prediction for some reason.
1201 float Parse::dynamic_branch_prediction(float &cnt, BoolTest::mask btest, Node* test) {
1202   ResourceMark rm;
1203 
1204   cnt  = COUNT_UNKNOWN;
1205 
1206   int     taken = 0;
1207   int not_taken = 0;
1208 
1209   bool use_mdo = !has_injected_profile(btest, test, taken, not_taken);
1210 
1211   if (use_mdo) {
1212     // Use MethodData information if it is available
1213     // FIXME: free the ProfileData structure
1214     ciMethodData* methodData = method()->method_data();
1215     if (!methodData->is_mature())  return PROB_UNKNOWN;
1216     ciProfileData* data = methodData->bci_to_data(bci());
1217     if (data == nullptr) {
1218       return PROB_UNKNOWN;
1219     }
1220     if (!data->is_JumpData())  return PROB_UNKNOWN;
1221 
1222     // get taken and not taken values
1223     // NOTE: saturated UINT_MAX values become negative,
1224     // as do counts above INT_MAX.
1225     taken = data->as_JumpData()->taken();
1226     not_taken = 0;
1227     if (data->is_BranchData()) {
1228       not_taken = data->as_BranchData()->not_taken();
1229     }
1230 
1231     // scale the counts to be commensurate with invocation counts:
1232     // NOTE: overflow for positive values is clamped at INT_MAX
1233     taken = method()->scale_count(taken);
1234     not_taken = method()->scale_count(not_taken);
1235   }
1236   // At this point, saturation or overflow is indicated by INT_MAX
1237   // or a negative value.
1238 
1239   // Give up if too few (or too many, in which case the sum will overflow) counts to be meaningful.
1240   // We also check that individual counters are positive first, otherwise the sum can become positive.
1241   if (!counters_are_meaningful(taken, not_taken, 40)) {
1242     if (C->log() != nullptr) {
1243       C->log()->elem("branch target_bci='%d' taken='%d' not_taken='%d'", iter().get_dest(), taken, not_taken);
1244     }
1245     return PROB_UNKNOWN;
1246   }
1247 
1248   // Compute frequency that we arrive here
1249   float sum = taken + not_taken;
1250   // Adjust, if this block is a cloned private block but the
1251   // Jump counts are shared.  Taken the private counts for
1252   // just this path instead of the shared counts.
1253   if( block()->count() > 0 )
1254     sum = block()->count();
1255   cnt = sum / FreqCountInvocations;
1256 
1257   // Pin probability to sane limits
1258   float prob;
1259   if( !taken )
1260     prob = (0+PROB_MIN) / 2;
1261   else if( !not_taken )
1262     prob = (1+PROB_MAX) / 2;
1263   else {                         // Compute probability of true path
1264     prob = (float)taken / (float)(taken + not_taken);
1265     if (prob > PROB_MAX)  prob = PROB_MAX;
1266     if (prob < PROB_MIN)   prob = PROB_MIN;
1267   }
1268 
1269   assert((cnt > 0.0f) && (prob > 0.0f),
1270          "Bad frequency assignment in if cnt=%g prob=%g taken=%d not_taken=%d", cnt, prob, taken, not_taken);
1271 
1272   if (C->log() != nullptr) {
1273     const char* prob_str = nullptr;
1274     if (prob >= PROB_MAX)  prob_str = (prob == PROB_MAX) ? "max" : "always";
1275     if (prob <= PROB_MIN)  prob_str = (prob == PROB_MIN) ? "min" : "never";
1276     char prob_str_buf[30];
1277     if (prob_str == nullptr) {
1278       jio_snprintf(prob_str_buf, sizeof(prob_str_buf), "%20.2f", prob);
1279       prob_str = prob_str_buf;
1280       // The %20.2f adds many spaces to the string, to avoid some
1281       // picky overflow warning as noted in 8211929.  But, 20 is the
1282       // *minimum* width, not *maximum*, so it's not clear how this
1283       // helps prevent overflow.  Looks like we were forced to work
1284       // around a bug in gcc.  In any case, strip the blanks.
1285       while (*prob_str == ' ')  ++prob_str;
1286     }
1287     C->log()->elem("branch target_bci='%d' taken='%d' not_taken='%d' cnt='%f' prob='%s'",
1288                    iter().get_dest(), taken, not_taken, cnt, prob_str);
1289   }
1290   return prob;
1291 }
1292 
1293 //-----------------------------branch_prediction-------------------------------
1294 float Parse::branch_prediction(float& cnt,
1295                                BoolTest::mask btest,
1296                                int target_bci,
1297                                Node* test) {
1298   float prob = dynamic_branch_prediction(cnt, btest, test);
1299   // If prob is unknown, switch to static prediction
1300   if (prob != PROB_UNKNOWN)  return prob;
1301 
1302   prob = PROB_FAIR;                   // Set default value
1303   if (btest == BoolTest::eq)          // Exactly equal test?
1304     prob = PROB_STATIC_INFREQUENT;    // Assume its relatively infrequent
1305   else if (btest == BoolTest::ne)
1306     prob = PROB_STATIC_FREQUENT;      // Assume its relatively frequent
1307 
1308   // If this is a conditional test guarding a backwards branch,
1309   // assume its a loop-back edge.  Make it a likely taken branch.
1310   if (target_bci < bci()) {
1311     if (is_osr_parse()) {    // Could be a hot OSR'd loop; force deopt
1312       // Since it's an OSR, we probably have profile data, but since
1313       // branch_prediction returned PROB_UNKNOWN, the counts are too small.
1314       // Let's make a special check here for completely zero counts.
1315       ciMethodData* methodData = method()->method_data();
1316       if (!methodData->is_empty()) {
1317         ciProfileData* data = methodData->bci_to_data(bci());
1318         // Only stop for truly zero counts, which mean an unknown part
1319         // of the OSR-ed method, and we want to deopt to gather more stats.
1320         // If you have ANY counts, then this loop is simply 'cold' relative
1321         // to the OSR loop.
1322         if (data == nullptr ||
1323             (data->as_BranchData()->taken() +  data->as_BranchData()->not_taken() == 0)) {
1324           // This is the only way to return PROB_UNKNOWN:
1325           return PROB_UNKNOWN;
1326         }
1327       }
1328     }
1329     prob = PROB_STATIC_FREQUENT;     // Likely to take backwards branch
1330   }
1331 
1332   assert(prob != PROB_UNKNOWN, "must have some guess at this point");
1333   return prob;
1334 }
1335 
1336 // The magic constants are chosen so as to match the output of
1337 // branch_prediction() when the profile reports a zero taken count.
1338 // It is important to distinguish zero counts unambiguously, because
1339 // some branches (e.g., _213_javac.Assembler.eliminate) validly produce
1340 // very small but nonzero probabilities, which if confused with zero
1341 // counts would keep the program recompiling indefinitely.
1342 bool Parse::seems_never_taken(float prob) const {
1343   return prob < PROB_MIN;
1344 }
1345 
1346 //-------------------------------repush_if_args--------------------------------
1347 // Push arguments of an "if" bytecode back onto the stack by adjusting _sp.
1348 inline int Parse::repush_if_args() {
1349   if (PrintOpto && WizardMode) {
1350     tty->print("defending against excessive implicit null exceptions on %s @%d in ",
1351                Bytecodes::name(iter().cur_bc()), iter().cur_bci());
1352     method()->print_name(); tty->cr();
1353   }
1354   int bc_depth = - Bytecodes::depth(iter().cur_bc());
1355   assert(bc_depth == 1 || bc_depth == 2, "only two kinds of branches");
1356   DEBUG_ONLY(sync_jvms());   // argument(n) requires a synced jvms
1357   assert(argument(0) != nullptr, "must exist");
1358   assert(bc_depth == 1 || argument(1) != nullptr, "two must exist");
1359   inc_sp(bc_depth);
1360   return bc_depth;
1361 }
1362 
1363 // Used by StressUnstableIfTraps
1364 static volatile int _trap_stress_counter = 0;
1365 
1366 void Parse::increment_trap_stress_counter(Node*& counter, Node*& incr_store) {
1367   Node* counter_addr = makecon(TypeRawPtr::make((address)&_trap_stress_counter));
1368   counter = make_load(control(), counter_addr, TypeInt::INT, T_INT, MemNode::unordered);
1369   counter = _gvn.transform(new AddINode(counter, intcon(1)));
1370   incr_store = store_to_memory(control(), counter_addr, counter, T_INT, MemNode::unordered);
1371 }
1372 
1373 //----------------------------------do_ifnull----------------------------------
1374 void Parse::do_ifnull(BoolTest::mask btest, Node *c) {
1375   int target_bci = iter().get_dest();
1376 
1377   Node* counter = nullptr;
1378   Node* incr_store = nullptr;
1379   bool do_stress_trap = StressUnstableIfTraps && ((C->random() % 2) == 0);
1380   if (do_stress_trap) {
1381     increment_trap_stress_counter(counter, incr_store);
1382   }
1383 
1384   Block* branch_block = successor_for_bci(target_bci);
1385   Block* next_block   = successor_for_bci(iter().next_bci());
1386 
1387   float cnt;
1388   float prob = branch_prediction(cnt, btest, target_bci, c);
1389   if (prob == PROB_UNKNOWN) {
1390     // (An earlier version of do_ifnull omitted this trap for OSR methods.)
1391     if (PrintOpto && Verbose) {
1392       tty->print_cr("Never-taken edge stops compilation at bci %d", bci());
1393     }
1394     repush_if_args(); // to gather stats on loop
1395     uncommon_trap(Deoptimization::Reason_unreached,
1396                   Deoptimization::Action_reinterpret,
1397                   nullptr, "cold");
1398     if (C->eliminate_boxing()) {
1399       // Mark the successor blocks as parsed
1400       branch_block->next_path_num();
1401       next_block->next_path_num();
1402     }
1403     return;
1404   }
1405 
1406   NOT_PRODUCT(explicit_null_checks_inserted++);
1407 
1408   // Generate real control flow
1409   Node   *tst = _gvn.transform( new BoolNode( c, btest ) );
1410 
1411   // Sanity check the probability value
1412   assert(prob > 0.0f,"Bad probability in Parser");
1413  // Need xform to put node in hash table
1414   IfNode *iff = create_and_xform_if( control(), tst, prob, cnt );
1415   assert(iff->_prob > 0.0f,"Optimizer made bad probability in parser");
1416   // True branch
1417   { PreserveJVMState pjvms(this);
1418     Node* iftrue  = _gvn.transform( new IfTrueNode (iff) );
1419     set_control(iftrue);
1420 
1421     if (stopped()) {            // Path is dead?
1422       NOT_PRODUCT(explicit_null_checks_elided++);
1423       if (C->eliminate_boxing()) {
1424         // Mark the successor block as parsed
1425         branch_block->next_path_num();
1426       }
1427     } else {                    // Path is live.
1428       adjust_map_after_if(btest, c, prob, branch_block);
1429       if (!stopped()) {
1430         merge(target_bci);
1431       }
1432     }
1433   }
1434 
1435   // False branch
1436   Node* iffalse = _gvn.transform( new IfFalseNode(iff) );
1437   set_control(iffalse);
1438 
1439   if (stopped()) {              // Path is dead?
1440     NOT_PRODUCT(explicit_null_checks_elided++);
1441     if (C->eliminate_boxing()) {
1442       // Mark the successor block as parsed
1443       next_block->next_path_num();
1444     }
1445   } else  {                     // Path is live.
1446     adjust_map_after_if(BoolTest(btest).negate(), c, 1.0-prob, next_block);
1447   }
1448 
1449   if (do_stress_trap) {
1450     stress_trap(iff, counter, incr_store);
1451   }
1452 }
1453 
1454 //------------------------------------do_if------------------------------------
1455 void Parse::do_if(BoolTest::mask btest, Node* c) {
1456   int target_bci = iter().get_dest();
1457 
1458   Block* branch_block = successor_for_bci(target_bci);
1459   Block* next_block   = successor_for_bci(iter().next_bci());
1460 
1461   float cnt;
1462   float prob = branch_prediction(cnt, btest, target_bci, c);
1463   float untaken_prob = 1.0 - prob;
1464 
1465   if (prob == PROB_UNKNOWN) {
1466     if (PrintOpto && Verbose) {
1467       tty->print_cr("Never-taken edge stops compilation at bci %d", bci());
1468     }
1469     repush_if_args(); // to gather stats on loop
1470     uncommon_trap(Deoptimization::Reason_unreached,
1471                   Deoptimization::Action_reinterpret,
1472                   nullptr, "cold");
1473     if (C->eliminate_boxing()) {
1474       // Mark the successor blocks as parsed
1475       branch_block->next_path_num();
1476       next_block->next_path_num();
1477     }
1478     return;
1479   }
1480 
1481   Node* counter = nullptr;
1482   Node* incr_store = nullptr;
1483   bool do_stress_trap = StressUnstableIfTraps && ((C->random() % 2) == 0);
1484   if (do_stress_trap) {
1485     increment_trap_stress_counter(counter, incr_store);
1486   }
1487 
1488   // Sanity check the probability value
1489   assert(0.0f < prob && prob < 1.0f,"Bad probability in Parser");
1490 
1491   bool taken_if_true = true;
1492   // Convert BoolTest to canonical form:
1493   if (!BoolTest(btest).is_canonical()) {
1494     btest         = BoolTest(btest).negate();
1495     taken_if_true = false;
1496     // prob is NOT updated here; it remains the probability of the taken
1497     // path (as opposed to the prob of the path guarded by an 'IfTrueNode').
1498   }
1499   assert(btest != BoolTest::eq, "!= is the only canonical exact test");
1500 
1501   Node* tst0 = new BoolNode(c, btest);
1502   Node* tst = _gvn.transform(tst0);
1503   BoolTest::mask taken_btest   = BoolTest::illegal;
1504   BoolTest::mask untaken_btest = BoolTest::illegal;
1505 
1506   if (tst->is_Bool()) {
1507     // Refresh c from the transformed bool node, since it may be
1508     // simpler than the original c.  Also re-canonicalize btest.
1509     // This wins when (Bool ne (Conv2B p) 0) => (Bool ne (CmpP p null)).
1510     // That can arise from statements like: if (x instanceof C) ...
1511     if (tst != tst0) {
1512       // Canonicalize one more time since transform can change it.
1513       btest = tst->as_Bool()->_test._test;
1514       if (!BoolTest(btest).is_canonical()) {
1515         // Reverse edges one more time...
1516         tst   = _gvn.transform( tst->as_Bool()->negate(&_gvn) );
1517         btest = tst->as_Bool()->_test._test;
1518         assert(BoolTest(btest).is_canonical(), "sanity");
1519         taken_if_true = !taken_if_true;
1520       }
1521       c = tst->in(1);
1522     }
1523     BoolTest::mask neg_btest = BoolTest(btest).negate();
1524     taken_btest   = taken_if_true ?     btest : neg_btest;
1525     untaken_btest = taken_if_true ? neg_btest :     btest;
1526   }
1527 
1528   // Generate real control flow
1529   float true_prob = (taken_if_true ? prob : untaken_prob);
1530   IfNode* iff = create_and_map_if(control(), tst, true_prob, cnt);
1531   assert(iff->_prob > 0.0f,"Optimizer made bad probability in parser");
1532   Node* taken_branch   = new IfTrueNode(iff);
1533   Node* untaken_branch = new IfFalseNode(iff);
1534   if (!taken_if_true) {  // Finish conversion to canonical form
1535     Node* tmp      = taken_branch;
1536     taken_branch   = untaken_branch;
1537     untaken_branch = tmp;
1538   }
1539 
1540   // Branch is taken:
1541   { PreserveJVMState pjvms(this);
1542     taken_branch = _gvn.transform(taken_branch);
1543     set_control(taken_branch);
1544 
1545     if (stopped()) {
1546       if (C->eliminate_boxing()) {
1547         // Mark the successor block as parsed
1548         branch_block->next_path_num();
1549       }
1550     } else {
1551       adjust_map_after_if(taken_btest, c, prob, branch_block);
1552       if (!stopped()) {
1553         merge(target_bci);
1554       }
1555     }
1556   }
1557 
1558   untaken_branch = _gvn.transform(untaken_branch);
1559   set_control(untaken_branch);
1560 
1561   // Branch not taken.
1562   if (stopped()) {
1563     if (C->eliminate_boxing()) {
1564       // Mark the successor block as parsed
1565       next_block->next_path_num();
1566     }
1567   } else {
1568     adjust_map_after_if(untaken_btest, c, untaken_prob, next_block);
1569   }
1570 
1571   if (do_stress_trap) {
1572     stress_trap(iff, counter, incr_store);
1573   }
1574 }
1575 
1576 // Force unstable if traps to be taken randomly to trigger intermittent bugs such as incorrect debug information.
1577 // Add another if before the unstable if that checks a "random" condition at runtime (a simple shared counter) and
1578 // then either takes the trap or executes the original, unstable if.
1579 void Parse::stress_trap(IfNode* orig_iff, Node* counter, Node* incr_store) {
1580   // Search for an unstable if trap
1581   CallStaticJavaNode* trap = nullptr;
1582   assert(orig_iff->Opcode() == Op_If && orig_iff->outcnt() == 2, "malformed if");
1583   ProjNode* trap_proj = orig_iff->uncommon_trap_proj(trap, Deoptimization::Reason_unstable_if);
1584   if (trap == nullptr || !trap->jvms()->should_reexecute()) {
1585     // No suitable trap found. Remove unused counter load and increment.
1586     C->gvn_replace_by(incr_store, incr_store->in(MemNode::Memory));
1587     return;
1588   }
1589 
1590   // Remove trap from optimization list since we add another path to the trap.
1591   bool success = C->remove_unstable_if_trap(trap, true);
1592   assert(success, "Trap already modified");
1593 
1594   // Add a check before the original if that will trap with a certain frequency and execute the original if otherwise
1595   int freq_log = (C->random() % 31) + 1; // Random logarithmic frequency in [1, 31]
1596   Node* mask = intcon(right_n_bits(freq_log));
1597   counter = _gvn.transform(new AndINode(counter, mask));
1598   Node* cmp = _gvn.transform(new CmpINode(counter, intcon(0)));
1599   Node* bol = _gvn.transform(new BoolNode(cmp, BoolTest::mask::eq));
1600   IfNode* iff = _gvn.transform(new IfNode(orig_iff->in(0), bol, orig_iff->_prob, orig_iff->_fcnt))->as_If();
1601   Node* if_true = _gvn.transform(new IfTrueNode(iff));
1602   Node* if_false = _gvn.transform(new IfFalseNode(iff));
1603   assert(!if_true->is_top() && !if_false->is_top(), "trap always / never taken");
1604 
1605   // Trap
1606   assert(trap_proj->outcnt() == 1, "some other nodes are dependent on the trap projection");
1607 
1608   Node* trap_region = new RegionNode(3);
1609   trap_region->set_req(1, trap_proj);
1610   trap_region->set_req(2, if_true);
1611   trap->set_req(0, _gvn.transform(trap_region));
1612 
1613   // Don't trap, execute original if
1614   orig_iff->set_req(0, if_false);
1615 }
1616 
1617 bool Parse::path_is_suitable_for_uncommon_trap(float prob) const {
1618   // Randomly skip emitting an uncommon trap
1619   if (StressUnstableIfTraps && ((C->random() % 2) == 0)) {
1620     return false;
1621   }
1622   // Don't want to speculate on uncommon traps when running with -Xcomp
1623   if (!UseInterpreter) {
1624     return false;
1625   }
1626   return seems_never_taken(prob) &&
1627          !C->too_many_traps(method(), bci(), Deoptimization::Reason_unstable_if);
1628 }
1629 
1630 void Parse::maybe_add_predicate_after_if(Block* path) {
1631   if (path->is_SEL_head() && path->preds_parsed() == 0) {
1632     // Add predicates at bci of if dominating the loop so traps can be
1633     // recorded on the if's profile data
1634     int bc_depth = repush_if_args();
1635     add_parse_predicates();
1636     dec_sp(bc_depth);
1637     path->set_has_predicates();
1638   }
1639 }
1640 
1641 
1642 //----------------------------adjust_map_after_if------------------------------
1643 // Adjust the JVM state to reflect the result of taking this path.
1644 // Basically, it means inspecting the CmpNode controlling this
1645 // branch, seeing how it constrains a tested value, and then
1646 // deciding if it's worth our while to encode this constraint
1647 // as graph nodes in the current abstract interpretation map.
1648 void Parse::adjust_map_after_if(BoolTest::mask btest, Node* c, float prob, Block* path) {
1649   if (!c->is_Cmp()) {
1650     maybe_add_predicate_after_if(path);
1651     return;
1652   }
1653 
1654   if (stopped() || btest == BoolTest::illegal) {
1655     return;                             // nothing to do
1656   }
1657 
1658   bool is_fallthrough = (path == successor_for_bci(iter().next_bci()));
1659 
1660   if (path_is_suitable_for_uncommon_trap(prob)) {
1661     repush_if_args();
1662     Node* call = uncommon_trap(Deoptimization::Reason_unstable_if,
1663                   Deoptimization::Action_reinterpret,
1664                   nullptr,
1665                   (is_fallthrough ? "taken always" : "taken never"));
1666 
1667     if (call != nullptr) {
1668       C->record_unstable_if_trap(new UnstableIfTrap(call->as_CallStaticJava(), path));
1669     }
1670     return;
1671   }
1672 
1673   Node* val = c->in(1);
1674   Node* con = c->in(2);
1675   const Type* tcon = _gvn.type(con);
1676   const Type* tval = _gvn.type(val);
1677   bool have_con = tcon->singleton();
1678   if (tval->singleton()) {
1679     if (!have_con) {
1680       // Swap, so constant is in con.
1681       con  = val;
1682       tcon = tval;
1683       val  = c->in(2);
1684       tval = _gvn.type(val);
1685       btest = BoolTest(btest).commute();
1686       have_con = true;
1687     } else {
1688       // Do we have two constants?  Then leave well enough alone.
1689       have_con = false;
1690     }
1691   }
1692   if (!have_con) {                        // remaining adjustments need a con
1693     maybe_add_predicate_after_if(path);
1694     return;
1695   }
1696 
1697   sharpen_type_after_if(btest, con, tcon, val, tval);
1698   maybe_add_predicate_after_if(path);
1699 }
1700 
1701 
1702 static Node* extract_obj_from_klass_load(PhaseGVN* gvn, Node* n) {
1703   Node* ldk;
1704   if (n->is_DecodeNKlass()) {
1705     if (n->in(1)->Opcode() != Op_LoadNKlass) {
1706       return nullptr;
1707     } else {
1708       ldk = n->in(1);
1709     }
1710   } else if (n->Opcode() != Op_LoadKlass) {
1711     return nullptr;
1712   } else {
1713     ldk = n;
1714   }
1715   assert(ldk != nullptr && ldk->is_Load(), "should have found a LoadKlass or LoadNKlass node");
1716 
1717   Node* adr = ldk->in(MemNode::Address);
1718   intptr_t off = 0;
1719   Node* obj = AddPNode::Ideal_base_and_offset(adr, gvn, off);
1720   if (obj == nullptr || off != oopDesc::klass_offset_in_bytes()) // loading oopDesc::_klass?
1721     return nullptr;
1722   const TypePtr* tp = gvn->type(obj)->is_ptr();
1723   if (tp == nullptr || !(tp->isa_instptr() || tp->isa_aryptr())) // is obj a Java object ptr?
1724     return nullptr;
1725 
1726   return obj;
1727 }
1728 
1729 // Matches exact and inexact type check IR shapes during parsing.
1730 // On successful match, returns type checked object node and its type after successful check
1731 // as out parameters.
1732 static bool match_type_check(PhaseGVN& gvn,
1733                              BoolTest::mask btest,
1734                              Node* con, const Type* tcon,
1735                              Node* val, const Type* tval,
1736                              Node** obj, const TypeOopPtr** cast_type) { // out-parameters
1737   // Look for opportunities to sharpen the type of a node whose klass is compared with a constant klass.
1738   // The constant klass being tested against can come from many bytecode instructions (implicitly or explicitly),
1739   // and also from profile data used by speculative casts.
1740   if (btest == BoolTest::eq && tcon->isa_klassptr()) {
1741     // Found:
1742     //   Bool(CmpP(LoadKlass(obj._klass), ConP(Foo.klass)), [eq])
1743     // or the narrowOop equivalent.
1744     (*obj) = extract_obj_from_klass_load(&gvn, val);
1745     (*cast_type) = tcon->isa_klassptr()->as_instance_type();
1746     return true; // found
1747   }
1748 
1749   // Match an instanceof check.
1750   // During parsing its IR shape is not canonicalized yet.
1751   //
1752   //             obj superklass
1753   //              |    |
1754   //           SubTypeCheck
1755   //                |
1756   //               Bool [eq] / [ne]
1757   //                |
1758   //                If
1759   //               / \
1760   //              T   F
1761   //               \ /
1762   //              Region
1763   //                 \  ConI ConI
1764   //                  \  |  /
1765   //          val ->    Phi  ConI  <- con
1766   //                     \  /
1767   //                     CmpI
1768   //                      |
1769   //                    Bool [btest]
1770   //                      |
1771   //
1772   if (tval->isa_int() && val->is_Phi() && val->in(0)->as_Region()->is_diamond()) {
1773     RegionNode* diamond = val->in(0)->as_Region();
1774     IfNode* if1 = diamond->in(1)->in(0)->as_If();
1775     BoolNode* b1 = if1->in(1)->isa_Bool();
1776     if (b1 != nullptr && b1->in(1)->isa_SubTypeCheck()) {
1777       assert(b1->_test._test == BoolTest::eq ||
1778              b1->_test._test == BoolTest::ne, "%d", b1->_test._test);
1779 
1780       ProjNode* success_proj = if1->proj_out(b1->_test._test == BoolTest::eq ? 1 : 0);
1781       int idx = diamond->find_edge(success_proj);
1782       assert(idx == 1 || idx == 2, "");
1783       Node* vcon = val->in(idx);
1784 
1785       assert(val->find_edge(con) > 0, "");
1786       if ((btest == BoolTest::eq && vcon == con) || (btest == BoolTest::ne && vcon != con)) {
1787         SubTypeCheckNode* sub = b1->in(1)->as_SubTypeCheck();
1788         Node* obj_or_subklass = sub->in(SubTypeCheckNode::ObjOrSubKlass);
1789         Node* superklass = sub->in(SubTypeCheckNode::SuperKlass);
1790 
1791         if (gvn.type(obj_or_subklass)->isa_oopptr()) {
1792           const TypeKlassPtr* klass_ptr_type = gvn.type(superklass)->is_klassptr();
1793           const TypeKlassPtr* improved_klass_ptr_type = klass_ptr_type->try_improve();
1794 
1795           (*obj) = obj_or_subklass;
1796           (*cast_type) = improved_klass_ptr_type->cast_to_exactness(false)->as_instance_type();
1797           return true; // found
1798         }
1799       }
1800     }
1801   }
1802   return false; // not found
1803 }
1804 
1805 void Parse::sharpen_type_after_if(BoolTest::mask btest,
1806                                   Node* con, const Type* tcon,
1807                                   Node* val, const Type* tval) {
1808   Node* obj = nullptr;
1809   const TypeOopPtr* cast_type = nullptr;
1810   // Insert a cast node with a narrowed type after a successful type check.
1811   if (match_type_check(_gvn, btest, con, tcon, val, tval,
1812                        &obj, &cast_type)) {
1813     assert(obj != nullptr && cast_type != nullptr, "missing type check info");
1814     const Type* obj_type = _gvn.type(obj);
1815     const TypeOopPtr* tboth = obj_type->join_speculative(cast_type)->isa_oopptr();
1816     if (tboth != nullptr && tboth != obj_type && tboth->higher_equal(obj_type)) {
1817       int obj_in_map = map()->find_edge(obj);
1818       JVMState* jvms = this->jvms();
1819       if (obj_in_map >= 0 &&
1820           (jvms->is_loc(obj_in_map) || jvms->is_stk(obj_in_map))) {
1821         TypeNode* ccast = new CheckCastPPNode(control(), obj, tboth);
1822         const Type* tcc = ccast->as_Type()->type();
1823         assert(tcc != obj_type && tcc->higher_equal(obj_type), "must improve");
1824         // Delay transform() call to allow recovery of pre-cast value
1825         // at the control merge.
1826         _gvn.set_type_bottom(ccast);
1827         record_for_igvn(ccast);
1828         // Here's the payoff.
1829         replace_in_map(obj, ccast);
1830       }
1831     }
1832   }
1833 
1834   int val_in_map = map()->find_edge(val);
1835   if (val_in_map < 0)  return;          // replace_in_map would be useless
1836   {
1837     JVMState* jvms = this->jvms();
1838     if (!(jvms->is_loc(val_in_map) ||
1839           jvms->is_stk(val_in_map)))
1840       return;                           // again, it would be useless
1841   }
1842 
1843   // Check for a comparison to a constant, and "know" that the compared
1844   // value is constrained on this path.
1845   assert(tcon->singleton(), "");
1846   ConstraintCastNode* ccast = nullptr;
1847   Node* cast = nullptr;
1848 
1849   switch (btest) {
1850   case BoolTest::eq:                    // Constant test?
1851     {
1852       const Type* tboth = tcon->join_speculative(tval);
1853       if (tboth == tval)  break;        // Nothing to gain.
1854       if (tcon->isa_int()) {
1855         ccast = new CastIINode(control(), val, tboth);
1856       } else if (tcon == TypePtr::NULL_PTR) {
1857         // Cast to null, but keep the pointer identity temporarily live.
1858         ccast = new CastPPNode(control(), val, tboth);
1859       } else {
1860         const TypeF* tf = tcon->isa_float_constant();
1861         const TypeD* td = tcon->isa_double_constant();
1862         // Exclude tests vs float/double 0 as these could be
1863         // either +0 or -0.  Just because you are equal to +0
1864         // doesn't mean you ARE +0!
1865         // Note, following code also replaces Long and Oop values.
1866         if ((!tf || tf->_f != 0.0) &&
1867             (!td || td->_d != 0.0))
1868           cast = con;                   // Replace non-constant val by con.
1869       }
1870     }
1871     break;
1872 
1873   case BoolTest::ne:
1874     if (tcon == TypePtr::NULL_PTR) {
1875       cast = cast_not_null(val, false);
1876     }
1877     break;
1878 
1879   default:
1880     // (At this point we could record int range types with CastII.)
1881     break;
1882   }
1883 
1884   if (ccast != nullptr) {
1885     const Type* tcc = ccast->as_Type()->type();
1886     assert(tcc != tval && tcc->higher_equal(tval), "must improve");
1887     // Delay transform() call to allow recovery of pre-cast value
1888     // at the control merge.
1889     _gvn.set_type_bottom(ccast);
1890     record_for_igvn(ccast);
1891     cast = ccast;
1892   }
1893 
1894   if (cast != nullptr) {                   // Here's the payoff.
1895     replace_in_map(val, cast);
1896   }
1897 }
1898 
1899 /**
1900  * Use speculative type to optimize CmpP node: if comparison is
1901  * against the low level class, cast the object to the speculative
1902  * type if any. CmpP should then go away.
1903  *
1904  * @param c  expected CmpP node
1905  * @return   result of CmpP on object casted to speculative type
1906  *
1907  */
1908 Node* Parse::optimize_cmp_with_klass(Node* c) {
1909   // If this is transformed by the _gvn to a comparison with the low
1910   // level klass then we may be able to use speculation
1911   if (c->Opcode() == Op_CmpP &&
1912       (c->in(1)->Opcode() == Op_LoadKlass || c->in(1)->Opcode() == Op_DecodeNKlass) &&
1913       c->in(2)->is_Con()) {
1914     Node* load_klass = nullptr;
1915     Node* decode = nullptr;
1916     if (c->in(1)->Opcode() == Op_DecodeNKlass) {
1917       decode = c->in(1);
1918       load_klass = c->in(1)->in(1);
1919     } else {
1920       load_klass = c->in(1);
1921     }
1922     if (load_klass->in(2)->is_AddP()) {
1923       Node* addp = load_klass->in(2);
1924       Node* obj = addp->in(AddPNode::Address);
1925       const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
1926       if (obj_type->speculative_type_not_null() != nullptr) {
1927         ciKlass* k = obj_type->speculative_type();
1928         inc_sp(2);
1929         obj = maybe_cast_profiled_obj(obj, k);
1930         dec_sp(2);
1931         // Make the CmpP use the casted obj
1932         addp = basic_plus_adr(obj, addp->in(AddPNode::Offset));
1933         load_klass = load_klass->clone();
1934         load_klass->set_req(2, addp);
1935         load_klass = _gvn.transform(load_klass);
1936         if (decode != nullptr) {
1937           decode = decode->clone();
1938           decode->set_req(1, load_klass);
1939           load_klass = _gvn.transform(decode);
1940         }
1941         c = c->clone();
1942         c->set_req(1, load_klass);
1943         c = _gvn.transform(c);
1944       }
1945     }
1946   }
1947   return c;
1948 }
1949 
1950 //------------------------------do_one_bytecode--------------------------------
1951 // Parse this bytecode, and alter the Parsers JVM->Node mapping
1952 void Parse::do_one_bytecode() {
1953   Node *a, *b, *c, *d;          // Handy temps
1954   BoolTest::mask btest;
1955   int i;
1956 
1957   assert(!has_exceptions(), "bytecode entry state must be clear of throws");
1958 
1959   if (C->check_node_count(NodeLimitFudgeFactor * 5,
1960                           "out of nodes parsing method")) {
1961     return;
1962   }
1963 
1964 #ifdef ASSERT
1965   // for setting breakpoints
1966   if (TraceOptoParse) {
1967     tty->print(" @");
1968     dump_bci(bci());
1969     tty->print(" %s", Bytecodes::name(bc()));
1970     tty->cr();
1971   }
1972 #endif
1973 
1974   switch (bc()) {
1975   case Bytecodes::_nop:
1976     // do nothing
1977     break;
1978   case Bytecodes::_lconst_0:
1979     push_pair(longcon(0));
1980     break;
1981 
1982   case Bytecodes::_lconst_1:
1983     push_pair(longcon(1));
1984     break;
1985 
1986   case Bytecodes::_fconst_0:
1987     push(zerocon(T_FLOAT));
1988     break;
1989 
1990   case Bytecodes::_fconst_1:
1991     push(makecon(TypeF::ONE));
1992     break;
1993 
1994   case Bytecodes::_fconst_2:
1995     push(makecon(TypeF::make(2.0f)));
1996     break;
1997 
1998   case Bytecodes::_dconst_0:
1999     push_pair(zerocon(T_DOUBLE));
2000     break;
2001 
2002   case Bytecodes::_dconst_1:
2003     push_pair(makecon(TypeD::ONE));
2004     break;
2005 
2006   case Bytecodes::_iconst_m1:push(intcon(-1)); break;
2007   case Bytecodes::_iconst_0: push(intcon( 0)); break;
2008   case Bytecodes::_iconst_1: push(intcon( 1)); break;
2009   case Bytecodes::_iconst_2: push(intcon( 2)); break;
2010   case Bytecodes::_iconst_3: push(intcon( 3)); break;
2011   case Bytecodes::_iconst_4: push(intcon( 4)); break;
2012   case Bytecodes::_iconst_5: push(intcon( 5)); break;
2013   case Bytecodes::_bipush:   push(intcon(iter().get_constant_u1())); break;
2014   case Bytecodes::_sipush:   push(intcon(iter().get_constant_u2())); break;
2015   case Bytecodes::_aconst_null: push(null());  break;
2016 
2017   case Bytecodes::_ldc:
2018   case Bytecodes::_ldc_w:
2019   case Bytecodes::_ldc2_w: {
2020     // ciTypeFlow should trap if the ldc is in error state or if the constant is not loaded
2021     assert(!iter().is_in_error(), "ldc is in error state");
2022     ciConstant constant = iter().get_constant();
2023     assert(constant.is_loaded(), "constant is not loaded");
2024     const Type* con_type = Type::make_from_constant(constant);
2025     if (con_type != nullptr) {
2026       push_node(con_type->basic_type(), makecon(con_type));
2027     }
2028     break;
2029   }
2030 
2031   case Bytecodes::_aload_0:
2032     push( local(0) );
2033     break;
2034   case Bytecodes::_aload_1:
2035     push( local(1) );
2036     break;
2037   case Bytecodes::_aload_2:
2038     push( local(2) );
2039     break;
2040   case Bytecodes::_aload_3:
2041     push( local(3) );
2042     break;
2043   case Bytecodes::_aload:
2044     push( local(iter().get_index()) );
2045     break;
2046 
2047   case Bytecodes::_fload_0:
2048   case Bytecodes::_iload_0:
2049     push( local(0) );
2050     break;
2051   case Bytecodes::_fload_1:
2052   case Bytecodes::_iload_1:
2053     push( local(1) );
2054     break;
2055   case Bytecodes::_fload_2:
2056   case Bytecodes::_iload_2:
2057     push( local(2) );
2058     break;
2059   case Bytecodes::_fload_3:
2060   case Bytecodes::_iload_3:
2061     push( local(3) );
2062     break;
2063   case Bytecodes::_fload:
2064   case Bytecodes::_iload:
2065     push( local(iter().get_index()) );
2066     break;
2067   case Bytecodes::_lload_0:
2068     push_pair_local( 0 );
2069     break;
2070   case Bytecodes::_lload_1:
2071     push_pair_local( 1 );
2072     break;
2073   case Bytecodes::_lload_2:
2074     push_pair_local( 2 );
2075     break;
2076   case Bytecodes::_lload_3:
2077     push_pair_local( 3 );
2078     break;
2079   case Bytecodes::_lload:
2080     push_pair_local( iter().get_index() );
2081     break;
2082 
2083   case Bytecodes::_dload_0:
2084     push_pair_local(0);
2085     break;
2086   case Bytecodes::_dload_1:
2087     push_pair_local(1);
2088     break;
2089   case Bytecodes::_dload_2:
2090     push_pair_local(2);
2091     break;
2092   case Bytecodes::_dload_3:
2093     push_pair_local(3);
2094     break;
2095   case Bytecodes::_dload:
2096     push_pair_local(iter().get_index());
2097     break;
2098   case Bytecodes::_fstore_0:
2099   case Bytecodes::_istore_0:
2100   case Bytecodes::_astore_0:
2101     set_local( 0, pop() );
2102     break;
2103   case Bytecodes::_fstore_1:
2104   case Bytecodes::_istore_1:
2105   case Bytecodes::_astore_1:
2106     set_local( 1, pop() );
2107     break;
2108   case Bytecodes::_fstore_2:
2109   case Bytecodes::_istore_2:
2110   case Bytecodes::_astore_2:
2111     set_local( 2, pop() );
2112     break;
2113   case Bytecodes::_fstore_3:
2114   case Bytecodes::_istore_3:
2115   case Bytecodes::_astore_3:
2116     set_local( 3, pop() );
2117     break;
2118   case Bytecodes::_fstore:
2119   case Bytecodes::_istore:
2120   case Bytecodes::_astore:
2121     set_local( iter().get_index(), pop() );
2122     break;
2123   // long stores
2124   case Bytecodes::_lstore_0:
2125     set_pair_local( 0, pop_pair() );
2126     break;
2127   case Bytecodes::_lstore_1:
2128     set_pair_local( 1, pop_pair() );
2129     break;
2130   case Bytecodes::_lstore_2:
2131     set_pair_local( 2, pop_pair() );
2132     break;
2133   case Bytecodes::_lstore_3:
2134     set_pair_local( 3, pop_pair() );
2135     break;
2136   case Bytecodes::_lstore:
2137     set_pair_local( iter().get_index(), pop_pair() );
2138     break;
2139 
2140   // double stores
2141   case Bytecodes::_dstore_0:
2142     set_pair_local( 0, pop_pair() );
2143     break;
2144   case Bytecodes::_dstore_1:
2145     set_pair_local( 1, pop_pair() );
2146     break;
2147   case Bytecodes::_dstore_2:
2148     set_pair_local( 2, pop_pair() );
2149     break;
2150   case Bytecodes::_dstore_3:
2151     set_pair_local( 3, pop_pair() );
2152     break;
2153   case Bytecodes::_dstore:
2154     set_pair_local( iter().get_index(), pop_pair() );
2155     break;
2156 
2157   case Bytecodes::_pop:  dec_sp(1);   break;
2158   case Bytecodes::_pop2: dec_sp(2);   break;
2159   case Bytecodes::_swap:
2160     a = pop();
2161     b = pop();
2162     push(a);
2163     push(b);
2164     break;
2165   case Bytecodes::_dup:
2166     a = pop();
2167     push(a);
2168     push(a);
2169     break;
2170   case Bytecodes::_dup_x1:
2171     a = pop();
2172     b = pop();
2173     push( a );
2174     push( b );
2175     push( a );
2176     break;
2177   case Bytecodes::_dup_x2:
2178     a = pop();
2179     b = pop();
2180     c = pop();
2181     push( a );
2182     push( c );
2183     push( b );
2184     push( a );
2185     break;
2186   case Bytecodes::_dup2:
2187     a = pop();
2188     b = pop();
2189     push( b );
2190     push( a );
2191     push( b );
2192     push( a );
2193     break;
2194 
2195   case Bytecodes::_dup2_x1:
2196     // before: .. c, b, a
2197     // after:  .. b, a, c, b, a
2198     // not tested
2199     a = pop();
2200     b = pop();
2201     c = pop();
2202     push( b );
2203     push( a );
2204     push( c );
2205     push( b );
2206     push( a );
2207     break;
2208   case Bytecodes::_dup2_x2:
2209     // before: .. d, c, b, a
2210     // after:  .. b, a, d, c, b, a
2211     // not tested
2212     a = pop();
2213     b = pop();
2214     c = pop();
2215     d = pop();
2216     push( b );
2217     push( a );
2218     push( d );
2219     push( c );
2220     push( b );
2221     push( a );
2222     break;
2223 
2224   case Bytecodes::_arraylength: {
2225     // Must do null-check with value on expression stack
2226     Node *ary = null_check(peek(), T_ARRAY);
2227     // Compile-time detect of null-exception?
2228     if (stopped())  return;
2229     a = pop();
2230     push(load_array_length(a));
2231     break;
2232   }
2233 
2234   case Bytecodes::_baload:  array_load(T_BYTE);    break;
2235   case Bytecodes::_caload:  array_load(T_CHAR);    break;
2236   case Bytecodes::_iaload:  array_load(T_INT);     break;
2237   case Bytecodes::_saload:  array_load(T_SHORT);   break;
2238   case Bytecodes::_faload:  array_load(T_FLOAT);   break;
2239   case Bytecodes::_aaload:  array_load(T_OBJECT);  break;
2240   case Bytecodes::_laload:  array_load(T_LONG);    break;
2241   case Bytecodes::_daload:  array_load(T_DOUBLE);  break;
2242   case Bytecodes::_bastore: array_store(T_BYTE);   break;
2243   case Bytecodes::_castore: array_store(T_CHAR);   break;
2244   case Bytecodes::_iastore: array_store(T_INT);    break;
2245   case Bytecodes::_sastore: array_store(T_SHORT);  break;
2246   case Bytecodes::_fastore: array_store(T_FLOAT);  break;
2247   case Bytecodes::_aastore: array_store(T_OBJECT); break;
2248   case Bytecodes::_lastore: array_store(T_LONG);   break;
2249   case Bytecodes::_dastore: array_store(T_DOUBLE); break;
2250 
2251   case Bytecodes::_getfield:
2252     do_getfield();
2253     break;
2254 
2255   case Bytecodes::_getstatic:
2256     do_getstatic();
2257     break;
2258 
2259   case Bytecodes::_putfield:
2260     do_putfield();
2261     break;
2262 
2263   case Bytecodes::_putstatic:
2264     do_putstatic();
2265     break;
2266 
2267   case Bytecodes::_irem:
2268     // Must keep both values on the expression-stack during null-check
2269     zero_check_int(peek());
2270     // Compile-time detect of null-exception?
2271     if (stopped())  return;
2272     b = pop();
2273     a = pop();
2274     push(_gvn.transform(new ModINode(control(), a, b)));
2275     break;
2276   case Bytecodes::_idiv:
2277     // Must keep both values on the expression-stack during null-check
2278     zero_check_int(peek());
2279     // Compile-time detect of null-exception?
2280     if (stopped())  return;
2281     b = pop();
2282     a = pop();
2283     push( _gvn.transform( new DivINode(control(),a,b) ) );
2284     break;
2285   case Bytecodes::_imul:
2286     b = pop(); a = pop();
2287     push( _gvn.transform( new MulINode(a,b) ) );
2288     break;
2289   case Bytecodes::_iadd:
2290     b = pop(); a = pop();
2291     push( _gvn.transform( new AddINode(a,b) ) );
2292     break;
2293   case Bytecodes::_ineg:
2294     a = pop();
2295     push( _gvn.transform( new SubINode(_gvn.intcon(0),a)) );
2296     break;
2297   case Bytecodes::_isub:
2298     b = pop(); a = pop();
2299     push( _gvn.transform( new SubINode(a,b) ) );
2300     break;
2301   case Bytecodes::_iand:
2302     b = pop(); a = pop();
2303     push( _gvn.transform( new AndINode(a,b) ) );
2304     break;
2305   case Bytecodes::_ior:
2306     b = pop(); a = pop();
2307     push( _gvn.transform( new OrINode(a,b) ) );
2308     break;
2309   case Bytecodes::_ixor:
2310     b = pop(); a = pop();
2311     push( _gvn.transform( new XorINode(a,b) ) );
2312     break;
2313   case Bytecodes::_ishl:
2314     b = pop(); a = pop();
2315     push( _gvn.transform( new LShiftINode(a,b) ) );
2316     break;
2317   case Bytecodes::_ishr:
2318     b = pop(); a = pop();
2319     push( _gvn.transform( new RShiftINode(a,b) ) );
2320     break;
2321   case Bytecodes::_iushr:
2322     b = pop(); a = pop();
2323     push( _gvn.transform( new URShiftINode(a,b) ) );
2324     break;
2325 
2326   case Bytecodes::_fneg:
2327     a = pop();
2328     b = _gvn.transform(new NegFNode (a));
2329     push(b);
2330     break;
2331 
2332   case Bytecodes::_fsub:
2333     b = pop();
2334     a = pop();
2335     c = _gvn.transform( new SubFNode(a,b) );
2336     push(c);
2337     break;
2338 
2339   case Bytecodes::_fadd:
2340     b = pop();
2341     a = pop();
2342     c = _gvn.transform( new AddFNode(a,b) );
2343     push(c);
2344     break;
2345 
2346   case Bytecodes::_fmul:
2347     b = pop();
2348     a = pop();
2349     c = _gvn.transform( new MulFNode(a,b) );
2350     push(c);
2351     break;
2352 
2353   case Bytecodes::_fdiv:
2354     b = pop();
2355     a = pop();
2356     c = _gvn.transform( new DivFNode(nullptr,a,b) );
2357     push(c);
2358     break;
2359 
2360   case Bytecodes::_frem:
2361     // Generate a ModF node.
2362     b = pop();
2363     a = pop();
2364     push(floating_point_mod(a, b, BasicType::T_FLOAT));
2365     break;
2366 
2367   case Bytecodes::_fcmpl:
2368     b = pop();
2369     a = pop();
2370     c = _gvn.transform( new CmpF3Node( a, b));
2371     push(c);
2372     break;
2373   case Bytecodes::_fcmpg:
2374     b = pop();
2375     a = pop();
2376 
2377     // Same as fcmpl but need to flip the unordered case.  Swap the inputs,
2378     // which negates the result sign except for unordered.  Flip the unordered
2379     // as well by using CmpF3 which implements unordered-lesser instead of
2380     // unordered-greater semantics.  Finally, commute the result bits.  Result
2381     // is same as using a CmpF3Greater except we did it with CmpF3 alone.
2382     c = _gvn.transform( new CmpF3Node( b, a));
2383     c = _gvn.transform( new SubINode(_gvn.intcon(0),c) );
2384     push(c);
2385     break;
2386 
2387   case Bytecodes::_f2i:
2388     a = pop();
2389     push(_gvn.transform(new ConvF2INode(a)));
2390     break;
2391 
2392   case Bytecodes::_d2i:
2393     a = pop_pair();
2394     b = _gvn.transform(new ConvD2INode(a));
2395     push( b );
2396     break;
2397 
2398   case Bytecodes::_f2d:
2399     a = pop();
2400     b = _gvn.transform( new ConvF2DNode(a));
2401     push_pair( b );
2402     break;
2403 
2404   case Bytecodes::_d2f:
2405     a = pop_pair();
2406     b = _gvn.transform( new ConvD2FNode(a));
2407     push( b );
2408     break;
2409 
2410   case Bytecodes::_l2f:
2411     if (Matcher::convL2FSupported()) {
2412       a = pop_pair();
2413       b = _gvn.transform( new ConvL2FNode(a));
2414       push(b);
2415     } else {
2416       l2f();
2417     }
2418     break;
2419 
2420   case Bytecodes::_l2d:
2421     a = pop_pair();
2422     b = _gvn.transform( new ConvL2DNode(a));
2423     push_pair(b);
2424     break;
2425 
2426   case Bytecodes::_f2l:
2427     a = pop();
2428     b = _gvn.transform( new ConvF2LNode(a));
2429     push_pair(b);
2430     break;
2431 
2432   case Bytecodes::_d2l:
2433     a = pop_pair();
2434     b = _gvn.transform( new ConvD2LNode(a));
2435     push_pair(b);
2436     break;
2437 
2438   case Bytecodes::_dsub:
2439     b = pop_pair();
2440     a = pop_pair();
2441     c = _gvn.transform( new SubDNode(a,b) );
2442     push_pair(c);
2443     break;
2444 
2445   case Bytecodes::_dadd:
2446     b = pop_pair();
2447     a = pop_pair();
2448     c = _gvn.transform( new AddDNode(a,b) );
2449     push_pair(c);
2450     break;
2451 
2452   case Bytecodes::_dmul:
2453     b = pop_pair();
2454     a = pop_pair();
2455     c = _gvn.transform( new MulDNode(a,b) );
2456     push_pair(c);
2457     break;
2458 
2459   case Bytecodes::_ddiv:
2460     b = pop_pair();
2461     a = pop_pair();
2462     c = _gvn.transform( new DivDNode(nullptr,a,b) );
2463     push_pair(c);
2464     break;
2465 
2466   case Bytecodes::_dneg:
2467     a = pop_pair();
2468     b = _gvn.transform(new NegDNode (a));
2469     push_pair(b);
2470     break;
2471 
2472   case Bytecodes::_drem:
2473     // Generate a ModD node.
2474     b = pop_pair();
2475     a = pop_pair();
2476     push_pair(floating_point_mod(a, b, BasicType::T_DOUBLE));
2477     break;
2478 
2479   case Bytecodes::_dcmpl:
2480     b = pop_pair();
2481     a = pop_pair();
2482     c = _gvn.transform( new CmpD3Node( a, b));
2483     push(c);
2484     break;
2485 
2486   case Bytecodes::_dcmpg:
2487     b = pop_pair();
2488     a = pop_pair();
2489     // Same as dcmpl but need to flip the unordered case.
2490     // Commute the inputs, which negates the result sign except for unordered.
2491     // Flip the unordered as well by using CmpD3 which implements
2492     // unordered-lesser instead of unordered-greater semantics.
2493     // Finally, negate the result bits.  Result is same as using a
2494     // CmpD3Greater except we did it with CmpD3 alone.
2495     c = _gvn.transform( new CmpD3Node( b, a));
2496     c = _gvn.transform( new SubINode(_gvn.intcon(0),c) );
2497     push(c);
2498     break;
2499 
2500 
2501     // Note for longs -> lo word is on TOS, hi word is on TOS - 1
2502   case Bytecodes::_land:
2503     b = pop_pair();
2504     a = pop_pair();
2505     c = _gvn.transform( new AndLNode(a,b) );
2506     push_pair(c);
2507     break;
2508   case Bytecodes::_lor:
2509     b = pop_pair();
2510     a = pop_pair();
2511     c = _gvn.transform( new OrLNode(a,b) );
2512     push_pair(c);
2513     break;
2514   case Bytecodes::_lxor:
2515     b = pop_pair();
2516     a = pop_pair();
2517     c = _gvn.transform( new XorLNode(a,b) );
2518     push_pair(c);
2519     break;
2520 
2521   case Bytecodes::_lshl:
2522     b = pop();                  // the shift count
2523     a = pop_pair();             // value to be shifted
2524     c = _gvn.transform( new LShiftLNode(a,b) );
2525     push_pair(c);
2526     break;
2527   case Bytecodes::_lshr:
2528     b = pop();                  // the shift count
2529     a = pop_pair();             // value to be shifted
2530     c = _gvn.transform( new RShiftLNode(a,b) );
2531     push_pair(c);
2532     break;
2533   case Bytecodes::_lushr:
2534     b = pop();                  // the shift count
2535     a = pop_pair();             // value to be shifted
2536     c = _gvn.transform( new URShiftLNode(a,b) );
2537     push_pair(c);
2538     break;
2539   case Bytecodes::_lmul:
2540     b = pop_pair();
2541     a = pop_pair();
2542     c = _gvn.transform( new MulLNode(a,b) );
2543     push_pair(c);
2544     break;
2545 
2546   case Bytecodes::_lrem:
2547     // Must keep both values on the expression-stack during null-check
2548     assert(peek(0) == top(), "long word order");
2549     zero_check_long(peek(1));
2550     // Compile-time detect of null-exception?
2551     if (stopped())  return;
2552     b = pop_pair();
2553     a = pop_pair();
2554     c = _gvn.transform( new ModLNode(control(),a,b) );
2555     push_pair(c);
2556     break;
2557 
2558   case Bytecodes::_ldiv:
2559     // Must keep both values on the expression-stack during null-check
2560     assert(peek(0) == top(), "long word order");
2561     zero_check_long(peek(1));
2562     // Compile-time detect of null-exception?
2563     if (stopped())  return;
2564     b = pop_pair();
2565     a = pop_pair();
2566     c = _gvn.transform( new DivLNode(control(),a,b) );
2567     push_pair(c);
2568     break;
2569 
2570   case Bytecodes::_ladd:
2571     b = pop_pair();
2572     a = pop_pair();
2573     c = _gvn.transform( new AddLNode(a,b) );
2574     push_pair(c);
2575     break;
2576   case Bytecodes::_lsub:
2577     b = pop_pair();
2578     a = pop_pair();
2579     c = _gvn.transform( new SubLNode(a,b) );
2580     push_pair(c);
2581     break;
2582   case Bytecodes::_lcmp:
2583     // Safepoints are now inserted _before_ branches.  The long-compare
2584     // bytecode painfully produces a 3-way value (-1,0,+1) which requires a
2585     // slew of control flow.  These are usually followed by a CmpI vs zero and
2586     // a branch; this pattern then optimizes to the obvious long-compare and
2587     // branch.  However, if the branch is backwards there's a Safepoint
2588     // inserted.  The inserted Safepoint captures the JVM state at the
2589     // pre-branch point, i.e. it captures the 3-way value.  Thus if a
2590     // long-compare is used to control a loop the debug info will force
2591     // computation of the 3-way value, even though the generated code uses a
2592     // long-compare and branch.  We try to rectify the situation by inserting
2593     // a SafePoint here and have it dominate and kill the safepoint added at a
2594     // following backwards branch.  At this point the JVM state merely holds 2
2595     // longs but not the 3-way value.
2596     switch (iter().next_bc()) {
2597       case Bytecodes::_ifgt:
2598       case Bytecodes::_iflt:
2599       case Bytecodes::_ifge:
2600       case Bytecodes::_ifle:
2601       case Bytecodes::_ifne:
2602       case Bytecodes::_ifeq:
2603         // If this is a backwards branch in the bytecodes, add Safepoint
2604         maybe_add_safepoint(iter().next_get_dest());
2605       default:
2606         break;
2607     }
2608     b = pop_pair();
2609     a = pop_pair();
2610     c = _gvn.transform( new CmpL3Node( a, b ));
2611     push(c);
2612     break;
2613 
2614   case Bytecodes::_lneg:
2615     a = pop_pair();
2616     b = _gvn.transform( new SubLNode(longcon(0),a));
2617     push_pair(b);
2618     break;
2619   case Bytecodes::_l2i:
2620     a = pop_pair();
2621     push( _gvn.transform( new ConvL2INode(a)));
2622     break;
2623   case Bytecodes::_i2l:
2624     a = pop();
2625     b = _gvn.transform( new ConvI2LNode(a));
2626     push_pair(b);
2627     break;
2628   case Bytecodes::_i2b:
2629     // Sign extend
2630     a = pop();
2631     a = Compile::narrow_value(T_BYTE, a, nullptr, &_gvn, true);
2632     push(a);
2633     break;
2634   case Bytecodes::_i2s:
2635     a = pop();
2636     a = Compile::narrow_value(T_SHORT, a, nullptr, &_gvn, true);
2637     push(a);
2638     break;
2639   case Bytecodes::_i2c:
2640     a = pop();
2641     a = Compile::narrow_value(T_CHAR, a, nullptr, &_gvn, true);
2642     push(a);
2643     break;
2644 
2645   case Bytecodes::_i2f:
2646     a = pop();
2647     b = _gvn.transform( new ConvI2FNode(a) ) ;
2648     push(b);
2649     break;
2650 
2651   case Bytecodes::_i2d:
2652     a = pop();
2653     b = _gvn.transform( new ConvI2DNode(a));
2654     push_pair(b);
2655     break;
2656 
2657   case Bytecodes::_iinc:        // Increment local
2658     i = iter().get_index();     // Get local index
2659     set_local( i, _gvn.transform( new AddINode( _gvn.intcon(iter().get_iinc_con()), local(i) ) ) );
2660     break;
2661 
2662   // Exit points of synchronized methods must have an unlock node
2663   case Bytecodes::_return:
2664     return_current(nullptr);
2665     break;
2666 
2667   case Bytecodes::_ireturn:
2668   case Bytecodes::_areturn:
2669   case Bytecodes::_freturn:
2670     return_current(pop());
2671     break;
2672   case Bytecodes::_lreturn:
2673     return_current(pop_pair());
2674     break;
2675   case Bytecodes::_dreturn:
2676     return_current(pop_pair());
2677     break;
2678 
2679   case Bytecodes::_athrow:
2680     // null exception oop throws null pointer exception
2681     null_check(peek());
2682     if (stopped())  return;
2683     // Hook the thrown exception directly to subsequent handlers.
2684     if (BailoutToInterpreterForThrows) {
2685       // Keep method interpreted from now on.
2686       uncommon_trap(Deoptimization::Reason_unhandled,
2687                     Deoptimization::Action_make_not_compilable);
2688       return;
2689     }
2690     if (env()->jvmti_can_post_on_exceptions()) {
2691       // check if we must post exception events, take uncommon trap if so (with must_throw = false)
2692       uncommon_trap_if_should_post_on_exceptions(Deoptimization::Reason_unhandled, false);
2693     }
2694     // Here if either can_post_on_exceptions or should_post_on_exceptions is false
2695     add_exception_state(make_exception_state(peek()));
2696     break;
2697 
2698   case Bytecodes::_goto:   // fall through
2699   case Bytecodes::_goto_w: {
2700     int target_bci = (bc() == Bytecodes::_goto) ? iter().get_dest() : iter().get_far_dest();
2701 
2702     // If this is a backwards branch in the bytecodes, add Safepoint
2703     maybe_add_safepoint(target_bci);
2704 
2705     // Merge the current control into the target basic block
2706     merge(target_bci);
2707 
2708     // See if we can get some profile data and hand it off to the next block
2709     Block *target_block = block()->successor_for_bci(target_bci);
2710     if (target_block->pred_count() != 1)  break;
2711     ciMethodData* methodData = method()->method_data();
2712     if (!methodData->is_mature())  break;
2713     ciProfileData* data = methodData->bci_to_data(bci());
2714     assert(data != nullptr && data->is_JumpData(), "need JumpData for taken branch");
2715     int taken = ((ciJumpData*)data)->taken();
2716     taken = method()->scale_count(taken);
2717     target_block->set_count(taken);
2718     break;
2719   }
2720 
2721   case Bytecodes::_ifnull:    btest = BoolTest::eq; goto handle_if_null;
2722   case Bytecodes::_ifnonnull: btest = BoolTest::ne; goto handle_if_null;
2723   handle_if_null:
2724     // If this is a backwards branch in the bytecodes, add Safepoint
2725     maybe_add_safepoint(iter().get_dest());
2726     a = null();
2727     b = pop();
2728     if (!_gvn.type(b)->speculative_maybe_null() &&
2729         !too_many_traps(Deoptimization::Reason_speculate_null_check)) {
2730       inc_sp(1);
2731       Node* null_ctl = top();
2732       b = null_check_oop(b, &null_ctl, true, true, true);
2733       assert(null_ctl->is_top(), "no null control here");
2734       dec_sp(1);
2735     } else if (_gvn.type(b)->speculative_always_null() &&
2736                !too_many_traps(Deoptimization::Reason_speculate_null_assert)) {
2737       inc_sp(1);
2738       b = null_assert(b);
2739       dec_sp(1);
2740     }
2741     c = _gvn.transform( new CmpPNode(b, a) );
2742     do_ifnull(btest, c);
2743     break;
2744 
2745   case Bytecodes::_if_acmpeq: btest = BoolTest::eq; goto handle_if_acmp;
2746   case Bytecodes::_if_acmpne: btest = BoolTest::ne; goto handle_if_acmp;
2747   handle_if_acmp:
2748     // If this is a backwards branch in the bytecodes, add Safepoint
2749     maybe_add_safepoint(iter().get_dest());
2750     a = pop();
2751     b = pop();
2752     c = _gvn.transform( new CmpPNode(b, a) );
2753     c = optimize_cmp_with_klass(c);
2754     do_if(btest, c);
2755     break;
2756 
2757   case Bytecodes::_ifeq: btest = BoolTest::eq; goto handle_ifxx;
2758   case Bytecodes::_ifne: btest = BoolTest::ne; goto handle_ifxx;
2759   case Bytecodes::_iflt: btest = BoolTest::lt; goto handle_ifxx;
2760   case Bytecodes::_ifle: btest = BoolTest::le; goto handle_ifxx;
2761   case Bytecodes::_ifgt: btest = BoolTest::gt; goto handle_ifxx;
2762   case Bytecodes::_ifge: btest = BoolTest::ge; goto handle_ifxx;
2763   handle_ifxx:
2764     // If this is a backwards branch in the bytecodes, add Safepoint
2765     maybe_add_safepoint(iter().get_dest());
2766     a = _gvn.intcon(0);
2767     b = pop();
2768     c = _gvn.transform( new CmpINode(b, a) );
2769     do_if(btest, c);
2770     break;
2771 
2772   case Bytecodes::_if_icmpeq: btest = BoolTest::eq; goto handle_if_icmp;
2773   case Bytecodes::_if_icmpne: btest = BoolTest::ne; goto handle_if_icmp;
2774   case Bytecodes::_if_icmplt: btest = BoolTest::lt; goto handle_if_icmp;
2775   case Bytecodes::_if_icmple: btest = BoolTest::le; goto handle_if_icmp;
2776   case Bytecodes::_if_icmpgt: btest = BoolTest::gt; goto handle_if_icmp;
2777   case Bytecodes::_if_icmpge: btest = BoolTest::ge; goto handle_if_icmp;
2778   handle_if_icmp:
2779     // If this is a backwards branch in the bytecodes, add Safepoint
2780     maybe_add_safepoint(iter().get_dest());
2781     a = pop();
2782     b = pop();
2783     c = _gvn.transform( new CmpINode( b, a ) );
2784     do_if(btest, c);
2785     break;
2786 
2787   case Bytecodes::_tableswitch:
2788     do_tableswitch();
2789     break;
2790 
2791   case Bytecodes::_lookupswitch:
2792     do_lookupswitch();
2793     break;
2794 
2795   case Bytecodes::_invokestatic:
2796   case Bytecodes::_invokedynamic:
2797   case Bytecodes::_invokespecial:
2798   case Bytecodes::_invokevirtual:
2799   case Bytecodes::_invokeinterface:
2800     do_call();
2801     break;
2802   case Bytecodes::_checkcast:
2803     do_checkcast();
2804     break;
2805   case Bytecodes::_instanceof:
2806     do_instanceof();
2807     break;
2808   case Bytecodes::_anewarray:
2809     do_anewarray();
2810     break;
2811   case Bytecodes::_newarray:
2812     do_newarray((BasicType)iter().get_index());
2813     break;
2814   case Bytecodes::_multianewarray:
2815     do_multianewarray();
2816     break;
2817   case Bytecodes::_new:
2818     do_new();
2819     break;
2820 
2821   case Bytecodes::_jsr:
2822   case Bytecodes::_jsr_w:
2823     do_jsr();
2824     break;
2825 
2826   case Bytecodes::_ret:
2827     do_ret();
2828     break;
2829 
2830 
2831   case Bytecodes::_monitorenter:
2832     do_monitor_enter();
2833     break;
2834 
2835   case Bytecodes::_monitorexit:
2836     do_monitor_exit();
2837     break;
2838 
2839   case Bytecodes::_breakpoint:
2840     // Breakpoint set concurrently to compile
2841     // %%% use an uncommon trap?
2842     C->record_failure("breakpoint in method");
2843     return;
2844 
2845   default:
2846 #ifndef PRODUCT
2847     map()->dump(99);
2848 #endif
2849     tty->print("\nUnhandled bytecode %s\n", Bytecodes::name(bc()) );
2850     ShouldNotReachHere();
2851   }
2852 
2853 #ifndef PRODUCT
2854   if (failing()) { return; }
2855   constexpr int perBytecode = 6;
2856   if (C->should_print_igv(perBytecode)) {
2857     IdealGraphPrinter* printer = C->igv_printer();
2858     char buffer[256];
2859     jio_snprintf(buffer, sizeof(buffer), "Bytecode %d: %s", bci(), Bytecodes::name(bc()));
2860     bool old = printer->traverse_outs();
2861     printer->set_traverse_outs(true);
2862     printer->set_parse(this);
2863     printer->print_graph(buffer);
2864     printer->set_traverse_outs(old);
2865     printer->set_parse(nullptr);
2866   }
2867 #endif
2868 }