1 /*
   2  * Copyright (c) 1998, 2023, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "ci/ciMethodData.hpp"
  27 #include "classfile/vmSymbols.hpp"
  28 #include "compiler/compileLog.hpp"
  29 #include "interpreter/linkResolver.hpp"
  30 #include "jvm_io.h"
  31 #include "memory/resourceArea.hpp"
  32 #include "memory/universe.hpp"
  33 #include "oops/oop.inline.hpp"
  34 #include "opto/addnode.hpp"
  35 #include "opto/castnode.hpp"
  36 #include "opto/convertnode.hpp"
  37 #include "opto/divnode.hpp"
  38 #include "opto/idealGraphPrinter.hpp"
  39 #include "opto/matcher.hpp"
  40 #include "opto/memnode.hpp"
  41 #include "opto/mulnode.hpp"
  42 #include "opto/opaquenode.hpp"
  43 #include "opto/parse.hpp"
  44 #include "opto/runtime.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 void Parse::modf() {
1100   Node *f2 = pop();
1101   Node *f1 = pop();
1102   Node* c = make_runtime_call(RC_LEAF, OptoRuntime::modf_Type(),
1103                               CAST_FROM_FN_PTR(address, SharedRuntime::frem),
1104                               "frem", nullptr, //no memory effects
1105                               f1, f2);
1106   Node* res = _gvn.transform(new ProjNode(c, TypeFunc::Parms + 0));
1107 
1108   push(res);
1109 }
1110 
1111 void Parse::modd() {
1112   Node *d2 = pop_pair();
1113   Node *d1 = pop_pair();
1114   Node* c = make_runtime_call(RC_LEAF, OptoRuntime::Math_DD_D_Type(),
1115                               CAST_FROM_FN_PTR(address, SharedRuntime::drem),
1116                               "drem", nullptr, //no memory effects
1117                               d1, top(), d2, top());
1118   Node* res_d   = _gvn.transform(new ProjNode(c, TypeFunc::Parms + 0));
1119 
1120 #ifdef ASSERT
1121   Node* res_top = _gvn.transform(new ProjNode(c, TypeFunc::Parms + 1));
1122   assert(res_top == top(), "second value must be top");
1123 #endif
1124 
1125   push_pair(res_d);
1126 }
1127 
1128 void Parse::l2f() {
1129   Node* f2 = pop();
1130   Node* f1 = pop();
1131   Node* c = make_runtime_call(RC_LEAF, OptoRuntime::l2f_Type(),
1132                               CAST_FROM_FN_PTR(address, SharedRuntime::l2f),
1133                               "l2f", nullptr, //no memory effects
1134                               f1, f2);
1135   Node* res = _gvn.transform(new ProjNode(c, TypeFunc::Parms + 0));
1136 
1137   push(res);
1138 }
1139 
1140 // Handle jsr and jsr_w bytecode
1141 void Parse::do_jsr() {
1142   assert(bc() == Bytecodes::_jsr || bc() == Bytecodes::_jsr_w, "wrong bytecode");
1143 
1144   // Store information about current state, tagged with new _jsr_bci
1145   int return_bci = iter().next_bci();
1146   int jsr_bci    = (bc() == Bytecodes::_jsr) ? iter().get_dest() : iter().get_far_dest();
1147 
1148   // The way we do things now, there is only one successor block
1149   // for the jsr, because the target code is cloned by ciTypeFlow.
1150   Block* target = successor_for_bci(jsr_bci);
1151 
1152   // What got pushed?
1153   const Type* ret_addr = target->peek();
1154   assert(ret_addr->singleton(), "must be a constant (cloned jsr body)");
1155 
1156   // Effect on jsr on stack
1157   push(_gvn.makecon(ret_addr));
1158 
1159   // Flow to the jsr.
1160   merge(jsr_bci);
1161 }
1162 
1163 // Handle ret bytecode
1164 void Parse::do_ret() {
1165   // Find to whom we return.
1166   assert(block()->num_successors() == 1, "a ret can only go one place now");
1167   Block* target = block()->successor_at(0);
1168   assert(!target->is_ready(), "our arrival must be expected");
1169   int pnum = target->next_path_num();
1170   merge_common(target, pnum);
1171 }
1172 
1173 static bool has_injected_profile(BoolTest::mask btest, Node* test, int& taken, int& not_taken) {
1174   if (btest != BoolTest::eq && btest != BoolTest::ne) {
1175     // Only ::eq and ::ne are supported for profile injection.
1176     return false;
1177   }
1178   if (test->is_Cmp() &&
1179       test->in(1)->Opcode() == Op_ProfileBoolean) {
1180     ProfileBooleanNode* profile = (ProfileBooleanNode*)test->in(1);
1181     int false_cnt = profile->false_count();
1182     int  true_cnt = profile->true_count();
1183 
1184     // Counts matching depends on the actual test operation (::eq or ::ne).
1185     // No need to scale the counts because profile injection was designed
1186     // to feed exact counts into VM.
1187     taken     = (btest == BoolTest::eq) ? false_cnt :  true_cnt;
1188     not_taken = (btest == BoolTest::eq) ?  true_cnt : false_cnt;
1189 
1190     profile->consume();
1191     return true;
1192   }
1193   return false;
1194 }
1195 
1196 // Give up if too few (or too many, in which case the sum will overflow) counts to be meaningful.
1197 // We also check that individual counters are positive first, otherwise the sum can become positive.
1198 // (check for saturation, integer overflow, and immature counts)
1199 static bool counters_are_meaningful(int counter1, int counter2, int min) {
1200   // check for saturation, including "uint" values too big to fit in "int"
1201   if (counter1 < 0 || counter2 < 0) {
1202     return false;
1203   }
1204   // check for integer overflow of the sum
1205   int64_t sum = (int64_t)counter1 + (int64_t)counter2;
1206   STATIC_ASSERT(sizeof(counter1) < sizeof(sum));
1207   if (sum > INT_MAX) {
1208     return false;
1209   }
1210   // check if mature
1211   return (counter1 + counter2) >= min;
1212 }
1213 
1214 //--------------------------dynamic_branch_prediction--------------------------
1215 // Try to gather dynamic branch prediction behavior.  Return a probability
1216 // of the branch being taken and set the "cnt" field.  Returns a -1.0
1217 // if we need to use static prediction for some reason.
1218 float Parse::dynamic_branch_prediction(float &cnt, BoolTest::mask btest, Node* test) {
1219   ResourceMark rm;
1220 
1221   cnt  = COUNT_UNKNOWN;
1222 
1223   int     taken = 0;
1224   int not_taken = 0;
1225 
1226   bool use_mdo = !has_injected_profile(btest, test, taken, not_taken);
1227 
1228   if (use_mdo) {
1229     // Use MethodData information if it is available
1230     // FIXME: free the ProfileData structure
1231     ciMethodData* methodData = method()->method_data();
1232     if (!methodData->is_mature())  return PROB_UNKNOWN;
1233     ciProfileData* data = methodData->bci_to_data(bci());
1234     if (data == nullptr) {
1235       return PROB_UNKNOWN;
1236     }
1237     if (!data->is_JumpData())  return PROB_UNKNOWN;
1238 
1239     // get taken and not taken values
1240     // NOTE: saturated UINT_MAX values become negative,
1241     // as do counts above INT_MAX.
1242     taken = data->as_JumpData()->taken();
1243     not_taken = 0;
1244     if (data->is_BranchData()) {
1245       not_taken = data->as_BranchData()->not_taken();
1246     }
1247 
1248     // scale the counts to be commensurate with invocation counts:
1249     // NOTE: overflow for positive values is clamped at INT_MAX
1250     taken = method()->scale_count(taken);
1251     not_taken = method()->scale_count(not_taken);
1252   }
1253   // At this point, saturation or overflow is indicated by INT_MAX
1254   // or a negative value.
1255 
1256   // Give up if too few (or too many, in which case the sum will overflow) counts to be meaningful.
1257   // We also check that individual counters are positive first, otherwise the sum can become positive.
1258   if (!counters_are_meaningful(taken, not_taken, 40)) {
1259     if (C->log() != nullptr) {
1260       C->log()->elem("branch target_bci='%d' taken='%d' not_taken='%d'", iter().get_dest(), taken, not_taken);
1261     }
1262     return PROB_UNKNOWN;
1263   }
1264 
1265   // Compute frequency that we arrive here
1266   float sum = taken + not_taken;
1267   // Adjust, if this block is a cloned private block but the
1268   // Jump counts are shared.  Taken the private counts for
1269   // just this path instead of the shared counts.
1270   if( block()->count() > 0 )
1271     sum = block()->count();
1272   cnt = sum / FreqCountInvocations;
1273 
1274   // Pin probability to sane limits
1275   float prob;
1276   if( !taken )
1277     prob = (0+PROB_MIN) / 2;
1278   else if( !not_taken )
1279     prob = (1+PROB_MAX) / 2;
1280   else {                         // Compute probability of true path
1281     prob = (float)taken / (float)(taken + not_taken);
1282     if (prob > PROB_MAX)  prob = PROB_MAX;
1283     if (prob < PROB_MIN)   prob = PROB_MIN;
1284   }
1285 
1286   assert((cnt > 0.0f) && (prob > 0.0f),
1287          "Bad frequency assignment in if cnt=%g prob=%g taken=%d not_taken=%d", cnt, prob, taken, not_taken);
1288 
1289   if (C->log() != nullptr) {
1290     const char* prob_str = nullptr;
1291     if (prob >= PROB_MAX)  prob_str = (prob == PROB_MAX) ? "max" : "always";
1292     if (prob <= PROB_MIN)  prob_str = (prob == PROB_MIN) ? "min" : "never";
1293     char prob_str_buf[30];
1294     if (prob_str == nullptr) {
1295       jio_snprintf(prob_str_buf, sizeof(prob_str_buf), "%20.2f", prob);
1296       prob_str = prob_str_buf;
1297     }
1298     C->log()->elem("branch target_bci='%d' taken='%d' not_taken='%d' cnt='%f' prob='%s'",
1299                    iter().get_dest(), taken, not_taken, cnt, prob_str);
1300   }
1301   return prob;
1302 }
1303 
1304 //-----------------------------branch_prediction-------------------------------
1305 float Parse::branch_prediction(float& cnt,
1306                                BoolTest::mask btest,
1307                                int target_bci,
1308                                Node* test) {
1309   float prob = dynamic_branch_prediction(cnt, btest, test);
1310   // If prob is unknown, switch to static prediction
1311   if (prob != PROB_UNKNOWN)  return prob;
1312 
1313   prob = PROB_FAIR;                   // Set default value
1314   if (btest == BoolTest::eq)          // Exactly equal test?
1315     prob = PROB_STATIC_INFREQUENT;    // Assume its relatively infrequent
1316   else if (btest == BoolTest::ne)
1317     prob = PROB_STATIC_FREQUENT;      // Assume its relatively frequent
1318 
1319   // If this is a conditional test guarding a backwards branch,
1320   // assume its a loop-back edge.  Make it a likely taken branch.
1321   if (target_bci < bci()) {
1322     if (is_osr_parse()) {    // Could be a hot OSR'd loop; force deopt
1323       // Since it's an OSR, we probably have profile data, but since
1324       // branch_prediction returned PROB_UNKNOWN, the counts are too small.
1325       // Let's make a special check here for completely zero counts.
1326       ciMethodData* methodData = method()->method_data();
1327       if (!methodData->is_empty()) {
1328         ciProfileData* data = methodData->bci_to_data(bci());
1329         // Only stop for truly zero counts, which mean an unknown part
1330         // of the OSR-ed method, and we want to deopt to gather more stats.
1331         // If you have ANY counts, then this loop is simply 'cold' relative
1332         // to the OSR loop.
1333         if (data == nullptr ||
1334             (data->as_BranchData()->taken() +  data->as_BranchData()->not_taken() == 0)) {
1335           // This is the only way to return PROB_UNKNOWN:
1336           return PROB_UNKNOWN;
1337         }
1338       }
1339     }
1340     prob = PROB_STATIC_FREQUENT;     // Likely to take backwards branch
1341   }
1342 
1343   assert(prob != PROB_UNKNOWN, "must have some guess at this point");
1344   return prob;
1345 }
1346 
1347 // The magic constants are chosen so as to match the output of
1348 // branch_prediction() when the profile reports a zero taken count.
1349 // It is important to distinguish zero counts unambiguously, because
1350 // some branches (e.g., _213_javac.Assembler.eliminate) validly produce
1351 // very small but nonzero probabilities, which if confused with zero
1352 // counts would keep the program recompiling indefinitely.
1353 bool Parse::seems_never_taken(float prob) const {
1354   return prob < PROB_MIN;
1355 }
1356 
1357 // True if the comparison seems to be the kind that will not change its
1358 // statistics from true to false.  See comments in adjust_map_after_if.
1359 // This question is only asked along paths which are already
1360 // classified as untaken (by seems_never_taken), so really,
1361 // if a path is never taken, its controlling comparison is
1362 // already acting in a stable fashion.  If the comparison
1363 // seems stable, we will put an expensive uncommon trap
1364 // on the untaken path.
1365 bool Parse::seems_stable_comparison() const {
1366   if (C->too_many_traps(method(), bci(), Deoptimization::Reason_unstable_if)) {
1367     return false;
1368   }
1369   return true;
1370 }
1371 
1372 //-------------------------------repush_if_args--------------------------------
1373 // Push arguments of an "if" bytecode back onto the stack by adjusting _sp.
1374 inline int Parse::repush_if_args() {
1375   if (PrintOpto && WizardMode) {
1376     tty->print("defending against excessive implicit null exceptions on %s @%d in ",
1377                Bytecodes::name(iter().cur_bc()), iter().cur_bci());
1378     method()->print_name(); tty->cr();
1379   }
1380   int bc_depth = - Bytecodes::depth(iter().cur_bc());
1381   assert(bc_depth == 1 || bc_depth == 2, "only two kinds of branches");
1382   DEBUG_ONLY(sync_jvms());   // argument(n) requires a synced jvms
1383   assert(argument(0) != nullptr, "must exist");
1384   assert(bc_depth == 1 || argument(1) != nullptr, "two must exist");
1385   inc_sp(bc_depth);
1386   return bc_depth;
1387 }
1388 
1389 //----------------------------------do_ifnull----------------------------------
1390 void Parse::do_ifnull(BoolTest::mask btest, Node *c) {
1391   int target_bci = iter().get_dest();
1392 
1393   Block* branch_block = successor_for_bci(target_bci);
1394   Block* next_block   = successor_for_bci(iter().next_bci());
1395 
1396   float cnt;
1397   float prob = branch_prediction(cnt, btest, target_bci, c);
1398   if (prob == PROB_UNKNOWN) {
1399     // (An earlier version of do_ifnull omitted this trap for OSR methods.)
1400     if (PrintOpto && Verbose) {
1401       tty->print_cr("Never-taken edge stops compilation at bci %d", bci());
1402     }
1403     repush_if_args(); // to gather stats on loop
1404     uncommon_trap(Deoptimization::Reason_unreached,
1405                   Deoptimization::Action_reinterpret,
1406                   nullptr, "cold");
1407     if (C->eliminate_boxing()) {
1408       // Mark the successor blocks as parsed
1409       branch_block->next_path_num();
1410       next_block->next_path_num();
1411     }
1412     return;
1413   }
1414 
1415   NOT_PRODUCT(explicit_null_checks_inserted++);
1416 
1417   // Generate real control flow
1418   Node   *tst = _gvn.transform( new BoolNode( c, btest ) );
1419 
1420   // Sanity check the probability value
1421   assert(prob > 0.0f,"Bad probability in Parser");
1422  // Need xform to put node in hash table
1423   IfNode *iff = create_and_xform_if( control(), tst, prob, cnt );
1424   assert(iff->_prob > 0.0f,"Optimizer made bad probability in parser");
1425   // True branch
1426   { PreserveJVMState pjvms(this);
1427     Node* iftrue  = _gvn.transform( new IfTrueNode (iff) );
1428     set_control(iftrue);
1429 
1430     if (stopped()) {            // Path is dead?
1431       NOT_PRODUCT(explicit_null_checks_elided++);
1432       if (C->eliminate_boxing()) {
1433         // Mark the successor block as parsed
1434         branch_block->next_path_num();
1435       }
1436     } else {                    // Path is live.
1437       adjust_map_after_if(btest, c, prob, branch_block);
1438       if (!stopped()) {
1439         merge(target_bci);
1440       }
1441     }
1442   }
1443 
1444   // False branch
1445   Node* iffalse = _gvn.transform( new IfFalseNode(iff) );
1446   set_control(iffalse);
1447 
1448   if (stopped()) {              // Path is dead?
1449     NOT_PRODUCT(explicit_null_checks_elided++);
1450     if (C->eliminate_boxing()) {
1451       // Mark the successor block as parsed
1452       next_block->next_path_num();
1453     }
1454   } else  {                     // Path is live.
1455     adjust_map_after_if(BoolTest(btest).negate(), c, 1.0-prob, next_block);
1456   }
1457 }
1458 
1459 //------------------------------------do_if------------------------------------
1460 void Parse::do_if(BoolTest::mask btest, Node* c) {
1461   int target_bci = iter().get_dest();
1462 
1463   Block* branch_block = successor_for_bci(target_bci);
1464   Block* next_block   = successor_for_bci(iter().next_bci());
1465 
1466   float cnt;
1467   float prob = branch_prediction(cnt, btest, target_bci, c);
1468   float untaken_prob = 1.0 - prob;
1469 
1470   if (prob == PROB_UNKNOWN) {
1471     if (PrintOpto && Verbose) {
1472       tty->print_cr("Never-taken edge stops compilation at bci %d", bci());
1473     }
1474     repush_if_args(); // to gather stats on loop
1475     uncommon_trap(Deoptimization::Reason_unreached,
1476                   Deoptimization::Action_reinterpret,
1477                   nullptr, "cold");
1478     if (C->eliminate_boxing()) {
1479       // Mark the successor blocks as parsed
1480       branch_block->next_path_num();
1481       next_block->next_path_num();
1482     }
1483     return;
1484   }
1485 
1486   // Sanity check the probability value
1487   assert(0.0f < prob && prob < 1.0f,"Bad probability in Parser");
1488 
1489   bool taken_if_true = true;
1490   // Convert BoolTest to canonical form:
1491   if (!BoolTest(btest).is_canonical()) {
1492     btest         = BoolTest(btest).negate();
1493     taken_if_true = false;
1494     // prob is NOT updated here; it remains the probability of the taken
1495     // path (as opposed to the prob of the path guarded by an 'IfTrueNode').
1496   }
1497   assert(btest != BoolTest::eq, "!= is the only canonical exact test");
1498 
1499   Node* tst0 = new BoolNode(c, btest);
1500   Node* tst = _gvn.transform(tst0);
1501   BoolTest::mask taken_btest   = BoolTest::illegal;
1502   BoolTest::mask untaken_btest = BoolTest::illegal;
1503 
1504   if (tst->is_Bool()) {
1505     // Refresh c from the transformed bool node, since it may be
1506     // simpler than the original c.  Also re-canonicalize btest.
1507     // This wins when (Bool ne (Conv2B p) 0) => (Bool ne (CmpP p null)).
1508     // That can arise from statements like: if (x instanceof C) ...
1509     if (tst != tst0) {
1510       // Canonicalize one more time since transform can change it.
1511       btest = tst->as_Bool()->_test._test;
1512       if (!BoolTest(btest).is_canonical()) {
1513         // Reverse edges one more time...
1514         tst   = _gvn.transform( tst->as_Bool()->negate(&_gvn) );
1515         btest = tst->as_Bool()->_test._test;
1516         assert(BoolTest(btest).is_canonical(), "sanity");
1517         taken_if_true = !taken_if_true;
1518       }
1519       c = tst->in(1);
1520     }
1521     BoolTest::mask neg_btest = BoolTest(btest).negate();
1522     taken_btest   = taken_if_true ?     btest : neg_btest;
1523     untaken_btest = taken_if_true ? neg_btest :     btest;
1524   }
1525 
1526   // Generate real control flow
1527   float true_prob = (taken_if_true ? prob : untaken_prob);
1528   IfNode* iff = create_and_map_if(control(), tst, true_prob, cnt);
1529   assert(iff->_prob > 0.0f,"Optimizer made bad probability in parser");
1530   Node* taken_branch   = new IfTrueNode(iff);
1531   Node* untaken_branch = new IfFalseNode(iff);
1532   if (!taken_if_true) {  // Finish conversion to canonical form
1533     Node* tmp      = taken_branch;
1534     taken_branch   = untaken_branch;
1535     untaken_branch = tmp;
1536   }
1537 
1538   // Branch is taken:
1539   { PreserveJVMState pjvms(this);
1540     taken_branch = _gvn.transform(taken_branch);
1541     set_control(taken_branch);
1542 
1543     if (stopped()) {
1544       if (C->eliminate_boxing()) {
1545         // Mark the successor block as parsed
1546         branch_block->next_path_num();
1547       }
1548     } else {
1549       adjust_map_after_if(taken_btest, c, prob, branch_block);
1550       if (!stopped()) {
1551         merge(target_bci);
1552       }
1553     }
1554   }
1555 
1556   untaken_branch = _gvn.transform(untaken_branch);
1557   set_control(untaken_branch);
1558 
1559   // Branch not taken.
1560   if (stopped()) {
1561     if (C->eliminate_boxing()) {
1562       // Mark the successor block as parsed
1563       next_block->next_path_num();
1564     }
1565   } else {
1566     adjust_map_after_if(untaken_btest, c, untaken_prob, next_block);
1567   }
1568 }
1569 
1570 bool Parse::path_is_suitable_for_uncommon_trap(float prob) const {
1571   // Don't want to speculate on uncommon traps when running with -Xcomp
1572   if (!UseInterpreter) {
1573     return false;
1574   }
1575   return (seems_never_taken(prob) && seems_stable_comparison());
1576 }
1577 
1578 void Parse::maybe_add_predicate_after_if(Block* path) {
1579   if (path->is_SEL_head() && path->preds_parsed() == 0) {
1580     // Add predicates at bci of if dominating the loop so traps can be
1581     // recorded on the if's profile data
1582     int bc_depth = repush_if_args();
1583     add_parse_predicates();
1584     dec_sp(bc_depth);
1585     path->set_has_predicates();
1586   }
1587 }
1588 
1589 
1590 //----------------------------adjust_map_after_if------------------------------
1591 // Adjust the JVM state to reflect the result of taking this path.
1592 // Basically, it means inspecting the CmpNode controlling this
1593 // branch, seeing how it constrains a tested value, and then
1594 // deciding if it's worth our while to encode this constraint
1595 // as graph nodes in the current abstract interpretation map.
1596 void Parse::adjust_map_after_if(BoolTest::mask btest, Node* c, float prob, Block* path) {
1597   if (!c->is_Cmp()) {
1598     maybe_add_predicate_after_if(path);
1599     return;
1600   }
1601 
1602   if (stopped() || btest == BoolTest::illegal) {
1603     return;                             // nothing to do
1604   }
1605 
1606   bool is_fallthrough = (path == successor_for_bci(iter().next_bci()));
1607 
1608   if (path_is_suitable_for_uncommon_trap(prob)) {
1609     repush_if_args();
1610     Node* call = uncommon_trap(Deoptimization::Reason_unstable_if,
1611                   Deoptimization::Action_reinterpret,
1612                   nullptr,
1613                   (is_fallthrough ? "taken always" : "taken never"));
1614 
1615     if (call != nullptr) {
1616       C->record_unstable_if_trap(new UnstableIfTrap(call->as_CallStaticJava(), path));
1617     }
1618     return;
1619   }
1620 
1621   Node* val = c->in(1);
1622   Node* con = c->in(2);
1623   const Type* tcon = _gvn.type(con);
1624   const Type* tval = _gvn.type(val);
1625   bool have_con = tcon->singleton();
1626   if (tval->singleton()) {
1627     if (!have_con) {
1628       // Swap, so constant is in con.
1629       con  = val;
1630       tcon = tval;
1631       val  = c->in(2);
1632       tval = _gvn.type(val);
1633       btest = BoolTest(btest).commute();
1634       have_con = true;
1635     } else {
1636       // Do we have two constants?  Then leave well enough alone.
1637       have_con = false;
1638     }
1639   }
1640   if (!have_con) {                        // remaining adjustments need a con
1641     maybe_add_predicate_after_if(path);
1642     return;
1643   }
1644 
1645   sharpen_type_after_if(btest, con, tcon, val, tval);
1646   maybe_add_predicate_after_if(path);
1647 }
1648 
1649 
1650 static Node* extract_obj_from_klass_load(PhaseGVN* gvn, Node* n) {
1651   Node* ldk;
1652   if (n->is_DecodeNKlass()) {
1653     if (n->in(1)->Opcode() != Op_LoadNKlass) {
1654       return nullptr;
1655     } else {
1656       ldk = n->in(1);
1657     }
1658   } else if (n->Opcode() != Op_LoadKlass) {
1659     return nullptr;
1660   } else {
1661     ldk = n;
1662   }
1663   assert(ldk != nullptr && ldk->is_Load(), "should have found a LoadKlass or LoadNKlass node");
1664 
1665   Node* adr = ldk->in(MemNode::Address);
1666   intptr_t off = 0;
1667   Node* obj = AddPNode::Ideal_base_and_offset(adr, gvn, off);
1668   if (obj == nullptr || off != oopDesc::klass_offset_in_bytes()) // loading oopDesc::_klass?
1669     return nullptr;
1670   const TypePtr* tp = gvn->type(obj)->is_ptr();
1671   if (tp == nullptr || !(tp->isa_instptr() || tp->isa_aryptr())) // is obj a Java object ptr?
1672     return nullptr;
1673 
1674   return obj;
1675 }
1676 
1677 void Parse::sharpen_type_after_if(BoolTest::mask btest,
1678                                   Node* con, const Type* tcon,
1679                                   Node* val, const Type* tval) {
1680   // Look for opportunities to sharpen the type of a node
1681   // whose klass is compared with a constant klass.
1682   if (btest == BoolTest::eq && tcon->isa_klassptr()) {
1683     Node* obj = extract_obj_from_klass_load(&_gvn, val);
1684     const TypeOopPtr* con_type = tcon->isa_klassptr()->as_instance_type();
1685     if (obj != nullptr && (con_type->isa_instptr() || con_type->isa_aryptr())) {
1686        // Found:
1687        //   Bool(CmpP(LoadKlass(obj._klass), ConP(Foo.klass)), [eq])
1688        // or the narrowOop equivalent.
1689        const Type* obj_type = _gvn.type(obj);
1690        const TypeOopPtr* tboth = obj_type->join_speculative(con_type)->isa_oopptr();
1691        if (tboth != nullptr && tboth->klass_is_exact() && tboth != obj_type &&
1692            tboth->higher_equal(obj_type)) {
1693           // obj has to be of the exact type Foo if the CmpP succeeds.
1694           int obj_in_map = map()->find_edge(obj);
1695           JVMState* jvms = this->jvms();
1696           if (obj_in_map >= 0 &&
1697               (jvms->is_loc(obj_in_map) || jvms->is_stk(obj_in_map))) {
1698             TypeNode* ccast = new CheckCastPPNode(control(), obj, tboth);
1699             const Type* tcc = ccast->as_Type()->type();
1700             assert(tcc != obj_type && tcc->higher_equal(obj_type), "must improve");
1701             // Delay transform() call to allow recovery of pre-cast value
1702             // at the control merge.
1703             _gvn.set_type_bottom(ccast);
1704             record_for_igvn(ccast);
1705             // Here's the payoff.
1706             replace_in_map(obj, ccast);
1707           }
1708        }
1709     }
1710   }
1711 
1712   int val_in_map = map()->find_edge(val);
1713   if (val_in_map < 0)  return;          // replace_in_map would be useless
1714   {
1715     JVMState* jvms = this->jvms();
1716     if (!(jvms->is_loc(val_in_map) ||
1717           jvms->is_stk(val_in_map)))
1718       return;                           // again, it would be useless
1719   }
1720 
1721   // Check for a comparison to a constant, and "know" that the compared
1722   // value is constrained on this path.
1723   assert(tcon->singleton(), "");
1724   ConstraintCastNode* ccast = nullptr;
1725   Node* cast = nullptr;
1726 
1727   switch (btest) {
1728   case BoolTest::eq:                    // Constant test?
1729     {
1730       const Type* tboth = tcon->join_speculative(tval);
1731       if (tboth == tval)  break;        // Nothing to gain.
1732       if (tcon->isa_int()) {
1733         ccast = new CastIINode(val, tboth);
1734       } else if (tcon == TypePtr::NULL_PTR) {
1735         // Cast to null, but keep the pointer identity temporarily live.
1736         ccast = new CastPPNode(val, tboth);
1737       } else {
1738         const TypeF* tf = tcon->isa_float_constant();
1739         const TypeD* td = tcon->isa_double_constant();
1740         // Exclude tests vs float/double 0 as these could be
1741         // either +0 or -0.  Just because you are equal to +0
1742         // doesn't mean you ARE +0!
1743         // Note, following code also replaces Long and Oop values.
1744         if ((!tf || tf->_f != 0.0) &&
1745             (!td || td->_d != 0.0))
1746           cast = con;                   // Replace non-constant val by con.
1747       }
1748     }
1749     break;
1750 
1751   case BoolTest::ne:
1752     if (tcon == TypePtr::NULL_PTR) {
1753       cast = cast_not_null(val, false);
1754     }
1755     break;
1756 
1757   default:
1758     // (At this point we could record int range types with CastII.)
1759     break;
1760   }
1761 
1762   if (ccast != nullptr) {
1763     const Type* tcc = ccast->as_Type()->type();
1764     assert(tcc != tval && tcc->higher_equal(tval), "must improve");
1765     // Delay transform() call to allow recovery of pre-cast value
1766     // at the control merge.
1767     ccast->set_req(0, control());
1768     _gvn.set_type_bottom(ccast);
1769     record_for_igvn(ccast);
1770     cast = ccast;
1771   }
1772 
1773   if (cast != nullptr) {                   // Here's the payoff.
1774     replace_in_map(val, cast);
1775   }
1776 }
1777 
1778 /**
1779  * Use speculative type to optimize CmpP node: if comparison is
1780  * against the low level class, cast the object to the speculative
1781  * type if any. CmpP should then go away.
1782  *
1783  * @param c  expected CmpP node
1784  * @return   result of CmpP on object casted to speculative type
1785  *
1786  */
1787 Node* Parse::optimize_cmp_with_klass(Node* c) {
1788   // If this is transformed by the _gvn to a comparison with the low
1789   // level klass then we may be able to use speculation
1790   if (c->Opcode() == Op_CmpP &&
1791       (c->in(1)->Opcode() == Op_LoadKlass || c->in(1)->Opcode() == Op_DecodeNKlass) &&
1792       c->in(2)->is_Con()) {
1793     Node* load_klass = nullptr;
1794     Node* decode = nullptr;
1795     if (c->in(1)->Opcode() == Op_DecodeNKlass) {
1796       decode = c->in(1);
1797       load_klass = c->in(1)->in(1);
1798     } else {
1799       load_klass = c->in(1);
1800     }
1801     if (load_klass->in(2)->is_AddP()) {
1802       Node* addp = load_klass->in(2);
1803       Node* obj = addp->in(AddPNode::Address);
1804       const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
1805       if (obj_type->speculative_type_not_null() != nullptr) {
1806         ciKlass* k = obj_type->speculative_type();
1807         inc_sp(2);
1808         obj = maybe_cast_profiled_obj(obj, k);
1809         dec_sp(2);
1810         // Make the CmpP use the casted obj
1811         addp = basic_plus_adr(obj, addp->in(AddPNode::Offset));
1812         load_klass = load_klass->clone();
1813         load_klass->set_req(2, addp);
1814         load_klass = _gvn.transform(load_klass);
1815         if (decode != nullptr) {
1816           decode = decode->clone();
1817           decode->set_req(1, load_klass);
1818           load_klass = _gvn.transform(decode);
1819         }
1820         c = c->clone();
1821         c->set_req(1, load_klass);
1822         c = _gvn.transform(c);
1823       }
1824     }
1825   }
1826   return c;
1827 }
1828 
1829 //------------------------------do_one_bytecode--------------------------------
1830 // Parse this bytecode, and alter the Parsers JVM->Node mapping
1831 void Parse::do_one_bytecode() {
1832   Node *a, *b, *c, *d;          // Handy temps
1833   BoolTest::mask btest;
1834   int i;
1835 
1836   assert(!has_exceptions(), "bytecode entry state must be clear of throws");
1837 
1838   if (C->check_node_count(NodeLimitFudgeFactor * 5,
1839                           "out of nodes parsing method")) {
1840     return;
1841   }
1842 
1843 #ifdef ASSERT
1844   // for setting breakpoints
1845   if (TraceOptoParse) {
1846     tty->print(" @");
1847     dump_bci(bci());
1848     tty->print(" %s", Bytecodes::name(bc()));
1849     tty->cr();
1850   }
1851 #endif
1852 
1853   switch (bc()) {
1854   case Bytecodes::_nop:
1855     // do nothing
1856     break;
1857   case Bytecodes::_lconst_0:
1858     push_pair(longcon(0));
1859     break;
1860 
1861   case Bytecodes::_lconst_1:
1862     push_pair(longcon(1));
1863     break;
1864 
1865   case Bytecodes::_fconst_0:
1866     push(zerocon(T_FLOAT));
1867     break;
1868 
1869   case Bytecodes::_fconst_1:
1870     push(makecon(TypeF::ONE));
1871     break;
1872 
1873   case Bytecodes::_fconst_2:
1874     push(makecon(TypeF::make(2.0f)));
1875     break;
1876 
1877   case Bytecodes::_dconst_0:
1878     push_pair(zerocon(T_DOUBLE));
1879     break;
1880 
1881   case Bytecodes::_dconst_1:
1882     push_pair(makecon(TypeD::ONE));
1883     break;
1884 
1885   case Bytecodes::_iconst_m1:push(intcon(-1)); break;
1886   case Bytecodes::_iconst_0: push(intcon( 0)); break;
1887   case Bytecodes::_iconst_1: push(intcon( 1)); break;
1888   case Bytecodes::_iconst_2: push(intcon( 2)); break;
1889   case Bytecodes::_iconst_3: push(intcon( 3)); break;
1890   case Bytecodes::_iconst_4: push(intcon( 4)); break;
1891   case Bytecodes::_iconst_5: push(intcon( 5)); break;
1892   case Bytecodes::_bipush:   push(intcon(iter().get_constant_u1())); break;
1893   case Bytecodes::_sipush:   push(intcon(iter().get_constant_u2())); break;
1894   case Bytecodes::_aconst_null: push(null());  break;
1895 
1896   case Bytecodes::_ldc:
1897   case Bytecodes::_ldc_w:
1898   case Bytecodes::_ldc2_w: {
1899     ciConstant constant = iter().get_constant();
1900     if (constant.is_loaded()) {
1901       const Type* con_type = Type::make_from_constant(constant);
1902       if (con_type != nullptr) {
1903         push_node(con_type->basic_type(), makecon(con_type));
1904       }
1905     } else {
1906       // If the constant is unresolved or in error state, run this BC in the interpreter.
1907       if (iter().is_in_error()) {
1908         uncommon_trap(Deoptimization::make_trap_request(Deoptimization::Reason_unhandled,
1909                                                         Deoptimization::Action_none),
1910                       nullptr, "constant in error state", true /* must_throw */);
1911 
1912       } else {
1913         int index = iter().get_constant_pool_index();
1914         uncommon_trap(Deoptimization::make_trap_request(Deoptimization::Reason_unloaded,
1915                                                         Deoptimization::Action_reinterpret,
1916                                                         index),
1917                       nullptr, "unresolved constant", false /* must_throw */);
1918       }
1919     }
1920     break;
1921   }
1922 
1923   case Bytecodes::_aload_0:
1924     push( local(0) );
1925     break;
1926   case Bytecodes::_aload_1:
1927     push( local(1) );
1928     break;
1929   case Bytecodes::_aload_2:
1930     push( local(2) );
1931     break;
1932   case Bytecodes::_aload_3:
1933     push( local(3) );
1934     break;
1935   case Bytecodes::_aload:
1936     push( local(iter().get_index()) );
1937     break;
1938 
1939   case Bytecodes::_fload_0:
1940   case Bytecodes::_iload_0:
1941     push( local(0) );
1942     break;
1943   case Bytecodes::_fload_1:
1944   case Bytecodes::_iload_1:
1945     push( local(1) );
1946     break;
1947   case Bytecodes::_fload_2:
1948   case Bytecodes::_iload_2:
1949     push( local(2) );
1950     break;
1951   case Bytecodes::_fload_3:
1952   case Bytecodes::_iload_3:
1953     push( local(3) );
1954     break;
1955   case Bytecodes::_fload:
1956   case Bytecodes::_iload:
1957     push( local(iter().get_index()) );
1958     break;
1959   case Bytecodes::_lload_0:
1960     push_pair_local( 0 );
1961     break;
1962   case Bytecodes::_lload_1:
1963     push_pair_local( 1 );
1964     break;
1965   case Bytecodes::_lload_2:
1966     push_pair_local( 2 );
1967     break;
1968   case Bytecodes::_lload_3:
1969     push_pair_local( 3 );
1970     break;
1971   case Bytecodes::_lload:
1972     push_pair_local( iter().get_index() );
1973     break;
1974 
1975   case Bytecodes::_dload_0:
1976     push_pair_local(0);
1977     break;
1978   case Bytecodes::_dload_1:
1979     push_pair_local(1);
1980     break;
1981   case Bytecodes::_dload_2:
1982     push_pair_local(2);
1983     break;
1984   case Bytecodes::_dload_3:
1985     push_pair_local(3);
1986     break;
1987   case Bytecodes::_dload:
1988     push_pair_local(iter().get_index());
1989     break;
1990   case Bytecodes::_fstore_0:
1991   case Bytecodes::_istore_0:
1992   case Bytecodes::_astore_0:
1993     set_local( 0, pop() );
1994     break;
1995   case Bytecodes::_fstore_1:
1996   case Bytecodes::_istore_1:
1997   case Bytecodes::_astore_1:
1998     set_local( 1, pop() );
1999     break;
2000   case Bytecodes::_fstore_2:
2001   case Bytecodes::_istore_2:
2002   case Bytecodes::_astore_2:
2003     set_local( 2, pop() );
2004     break;
2005   case Bytecodes::_fstore_3:
2006   case Bytecodes::_istore_3:
2007   case Bytecodes::_astore_3:
2008     set_local( 3, pop() );
2009     break;
2010   case Bytecodes::_fstore:
2011   case Bytecodes::_istore:
2012   case Bytecodes::_astore:
2013     set_local( iter().get_index(), pop() );
2014     break;
2015   // long stores
2016   case Bytecodes::_lstore_0:
2017     set_pair_local( 0, pop_pair() );
2018     break;
2019   case Bytecodes::_lstore_1:
2020     set_pair_local( 1, pop_pair() );
2021     break;
2022   case Bytecodes::_lstore_2:
2023     set_pair_local( 2, pop_pair() );
2024     break;
2025   case Bytecodes::_lstore_3:
2026     set_pair_local( 3, pop_pair() );
2027     break;
2028   case Bytecodes::_lstore:
2029     set_pair_local( iter().get_index(), pop_pair() );
2030     break;
2031 
2032   // double stores
2033   case Bytecodes::_dstore_0:
2034     set_pair_local( 0, dprecision_rounding(pop_pair()) );
2035     break;
2036   case Bytecodes::_dstore_1:
2037     set_pair_local( 1, dprecision_rounding(pop_pair()) );
2038     break;
2039   case Bytecodes::_dstore_2:
2040     set_pair_local( 2, dprecision_rounding(pop_pair()) );
2041     break;
2042   case Bytecodes::_dstore_3:
2043     set_pair_local( 3, dprecision_rounding(pop_pair()) );
2044     break;
2045   case Bytecodes::_dstore:
2046     set_pair_local( iter().get_index(), dprecision_rounding(pop_pair()) );
2047     break;
2048 
2049   case Bytecodes::_pop:  dec_sp(1);   break;
2050   case Bytecodes::_pop2: dec_sp(2);   break;
2051   case Bytecodes::_swap:
2052     a = pop();
2053     b = pop();
2054     push(a);
2055     push(b);
2056     break;
2057   case Bytecodes::_dup:
2058     a = pop();
2059     push(a);
2060     push(a);
2061     break;
2062   case Bytecodes::_dup_x1:
2063     a = pop();
2064     b = pop();
2065     push( a );
2066     push( b );
2067     push( a );
2068     break;
2069   case Bytecodes::_dup_x2:
2070     a = pop();
2071     b = pop();
2072     c = pop();
2073     push( a );
2074     push( c );
2075     push( b );
2076     push( a );
2077     break;
2078   case Bytecodes::_dup2:
2079     a = pop();
2080     b = pop();
2081     push( b );
2082     push( a );
2083     push( b );
2084     push( a );
2085     break;
2086 
2087   case Bytecodes::_dup2_x1:
2088     // before: .. c, b, a
2089     // after:  .. b, a, c, b, a
2090     // not tested
2091     a = pop();
2092     b = pop();
2093     c = pop();
2094     push( b );
2095     push( a );
2096     push( c );
2097     push( b );
2098     push( a );
2099     break;
2100   case Bytecodes::_dup2_x2:
2101     // before: .. d, c, b, a
2102     // after:  .. b, a, d, c, b, a
2103     // not tested
2104     a = pop();
2105     b = pop();
2106     c = pop();
2107     d = pop();
2108     push( b );
2109     push( a );
2110     push( d );
2111     push( c );
2112     push( b );
2113     push( a );
2114     break;
2115 
2116   case Bytecodes::_arraylength: {
2117     // Must do null-check with value on expression stack
2118     Node *ary = null_check(peek(), T_ARRAY);
2119     // Compile-time detect of null-exception?
2120     if (stopped())  return;
2121     a = pop();
2122     push(load_array_length(a));
2123     break;
2124   }
2125 
2126   case Bytecodes::_baload:  array_load(T_BYTE);    break;
2127   case Bytecodes::_caload:  array_load(T_CHAR);    break;
2128   case Bytecodes::_iaload:  array_load(T_INT);     break;
2129   case Bytecodes::_saload:  array_load(T_SHORT);   break;
2130   case Bytecodes::_faload:  array_load(T_FLOAT);   break;
2131   case Bytecodes::_aaload:  array_load(T_OBJECT);  break;
2132   case Bytecodes::_laload:  array_load(T_LONG);    break;
2133   case Bytecodes::_daload:  array_load(T_DOUBLE);  break;
2134   case Bytecodes::_bastore: array_store(T_BYTE);   break;
2135   case Bytecodes::_castore: array_store(T_CHAR);   break;
2136   case Bytecodes::_iastore: array_store(T_INT);    break;
2137   case Bytecodes::_sastore: array_store(T_SHORT);  break;
2138   case Bytecodes::_fastore: array_store(T_FLOAT);  break;
2139   case Bytecodes::_aastore: array_store(T_OBJECT); break;
2140   case Bytecodes::_lastore: array_store(T_LONG);   break;
2141   case Bytecodes::_dastore: array_store(T_DOUBLE); break;
2142 
2143   case Bytecodes::_getfield:
2144     do_getfield();
2145     break;
2146 
2147   case Bytecodes::_getstatic:
2148     do_getstatic();
2149     break;
2150 
2151   case Bytecodes::_putfield:
2152     do_putfield();
2153     break;
2154 
2155   case Bytecodes::_putstatic:
2156     do_putstatic();
2157     break;
2158 
2159   case Bytecodes::_irem:
2160     // Must keep both values on the expression-stack during null-check
2161     zero_check_int(peek());
2162     // Compile-time detect of null-exception?
2163     if (stopped())  return;
2164     b = pop();
2165     a = pop();
2166     push(_gvn.transform(new ModINode(control(), a, b)));
2167     break;
2168   case Bytecodes::_idiv:
2169     // Must keep both values on the expression-stack during null-check
2170     zero_check_int(peek());
2171     // Compile-time detect of null-exception?
2172     if (stopped())  return;
2173     b = pop();
2174     a = pop();
2175     push( _gvn.transform( new DivINode(control(),a,b) ) );
2176     break;
2177   case Bytecodes::_imul:
2178     b = pop(); a = pop();
2179     push( _gvn.transform( new MulINode(a,b) ) );
2180     break;
2181   case Bytecodes::_iadd:
2182     b = pop(); a = pop();
2183     push( _gvn.transform( new AddINode(a,b) ) );
2184     break;
2185   case Bytecodes::_ineg:
2186     a = pop();
2187     push( _gvn.transform( new SubINode(_gvn.intcon(0),a)) );
2188     break;
2189   case Bytecodes::_isub:
2190     b = pop(); a = pop();
2191     push( _gvn.transform( new SubINode(a,b) ) );
2192     break;
2193   case Bytecodes::_iand:
2194     b = pop(); a = pop();
2195     push( _gvn.transform( new AndINode(a,b) ) );
2196     break;
2197   case Bytecodes::_ior:
2198     b = pop(); a = pop();
2199     push( _gvn.transform( new OrINode(a,b) ) );
2200     break;
2201   case Bytecodes::_ixor:
2202     b = pop(); a = pop();
2203     push( _gvn.transform( new XorINode(a,b) ) );
2204     break;
2205   case Bytecodes::_ishl:
2206     b = pop(); a = pop();
2207     push( _gvn.transform( new LShiftINode(a,b) ) );
2208     break;
2209   case Bytecodes::_ishr:
2210     b = pop(); a = pop();
2211     push( _gvn.transform( new RShiftINode(a,b) ) );
2212     break;
2213   case Bytecodes::_iushr:
2214     b = pop(); a = pop();
2215     push( _gvn.transform( new URShiftINode(a,b) ) );
2216     break;
2217 
2218   case Bytecodes::_fneg:
2219     a = pop();
2220     b = _gvn.transform(new NegFNode (a));
2221     push(b);
2222     break;
2223 
2224   case Bytecodes::_fsub:
2225     b = pop();
2226     a = pop();
2227     c = _gvn.transform( new SubFNode(a,b) );
2228     d = precision_rounding(c);
2229     push( d );
2230     break;
2231 
2232   case Bytecodes::_fadd:
2233     b = pop();
2234     a = pop();
2235     c = _gvn.transform( new AddFNode(a,b) );
2236     d = precision_rounding(c);
2237     push( d );
2238     break;
2239 
2240   case Bytecodes::_fmul:
2241     b = pop();
2242     a = pop();
2243     c = _gvn.transform( new MulFNode(a,b) );
2244     d = precision_rounding(c);
2245     push( d );
2246     break;
2247 
2248   case Bytecodes::_fdiv:
2249     b = pop();
2250     a = pop();
2251     c = _gvn.transform( new DivFNode(0,a,b) );
2252     d = precision_rounding(c);
2253     push( d );
2254     break;
2255 
2256   case Bytecodes::_frem:
2257     if (Matcher::has_match_rule(Op_ModF)) {
2258       // Generate a ModF node.
2259       b = pop();
2260       a = pop();
2261       c = _gvn.transform( new ModFNode(0,a,b) );
2262       d = precision_rounding(c);
2263       push( d );
2264     }
2265     else {
2266       // Generate a call.
2267       modf();
2268     }
2269     break;
2270 
2271   case Bytecodes::_fcmpl:
2272     b = pop();
2273     a = pop();
2274     c = _gvn.transform( new CmpF3Node( a, b));
2275     push(c);
2276     break;
2277   case Bytecodes::_fcmpg:
2278     b = pop();
2279     a = pop();
2280 
2281     // Same as fcmpl but need to flip the unordered case.  Swap the inputs,
2282     // which negates the result sign except for unordered.  Flip the unordered
2283     // as well by using CmpF3 which implements unordered-lesser instead of
2284     // unordered-greater semantics.  Finally, commute the result bits.  Result
2285     // is same as using a CmpF3Greater except we did it with CmpF3 alone.
2286     c = _gvn.transform( new CmpF3Node( b, a));
2287     c = _gvn.transform( new SubINode(_gvn.intcon(0),c) );
2288     push(c);
2289     break;
2290 
2291   case Bytecodes::_f2i:
2292     a = pop();
2293     push(_gvn.transform(new ConvF2INode(a)));
2294     break;
2295 
2296   case Bytecodes::_d2i:
2297     a = pop_pair();
2298     b = _gvn.transform(new ConvD2INode(a));
2299     push( b );
2300     break;
2301 
2302   case Bytecodes::_f2d:
2303     a = pop();
2304     b = _gvn.transform( new ConvF2DNode(a));
2305     push_pair( b );
2306     break;
2307 
2308   case Bytecodes::_d2f:
2309     a = pop_pair();
2310     b = _gvn.transform( new ConvD2FNode(a));
2311     // This breaks _227_mtrt (speed & correctness) and _222_mpegaudio (speed)
2312     //b = _gvn.transform(new RoundFloatNode(0, b) );
2313     push( b );
2314     break;
2315 
2316   case Bytecodes::_l2f:
2317     if (Matcher::convL2FSupported()) {
2318       a = pop_pair();
2319       b = _gvn.transform( new ConvL2FNode(a));
2320       // For x86_32.ad, FILD doesn't restrict precision to 24 or 53 bits.
2321       // Rather than storing the result into an FP register then pushing
2322       // out to memory to round, the machine instruction that implements
2323       // ConvL2D is responsible for rounding.
2324       // c = precision_rounding(b);
2325       push(b);
2326     } else {
2327       l2f();
2328     }
2329     break;
2330 
2331   case Bytecodes::_l2d:
2332     a = pop_pair();
2333     b = _gvn.transform( new ConvL2DNode(a));
2334     // For x86_32.ad, rounding is always necessary (see _l2f above).
2335     // c = dprecision_rounding(b);
2336     push_pair(b);
2337     break;
2338 
2339   case Bytecodes::_f2l:
2340     a = pop();
2341     b = _gvn.transform( new ConvF2LNode(a));
2342     push_pair(b);
2343     break;
2344 
2345   case Bytecodes::_d2l:
2346     a = pop_pair();
2347     b = _gvn.transform( new ConvD2LNode(a));
2348     push_pair(b);
2349     break;
2350 
2351   case Bytecodes::_dsub:
2352     b = pop_pair();
2353     a = pop_pair();
2354     c = _gvn.transform( new SubDNode(a,b) );
2355     d = dprecision_rounding(c);
2356     push_pair( d );
2357     break;
2358 
2359   case Bytecodes::_dadd:
2360     b = pop_pair();
2361     a = pop_pair();
2362     c = _gvn.transform( new AddDNode(a,b) );
2363     d = dprecision_rounding(c);
2364     push_pair( d );
2365     break;
2366 
2367   case Bytecodes::_dmul:
2368     b = pop_pair();
2369     a = pop_pair();
2370     c = _gvn.transform( new MulDNode(a,b) );
2371     d = dprecision_rounding(c);
2372     push_pair( d );
2373     break;
2374 
2375   case Bytecodes::_ddiv:
2376     b = pop_pair();
2377     a = pop_pair();
2378     c = _gvn.transform( new DivDNode(0,a,b) );
2379     d = dprecision_rounding(c);
2380     push_pair( d );
2381     break;
2382 
2383   case Bytecodes::_dneg:
2384     a = pop_pair();
2385     b = _gvn.transform(new NegDNode (a));
2386     push_pair(b);
2387     break;
2388 
2389   case Bytecodes::_drem:
2390     if (Matcher::has_match_rule(Op_ModD)) {
2391       // Generate a ModD node.
2392       b = pop_pair();
2393       a = pop_pair();
2394       // a % b
2395 
2396       c = _gvn.transform( new ModDNode(0,a,b) );
2397       d = dprecision_rounding(c);
2398       push_pair( d );
2399     }
2400     else {
2401       // Generate a call.
2402       modd();
2403     }
2404     break;
2405 
2406   case Bytecodes::_dcmpl:
2407     b = pop_pair();
2408     a = pop_pair();
2409     c = _gvn.transform( new CmpD3Node( a, b));
2410     push(c);
2411     break;
2412 
2413   case Bytecodes::_dcmpg:
2414     b = pop_pair();
2415     a = pop_pair();
2416     // Same as dcmpl but need to flip the unordered case.
2417     // Commute the inputs, which negates the result sign except for unordered.
2418     // Flip the unordered as well by using CmpD3 which implements
2419     // unordered-lesser instead of unordered-greater semantics.
2420     // Finally, negate the result bits.  Result is same as using a
2421     // CmpD3Greater except we did it with CmpD3 alone.
2422     c = _gvn.transform( new CmpD3Node( b, a));
2423     c = _gvn.transform( new SubINode(_gvn.intcon(0),c) );
2424     push(c);
2425     break;
2426 
2427 
2428     // Note for longs -> lo word is on TOS, hi word is on TOS - 1
2429   case Bytecodes::_land:
2430     b = pop_pair();
2431     a = pop_pair();
2432     c = _gvn.transform( new AndLNode(a,b) );
2433     push_pair(c);
2434     break;
2435   case Bytecodes::_lor:
2436     b = pop_pair();
2437     a = pop_pair();
2438     c = _gvn.transform( new OrLNode(a,b) );
2439     push_pair(c);
2440     break;
2441   case Bytecodes::_lxor:
2442     b = pop_pair();
2443     a = pop_pair();
2444     c = _gvn.transform( new XorLNode(a,b) );
2445     push_pair(c);
2446     break;
2447 
2448   case Bytecodes::_lshl:
2449     b = pop();                  // the shift count
2450     a = pop_pair();             // value to be shifted
2451     c = _gvn.transform( new LShiftLNode(a,b) );
2452     push_pair(c);
2453     break;
2454   case Bytecodes::_lshr:
2455     b = pop();                  // the shift count
2456     a = pop_pair();             // value to be shifted
2457     c = _gvn.transform( new RShiftLNode(a,b) );
2458     push_pair(c);
2459     break;
2460   case Bytecodes::_lushr:
2461     b = pop();                  // the shift count
2462     a = pop_pair();             // value to be shifted
2463     c = _gvn.transform( new URShiftLNode(a,b) );
2464     push_pair(c);
2465     break;
2466   case Bytecodes::_lmul:
2467     b = pop_pair();
2468     a = pop_pair();
2469     c = _gvn.transform( new MulLNode(a,b) );
2470     push_pair(c);
2471     break;
2472 
2473   case Bytecodes::_lrem:
2474     // Must keep both values on the expression-stack during null-check
2475     assert(peek(0) == top(), "long word order");
2476     zero_check_long(peek(1));
2477     // Compile-time detect of null-exception?
2478     if (stopped())  return;
2479     b = pop_pair();
2480     a = pop_pair();
2481     c = _gvn.transform( new ModLNode(control(),a,b) );
2482     push_pair(c);
2483     break;
2484 
2485   case Bytecodes::_ldiv:
2486     // Must keep both values on the expression-stack during null-check
2487     assert(peek(0) == top(), "long word order");
2488     zero_check_long(peek(1));
2489     // Compile-time detect of null-exception?
2490     if (stopped())  return;
2491     b = pop_pair();
2492     a = pop_pair();
2493     c = _gvn.transform( new DivLNode(control(),a,b) );
2494     push_pair(c);
2495     break;
2496 
2497   case Bytecodes::_ladd:
2498     b = pop_pair();
2499     a = pop_pair();
2500     c = _gvn.transform( new AddLNode(a,b) );
2501     push_pair(c);
2502     break;
2503   case Bytecodes::_lsub:
2504     b = pop_pair();
2505     a = pop_pair();
2506     c = _gvn.transform( new SubLNode(a,b) );
2507     push_pair(c);
2508     break;
2509   case Bytecodes::_lcmp:
2510     // Safepoints are now inserted _before_ branches.  The long-compare
2511     // bytecode painfully produces a 3-way value (-1,0,+1) which requires a
2512     // slew of control flow.  These are usually followed by a CmpI vs zero and
2513     // a branch; this pattern then optimizes to the obvious long-compare and
2514     // branch.  However, if the branch is backwards there's a Safepoint
2515     // inserted.  The inserted Safepoint captures the JVM state at the
2516     // pre-branch point, i.e. it captures the 3-way value.  Thus if a
2517     // long-compare is used to control a loop the debug info will force
2518     // computation of the 3-way value, even though the generated code uses a
2519     // long-compare and branch.  We try to rectify the situation by inserting
2520     // a SafePoint here and have it dominate and kill the safepoint added at a
2521     // following backwards branch.  At this point the JVM state merely holds 2
2522     // longs but not the 3-way value.
2523     switch (iter().next_bc()) {
2524       case Bytecodes::_ifgt:
2525       case Bytecodes::_iflt:
2526       case Bytecodes::_ifge:
2527       case Bytecodes::_ifle:
2528       case Bytecodes::_ifne:
2529       case Bytecodes::_ifeq:
2530         // If this is a backwards branch in the bytecodes, add Safepoint
2531         maybe_add_safepoint(iter().next_get_dest());
2532       default:
2533         break;
2534     }
2535     b = pop_pair();
2536     a = pop_pair();
2537     c = _gvn.transform( new CmpL3Node( a, b ));
2538     push(c);
2539     break;
2540 
2541   case Bytecodes::_lneg:
2542     a = pop_pair();
2543     b = _gvn.transform( new SubLNode(longcon(0),a));
2544     push_pair(b);
2545     break;
2546   case Bytecodes::_l2i:
2547     a = pop_pair();
2548     push( _gvn.transform( new ConvL2INode(a)));
2549     break;
2550   case Bytecodes::_i2l:
2551     a = pop();
2552     b = _gvn.transform( new ConvI2LNode(a));
2553     push_pair(b);
2554     break;
2555   case Bytecodes::_i2b:
2556     // Sign extend
2557     a = pop();
2558     a = Compile::narrow_value(T_BYTE, a, nullptr, &_gvn, true);
2559     push(a);
2560     break;
2561   case Bytecodes::_i2s:
2562     a = pop();
2563     a = Compile::narrow_value(T_SHORT, a, nullptr, &_gvn, true);
2564     push(a);
2565     break;
2566   case Bytecodes::_i2c:
2567     a = pop();
2568     a = Compile::narrow_value(T_CHAR, a, nullptr, &_gvn, true);
2569     push(a);
2570     break;
2571 
2572   case Bytecodes::_i2f:
2573     a = pop();
2574     b = _gvn.transform( new ConvI2FNode(a) ) ;
2575     c = precision_rounding(b);
2576     push (b);
2577     break;
2578 
2579   case Bytecodes::_i2d:
2580     a = pop();
2581     b = _gvn.transform( new ConvI2DNode(a));
2582     push_pair(b);
2583     break;
2584 
2585   case Bytecodes::_iinc:        // Increment local
2586     i = iter().get_index();     // Get local index
2587     set_local( i, _gvn.transform( new AddINode( _gvn.intcon(iter().get_iinc_con()), local(i) ) ) );
2588     break;
2589 
2590   // Exit points of synchronized methods must have an unlock node
2591   case Bytecodes::_return:
2592     return_current(nullptr);
2593     break;
2594 
2595   case Bytecodes::_ireturn:
2596   case Bytecodes::_areturn:
2597   case Bytecodes::_freturn:
2598     return_current(pop());
2599     break;
2600   case Bytecodes::_lreturn:
2601     return_current(pop_pair());
2602     break;
2603   case Bytecodes::_dreturn:
2604     return_current(pop_pair());
2605     break;
2606 
2607   case Bytecodes::_athrow:
2608     // null exception oop throws null pointer exception
2609     null_check(peek());
2610     if (stopped())  return;
2611     // Hook the thrown exception directly to subsequent handlers.
2612     if (BailoutToInterpreterForThrows) {
2613       // Keep method interpreted from now on.
2614       uncommon_trap(Deoptimization::Reason_unhandled,
2615                     Deoptimization::Action_make_not_compilable);
2616       return;
2617     }
2618     if (env()->jvmti_can_post_on_exceptions()) {
2619       // check if we must post exception events, take uncommon trap if so (with must_throw = false)
2620       uncommon_trap_if_should_post_on_exceptions(Deoptimization::Reason_unhandled, false);
2621     }
2622     // Here if either can_post_on_exceptions or should_post_on_exceptions is false
2623     add_exception_state(make_exception_state(peek()));
2624     break;
2625 
2626   case Bytecodes::_goto:   // fall through
2627   case Bytecodes::_goto_w: {
2628     int target_bci = (bc() == Bytecodes::_goto) ? iter().get_dest() : iter().get_far_dest();
2629 
2630     // If this is a backwards branch in the bytecodes, add Safepoint
2631     maybe_add_safepoint(target_bci);
2632 
2633     // Merge the current control into the target basic block
2634     merge(target_bci);
2635 
2636     // See if we can get some profile data and hand it off to the next block
2637     Block *target_block = block()->successor_for_bci(target_bci);
2638     if (target_block->pred_count() != 1)  break;
2639     ciMethodData* methodData = method()->method_data();
2640     if (!methodData->is_mature())  break;
2641     ciProfileData* data = methodData->bci_to_data(bci());
2642     assert(data != nullptr && data->is_JumpData(), "need JumpData for taken branch");
2643     int taken = ((ciJumpData*)data)->taken();
2644     taken = method()->scale_count(taken);
2645     target_block->set_count(taken);
2646     break;
2647   }
2648 
2649   case Bytecodes::_ifnull:    btest = BoolTest::eq; goto handle_if_null;
2650   case Bytecodes::_ifnonnull: btest = BoolTest::ne; goto handle_if_null;
2651   handle_if_null:
2652     // If this is a backwards branch in the bytecodes, add Safepoint
2653     maybe_add_safepoint(iter().get_dest());
2654     a = null();
2655     b = pop();
2656     if (!_gvn.type(b)->speculative_maybe_null() &&
2657         !too_many_traps(Deoptimization::Reason_speculate_null_check)) {
2658       inc_sp(1);
2659       Node* null_ctl = top();
2660       b = null_check_oop(b, &null_ctl, true, true, true);
2661       assert(null_ctl->is_top(), "no null control here");
2662       dec_sp(1);
2663     } else if (_gvn.type(b)->speculative_always_null() &&
2664                !too_many_traps(Deoptimization::Reason_speculate_null_assert)) {
2665       inc_sp(1);
2666       b = null_assert(b);
2667       dec_sp(1);
2668     }
2669     c = _gvn.transform( new CmpPNode(b, a) );
2670     do_ifnull(btest, c);
2671     break;
2672 
2673   case Bytecodes::_if_acmpeq: btest = BoolTest::eq; goto handle_if_acmp;
2674   case Bytecodes::_if_acmpne: btest = BoolTest::ne; goto handle_if_acmp;
2675   handle_if_acmp:
2676     // If this is a backwards branch in the bytecodes, add Safepoint
2677     maybe_add_safepoint(iter().get_dest());
2678     a = pop();
2679     b = pop();
2680     c = _gvn.transform( new CmpPNode(b, a) );
2681     c = optimize_cmp_with_klass(c);
2682     do_if(btest, c);
2683     break;
2684 
2685   case Bytecodes::_ifeq: btest = BoolTest::eq; goto handle_ifxx;
2686   case Bytecodes::_ifne: btest = BoolTest::ne; goto handle_ifxx;
2687   case Bytecodes::_iflt: btest = BoolTest::lt; goto handle_ifxx;
2688   case Bytecodes::_ifle: btest = BoolTest::le; goto handle_ifxx;
2689   case Bytecodes::_ifgt: btest = BoolTest::gt; goto handle_ifxx;
2690   case Bytecodes::_ifge: btest = BoolTest::ge; goto handle_ifxx;
2691   handle_ifxx:
2692     // If this is a backwards branch in the bytecodes, add Safepoint
2693     maybe_add_safepoint(iter().get_dest());
2694     a = _gvn.intcon(0);
2695     b = pop();
2696     c = _gvn.transform( new CmpINode(b, a) );
2697     do_if(btest, c);
2698     break;
2699 
2700   case Bytecodes::_if_icmpeq: btest = BoolTest::eq; goto handle_if_icmp;
2701   case Bytecodes::_if_icmpne: btest = BoolTest::ne; goto handle_if_icmp;
2702   case Bytecodes::_if_icmplt: btest = BoolTest::lt; goto handle_if_icmp;
2703   case Bytecodes::_if_icmple: btest = BoolTest::le; goto handle_if_icmp;
2704   case Bytecodes::_if_icmpgt: btest = BoolTest::gt; goto handle_if_icmp;
2705   case Bytecodes::_if_icmpge: btest = BoolTest::ge; goto handle_if_icmp;
2706   handle_if_icmp:
2707     // If this is a backwards branch in the bytecodes, add Safepoint
2708     maybe_add_safepoint(iter().get_dest());
2709     a = pop();
2710     b = pop();
2711     c = _gvn.transform( new CmpINode( b, a ) );
2712     do_if(btest, c);
2713     break;
2714 
2715   case Bytecodes::_tableswitch:
2716     do_tableswitch();
2717     break;
2718 
2719   case Bytecodes::_lookupswitch:
2720     do_lookupswitch();
2721     break;
2722 
2723   case Bytecodes::_invokestatic:
2724   case Bytecodes::_invokedynamic:
2725   case Bytecodes::_invokespecial:
2726   case Bytecodes::_invokevirtual:
2727   case Bytecodes::_invokeinterface:
2728     do_call();
2729     break;
2730   case Bytecodes::_checkcast:
2731     do_checkcast();
2732     break;
2733   case Bytecodes::_instanceof:
2734     do_instanceof();
2735     break;
2736   case Bytecodes::_anewarray:
2737     do_anewarray();
2738     break;
2739   case Bytecodes::_newarray:
2740     do_newarray((BasicType)iter().get_index());
2741     break;
2742   case Bytecodes::_multianewarray:
2743     do_multianewarray();
2744     break;
2745   case Bytecodes::_new:
2746     do_new();
2747     break;
2748 
2749   case Bytecodes::_jsr:
2750   case Bytecodes::_jsr_w:
2751     do_jsr();
2752     break;
2753 
2754   case Bytecodes::_ret:
2755     do_ret();
2756     break;
2757 
2758 
2759   case Bytecodes::_monitorenter:
2760     do_monitor_enter();
2761     break;
2762 
2763   case Bytecodes::_monitorexit:
2764     do_monitor_exit();
2765     break;
2766 
2767   case Bytecodes::_breakpoint:
2768     // Breakpoint set concurrently to compile
2769     // %%% use an uncommon trap?
2770     C->record_failure("breakpoint in method");
2771     return;
2772 
2773   default:
2774 #ifndef PRODUCT
2775     map()->dump(99);
2776 #endif
2777     tty->print("\nUnhandled bytecode %s\n", Bytecodes::name(bc()) );
2778     ShouldNotReachHere();
2779   }
2780 
2781 #ifndef PRODUCT
2782   constexpr int perBytecode = 5;
2783   if (C->should_print_igv(perBytecode)) {
2784     IdealGraphPrinter* printer = C->igv_printer();
2785     char buffer[256];
2786     jio_snprintf(buffer, sizeof(buffer), "Bytecode %d: %s", bci(), Bytecodes::name(bc()));
2787     bool old = printer->traverse_outs();
2788     printer->set_traverse_outs(true);
2789     printer->print_method(buffer, perBytecode);
2790     printer->set_traverse_outs(old);
2791   }
2792 #endif
2793 }