1 /*
   2  * Copyright (c) 1998, 2016, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "ci/ciMethodData.hpp"
  27 #include "classfile/systemDictionary.hpp"
  28 #include "classfile/vmSymbols.hpp"
  29 #include "compiler/compileLog.hpp"
  30 #include "interpreter/linkResolver.hpp"
  31 #include "memory/universe.inline.hpp"
  32 #include "opto/addnode.hpp"
  33 #include "opto/divnode.hpp"
  34 #include "opto/idealGraphPrinter.hpp"
  35 #include "opto/matcher.hpp"
  36 #include "opto/memnode.hpp"
  37 #include "opto/mulnode.hpp"
  38 #include "opto/parse.hpp"
  39 #include "opto/runtime.hpp"
  40 #include "runtime/deoptimization.hpp"
  41 #include "runtime/sharedRuntime.hpp"
  42 
  43 extern int explicit_null_checks_inserted,
  44            explicit_null_checks_elided;
  45 
  46 //---------------------------------array_load----------------------------------
  47 void Parse::array_load(BasicType elem_type) {
  48   const Type* elem = Type::TOP;
  49   Node* adr = array_addressing(elem_type, 0, &elem);
  50   if (stopped())  return;     // guaranteed null or range check
  51   dec_sp(2);                  // Pop array and index
  52   const TypeAryPtr* adr_type = TypeAryPtr::get_array_body_type(elem_type);
  53   Node* ld = make_load(control(), adr, elem, elem_type, adr_type, MemNode::unordered);
  54   push(ld);
  55 }
  56 
  57 
  58 //--------------------------------array_store----------------------------------
  59 void Parse::array_store(BasicType elem_type) {
  60   const Type* elem = Type::TOP;
  61   Node* adr = array_addressing(elem_type, 1, &elem);
  62   if (stopped())  return;     // guaranteed null or range check
  63   Node* val = pop();
  64   dec_sp(2);                  // Pop array and index
  65   const TypeAryPtr* adr_type = TypeAryPtr::get_array_body_type(elem_type);
  66   if (elem == TypeInt::BOOL) {
  67     elem_type = T_BOOLEAN;
  68   }
  69   store_to_memory(control(), adr, val, elem_type, adr_type, StoreNode::release_if_reference(elem_type));
  70 }
  71 
  72 
  73 //------------------------------array_addressing-------------------------------
  74 // Pull array and index from the stack.  Compute pointer-to-element.
  75 Node* Parse::array_addressing(BasicType type, int vals, const Type* *result2) {
  76   Node *idx   = peek(0+vals);   // Get from stack without popping
  77   Node *ary   = peek(1+vals);   // in case of exception
  78 
  79   // Null check the array base, with correct stack contents
  80   ary = null_check(ary, T_ARRAY);
  81   // Compile-time detect of null-exception?
  82   if (stopped())  return top();
  83 
  84   const TypeAryPtr* arytype  = _gvn.type(ary)->is_aryptr();
  85   const TypeInt*    sizetype = arytype->size();
  86   const Type*       elemtype = arytype->elem();
  87 
  88   if (UseUniqueSubclasses && result2 != NULL) {
  89     const Type* el = elemtype->make_ptr();
  90     if (el && el->isa_instptr()) {
  91       const TypeInstPtr* toop = el->is_instptr();
  92       if (toop->klass()->as_instance_klass()->unique_concrete_subklass()) {
  93         // If we load from "AbstractClass[]" we must see "ConcreteSubClass".
  94         const Type* subklass = Type::get_const_type(toop->klass());
  95         elemtype = subklass->join_speculative(el);
  96       }
  97     }
  98   }
  99 
 100   // Check for big class initializers with all constant offsets
 101   // feeding into a known-size array.
 102   const TypeInt* idxtype = _gvn.type(idx)->is_int();
 103   // See if the highest idx value is less than the lowest array bound,
 104   // and if the idx value cannot be negative:
 105   bool need_range_check = true;
 106   if (idxtype->_hi < sizetype->_lo && idxtype->_lo >= 0) {
 107     need_range_check = false;
 108     if (C->log() != NULL)   C->log()->elem("observe that='!need_range_check'");
 109   }
 110 
 111   ciKlass * arytype_klass = arytype->klass();
 112   if ((arytype_klass != NULL) && (!arytype_klass->is_loaded())) {
 113     // Only fails for some -Xcomp runs
 114     // The class is unloaded.  We have to run this bytecode in the interpreter.
 115     uncommon_trap(Deoptimization::Reason_unloaded,
 116                   Deoptimization::Action_reinterpret,
 117                   arytype->klass(), "!loaded array");
 118     return top();
 119   }
 120 
 121   // Do the range check
 122   if (GenerateRangeChecks && need_range_check) {
 123     Node* tst;
 124     if (sizetype->_hi <= 0) {
 125       // The greatest array bound is negative, so we can conclude that we're
 126       // compiling unreachable code, but the unsigned compare trick used below
 127       // only works with non-negative lengths.  Instead, hack "tst" to be zero so
 128       // the uncommon_trap path will always be taken.
 129       tst = _gvn.intcon(0);
 130     } else {
 131       // Range is constant in array-oop, so we can use the original state of mem
 132       Node* len = load_array_length(ary);
 133 
 134       // Test length vs index (standard trick using unsigned compare)
 135       Node* chk = _gvn.transform( new (C) CmpUNode(idx, len) );
 136       BoolTest::mask btest = BoolTest::lt;
 137       tst = _gvn.transform( new (C) BoolNode(chk, btest) );
 138     }
 139     // Branch to failure if out of bounds
 140     { BuildCutout unless(this, tst, PROB_MAX);
 141       if (C->allow_range_check_smearing()) {
 142         // Do not use builtin_throw, since range checks are sometimes
 143         // made more stringent by an optimistic transformation.
 144         // This creates "tentative" range checks at this point,
 145         // which are not guaranteed to throw exceptions.
 146         // See IfNode::Ideal, is_range_check, adjust_check.
 147         uncommon_trap(Deoptimization::Reason_range_check,
 148                       Deoptimization::Action_make_not_entrant,
 149                       NULL, "range_check");
 150       } else {
 151         // If we have already recompiled with the range-check-widening
 152         // heroic optimization turned off, then we must really be throwing
 153         // range check exceptions.
 154         builtin_throw(Deoptimization::Reason_range_check, idx);
 155       }
 156     }
 157   }
 158   // Check for always knowing you are throwing a range-check exception
 159   if (stopped())  return top();
 160 
 161   // Make array address computation control dependent to prevent it
 162   // from floating above the range check during loop optimizations.
 163   Node* ptr = array_element_address(ary, idx, type, sizetype, control());
 164 
 165   if (result2 != NULL)  *result2 = elemtype;
 166 
 167   assert(ptr != top(), "top should go hand-in-hand with stopped");
 168 
 169   return ptr;
 170 }
 171 
 172 
 173 // returns IfNode
 174 IfNode* Parse::jump_if_fork_int(Node* a, Node* b, BoolTest::mask mask) {
 175   Node   *cmp = _gvn.transform( new (C) CmpINode( a, b)); // two cases: shiftcount > 32 and shiftcount <= 32
 176   Node   *tst = _gvn.transform( new (C) BoolNode( cmp, mask));
 177   IfNode *iff = create_and_map_if( control(), tst, ((mask == BoolTest::eq) ? PROB_STATIC_INFREQUENT : PROB_FAIR), COUNT_UNKNOWN );
 178   return iff;
 179 }
 180 
 181 // return Region node
 182 Node* Parse::jump_if_join(Node* iffalse, Node* iftrue) {
 183   Node *region  = new (C) RegionNode(3); // 2 results
 184   record_for_igvn(region);
 185   region->init_req(1, iffalse);
 186   region->init_req(2, iftrue );
 187   _gvn.set_type(region, Type::CONTROL);
 188   region = _gvn.transform(region);
 189   set_control (region);
 190   return region;
 191 }
 192 
 193 
 194 //------------------------------helper for tableswitch-------------------------
 195 void Parse::jump_if_true_fork(IfNode *iff, int dest_bci_if_true, int prof_table_index) {
 196   // True branch, use existing map info
 197   { PreserveJVMState pjvms(this);
 198     Node *iftrue  = _gvn.transform( new (C) IfTrueNode (iff) );
 199     set_control( iftrue );
 200     profile_switch_case(prof_table_index);
 201     merge_new_path(dest_bci_if_true);
 202   }
 203 
 204   // False branch
 205   Node *iffalse = _gvn.transform( new (C) IfFalseNode(iff) );
 206   set_control( iffalse );
 207 }
 208 
 209 void Parse::jump_if_false_fork(IfNode *iff, int dest_bci_if_true, int prof_table_index) {
 210   // True branch, use existing map info
 211   { PreserveJVMState pjvms(this);
 212     Node *iffalse  = _gvn.transform( new (C) IfFalseNode (iff) );
 213     set_control( iffalse );
 214     profile_switch_case(prof_table_index);
 215     merge_new_path(dest_bci_if_true);
 216   }
 217 
 218   // False branch
 219   Node *iftrue = _gvn.transform( new (C) IfTrueNode(iff) );
 220   set_control( iftrue );
 221 }
 222 
 223 void Parse::jump_if_always_fork(int dest_bci, int prof_table_index) {
 224   // False branch, use existing map and control()
 225   profile_switch_case(prof_table_index);
 226   merge_new_path(dest_bci);
 227 }
 228 
 229 
 230 extern "C" {
 231   static int jint_cmp(const void *i, const void *j) {
 232     int a = *(jint *)i;
 233     int b = *(jint *)j;
 234     return a > b ? 1 : a < b ? -1 : 0;
 235   }
 236 }
 237 
 238 
 239 // Default value for methodData switch indexing. Must be a negative value to avoid
 240 // conflict with any legal switch index.
 241 #define NullTableIndex -1
 242 
 243 class SwitchRange : public StackObj {
 244   // a range of integers coupled with a bci destination
 245   jint _lo;                     // inclusive lower limit
 246   jint _hi;                     // inclusive upper limit
 247   int _dest;
 248   int _table_index;             // index into method data table
 249 
 250 public:
 251   jint lo() const              { return _lo;   }
 252   jint hi() const              { return _hi;   }
 253   int  dest() const            { return _dest; }
 254   int  table_index() const     { return _table_index; }
 255   bool is_singleton() const    { return _lo == _hi; }
 256 
 257   void setRange(jint lo, jint hi, int dest, int table_index) {
 258     assert(lo <= hi, "must be a non-empty range");
 259     _lo = lo, _hi = hi; _dest = dest; _table_index = table_index;
 260   }
 261   bool adjoinRange(jint lo, jint hi, int dest, int table_index) {
 262     assert(lo <= hi, "must be a non-empty range");
 263     if (lo == _hi+1 && dest == _dest && table_index == _table_index) {
 264       _hi = hi;
 265       return true;
 266     }
 267     return false;
 268   }
 269 
 270   void set (jint value, int dest, int table_index) {
 271     setRange(value, value, dest, table_index);
 272   }
 273   bool adjoin(jint value, int dest, int table_index) {
 274     return adjoinRange(value, value, dest, table_index);
 275   }
 276 
 277   void print() {
 278     if (is_singleton())
 279       tty->print(" {%d}=>%d", lo(), dest());
 280     else if (lo() == min_jint)
 281       tty->print(" {..%d}=>%d", hi(), dest());
 282     else if (hi() == max_jint)
 283       tty->print(" {%d..}=>%d", lo(), dest());
 284     else
 285       tty->print(" {%d..%d}=>%d", lo(), hi(), dest());
 286   }
 287 };
 288 
 289 
 290 //-------------------------------do_tableswitch--------------------------------
 291 void Parse::do_tableswitch() {
 292   Node* lookup = pop();
 293 
 294   // Get information about tableswitch
 295   int default_dest = iter().get_dest_table(0);
 296   int lo_index     = iter().get_int_table(1);
 297   int hi_index     = iter().get_int_table(2);
 298   int len          = hi_index - lo_index + 1;
 299 
 300   if (len < 1) {
 301     // If this is a backward branch, add safepoint
 302     maybe_add_safepoint(default_dest);
 303     merge(default_dest);
 304     return;
 305   }
 306 
 307   // generate decision tree, using trichotomy when possible
 308   int rnum = len+2;
 309   bool makes_backward_branch = false;
 310   SwitchRange* ranges = NEW_RESOURCE_ARRAY(SwitchRange, rnum);
 311   int rp = -1;
 312   if (lo_index != min_jint) {
 313     ranges[++rp].setRange(min_jint, lo_index-1, default_dest, NullTableIndex);
 314   }
 315   for (int j = 0; j < len; j++) {
 316     jint match_int = lo_index+j;
 317     int  dest      = iter().get_dest_table(j+3);
 318     makes_backward_branch |= (dest <= bci());
 319     int  table_index = method_data_update() ? j : NullTableIndex;
 320     if (rp < 0 || !ranges[rp].adjoin(match_int, dest, table_index)) {
 321       ranges[++rp].set(match_int, dest, table_index);
 322     }
 323   }
 324   jint highest = lo_index+(len-1);
 325   assert(ranges[rp].hi() == highest, "");
 326   if (highest != max_jint
 327       && !ranges[rp].adjoinRange(highest+1, max_jint, default_dest, NullTableIndex)) {
 328     ranges[++rp].setRange(highest+1, max_jint, default_dest, NullTableIndex);
 329   }
 330   assert(rp < len+2, "not too many ranges");
 331 
 332   // Safepoint in case if backward branch observed
 333   if( makes_backward_branch && UseLoopSafepoints )
 334     add_safepoint();
 335 
 336   jump_switch_ranges(lookup, &ranges[0], &ranges[rp]);
 337 }
 338 
 339 
 340 //------------------------------do_lookupswitch--------------------------------
 341 void Parse::do_lookupswitch() {
 342   Node *lookup = pop();         // lookup value
 343   // Get information about lookupswitch
 344   int default_dest = iter().get_dest_table(0);
 345   int len          = iter().get_int_table(1);
 346 
 347   if (len < 1) {    // If this is a backward branch, add safepoint
 348     maybe_add_safepoint(default_dest);
 349     merge(default_dest);
 350     return;
 351   }
 352 
 353   // generate decision tree, using trichotomy when possible
 354   jint* table = NEW_RESOURCE_ARRAY(jint, len*2);
 355   {
 356     for( int j = 0; j < len; j++ ) {
 357       table[j+j+0] = iter().get_int_table(2+j+j);
 358       table[j+j+1] = iter().get_dest_table(2+j+j+1);
 359     }
 360     qsort( table, len, 2*sizeof(table[0]), jint_cmp );
 361   }
 362 
 363   int rnum = len*2+1;
 364   bool makes_backward_branch = false;
 365   SwitchRange* ranges = NEW_RESOURCE_ARRAY(SwitchRange, rnum);
 366   int rp = -1;
 367   for( int j = 0; j < len; j++ ) {
 368     jint match_int   = table[j+j+0];
 369     int  dest        = table[j+j+1];
 370     int  next_lo     = rp < 0 ? min_jint : ranges[rp].hi()+1;
 371     int  table_index = method_data_update() ? j : NullTableIndex;
 372     makes_backward_branch |= (dest <= bci());
 373     if( match_int != next_lo ) {
 374       ranges[++rp].setRange(next_lo, match_int-1, default_dest, NullTableIndex);
 375     }
 376     if( rp < 0 || !ranges[rp].adjoin(match_int, dest, table_index) ) {
 377       ranges[++rp].set(match_int, dest, table_index);
 378     }
 379   }
 380   jint highest = table[2*(len-1)];
 381   assert(ranges[rp].hi() == highest, "");
 382   if( highest != max_jint
 383       && !ranges[rp].adjoinRange(highest+1, max_jint, default_dest, NullTableIndex) ) {
 384     ranges[++rp].setRange(highest+1, max_jint, default_dest, NullTableIndex);
 385   }
 386   assert(rp < rnum, "not too many ranges");
 387 
 388   // Safepoint in case backward branch observed
 389   if( makes_backward_branch && UseLoopSafepoints )
 390     add_safepoint();
 391 
 392   jump_switch_ranges(lookup, &ranges[0], &ranges[rp]);
 393 }
 394 
 395 //----------------------------create_jump_tables-------------------------------
 396 bool Parse::create_jump_tables(Node* key_val, SwitchRange* lo, SwitchRange* hi) {
 397   // Are jumptables enabled
 398   if (!UseJumpTables)  return false;
 399 
 400   // Are jumptables supported
 401   if (!Matcher::has_match_rule(Op_Jump))  return false;
 402 
 403   // Don't make jump table if profiling
 404   if (method_data_update())  return false;
 405 
 406   // Decide if a guard is needed to lop off big ranges at either (or
 407   // both) end(s) of the input set. We'll call this the default target
 408   // even though we can't be sure that it is the true "default".
 409 
 410   bool needs_guard = false;
 411   int default_dest;
 412   int64 total_outlier_size = 0;
 413   int64 hi_size = ((int64)hi->hi()) - ((int64)hi->lo()) + 1;
 414   int64 lo_size = ((int64)lo->hi()) - ((int64)lo->lo()) + 1;
 415 
 416   if (lo->dest() == hi->dest()) {
 417     total_outlier_size = hi_size + lo_size;
 418     default_dest = lo->dest();
 419   } else if (lo_size > hi_size) {
 420     total_outlier_size = lo_size;
 421     default_dest = lo->dest();
 422   } else {
 423     total_outlier_size = hi_size;
 424     default_dest = hi->dest();
 425   }
 426 
 427   // If a guard test will eliminate very sparse end ranges, then
 428   // it is worth the cost of an extra jump.
 429   if (total_outlier_size > (MaxJumpTableSparseness * 4)) {
 430     needs_guard = true;
 431     if (default_dest == lo->dest()) lo++;
 432     if (default_dest == hi->dest()) hi--;
 433   }
 434 
 435   // Find the total number of cases and ranges
 436   int64 num_cases = ((int64)hi->hi()) - ((int64)lo->lo()) + 1;
 437   int num_range = hi - lo + 1;
 438 
 439   // Don't create table if: too large, too small, or too sparse.
 440   if (num_cases < MinJumpTableSize || num_cases > MaxJumpTableSize)
 441     return false;
 442   if (num_cases > (MaxJumpTableSparseness * num_range))
 443     return false;
 444 
 445   // Normalize table lookups to zero
 446   int lowval = lo->lo();
 447   key_val = _gvn.transform( new (C) SubINode(key_val, _gvn.intcon(lowval)) );
 448 
 449   // Generate a guard to protect against input keyvals that aren't
 450   // in the switch domain.
 451   if (needs_guard) {
 452     Node*   size = _gvn.intcon(num_cases);
 453     Node*   cmp = _gvn.transform( new (C) CmpUNode(key_val, size) );
 454     Node*   tst = _gvn.transform( new (C) BoolNode(cmp, BoolTest::ge) );
 455     IfNode* iff = create_and_map_if( control(), tst, PROB_FAIR, COUNT_UNKNOWN);
 456     jump_if_true_fork(iff, default_dest, NullTableIndex);
 457   }
 458 
 459   // Create an ideal node JumpTable that has projections
 460   // of all possible ranges for a switch statement
 461   // The key_val input must be converted to a pointer offset and scaled.
 462   // Compare Parse::array_addressing above.
 463 #ifdef _LP64
 464   // Clean the 32-bit int into a real 64-bit offset.
 465   // Otherwise, the jint value 0 might turn into an offset of 0x0800000000.
 466   const TypeInt* ikeytype = TypeInt::make(0, num_cases-1, Type::WidenMin);
 467   // Make I2L conversion control dependent to prevent it from
 468   // floating above the range check during loop optimizations.
 469   key_val = C->constrained_convI2L(&_gvn, key_val, ikeytype, control());
 470 #endif
 471 
 472   // Shift the value by wordsize so we have an index into the table, rather
 473   // than a switch value
 474   Node *shiftWord = _gvn.MakeConX(wordSize);
 475   key_val = _gvn.transform( new (C) MulXNode( key_val, shiftWord));
 476 
 477   // Create the JumpNode
 478   Node* jtn = _gvn.transform( new (C) JumpNode(control(), key_val, num_cases) );
 479 
 480   // These are the switch destinations hanging off the jumpnode
 481   int i = 0;
 482   for (SwitchRange* r = lo; r <= hi; r++) {
 483     for (int64 j = r->lo(); j <= r->hi(); j++, i++) {
 484       Node* input = _gvn.transform(new (C) JumpProjNode(jtn, i, r->dest(), (int)(j - lowval)));
 485       {
 486         PreserveJVMState pjvms(this);
 487         set_control(input);
 488         jump_if_always_fork(r->dest(), r->table_index());
 489       }
 490     }
 491   }
 492   assert(i == num_cases, "miscount of cases");
 493   stop_and_kill_map();  // no more uses for this JVMS
 494   return true;
 495 }
 496 
 497 //----------------------------jump_switch_ranges-------------------------------
 498 void Parse::jump_switch_ranges(Node* key_val, SwitchRange *lo, SwitchRange *hi, int switch_depth) {
 499   Block* switch_block = block();
 500 
 501   if (switch_depth == 0) {
 502     // Do special processing for the top-level call.
 503     assert(lo->lo() == min_jint, "initial range must exhaust Type::INT");
 504     assert(hi->hi() == max_jint, "initial range must exhaust Type::INT");
 505 
 506     // Decrement pred-numbers for the unique set of nodes.
 507 #ifdef ASSERT
 508     // Ensure that the block's successors are a (duplicate-free) set.
 509     int successors_counted = 0;  // block occurrences in [hi..lo]
 510     int unique_successors = switch_block->num_successors();
 511     for (int i = 0; i < unique_successors; i++) {
 512       Block* target = switch_block->successor_at(i);
 513 
 514       // Check that the set of successors is the same in both places.
 515       int successors_found = 0;
 516       for (SwitchRange* p = lo; p <= hi; p++) {
 517         if (p->dest() == target->start())  successors_found++;
 518       }
 519       assert(successors_found > 0, "successor must be known");
 520       successors_counted += successors_found;
 521     }
 522     assert(successors_counted == (hi-lo)+1, "no unexpected successors");
 523 #endif
 524 
 525     // Maybe prune the inputs, based on the type of key_val.
 526     jint min_val = min_jint;
 527     jint max_val = max_jint;
 528     const TypeInt* ti = key_val->bottom_type()->isa_int();
 529     if (ti != NULL) {
 530       min_val = ti->_lo;
 531       max_val = ti->_hi;
 532       assert(min_val <= max_val, "invalid int type");
 533     }
 534     while (lo->hi() < min_val)  lo++;
 535     if (lo->lo() < min_val)  lo->setRange(min_val, lo->hi(), lo->dest(), lo->table_index());
 536     while (hi->lo() > max_val)  hi--;
 537     if (hi->hi() > max_val)  hi->setRange(hi->lo(), max_val, hi->dest(), hi->table_index());
 538   }
 539 
 540 #ifndef PRODUCT
 541   if (switch_depth == 0) {
 542     _max_switch_depth = 0;
 543     _est_switch_depth = log2_intptr((hi-lo+1)-1)+1;
 544   }
 545 #endif
 546 
 547   assert(lo <= hi, "must be a non-empty set of ranges");
 548   if (lo == hi) {
 549     jump_if_always_fork(lo->dest(), lo->table_index());
 550   } else {
 551     assert(lo->hi() == (lo+1)->lo()-1, "contiguous ranges");
 552     assert(hi->lo() == (hi-1)->hi()+1, "contiguous ranges");
 553 
 554     if (create_jump_tables(key_val, lo, hi)) return;
 555 
 556     int nr = hi - lo + 1;
 557 
 558     SwitchRange* mid = lo + nr/2;
 559     // if there is an easy choice, pivot at a singleton:
 560     if (nr > 3 && !mid->is_singleton() && (mid-1)->is_singleton())  mid--;
 561 
 562     assert(lo < mid && mid <= hi, "good pivot choice");
 563     assert(nr != 2 || mid == hi,   "should pick higher of 2");
 564     assert(nr != 3 || mid == hi-1, "should pick middle of 3");
 565 
 566     Node *test_val = _gvn.intcon(mid->lo());
 567 
 568     if (mid->is_singleton()) {
 569       IfNode *iff_ne = jump_if_fork_int(key_val, test_val, BoolTest::ne);
 570       jump_if_false_fork(iff_ne, mid->dest(), mid->table_index());
 571 
 572       // Special Case:  If there are exactly three ranges, and the high
 573       // and low range each go to the same place, omit the "gt" test,
 574       // since it will not discriminate anything.
 575       bool eq_test_only = (hi == lo+2 && hi->dest() == lo->dest());
 576       if (eq_test_only) {
 577         assert(mid == hi-1, "");
 578       }
 579 
 580       // if there is a higher range, test for it and process it:
 581       if (mid < hi && !eq_test_only) {
 582         // two comparisons of same values--should enable 1 test for 2 branches
 583         // Use BoolTest::le instead of BoolTest::gt
 584         IfNode *iff_le  = jump_if_fork_int(key_val, test_val, BoolTest::le);
 585         Node   *iftrue  = _gvn.transform( new (C) IfTrueNode(iff_le) );
 586         Node   *iffalse = _gvn.transform( new (C) IfFalseNode(iff_le) );
 587         { PreserveJVMState pjvms(this);
 588           set_control(iffalse);
 589           jump_switch_ranges(key_val, mid+1, hi, switch_depth+1);
 590         }
 591         set_control(iftrue);
 592       }
 593 
 594     } else {
 595       // mid is a range, not a singleton, so treat mid..hi as a unit
 596       IfNode *iff_ge = jump_if_fork_int(key_val, test_val, BoolTest::ge);
 597 
 598       // if there is a higher range, test for it and process it:
 599       if (mid == hi) {
 600         jump_if_true_fork(iff_ge, mid->dest(), mid->table_index());
 601       } else {
 602         Node *iftrue  = _gvn.transform( new (C) IfTrueNode(iff_ge) );
 603         Node *iffalse = _gvn.transform( new (C) IfFalseNode(iff_ge) );
 604         { PreserveJVMState pjvms(this);
 605           set_control(iftrue);
 606           jump_switch_ranges(key_val, mid, hi, switch_depth+1);
 607         }
 608         set_control(iffalse);
 609       }
 610     }
 611 
 612     // in any case, process the lower range
 613     jump_switch_ranges(key_val, lo, mid-1, switch_depth+1);
 614   }
 615 
 616   // Decrease pred_count for each successor after all is done.
 617   if (switch_depth == 0) {
 618     int unique_successors = switch_block->num_successors();
 619     for (int i = 0; i < unique_successors; i++) {
 620       Block* target = switch_block->successor_at(i);
 621       // Throw away the pre-allocated path for each unique successor.
 622       target->next_path_num();
 623     }
 624   }
 625 
 626 #ifndef PRODUCT
 627   _max_switch_depth = MAX2(switch_depth, _max_switch_depth);
 628   if (TraceOptoParse && Verbose && WizardMode && switch_depth == 0) {
 629     SwitchRange* r;
 630     int nsing = 0;
 631     for( r = lo; r <= hi; r++ ) {
 632       if( r->is_singleton() )  nsing++;
 633     }
 634     tty->print(">>> ");
 635     _method->print_short_name();
 636     tty->print_cr(" switch decision tree");
 637     tty->print_cr("    %d ranges (%d singletons), max_depth=%d, est_depth=%d",
 638                   (int) (hi-lo+1), nsing, _max_switch_depth, _est_switch_depth);
 639     if (_max_switch_depth > _est_switch_depth) {
 640       tty->print_cr("******** BAD SWITCH DEPTH ********");
 641     }
 642     tty->print("   ");
 643     for( r = lo; r <= hi; r++ ) {
 644       r->print();
 645     }
 646     tty->cr();
 647   }
 648 #endif
 649 }
 650 
 651 void Parse::modf() {
 652   Node *f2 = pop();
 653   Node *f1 = pop();
 654   Node* c = make_runtime_call(RC_LEAF, OptoRuntime::modf_Type(),
 655                               CAST_FROM_FN_PTR(address, SharedRuntime::frem),
 656                               "frem", NULL, //no memory effects
 657                               f1, f2);
 658   Node* res = _gvn.transform(new (C) ProjNode(c, TypeFunc::Parms + 0));
 659 
 660   push(res);
 661 }
 662 
 663 void Parse::modd() {
 664   Node *d2 = pop_pair();
 665   Node *d1 = pop_pair();
 666   Node* c = make_runtime_call(RC_LEAF, OptoRuntime::Math_DD_D_Type(),
 667                               CAST_FROM_FN_PTR(address, SharedRuntime::drem),
 668                               "drem", NULL, //no memory effects
 669                               d1, top(), d2, top());
 670   Node* res_d   = _gvn.transform(new (C) ProjNode(c, TypeFunc::Parms + 0));
 671 
 672 #ifdef ASSERT
 673   Node* res_top = _gvn.transform(new (C) ProjNode(c, TypeFunc::Parms + 1));
 674   assert(res_top == top(), "second value must be top");
 675 #endif
 676 
 677   push_pair(res_d);
 678 }
 679 
 680 void Parse::l2f() {
 681   Node* f2 = pop();
 682   Node* f1 = pop();
 683   Node* c = make_runtime_call(RC_LEAF, OptoRuntime::l2f_Type(),
 684                               CAST_FROM_FN_PTR(address, SharedRuntime::l2f),
 685                               "l2f", NULL, //no memory effects
 686                               f1, f2);
 687   Node* res = _gvn.transform(new (C) ProjNode(c, TypeFunc::Parms + 0));
 688 
 689   push(res);
 690 }
 691 
 692 void Parse::do_irem() {
 693   // Must keep both values on the expression-stack during null-check
 694   zero_check_int(peek());
 695   // Compile-time detect of null-exception?
 696   if (stopped())  return;
 697 
 698   Node* b = pop();
 699   Node* a = pop();
 700 
 701   const Type *t = _gvn.type(b);
 702   if (t != Type::TOP) {
 703     const TypeInt *ti = t->is_int();
 704     if (ti->is_con()) {
 705       int divisor = ti->get_con();
 706       // check for positive power of 2
 707       if (divisor > 0 &&
 708           (divisor & ~(divisor-1)) == divisor) {
 709         // yes !
 710         Node *mask = _gvn.intcon((divisor - 1));
 711         // Sigh, must handle negative dividends
 712         Node *zero = _gvn.intcon(0);
 713         IfNode *ifff = jump_if_fork_int(a, zero, BoolTest::lt);
 714         Node *iff = _gvn.transform( new (C) IfFalseNode(ifff) );
 715         Node *ift = _gvn.transform( new (C) IfTrueNode (ifff) );
 716         Node *reg = jump_if_join(ift, iff);
 717         Node *phi = PhiNode::make(reg, NULL, TypeInt::INT);
 718         // Negative path; negate/and/negate
 719         Node *neg = _gvn.transform( new (C) SubINode(zero, a) );
 720         Node *andn= _gvn.transform( new (C) AndINode(neg, mask) );
 721         Node *negn= _gvn.transform( new (C) SubINode(zero, andn) );
 722         phi->init_req(1, negn);
 723         // Fast positive case
 724         Node *andx = _gvn.transform( new (C) AndINode(a, mask) );
 725         phi->init_req(2, andx);
 726         // Push the merge
 727         push( _gvn.transform(phi) );
 728         return;
 729       }
 730     }
 731   }
 732   // Default case
 733   push( _gvn.transform( new (C) ModINode(control(),a,b) ) );
 734 }
 735 
 736 // Handle jsr and jsr_w bytecode
 737 void Parse::do_jsr() {
 738   assert(bc() == Bytecodes::_jsr || bc() == Bytecodes::_jsr_w, "wrong bytecode");
 739 
 740   // Store information about current state, tagged with new _jsr_bci
 741   int return_bci = iter().next_bci();
 742   int jsr_bci    = (bc() == Bytecodes::_jsr) ? iter().get_dest() : iter().get_far_dest();
 743 
 744   // Update method data
 745   profile_taken_branch(jsr_bci);
 746 
 747   // The way we do things now, there is only one successor block
 748   // for the jsr, because the target code is cloned by ciTypeFlow.
 749   Block* target = successor_for_bci(jsr_bci);
 750 
 751   // What got pushed?
 752   const Type* ret_addr = target->peek();
 753   assert(ret_addr->singleton(), "must be a constant (cloned jsr body)");
 754 
 755   // Effect on jsr on stack
 756   push(_gvn.makecon(ret_addr));
 757 
 758   // Flow to the jsr.
 759   merge(jsr_bci);
 760 }
 761 
 762 // Handle ret bytecode
 763 void Parse::do_ret() {
 764   // Find to whom we return.
 765   assert(block()->num_successors() == 1, "a ret can only go one place now");
 766   Block* target = block()->successor_at(0);
 767   assert(!target->is_ready(), "our arrival must be expected");
 768   profile_ret(target->flow()->start());
 769   int pnum = target->next_path_num();
 770   merge_common(target, pnum);
 771 }
 772 
 773 static bool has_injected_profile(BoolTest::mask btest, Node* test, int& taken, int& not_taken) {
 774   if (btest != BoolTest::eq && btest != BoolTest::ne) {
 775     // Only ::eq and ::ne are supported for profile injection.
 776     return false;
 777   }
 778   if (test->is_Cmp() &&
 779       test->in(1)->Opcode() == Op_ProfileBoolean) {
 780     ProfileBooleanNode* profile = (ProfileBooleanNode*)test->in(1);
 781     int false_cnt = profile->false_count();
 782     int  true_cnt = profile->true_count();
 783 
 784     // Counts matching depends on the actual test operation (::eq or ::ne).
 785     // No need to scale the counts because profile injection was designed
 786     // to feed exact counts into VM.
 787     taken     = (btest == BoolTest::eq) ? false_cnt :  true_cnt;
 788     not_taken = (btest == BoolTest::eq) ?  true_cnt : false_cnt;
 789 
 790     profile->consume();
 791     return true;
 792   }
 793   return false;
 794 }
 795 //--------------------------dynamic_branch_prediction--------------------------
 796 // Try to gather dynamic branch prediction behavior.  Return a probability
 797 // of the branch being taken and set the "cnt" field.  Returns a -1.0
 798 // if we need to use static prediction for some reason.
 799 float Parse::dynamic_branch_prediction(float &cnt, BoolTest::mask btest, Node* test) {
 800   ResourceMark rm;
 801 
 802   cnt  = COUNT_UNKNOWN;
 803 
 804   int     taken = 0;
 805   int not_taken = 0;
 806 
 807   bool use_mdo = !has_injected_profile(btest, test, taken, not_taken);
 808 
 809   if (use_mdo) {
 810     // Use MethodData information if it is available
 811     // FIXME: free the ProfileData structure
 812     ciMethodData* methodData = method()->method_data();
 813     if (!methodData->is_mature())  return PROB_UNKNOWN;
 814     ciProfileData* data = methodData->bci_to_data(bci());
 815     if (data == NULL) {
 816       return PROB_UNKNOWN;
 817     }
 818     if (!data->is_JumpData())  return PROB_UNKNOWN;
 819 
 820     // get taken and not taken values
 821     taken = data->as_JumpData()->taken();
 822     not_taken = 0;
 823     if (data->is_BranchData()) {
 824       not_taken = data->as_BranchData()->not_taken();
 825     }
 826 
 827     // scale the counts to be commensurate with invocation counts:
 828     taken = method()->scale_count(taken);
 829     not_taken = method()->scale_count(not_taken);
 830   }
 831 
 832   // Give up if too few (or too many, in which case the sum will overflow) counts to be meaningful.
 833   // We also check that individual counters are positive first, otherwise the sum can become positive.
 834   if (taken < 0 || not_taken < 0 || taken + not_taken < 40) {
 835     if (C->log() != NULL) {
 836       C->log()->elem("branch target_bci='%d' taken='%d' not_taken='%d'", iter().get_dest(), taken, not_taken);
 837     }
 838     return PROB_UNKNOWN;
 839   }
 840 
 841   // Compute frequency that we arrive here
 842   float sum = taken + not_taken;
 843   // Adjust, if this block is a cloned private block but the
 844   // Jump counts are shared.  Taken the private counts for
 845   // just this path instead of the shared counts.
 846   if( block()->count() > 0 )
 847     sum = block()->count();
 848   cnt = sum / FreqCountInvocations;
 849 
 850   // Pin probability to sane limits
 851   float prob;
 852   if( !taken )
 853     prob = (0+PROB_MIN) / 2;
 854   else if( !not_taken )
 855     prob = (1+PROB_MAX) / 2;
 856   else {                         // Compute probability of true path
 857     prob = (float)taken / (float)(taken + not_taken);
 858     if (prob > PROB_MAX)  prob = PROB_MAX;
 859     if (prob < PROB_MIN)   prob = PROB_MIN;
 860   }
 861 
 862   assert((cnt > 0.0f) && (prob > 0.0f),
 863          "Bad frequency assignment in if");
 864 
 865   if (C->log() != NULL) {
 866     const char* prob_str = NULL;
 867     if (prob >= PROB_MAX)  prob_str = (prob == PROB_MAX) ? "max" : "always";
 868     if (prob <= PROB_MIN)  prob_str = (prob == PROB_MIN) ? "min" : "never";
 869     char prob_str_buf[30];
 870     if (prob_str == NULL) {
 871       sprintf(prob_str_buf, "%g", prob);
 872       prob_str = prob_str_buf;
 873     }
 874     C->log()->elem("branch target_bci='%d' taken='%d' not_taken='%d' cnt='%g' prob='%s'",
 875                    iter().get_dest(), taken, not_taken, cnt, prob_str);
 876   }
 877   return prob;
 878 }
 879 
 880 //-----------------------------branch_prediction-------------------------------
 881 float Parse::branch_prediction(float& cnt,
 882                                BoolTest::mask btest,
 883                                int target_bci,
 884                                Node* test) {
 885   float prob = dynamic_branch_prediction(cnt, btest, test);
 886   // If prob is unknown, switch to static prediction
 887   if (prob != PROB_UNKNOWN)  return prob;
 888 
 889   prob = PROB_FAIR;                   // Set default value
 890   if (btest == BoolTest::eq)          // Exactly equal test?
 891     prob = PROB_STATIC_INFREQUENT;    // Assume its relatively infrequent
 892   else if (btest == BoolTest::ne)
 893     prob = PROB_STATIC_FREQUENT;      // Assume its relatively frequent
 894 
 895   // If this is a conditional test guarding a backwards branch,
 896   // assume its a loop-back edge.  Make it a likely taken branch.
 897   if (target_bci < bci()) {
 898     if (is_osr_parse()) {    // Could be a hot OSR'd loop; force deopt
 899       // Since it's an OSR, we probably have profile data, but since
 900       // branch_prediction returned PROB_UNKNOWN, the counts are too small.
 901       // Let's make a special check here for completely zero counts.
 902       ciMethodData* methodData = method()->method_data();
 903       if (!methodData->is_empty()) {
 904         ciProfileData* data = methodData->bci_to_data(bci());
 905         // Only stop for truly zero counts, which mean an unknown part
 906         // of the OSR-ed method, and we want to deopt to gather more stats.
 907         // If you have ANY counts, then this loop is simply 'cold' relative
 908         // to the OSR loop.
 909         if (data == NULL ||
 910             (data->as_BranchData()->taken() +  data->as_BranchData()->not_taken() == 0)) {
 911           // This is the only way to return PROB_UNKNOWN:
 912           return PROB_UNKNOWN;
 913         }
 914       }
 915     }
 916     prob = PROB_STATIC_FREQUENT;     // Likely to take backwards branch
 917   }
 918 
 919   assert(prob != PROB_UNKNOWN, "must have some guess at this point");
 920   return prob;
 921 }
 922 
 923 // The magic constants are chosen so as to match the output of
 924 // branch_prediction() when the profile reports a zero taken count.
 925 // It is important to distinguish zero counts unambiguously, because
 926 // some branches (e.g., _213_javac.Assembler.eliminate) validly produce
 927 // very small but nonzero probabilities, which if confused with zero
 928 // counts would keep the program recompiling indefinitely.
 929 bool Parse::seems_never_taken(float prob) const {
 930   return prob < PROB_MIN;
 931 }
 932 
 933 // True if the comparison seems to be the kind that will not change its
 934 // statistics from true to false.  See comments in adjust_map_after_if.
 935 // This question is only asked along paths which are already
 936 // classifed as untaken (by seems_never_taken), so really,
 937 // if a path is never taken, its controlling comparison is
 938 // already acting in a stable fashion.  If the comparison
 939 // seems stable, we will put an expensive uncommon trap
 940 // on the untaken path.
 941 bool Parse::seems_stable_comparison() const {
 942   if (C->too_many_traps(method(), bci(), Deoptimization::Reason_unstable_if)) {
 943     return false;
 944   }
 945   return true;
 946 }
 947 
 948 //-------------------------------repush_if_args--------------------------------
 949 // Push arguments of an "if" bytecode back onto the stack by adjusting _sp.
 950 inline int Parse::repush_if_args() {
 951 #ifndef PRODUCT
 952   if (PrintOpto && WizardMode) {
 953     tty->print("defending against excessive implicit null exceptions on %s @%d in ",
 954                Bytecodes::name(iter().cur_bc()), iter().cur_bci());
 955     method()->print_name(); tty->cr();
 956   }
 957 #endif
 958   int bc_depth = - Bytecodes::depth(iter().cur_bc());
 959   assert(bc_depth == 1 || bc_depth == 2, "only two kinds of branches");
 960   DEBUG_ONLY(sync_jvms());   // argument(n) requires a synced jvms
 961   assert(argument(0) != NULL, "must exist");
 962   assert(bc_depth == 1 || argument(1) != NULL, "two must exist");
 963   inc_sp(bc_depth);
 964   return bc_depth;
 965 }
 966 
 967 //----------------------------------do_ifnull----------------------------------
 968 void Parse::do_ifnull(BoolTest::mask btest, Node *c) {
 969   int target_bci = iter().get_dest();
 970 
 971   Block* branch_block = successor_for_bci(target_bci);
 972   Block* next_block   = successor_for_bci(iter().next_bci());
 973 
 974   float cnt;
 975   float prob = branch_prediction(cnt, btest, target_bci, c);
 976   if (prob == PROB_UNKNOWN) {
 977     // (An earlier version of do_ifnull omitted this trap for OSR methods.)
 978 #ifndef PRODUCT
 979     if (PrintOpto && Verbose)
 980       tty->print_cr("Never-taken edge stops compilation at bci %d",bci());
 981 #endif
 982     repush_if_args(); // to gather stats on loop
 983     // We need to mark this branch as taken so that if we recompile we will
 984     // see that it is possible. In the tiered system the interpreter doesn't
 985     // do profiling and by the time we get to the lower tier from the interpreter
 986     // the path may be cold again. Make sure it doesn't look untaken
 987     profile_taken_branch(target_bci, !ProfileInterpreter);
 988     uncommon_trap(Deoptimization::Reason_unreached,
 989                   Deoptimization::Action_reinterpret,
 990                   NULL, "cold");
 991     if (C->eliminate_boxing()) {
 992       // Mark the successor blocks as parsed
 993       branch_block->next_path_num();
 994       next_block->next_path_num();
 995     }
 996     return;
 997   }
 998 
 999   explicit_null_checks_inserted++;
1000 
1001   // Generate real control flow
1002   Node   *tst = _gvn.transform( new (C) BoolNode( c, btest ) );
1003 
1004   // Sanity check the probability value
1005   assert(prob > 0.0f,"Bad probability in Parser");
1006  // Need xform to put node in hash table
1007   IfNode *iff = create_and_xform_if( control(), tst, prob, cnt );
1008   assert(iff->_prob > 0.0f,"Optimizer made bad probability in parser");
1009   // True branch
1010   { PreserveJVMState pjvms(this);
1011     Node* iftrue  = _gvn.transform( new (C) IfTrueNode (iff) );
1012     set_control(iftrue);
1013 
1014     if (stopped()) {            // Path is dead?
1015       explicit_null_checks_elided++;
1016       if (C->eliminate_boxing()) {
1017         // Mark the successor block as parsed
1018         branch_block->next_path_num();
1019       }
1020     } else {                    // Path is live.
1021       // Update method data
1022       profile_taken_branch(target_bci);
1023       adjust_map_after_if(btest, c, prob, branch_block, next_block);
1024       if (!stopped()) {
1025         merge(target_bci);
1026       }
1027     }
1028   }
1029 
1030   // False branch
1031   Node* iffalse = _gvn.transform( new (C) IfFalseNode(iff) );
1032   set_control(iffalse);
1033 
1034   if (stopped()) {              // Path is dead?
1035     explicit_null_checks_elided++;
1036     if (C->eliminate_boxing()) {
1037       // Mark the successor block as parsed
1038       next_block->next_path_num();
1039     }
1040   } else  {                     // Path is live.
1041     // Update method data
1042     profile_not_taken_branch();
1043     adjust_map_after_if(BoolTest(btest).negate(), c, 1.0-prob,
1044                         next_block, branch_block);
1045   }
1046 }
1047 
1048 //------------------------------------do_if------------------------------------
1049 void Parse::do_if(BoolTest::mask btest, Node* c) {
1050   int target_bci = iter().get_dest();
1051 
1052   Block* branch_block = successor_for_bci(target_bci);
1053   Block* next_block   = successor_for_bci(iter().next_bci());
1054 
1055   float cnt;
1056   float prob = branch_prediction(cnt, btest, target_bci, c);
1057   float untaken_prob = 1.0 - prob;
1058 
1059   if (prob == PROB_UNKNOWN) {
1060 #ifndef PRODUCT
1061     if (PrintOpto && Verbose)
1062       tty->print_cr("Never-taken edge stops compilation at bci %d",bci());
1063 #endif
1064     repush_if_args(); // to gather stats on loop
1065     // We need to mark this branch as taken so that if we recompile we will
1066     // see that it is possible. In the tiered system the interpreter doesn't
1067     // do profiling and by the time we get to the lower tier from the interpreter
1068     // the path may be cold again. Make sure it doesn't look untaken
1069     profile_taken_branch(target_bci, !ProfileInterpreter);
1070     uncommon_trap(Deoptimization::Reason_unreached,
1071                   Deoptimization::Action_reinterpret,
1072                   NULL, "cold");
1073     if (C->eliminate_boxing()) {
1074       // Mark the successor blocks as parsed
1075       branch_block->next_path_num();
1076       next_block->next_path_num();
1077     }
1078     return;
1079   }
1080 
1081   // Sanity check the probability value
1082   assert(0.0f < prob && prob < 1.0f,"Bad probability in Parser");
1083 
1084   bool taken_if_true = true;
1085   // Convert BoolTest to canonical form:
1086   if (!BoolTest(btest).is_canonical()) {
1087     btest         = BoolTest(btest).negate();
1088     taken_if_true = false;
1089     // prob is NOT updated here; it remains the probability of the taken
1090     // path (as opposed to the prob of the path guarded by an 'IfTrueNode').
1091   }
1092   assert(btest != BoolTest::eq, "!= is the only canonical exact test");
1093 
1094   Node* tst0 = new (C) BoolNode(c, btest);
1095   Node* tst = _gvn.transform(tst0);
1096   BoolTest::mask taken_btest   = BoolTest::illegal;
1097   BoolTest::mask untaken_btest = BoolTest::illegal;
1098 
1099   if (tst->is_Bool()) {
1100     // Refresh c from the transformed bool node, since it may be
1101     // simpler than the original c.  Also re-canonicalize btest.
1102     // This wins when (Bool ne (Conv2B p) 0) => (Bool ne (CmpP p NULL)).
1103     // That can arise from statements like: if (x instanceof C) ...
1104     if (tst != tst0) {
1105       // Canonicalize one more time since transform can change it.
1106       btest = tst->as_Bool()->_test._test;
1107       if (!BoolTest(btest).is_canonical()) {
1108         // Reverse edges one more time...
1109         tst   = _gvn.transform( tst->as_Bool()->negate(&_gvn) );
1110         btest = tst->as_Bool()->_test._test;
1111         assert(BoolTest(btest).is_canonical(), "sanity");
1112         taken_if_true = !taken_if_true;
1113       }
1114       c = tst->in(1);
1115     }
1116     BoolTest::mask neg_btest = BoolTest(btest).negate();
1117     taken_btest   = taken_if_true ?     btest : neg_btest;
1118     untaken_btest = taken_if_true ? neg_btest :     btest;
1119   }
1120 
1121   // Generate real control flow
1122   float true_prob = (taken_if_true ? prob : untaken_prob);
1123   IfNode* iff = create_and_map_if(control(), tst, true_prob, cnt);
1124   assert(iff->_prob > 0.0f,"Optimizer made bad probability in parser");
1125   Node* taken_branch   = new (C) IfTrueNode(iff);
1126   Node* untaken_branch = new (C) IfFalseNode(iff);
1127   if (!taken_if_true) {  // Finish conversion to canonical form
1128     Node* tmp      = taken_branch;
1129     taken_branch   = untaken_branch;
1130     untaken_branch = tmp;
1131   }
1132 
1133   // Branch is taken:
1134   { PreserveJVMState pjvms(this);
1135     taken_branch = _gvn.transform(taken_branch);
1136     set_control(taken_branch);
1137 
1138     if (stopped()) {
1139       if (C->eliminate_boxing()) {
1140         // Mark the successor block as parsed
1141         branch_block->next_path_num();
1142       }
1143     } else {
1144       // Update method data
1145       profile_taken_branch(target_bci);
1146       adjust_map_after_if(taken_btest, c, prob, branch_block, next_block);
1147       if (!stopped()) {
1148         merge(target_bci);
1149       }
1150     }
1151   }
1152 
1153   untaken_branch = _gvn.transform(untaken_branch);
1154   set_control(untaken_branch);
1155 
1156   // Branch not taken.
1157   if (stopped()) {
1158     if (C->eliminate_boxing()) {
1159       // Mark the successor block as parsed
1160       next_block->next_path_num();
1161     }
1162   } else {
1163     // Update method data
1164     profile_not_taken_branch();
1165     adjust_map_after_if(untaken_btest, c, untaken_prob,
1166                         next_block, branch_block);
1167   }
1168 }
1169 
1170 bool Parse::path_is_suitable_for_uncommon_trap(float prob) const {
1171   // Don't want to speculate on uncommon traps when running with -Xcomp
1172   if (!UseInterpreter) {
1173     return false;
1174   }
1175   return (seems_never_taken(prob) && seems_stable_comparison());
1176 }
1177 
1178 //----------------------------adjust_map_after_if------------------------------
1179 // Adjust the JVM state to reflect the result of taking this path.
1180 // Basically, it means inspecting the CmpNode controlling this
1181 // branch, seeing how it constrains a tested value, and then
1182 // deciding if it's worth our while to encode this constraint
1183 // as graph nodes in the current abstract interpretation map.
1184 void Parse::adjust_map_after_if(BoolTest::mask btest, Node* c, float prob,
1185                                 Block* path, Block* other_path) {
1186   if (stopped() || !c->is_Cmp() || btest == BoolTest::illegal)
1187     return;                             // nothing to do
1188 
1189   bool is_fallthrough = (path == successor_for_bci(iter().next_bci()));
1190 
1191   if (path_is_suitable_for_uncommon_trap(prob)) {
1192     repush_if_args();
1193     uncommon_trap(Deoptimization::Reason_unstable_if,
1194                   Deoptimization::Action_reinterpret,
1195                   NULL,
1196                   (is_fallthrough ? "taken always" : "taken never"));
1197     return;
1198   }
1199 
1200   Node* val = c->in(1);
1201   Node* con = c->in(2);
1202   const Type* tcon = _gvn.type(con);
1203   const Type* tval = _gvn.type(val);
1204   bool have_con = tcon->singleton();
1205   if (tval->singleton()) {
1206     if (!have_con) {
1207       // Swap, so constant is in con.
1208       con  = val;
1209       tcon = tval;
1210       val  = c->in(2);
1211       tval = _gvn.type(val);
1212       btest = BoolTest(btest).commute();
1213       have_con = true;
1214     } else {
1215       // Do we have two constants?  Then leave well enough alone.
1216       have_con = false;
1217     }
1218   }
1219   if (!have_con)                        // remaining adjustments need a con
1220     return;
1221 
1222   sharpen_type_after_if(btest, con, tcon, val, tval);
1223 }
1224 
1225 
1226 static Node* extract_obj_from_klass_load(PhaseGVN* gvn, Node* n) {
1227   Node* ldk;
1228   if (n->is_DecodeNKlass()) {
1229     if (n->in(1)->Opcode() != Op_LoadNKlass) {
1230       return NULL;
1231     } else {
1232       ldk = n->in(1);
1233     }
1234   } else if (n->Opcode() != Op_LoadKlass) {
1235     return NULL;
1236   } else {
1237     ldk = n;
1238   }
1239   assert(ldk != NULL && ldk->is_Load(), "should have found a LoadKlass or LoadNKlass node");
1240 
1241   Node* adr = ldk->in(MemNode::Address);
1242   intptr_t off = 0;
1243   Node* obj = AddPNode::Ideal_base_and_offset(adr, gvn, off);
1244   if (obj == NULL || off != oopDesc::klass_offset_in_bytes()) // loading oopDesc::_klass?
1245     return NULL;
1246   const TypePtr* tp = gvn->type(obj)->is_ptr();
1247   if (tp == NULL || !(tp->isa_instptr() || tp->isa_aryptr())) // is obj a Java object ptr?
1248     return NULL;
1249 
1250   return obj;
1251 }
1252 
1253 void Parse::sharpen_type_after_if(BoolTest::mask btest,
1254                                   Node* con, const Type* tcon,
1255                                   Node* val, const Type* tval) {
1256   // Look for opportunities to sharpen the type of a node
1257   // whose klass is compared with a constant klass.
1258   if (btest == BoolTest::eq && tcon->isa_klassptr()) {
1259     Node* obj = extract_obj_from_klass_load(&_gvn, val);
1260     const TypeOopPtr* con_type = tcon->isa_klassptr()->as_instance_type();
1261     if (obj != NULL && (con_type->isa_instptr() || con_type->isa_aryptr())) {
1262        // Found:
1263        //   Bool(CmpP(LoadKlass(obj._klass), ConP(Foo.klass)), [eq])
1264        // or the narrowOop equivalent.
1265        const Type* obj_type = _gvn.type(obj);
1266        const TypeOopPtr* tboth = obj_type->join_speculative(con_type)->isa_oopptr();
1267        if (tboth != NULL && tboth->klass_is_exact() && tboth != obj_type &&
1268            tboth->higher_equal(obj_type)) {
1269           // obj has to be of the exact type Foo if the CmpP succeeds.
1270           int obj_in_map = map()->find_edge(obj);
1271           JVMState* jvms = this->jvms();
1272           if (obj_in_map >= 0 &&
1273               (jvms->is_loc(obj_in_map) || jvms->is_stk(obj_in_map))) {
1274             TypeNode* ccast = new (C) CheckCastPPNode(control(), obj, tboth);
1275             const Type* tcc = ccast->as_Type()->type();
1276             assert(tcc != obj_type && tcc->higher_equal_speculative(obj_type), "must improve");
1277             // Delay transform() call to allow recovery of pre-cast value
1278             // at the control merge.
1279             _gvn.set_type_bottom(ccast);
1280             record_for_igvn(ccast);
1281             // Here's the payoff.
1282             replace_in_map(obj, ccast);
1283           }
1284        }
1285     }
1286   }
1287 
1288   int val_in_map = map()->find_edge(val);
1289   if (val_in_map < 0)  return;          // replace_in_map would be useless
1290   {
1291     JVMState* jvms = this->jvms();
1292     if (!(jvms->is_loc(val_in_map) ||
1293           jvms->is_stk(val_in_map)))
1294       return;                           // again, it would be useless
1295   }
1296 
1297   // Check for a comparison to a constant, and "know" that the compared
1298   // value is constrained on this path.
1299   assert(tcon->singleton(), "");
1300   ConstraintCastNode* ccast = NULL;
1301   Node* cast = NULL;
1302 
1303   switch (btest) {
1304   case BoolTest::eq:                    // Constant test?
1305     {
1306       const Type* tboth = tcon->join_speculative(tval);
1307       if (tboth == tval)  break;        // Nothing to gain.
1308       if (tcon->isa_int()) {
1309         ccast = new (C) CastIINode(val, tboth);
1310       } else if (tcon == TypePtr::NULL_PTR) {
1311         // Cast to null, but keep the pointer identity temporarily live.
1312         ccast = new (C) CastPPNode(val, tboth);
1313       } else {
1314         const TypeF* tf = tcon->isa_float_constant();
1315         const TypeD* td = tcon->isa_double_constant();
1316         // Exclude tests vs float/double 0 as these could be
1317         // either +0 or -0.  Just because you are equal to +0
1318         // doesn't mean you ARE +0!
1319         // Note, following code also replaces Long and Oop values.
1320         if ((!tf || tf->_f != 0.0) &&
1321             (!td || td->_d != 0.0))
1322           cast = con;                   // Replace non-constant val by con.
1323       }
1324     }
1325     break;
1326 
1327   case BoolTest::ne:
1328     if (tcon == TypePtr::NULL_PTR) {
1329       cast = cast_not_null(val, false);
1330     }
1331     break;
1332 
1333   default:
1334     // (At this point we could record int range types with CastII.)
1335     break;
1336   }
1337 
1338   if (ccast != NULL) {
1339     const Type* tcc = ccast->as_Type()->type();
1340     assert(tcc != tval && tcc->higher_equal_speculative(tval), "must improve");
1341     // Delay transform() call to allow recovery of pre-cast value
1342     // at the control merge.
1343     ccast->set_req(0, control());
1344     _gvn.set_type_bottom(ccast);
1345     record_for_igvn(ccast);
1346     cast = ccast;
1347   }
1348 
1349   if (cast != NULL) {                   // Here's the payoff.
1350     replace_in_map(val, cast);
1351   }
1352 }
1353 
1354 /**
1355  * Use speculative type to optimize CmpP node: if comparison is
1356  * against the low level class, cast the object to the speculative
1357  * type if any. CmpP should then go away.
1358  *
1359  * @param c  expected CmpP node
1360  * @return   result of CmpP on object casted to speculative type
1361  *
1362  */
1363 Node* Parse::optimize_cmp_with_klass(Node* c) {
1364   // If this is transformed by the _gvn to a comparison with the low
1365   // level klass then we may be able to use speculation
1366   if (c->Opcode() == Op_CmpP &&
1367       (c->in(1)->Opcode() == Op_LoadKlass || c->in(1)->Opcode() == Op_DecodeNKlass) &&
1368       c->in(2)->is_Con()) {
1369     Node* load_klass = NULL;
1370     Node* decode = NULL;
1371     if (c->in(1)->Opcode() == Op_DecodeNKlass) {
1372       decode = c->in(1);
1373       load_klass = c->in(1)->in(1);
1374     } else {
1375       load_klass = c->in(1);
1376     }
1377     if (load_klass->in(2)->is_AddP()) {
1378       Node* addp = load_klass->in(2);
1379       Node* obj = addp->in(AddPNode::Address);
1380       const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
1381       if (obj_type->speculative_type() != NULL) {
1382         ciKlass* k = obj_type->speculative_type();
1383         inc_sp(2);
1384         obj = maybe_cast_profiled_obj(obj, k);
1385         dec_sp(2);
1386         // Make the CmpP use the casted obj
1387         addp = basic_plus_adr(obj, addp->in(AddPNode::Offset));
1388         load_klass = load_klass->clone();
1389         load_klass->set_req(2, addp);
1390         load_klass = _gvn.transform(load_klass);
1391         if (decode != NULL) {
1392           decode = decode->clone();
1393           decode->set_req(1, load_klass);
1394           load_klass = _gvn.transform(decode);
1395         }
1396         c = c->clone();
1397         c->set_req(1, load_klass);
1398         c = _gvn.transform(c);
1399       }
1400     }
1401   }
1402   return c;
1403 }
1404 
1405 //------------------------------do_one_bytecode--------------------------------
1406 // Parse this bytecode, and alter the Parsers JVM->Node mapping
1407 void Parse::do_one_bytecode() {
1408   Node *a, *b, *c, *d;          // Handy temps
1409   BoolTest::mask btest;
1410   int i;
1411 
1412   assert(!has_exceptions(), "bytecode entry state must be clear of throws");
1413 
1414   if (C->check_node_count(NodeLimitFudgeFactor * 5,
1415                           "out of nodes parsing method")) {
1416     return;
1417   }
1418 
1419 #ifdef ASSERT
1420   // for setting breakpoints
1421   if (TraceOptoParse) {
1422     tty->print(" @");
1423     dump_bci(bci());
1424     tty->cr();
1425   }
1426 #endif
1427 
1428   switch (bc()) {
1429   case Bytecodes::_nop:
1430     // do nothing
1431     break;
1432   case Bytecodes::_lconst_0:
1433     push_pair(longcon(0));
1434     break;
1435 
1436   case Bytecodes::_lconst_1:
1437     push_pair(longcon(1));
1438     break;
1439 
1440   case Bytecodes::_fconst_0:
1441     push(zerocon(T_FLOAT));
1442     break;
1443 
1444   case Bytecodes::_fconst_1:
1445     push(makecon(TypeF::ONE));
1446     break;
1447 
1448   case Bytecodes::_fconst_2:
1449     push(makecon(TypeF::make(2.0f)));
1450     break;
1451 
1452   case Bytecodes::_dconst_0:
1453     push_pair(zerocon(T_DOUBLE));
1454     break;
1455 
1456   case Bytecodes::_dconst_1:
1457     push_pair(makecon(TypeD::ONE));
1458     break;
1459 
1460   case Bytecodes::_iconst_m1:push(intcon(-1)); break;
1461   case Bytecodes::_iconst_0: push(intcon( 0)); break;
1462   case Bytecodes::_iconst_1: push(intcon( 1)); break;
1463   case Bytecodes::_iconst_2: push(intcon( 2)); break;
1464   case Bytecodes::_iconst_3: push(intcon( 3)); break;
1465   case Bytecodes::_iconst_4: push(intcon( 4)); break;
1466   case Bytecodes::_iconst_5: push(intcon( 5)); break;
1467   case Bytecodes::_bipush:   push(intcon(iter().get_constant_u1())); break;
1468   case Bytecodes::_sipush:   push(intcon(iter().get_constant_u2())); break;
1469   case Bytecodes::_aconst_null: push(null());  break;
1470   case Bytecodes::_ldc:
1471   case Bytecodes::_ldc_w:
1472   case Bytecodes::_ldc2_w:
1473     // If the constant is unresolved, run this BC once in the interpreter.
1474     {
1475       ciConstant constant = iter().get_constant();
1476       if (constant.basic_type() == T_OBJECT &&
1477           !constant.as_object()->is_loaded()) {
1478         int index = iter().get_constant_pool_index();
1479         constantTag tag = iter().get_constant_pool_tag(index);
1480         uncommon_trap(Deoptimization::make_trap_request
1481                       (Deoptimization::Reason_unloaded,
1482                        Deoptimization::Action_reinterpret,
1483                        index),
1484                       NULL, tag.internal_name());
1485         break;
1486       }
1487       assert(constant.basic_type() != T_OBJECT || constant.as_object()->is_instance(),
1488              "must be java_mirror of klass");
1489       bool pushed = push_constant(constant, true);
1490       guarantee(pushed, "must be possible to push this constant");
1491     }
1492 
1493     break;
1494 
1495   case Bytecodes::_aload_0:
1496     push( local(0) );
1497     break;
1498   case Bytecodes::_aload_1:
1499     push( local(1) );
1500     break;
1501   case Bytecodes::_aload_2:
1502     push( local(2) );
1503     break;
1504   case Bytecodes::_aload_3:
1505     push( local(3) );
1506     break;
1507   case Bytecodes::_aload:
1508     push( local(iter().get_index()) );
1509     break;
1510 
1511   case Bytecodes::_fload_0:
1512   case Bytecodes::_iload_0:
1513     push( local(0) );
1514     break;
1515   case Bytecodes::_fload_1:
1516   case Bytecodes::_iload_1:
1517     push( local(1) );
1518     break;
1519   case Bytecodes::_fload_2:
1520   case Bytecodes::_iload_2:
1521     push( local(2) );
1522     break;
1523   case Bytecodes::_fload_3:
1524   case Bytecodes::_iload_3:
1525     push( local(3) );
1526     break;
1527   case Bytecodes::_fload:
1528   case Bytecodes::_iload:
1529     push( local(iter().get_index()) );
1530     break;
1531   case Bytecodes::_lload_0:
1532     push_pair_local( 0 );
1533     break;
1534   case Bytecodes::_lload_1:
1535     push_pair_local( 1 );
1536     break;
1537   case Bytecodes::_lload_2:
1538     push_pair_local( 2 );
1539     break;
1540   case Bytecodes::_lload_3:
1541     push_pair_local( 3 );
1542     break;
1543   case Bytecodes::_lload:
1544     push_pair_local( iter().get_index() );
1545     break;
1546 
1547   case Bytecodes::_dload_0:
1548     push_pair_local(0);
1549     break;
1550   case Bytecodes::_dload_1:
1551     push_pair_local(1);
1552     break;
1553   case Bytecodes::_dload_2:
1554     push_pair_local(2);
1555     break;
1556   case Bytecodes::_dload_3:
1557     push_pair_local(3);
1558     break;
1559   case Bytecodes::_dload:
1560     push_pair_local(iter().get_index());
1561     break;
1562   case Bytecodes::_fstore_0:
1563   case Bytecodes::_istore_0:
1564   case Bytecodes::_astore_0:
1565     set_local( 0, pop() );
1566     break;
1567   case Bytecodes::_fstore_1:
1568   case Bytecodes::_istore_1:
1569   case Bytecodes::_astore_1:
1570     set_local( 1, pop() );
1571     break;
1572   case Bytecodes::_fstore_2:
1573   case Bytecodes::_istore_2:
1574   case Bytecodes::_astore_2:
1575     set_local( 2, pop() );
1576     break;
1577   case Bytecodes::_fstore_3:
1578   case Bytecodes::_istore_3:
1579   case Bytecodes::_astore_3:
1580     set_local( 3, pop() );
1581     break;
1582   case Bytecodes::_fstore:
1583   case Bytecodes::_istore:
1584   case Bytecodes::_astore:
1585     set_local( iter().get_index(), pop() );
1586     break;
1587   // long stores
1588   case Bytecodes::_lstore_0:
1589     set_pair_local( 0, pop_pair() );
1590     break;
1591   case Bytecodes::_lstore_1:
1592     set_pair_local( 1, pop_pair() );
1593     break;
1594   case Bytecodes::_lstore_2:
1595     set_pair_local( 2, pop_pair() );
1596     break;
1597   case Bytecodes::_lstore_3:
1598     set_pair_local( 3, pop_pair() );
1599     break;
1600   case Bytecodes::_lstore:
1601     set_pair_local( iter().get_index(), pop_pair() );
1602     break;
1603 
1604   // double stores
1605   case Bytecodes::_dstore_0:
1606     set_pair_local( 0, dstore_rounding(pop_pair()) );
1607     break;
1608   case Bytecodes::_dstore_1:
1609     set_pair_local( 1, dstore_rounding(pop_pair()) );
1610     break;
1611   case Bytecodes::_dstore_2:
1612     set_pair_local( 2, dstore_rounding(pop_pair()) );
1613     break;
1614   case Bytecodes::_dstore_3:
1615     set_pair_local( 3, dstore_rounding(pop_pair()) );
1616     break;
1617   case Bytecodes::_dstore:
1618     set_pair_local( iter().get_index(), dstore_rounding(pop_pair()) );
1619     break;
1620 
1621   case Bytecodes::_pop:  dec_sp(1);   break;
1622   case Bytecodes::_pop2: dec_sp(2);   break;
1623   case Bytecodes::_swap:
1624     a = pop();
1625     b = pop();
1626     push(a);
1627     push(b);
1628     break;
1629   case Bytecodes::_dup:
1630     a = pop();
1631     push(a);
1632     push(a);
1633     break;
1634   case Bytecodes::_dup_x1:
1635     a = pop();
1636     b = pop();
1637     push( a );
1638     push( b );
1639     push( a );
1640     break;
1641   case Bytecodes::_dup_x2:
1642     a = pop();
1643     b = pop();
1644     c = pop();
1645     push( a );
1646     push( c );
1647     push( b );
1648     push( a );
1649     break;
1650   case Bytecodes::_dup2:
1651     a = pop();
1652     b = pop();
1653     push( b );
1654     push( a );
1655     push( b );
1656     push( a );
1657     break;
1658 
1659   case Bytecodes::_dup2_x1:
1660     // before: .. c, b, a
1661     // after:  .. b, a, c, b, a
1662     // not tested
1663     a = pop();
1664     b = pop();
1665     c = pop();
1666     push( b );
1667     push( a );
1668     push( c );
1669     push( b );
1670     push( a );
1671     break;
1672   case Bytecodes::_dup2_x2:
1673     // before: .. d, c, b, a
1674     // after:  .. b, a, d, c, b, a
1675     // not tested
1676     a = pop();
1677     b = pop();
1678     c = pop();
1679     d = pop();
1680     push( b );
1681     push( a );
1682     push( d );
1683     push( c );
1684     push( b );
1685     push( a );
1686     break;
1687 
1688   case Bytecodes::_arraylength: {
1689     // Must do null-check with value on expression stack
1690     Node *ary = null_check(peek(), T_ARRAY);
1691     // Compile-time detect of null-exception?
1692     if (stopped())  return;
1693     a = pop();
1694     push(load_array_length(a));
1695     break;
1696   }
1697 
1698   case Bytecodes::_baload: array_load(T_BYTE);   break;
1699   case Bytecodes::_caload: array_load(T_CHAR);   break;
1700   case Bytecodes::_iaload: array_load(T_INT);    break;
1701   case Bytecodes::_saload: array_load(T_SHORT);  break;
1702   case Bytecodes::_faload: array_load(T_FLOAT);  break;
1703   case Bytecodes::_aaload: array_load(T_OBJECT); break;
1704   case Bytecodes::_laload: {
1705     a = array_addressing(T_LONG, 0);
1706     if (stopped())  return;     // guaranteed null or range check
1707     dec_sp(2);                  // Pop array and index
1708     push_pair(make_load(control(), a, TypeLong::LONG, T_LONG, TypeAryPtr::LONGS, MemNode::unordered));
1709     break;
1710   }
1711   case Bytecodes::_daload: {
1712     a = array_addressing(T_DOUBLE, 0);
1713     if (stopped())  return;     // guaranteed null or range check
1714     dec_sp(2);                  // Pop array and index
1715     push_pair(make_load(control(), a, Type::DOUBLE, T_DOUBLE, TypeAryPtr::DOUBLES, MemNode::unordered));
1716     break;
1717   }
1718   case Bytecodes::_bastore: array_store(T_BYTE);  break;
1719   case Bytecodes::_castore: array_store(T_CHAR);  break;
1720   case Bytecodes::_iastore: array_store(T_INT);   break;
1721   case Bytecodes::_sastore: array_store(T_SHORT); break;
1722   case Bytecodes::_fastore: array_store(T_FLOAT); break;
1723   case Bytecodes::_aastore: {
1724     d = array_addressing(T_OBJECT, 1);
1725     if (stopped())  return;     // guaranteed null or range check
1726     array_store_check();
1727     c = pop();                  // Oop to store
1728     b = pop();                  // index (already used)
1729     a = pop();                  // the array itself
1730     const TypeOopPtr* elemtype  = _gvn.type(a)->is_aryptr()->elem()->make_oopptr();
1731     const TypeAryPtr* adr_type = TypeAryPtr::OOPS;
1732     Node* store = store_oop_to_array(control(), a, d, adr_type, c, elemtype, T_OBJECT, MemNode::release);
1733     break;
1734   }
1735   case Bytecodes::_lastore: {
1736     a = array_addressing(T_LONG, 2);
1737     if (stopped())  return;     // guaranteed null or range check
1738     c = pop_pair();
1739     dec_sp(2);                  // Pop array and index
1740     store_to_memory(control(), a, c, T_LONG, TypeAryPtr::LONGS, MemNode::unordered);
1741     break;
1742   }
1743   case Bytecodes::_dastore: {
1744     a = array_addressing(T_DOUBLE, 2);
1745     if (stopped())  return;     // guaranteed null or range check
1746     c = pop_pair();
1747     dec_sp(2);                  // Pop array and index
1748     c = dstore_rounding(c);
1749     store_to_memory(control(), a, c, T_DOUBLE, TypeAryPtr::DOUBLES, MemNode::unordered);
1750     break;
1751   }
1752   case Bytecodes::_getfield:
1753     do_getfield();
1754     break;
1755 
1756   case Bytecodes::_getstatic:
1757     do_getstatic();
1758     break;
1759 
1760   case Bytecodes::_putfield:
1761     do_putfield();
1762     break;
1763 
1764   case Bytecodes::_putstatic:
1765     do_putstatic();
1766     break;
1767 
1768   case Bytecodes::_irem:
1769     do_irem();
1770     break;
1771   case Bytecodes::_idiv:
1772     // Must keep both values on the expression-stack during null-check
1773     zero_check_int(peek());
1774     // Compile-time detect of null-exception?
1775     if (stopped())  return;
1776     b = pop();
1777     a = pop();
1778     push( _gvn.transform( new (C) DivINode(control(),a,b) ) );
1779     break;
1780   case Bytecodes::_imul:
1781     b = pop(); a = pop();
1782     push( _gvn.transform( new (C) MulINode(a,b) ) );
1783     break;
1784   case Bytecodes::_iadd:
1785     b = pop(); a = pop();
1786     push( _gvn.transform( new (C) AddINode(a,b) ) );
1787     break;
1788   case Bytecodes::_ineg:
1789     a = pop();
1790     push( _gvn.transform( new (C) SubINode(_gvn.intcon(0),a)) );
1791     break;
1792   case Bytecodes::_isub:
1793     b = pop(); a = pop();
1794     push( _gvn.transform( new (C) SubINode(a,b) ) );
1795     break;
1796   case Bytecodes::_iand:
1797     b = pop(); a = pop();
1798     push( _gvn.transform( new (C) AndINode(a,b) ) );
1799     break;
1800   case Bytecodes::_ior:
1801     b = pop(); a = pop();
1802     push( _gvn.transform( new (C) OrINode(a,b) ) );
1803     break;
1804   case Bytecodes::_ixor:
1805     b = pop(); a = pop();
1806     push( _gvn.transform( new (C) XorINode(a,b) ) );
1807     break;
1808   case Bytecodes::_ishl:
1809     b = pop(); a = pop();
1810     push( _gvn.transform( new (C) LShiftINode(a,b) ) );
1811     break;
1812   case Bytecodes::_ishr:
1813     b = pop(); a = pop();
1814     push( _gvn.transform( new (C) RShiftINode(a,b) ) );
1815     break;
1816   case Bytecodes::_iushr:
1817     b = pop(); a = pop();
1818     push( _gvn.transform( new (C) URShiftINode(a,b) ) );
1819     break;
1820 
1821   case Bytecodes::_fneg:
1822     a = pop();
1823     b = _gvn.transform(new (C) NegFNode (a));
1824     push(b);
1825     break;
1826 
1827   case Bytecodes::_fsub:
1828     b = pop();
1829     a = pop();
1830     c = _gvn.transform( new (C) SubFNode(a,b) );
1831     d = precision_rounding(c);
1832     push( d );
1833     break;
1834 
1835   case Bytecodes::_fadd:
1836     b = pop();
1837     a = pop();
1838     c = _gvn.transform( new (C) AddFNode(a,b) );
1839     d = precision_rounding(c);
1840     push( d );
1841     break;
1842 
1843   case Bytecodes::_fmul:
1844     b = pop();
1845     a = pop();
1846     c = _gvn.transform( new (C) MulFNode(a,b) );
1847     d = precision_rounding(c);
1848     push( d );
1849     break;
1850 
1851   case Bytecodes::_fdiv:
1852     b = pop();
1853     a = pop();
1854     c = _gvn.transform( new (C) DivFNode(0,a,b) );
1855     d = precision_rounding(c);
1856     push( d );
1857     break;
1858 
1859   case Bytecodes::_frem:
1860     if (Matcher::has_match_rule(Op_ModF)) {
1861       // Generate a ModF node.
1862       b = pop();
1863       a = pop();
1864       c = _gvn.transform( new (C) ModFNode(0,a,b) );
1865       d = precision_rounding(c);
1866       push( d );
1867     }
1868     else {
1869       // Generate a call.
1870       modf();
1871     }
1872     break;
1873 
1874   case Bytecodes::_fcmpl:
1875     b = pop();
1876     a = pop();
1877     c = _gvn.transform( new (C) CmpF3Node( a, b));
1878     push(c);
1879     break;
1880   case Bytecodes::_fcmpg:
1881     b = pop();
1882     a = pop();
1883 
1884     // Same as fcmpl but need to flip the unordered case.  Swap the inputs,
1885     // which negates the result sign except for unordered.  Flip the unordered
1886     // as well by using CmpF3 which implements unordered-lesser instead of
1887     // unordered-greater semantics.  Finally, commute the result bits.  Result
1888     // is same as using a CmpF3Greater except we did it with CmpF3 alone.
1889     c = _gvn.transform( new (C) CmpF3Node( b, a));
1890     c = _gvn.transform( new (C) SubINode(_gvn.intcon(0),c) );
1891     push(c);
1892     break;
1893 
1894   case Bytecodes::_f2i:
1895     a = pop();
1896     push(_gvn.transform(new (C) ConvF2INode(a)));
1897     break;
1898 
1899   case Bytecodes::_d2i:
1900     a = pop_pair();
1901     b = _gvn.transform(new (C) ConvD2INode(a));
1902     push( b );
1903     break;
1904 
1905   case Bytecodes::_f2d:
1906     a = pop();
1907     b = _gvn.transform( new (C) ConvF2DNode(a));
1908     push_pair( b );
1909     break;
1910 
1911   case Bytecodes::_d2f:
1912     a = pop_pair();
1913     b = _gvn.transform( new (C) ConvD2FNode(a));
1914     // This breaks _227_mtrt (speed & correctness) and _222_mpegaudio (speed)
1915     //b = _gvn.transform(new (C) RoundFloatNode(0, b) );
1916     push( b );
1917     break;
1918 
1919   case Bytecodes::_l2f:
1920     if (Matcher::convL2FSupported()) {
1921       a = pop_pair();
1922       b = _gvn.transform( new (C) ConvL2FNode(a));
1923       // For i486.ad, FILD doesn't restrict precision to 24 or 53 bits.
1924       // Rather than storing the result into an FP register then pushing
1925       // out to memory to round, the machine instruction that implements
1926       // ConvL2D is responsible for rounding.
1927       // c = precision_rounding(b);
1928       c = _gvn.transform(b);
1929       push(c);
1930     } else {
1931       l2f();
1932     }
1933     break;
1934 
1935   case Bytecodes::_l2d:
1936     a = pop_pair();
1937     b = _gvn.transform( new (C) ConvL2DNode(a));
1938     // For i486.ad, rounding is always necessary (see _l2f above).
1939     // c = dprecision_rounding(b);
1940     c = _gvn.transform(b);
1941     push_pair(c);
1942     break;
1943 
1944   case Bytecodes::_f2l:
1945     a = pop();
1946     b = _gvn.transform( new (C) ConvF2LNode(a));
1947     push_pair(b);
1948     break;
1949 
1950   case Bytecodes::_d2l:
1951     a = pop_pair();
1952     b = _gvn.transform( new (C) ConvD2LNode(a));
1953     push_pair(b);
1954     break;
1955 
1956   case Bytecodes::_dsub:
1957     b = pop_pair();
1958     a = pop_pair();
1959     c = _gvn.transform( new (C) SubDNode(a,b) );
1960     d = dprecision_rounding(c);
1961     push_pair( d );
1962     break;
1963 
1964   case Bytecodes::_dadd:
1965     b = pop_pair();
1966     a = pop_pair();
1967     c = _gvn.transform( new (C) AddDNode(a,b) );
1968     d = dprecision_rounding(c);
1969     push_pair( d );
1970     break;
1971 
1972   case Bytecodes::_dmul:
1973     b = pop_pair();
1974     a = pop_pair();
1975     c = _gvn.transform( new (C) MulDNode(a,b) );
1976     d = dprecision_rounding(c);
1977     push_pair( d );
1978     break;
1979 
1980   case Bytecodes::_ddiv:
1981     b = pop_pair();
1982     a = pop_pair();
1983     c = _gvn.transform( new (C) DivDNode(0,a,b) );
1984     d = dprecision_rounding(c);
1985     push_pair( d );
1986     break;
1987 
1988   case Bytecodes::_dneg:
1989     a = pop_pair();
1990     b = _gvn.transform(new (C) NegDNode (a));
1991     push_pair(b);
1992     break;
1993 
1994   case Bytecodes::_drem:
1995     if (Matcher::has_match_rule(Op_ModD)) {
1996       // Generate a ModD node.
1997       b = pop_pair();
1998       a = pop_pair();
1999       // a % b
2000 
2001       c = _gvn.transform( new (C) ModDNode(0,a,b) );
2002       d = dprecision_rounding(c);
2003       push_pair( d );
2004     }
2005     else {
2006       // Generate a call.
2007       modd();
2008     }
2009     break;
2010 
2011   case Bytecodes::_dcmpl:
2012     b = pop_pair();
2013     a = pop_pair();
2014     c = _gvn.transform( new (C) CmpD3Node( a, b));
2015     push(c);
2016     break;
2017 
2018   case Bytecodes::_dcmpg:
2019     b = pop_pair();
2020     a = pop_pair();
2021     // Same as dcmpl but need to flip the unordered case.
2022     // Commute the inputs, which negates the result sign except for unordered.
2023     // Flip the unordered as well by using CmpD3 which implements
2024     // unordered-lesser instead of unordered-greater semantics.
2025     // Finally, negate the result bits.  Result is same as using a
2026     // CmpD3Greater except we did it with CmpD3 alone.
2027     c = _gvn.transform( new (C) CmpD3Node( b, a));
2028     c = _gvn.transform( new (C) SubINode(_gvn.intcon(0),c) );
2029     push(c);
2030     break;
2031 
2032 
2033     // Note for longs -> lo word is on TOS, hi word is on TOS - 1
2034   case Bytecodes::_land:
2035     b = pop_pair();
2036     a = pop_pair();
2037     c = _gvn.transform( new (C) AndLNode(a,b) );
2038     push_pair(c);
2039     break;
2040   case Bytecodes::_lor:
2041     b = pop_pair();
2042     a = pop_pair();
2043     c = _gvn.transform( new (C) OrLNode(a,b) );
2044     push_pair(c);
2045     break;
2046   case Bytecodes::_lxor:
2047     b = pop_pair();
2048     a = pop_pair();
2049     c = _gvn.transform( new (C) XorLNode(a,b) );
2050     push_pair(c);
2051     break;
2052 
2053   case Bytecodes::_lshl:
2054     b = pop();                  // the shift count
2055     a = pop_pair();             // value to be shifted
2056     c = _gvn.transform( new (C) LShiftLNode(a,b) );
2057     push_pair(c);
2058     break;
2059   case Bytecodes::_lshr:
2060     b = pop();                  // the shift count
2061     a = pop_pair();             // value to be shifted
2062     c = _gvn.transform( new (C) RShiftLNode(a,b) );
2063     push_pair(c);
2064     break;
2065   case Bytecodes::_lushr:
2066     b = pop();                  // the shift count
2067     a = pop_pair();             // value to be shifted
2068     c = _gvn.transform( new (C) URShiftLNode(a,b) );
2069     push_pair(c);
2070     break;
2071   case Bytecodes::_lmul:
2072     b = pop_pair();
2073     a = pop_pair();
2074     c = _gvn.transform( new (C) MulLNode(a,b) );
2075     push_pair(c);
2076     break;
2077 
2078   case Bytecodes::_lrem:
2079     // Must keep both values on the expression-stack during null-check
2080     assert(peek(0) == top(), "long word order");
2081     zero_check_long(peek(1));
2082     // Compile-time detect of null-exception?
2083     if (stopped())  return;
2084     b = pop_pair();
2085     a = pop_pair();
2086     c = _gvn.transform( new (C) ModLNode(control(),a,b) );
2087     push_pair(c);
2088     break;
2089 
2090   case Bytecodes::_ldiv:
2091     // Must keep both values on the expression-stack during null-check
2092     assert(peek(0) == top(), "long word order");
2093     zero_check_long(peek(1));
2094     // Compile-time detect of null-exception?
2095     if (stopped())  return;
2096     b = pop_pair();
2097     a = pop_pair();
2098     c = _gvn.transform( new (C) DivLNode(control(),a,b) );
2099     push_pair(c);
2100     break;
2101 
2102   case Bytecodes::_ladd:
2103     b = pop_pair();
2104     a = pop_pair();
2105     c = _gvn.transform( new (C) AddLNode(a,b) );
2106     push_pair(c);
2107     break;
2108   case Bytecodes::_lsub:
2109     b = pop_pair();
2110     a = pop_pair();
2111     c = _gvn.transform( new (C) SubLNode(a,b) );
2112     push_pair(c);
2113     break;
2114   case Bytecodes::_lcmp:
2115     // Safepoints are now inserted _before_ branches.  The long-compare
2116     // bytecode painfully produces a 3-way value (-1,0,+1) which requires a
2117     // slew of control flow.  These are usually followed by a CmpI vs zero and
2118     // a branch; this pattern then optimizes to the obvious long-compare and
2119     // branch.  However, if the branch is backwards there's a Safepoint
2120     // inserted.  The inserted Safepoint captures the JVM state at the
2121     // pre-branch point, i.e. it captures the 3-way value.  Thus if a
2122     // long-compare is used to control a loop the debug info will force
2123     // computation of the 3-way value, even though the generated code uses a
2124     // long-compare and branch.  We try to rectify the situation by inserting
2125     // a SafePoint here and have it dominate and kill the safepoint added at a
2126     // following backwards branch.  At this point the JVM state merely holds 2
2127     // longs but not the 3-way value.
2128     if( UseLoopSafepoints ) {
2129       switch( iter().next_bc() ) {
2130       case Bytecodes::_ifgt:
2131       case Bytecodes::_iflt:
2132       case Bytecodes::_ifge:
2133       case Bytecodes::_ifle:
2134       case Bytecodes::_ifne:
2135       case Bytecodes::_ifeq:
2136         // If this is a backwards branch in the bytecodes, add Safepoint
2137         maybe_add_safepoint(iter().next_get_dest());
2138       }
2139     }
2140     b = pop_pair();
2141     a = pop_pair();
2142     c = _gvn.transform( new (C) CmpL3Node( a, b ));
2143     push(c);
2144     break;
2145 
2146   case Bytecodes::_lneg:
2147     a = pop_pair();
2148     b = _gvn.transform( new (C) SubLNode(longcon(0),a));
2149     push_pair(b);
2150     break;
2151   case Bytecodes::_l2i:
2152     a = pop_pair();
2153     push( _gvn.transform( new (C) ConvL2INode(a)));
2154     break;
2155   case Bytecodes::_i2l:
2156     a = pop();
2157     b = _gvn.transform( new (C) ConvI2LNode(a));
2158     push_pair(b);
2159     break;
2160   case Bytecodes::_i2b:
2161     // Sign extend
2162     a = pop();
2163     a = _gvn.transform( new (C) LShiftINode(a,_gvn.intcon(24)) );
2164     a = _gvn.transform( new (C) RShiftINode(a,_gvn.intcon(24)) );
2165     push( a );
2166     break;
2167   case Bytecodes::_i2s:
2168     a = pop();
2169     a = _gvn.transform( new (C) LShiftINode(a,_gvn.intcon(16)) );
2170     a = _gvn.transform( new (C) RShiftINode(a,_gvn.intcon(16)) );
2171     push( a );
2172     break;
2173   case Bytecodes::_i2c:
2174     a = pop();
2175     push( _gvn.transform( new (C) AndINode(a,_gvn.intcon(0xFFFF)) ) );
2176     break;
2177 
2178   case Bytecodes::_i2f:
2179     a = pop();
2180     b = _gvn.transform( new (C) ConvI2FNode(a) ) ;
2181     c = precision_rounding(b);
2182     push (b);
2183     break;
2184 
2185   case Bytecodes::_i2d:
2186     a = pop();
2187     b = _gvn.transform( new (C) ConvI2DNode(a));
2188     push_pair(b);
2189     break;
2190 
2191   case Bytecodes::_iinc:        // Increment local
2192     i = iter().get_index();     // Get local index
2193     set_local( i, _gvn.transform( new (C) AddINode( _gvn.intcon(iter().get_iinc_con()), local(i) ) ) );
2194     break;
2195 
2196   // Exit points of synchronized methods must have an unlock node
2197   case Bytecodes::_return:
2198     return_current(NULL);
2199     break;
2200 
2201   case Bytecodes::_ireturn:
2202   case Bytecodes::_areturn:
2203   case Bytecodes::_freturn:
2204     return_current(pop());
2205     break;
2206   case Bytecodes::_lreturn:
2207     return_current(pop_pair());
2208     break;
2209   case Bytecodes::_dreturn:
2210     return_current(pop_pair());
2211     break;
2212 
2213   case Bytecodes::_athrow:
2214     // null exception oop throws NULL pointer exception
2215     null_check(peek());
2216     if (stopped())  return;
2217     // Hook the thrown exception directly to subsequent handlers.
2218     if (BailoutToInterpreterForThrows) {
2219       // Keep method interpreted from now on.
2220       uncommon_trap(Deoptimization::Reason_unhandled,
2221                     Deoptimization::Action_make_not_compilable);
2222       return;
2223     }
2224     if (env()->jvmti_can_post_on_exceptions()) {
2225       // check if we must post exception events, take uncommon trap if so (with must_throw = false)
2226       uncommon_trap_if_should_post_on_exceptions(Deoptimization::Reason_unhandled, false);
2227     }
2228     // Here if either can_post_on_exceptions or should_post_on_exceptions is false
2229     add_exception_state(make_exception_state(peek()));
2230     break;
2231 
2232   case Bytecodes::_goto:   // fall through
2233   case Bytecodes::_goto_w: {
2234     int target_bci = (bc() == Bytecodes::_goto) ? iter().get_dest() : iter().get_far_dest();
2235 
2236     // If this is a backwards branch in the bytecodes, add Safepoint
2237     maybe_add_safepoint(target_bci);
2238 
2239     // Update method data
2240     profile_taken_branch(target_bci);
2241 
2242     // Merge the current control into the target basic block
2243     merge(target_bci);
2244 
2245     // See if we can get some profile data and hand it off to the next block
2246     Block *target_block = block()->successor_for_bci(target_bci);
2247     if (target_block->pred_count() != 1)  break;
2248     ciMethodData* methodData = method()->method_data();
2249     if (!methodData->is_mature())  break;
2250     ciProfileData* data = methodData->bci_to_data(bci());
2251     assert( data->is_JumpData(), "" );
2252     int taken = ((ciJumpData*)data)->taken();
2253     taken = method()->scale_count(taken);
2254     target_block->set_count(taken);
2255     break;
2256   }
2257 
2258   case Bytecodes::_ifnull:    btest = BoolTest::eq; goto handle_if_null;
2259   case Bytecodes::_ifnonnull: btest = BoolTest::ne; goto handle_if_null;
2260   handle_if_null:
2261     // If this is a backwards branch in the bytecodes, add Safepoint
2262     maybe_add_safepoint(iter().get_dest());
2263     a = null();
2264     b = pop();
2265     c = _gvn.transform( new (C) CmpPNode(b, a) );
2266     do_ifnull(btest, c);
2267     break;
2268 
2269   case Bytecodes::_if_acmpeq: btest = BoolTest::eq; goto handle_if_acmp;
2270   case Bytecodes::_if_acmpne: btest = BoolTest::ne; goto handle_if_acmp;
2271   handle_if_acmp:
2272     // If this is a backwards branch in the bytecodes, add Safepoint
2273     maybe_add_safepoint(iter().get_dest());
2274     a = pop();
2275     b = pop();
2276     c = _gvn.transform( new (C) CmpPNode(b, a) );
2277     c = optimize_cmp_with_klass(c);
2278     do_if(btest, c);
2279     break;
2280 
2281   case Bytecodes::_ifeq: btest = BoolTest::eq; goto handle_ifxx;
2282   case Bytecodes::_ifne: btest = BoolTest::ne; goto handle_ifxx;
2283   case Bytecodes::_iflt: btest = BoolTest::lt; goto handle_ifxx;
2284   case Bytecodes::_ifle: btest = BoolTest::le; goto handle_ifxx;
2285   case Bytecodes::_ifgt: btest = BoolTest::gt; goto handle_ifxx;
2286   case Bytecodes::_ifge: btest = BoolTest::ge; goto handle_ifxx;
2287   handle_ifxx:
2288     // If this is a backwards branch in the bytecodes, add Safepoint
2289     maybe_add_safepoint(iter().get_dest());
2290     a = _gvn.intcon(0);
2291     b = pop();
2292     c = _gvn.transform( new (C) CmpINode(b, a) );
2293     do_if(btest, c);
2294     break;
2295 
2296   case Bytecodes::_if_icmpeq: btest = BoolTest::eq; goto handle_if_icmp;
2297   case Bytecodes::_if_icmpne: btest = BoolTest::ne; goto handle_if_icmp;
2298   case Bytecodes::_if_icmplt: btest = BoolTest::lt; goto handle_if_icmp;
2299   case Bytecodes::_if_icmple: btest = BoolTest::le; goto handle_if_icmp;
2300   case Bytecodes::_if_icmpgt: btest = BoolTest::gt; goto handle_if_icmp;
2301   case Bytecodes::_if_icmpge: btest = BoolTest::ge; goto handle_if_icmp;
2302   handle_if_icmp:
2303     // If this is a backwards branch in the bytecodes, add Safepoint
2304     maybe_add_safepoint(iter().get_dest());
2305     a = pop();
2306     b = pop();
2307     c = _gvn.transform( new (C) CmpINode( b, a ) );
2308     do_if(btest, c);
2309     break;
2310 
2311   case Bytecodes::_tableswitch:
2312     do_tableswitch();
2313     break;
2314 
2315   case Bytecodes::_lookupswitch:
2316     do_lookupswitch();
2317     break;
2318 
2319   case Bytecodes::_invokestatic:
2320   case Bytecodes::_invokedynamic:
2321   case Bytecodes::_invokespecial:
2322   case Bytecodes::_invokevirtual:
2323   case Bytecodes::_invokeinterface:
2324     do_call();
2325     break;
2326   case Bytecodes::_checkcast:
2327     do_checkcast();
2328     break;
2329   case Bytecodes::_instanceof:
2330     do_instanceof();
2331     break;
2332   case Bytecodes::_anewarray:
2333     do_anewarray();
2334     break;
2335   case Bytecodes::_newarray:
2336     do_newarray((BasicType)iter().get_index());
2337     break;
2338   case Bytecodes::_multianewarray:
2339     do_multianewarray();
2340     break;
2341   case Bytecodes::_new:
2342     do_new();
2343     break;
2344 
2345   case Bytecodes::_jsr:
2346   case Bytecodes::_jsr_w:
2347     do_jsr();
2348     break;
2349 
2350   case Bytecodes::_ret:
2351     do_ret();
2352     break;
2353 
2354 
2355   case Bytecodes::_monitorenter:
2356     do_monitor_enter();
2357     break;
2358 
2359   case Bytecodes::_monitorexit:
2360     do_monitor_exit();
2361     break;
2362 
2363   case Bytecodes::_breakpoint:
2364     // Breakpoint set concurrently to compile
2365     // %%% use an uncommon trap?
2366     C->record_failure("breakpoint in method");
2367     return;
2368 
2369   default:
2370 #ifndef PRODUCT
2371     map()->dump(99);
2372 #endif
2373     tty->print("\nUnhandled bytecode %s\n", Bytecodes::name(bc()) );
2374     ShouldNotReachHere();
2375   }
2376 
2377 #ifndef PRODUCT
2378   IdealGraphPrinter *printer = IdealGraphPrinter::printer();
2379   if(printer) {
2380     char buffer[256];
2381     sprintf(buffer, "Bytecode %d: %s", bci(), Bytecodes::name(bc()));
2382     bool old = printer->traverse_outs();
2383     printer->set_traverse_outs(true);
2384     printer->print_method(C, buffer, 4);
2385     printer->set_traverse_outs(old);
2386   }
2387 #endif
2388 }