1 /*
   2  * Copyright 1998-2009 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  20  * CA 95054 USA or visit www.sun.com if you need additional information or
  21  * have any questions.
  22  *
  23  */
  24 
  25 #include "incls/_precompiled.incl"
  26 #include "incls/_parse2.cpp.incl"
  27 
  28 extern int explicit_null_checks_inserted,
  29            explicit_null_checks_elided;
  30 
  31 //---------------------------------array_load----------------------------------
  32 void Parse::array_load(BasicType elem_type) {
  33   const Type* elem = Type::TOP;
  34   Node* adr = array_addressing(elem_type, 0, &elem);
  35   if (stopped())  return;     // guaranteed null or range check
  36   _sp -= 2;                   // Pop array and index
  37   const TypeAryPtr* adr_type = TypeAryPtr::get_array_body_type(elem_type);
  38   Node* ld = make_load(control(), adr, elem, elem_type, adr_type);
  39   push(ld);
  40 }
  41 
  42 
  43 //--------------------------------array_store----------------------------------
  44 void Parse::array_store(BasicType elem_type) {
  45   Node* adr = array_addressing(elem_type, 1);
  46   if (stopped())  return;     // guaranteed null or range check
  47   Node* val = pop();
  48   _sp -= 2;                   // Pop array and index
  49   const TypeAryPtr* adr_type = TypeAryPtr::get_array_body_type(elem_type);
  50   store_to_memory(control(), adr, val, elem_type, adr_type);
  51 }
  52 
  53 
  54 //------------------------------array_addressing-------------------------------
  55 // Pull array and index from the stack.  Compute pointer-to-element.
  56 Node* Parse::array_addressing(BasicType type, int vals, const Type* *result2) {
  57   Node *idx   = peek(0+vals);   // Get from stack without popping
  58   Node *ary   = peek(1+vals);   // in case of exception
  59 
  60   // Null check the array base, with correct stack contents
  61   ary = do_null_check(ary, T_ARRAY);
  62   // Compile-time detect of null-exception?
  63   if (stopped())  return top();
  64 
  65   const TypeAryPtr* arytype  = _gvn.type(ary)->is_aryptr();
  66   const TypeInt*    sizetype = arytype->size();
  67   const Type*       elemtype = arytype->elem();
  68 
  69   if (UseUniqueSubclasses && result2 != NULL) {
  70     const Type* el = elemtype->make_ptr();
  71     if (el && el->isa_instptr()) {
  72       const TypeInstPtr* toop = el->is_instptr();
  73       if (toop->klass()->as_instance_klass()->unique_concrete_subklass()) {
  74         // If we load from "AbstractClass[]" we must see "ConcreteSubClass".
  75         const Type* subklass = Type::get_const_type(toop->klass());
  76         elemtype = subklass->join(el);
  77       }
  78     }
  79   }
  80 
  81   // Check for big class initializers with all constant offsets
  82   // feeding into a known-size array.
  83   const TypeInt* idxtype = _gvn.type(idx)->is_int();
  84   // See if the highest idx value is less than the lowest array bound,
  85   // and if the idx value cannot be negative:
  86   bool need_range_check = true;
  87   if (idxtype->_hi < sizetype->_lo && idxtype->_lo >= 0) {
  88     need_range_check = false;
  89     if (C->log() != NULL)   C->log()->elem("observe that='!need_range_check'");
  90   }
  91 
  92   if (!arytype->klass()->is_loaded()) {
  93     // Only fails for some -Xcomp runs
  94     // The class is unloaded.  We have to run this bytecode in the interpreter.
  95     uncommon_trap(Deoptimization::Reason_unloaded,
  96                   Deoptimization::Action_reinterpret,
  97                   arytype->klass(), "!loaded array");
  98     return top();
  99   }
 100 
 101   // Do the range check
 102   if (GenerateRangeChecks && need_range_check) {
 103     Node* tst;
 104     if (sizetype->_hi <= 0) {
 105       // The greatest array bound is negative, so we can conclude that we're
 106       // compiling unreachable code, but the unsigned compare trick used below
 107       // only works with non-negative lengths.  Instead, hack "tst" to be zero so
 108       // the uncommon_trap path will always be taken.
 109       tst = _gvn.intcon(0);
 110     } else {
 111       // Range is constant in array-oop, so we can use the original state of mem
 112       Node* len = load_array_length(ary);
 113 
 114       // Test length vs index (standard trick using unsigned compare)
 115       Node* chk = _gvn.transform( new (C, 3) CmpUNode(idx, len) );
 116       BoolTest::mask btest = BoolTest::lt;
 117       tst = _gvn.transform( new (C, 2) BoolNode(chk, btest) );
 118     }
 119     // Branch to failure if out of bounds
 120     { BuildCutout unless(this, tst, PROB_MAX);
 121       if (C->allow_range_check_smearing()) {
 122         // Do not use builtin_throw, since range checks are sometimes
 123         // made more stringent by an optimistic transformation.
 124         // This creates "tentative" range checks at this point,
 125         // which are not guaranteed to throw exceptions.
 126         // See IfNode::Ideal, is_range_check, adjust_check.
 127         uncommon_trap(Deoptimization::Reason_range_check,
 128                       Deoptimization::Action_make_not_entrant,
 129                       NULL, "range_check");
 130       } else {
 131         // If we have already recompiled with the range-check-widening
 132         // heroic optimization turned off, then we must really be throwing
 133         // range check exceptions.
 134         builtin_throw(Deoptimization::Reason_range_check, idx);
 135       }
 136     }
 137   }
 138   // Check for always knowing you are throwing a range-check exception
 139   if (stopped())  return top();
 140 
 141   Node* ptr = array_element_address(ary, idx, type, sizetype);
 142 
 143   if (result2 != NULL)  *result2 = elemtype;
 144 
 145   assert(ptr != top(), "top should go hand-in-hand with stopped");
 146 
 147   return ptr;
 148 }
 149 
 150 
 151 // returns IfNode
 152 IfNode* Parse::jump_if_fork_int(Node* a, Node* b, BoolTest::mask mask) {
 153   Node   *cmp = _gvn.transform( new (C, 3) CmpINode( a, b)); // two cases: shiftcount > 32 and shiftcount <= 32
 154   Node   *tst = _gvn.transform( new (C, 2) BoolNode( cmp, mask));
 155   IfNode *iff = create_and_map_if( control(), tst, ((mask == BoolTest::eq) ? PROB_STATIC_INFREQUENT : PROB_FAIR), COUNT_UNKNOWN );
 156   return iff;
 157 }
 158 
 159 // return Region node
 160 Node* Parse::jump_if_join(Node* iffalse, Node* iftrue) {
 161   Node *region  = new (C, 3) RegionNode(3); // 2 results
 162   record_for_igvn(region);
 163   region->init_req(1, iffalse);
 164   region->init_req(2, iftrue );
 165   _gvn.set_type(region, Type::CONTROL);
 166   region = _gvn.transform(region);
 167   set_control (region);
 168   return region;
 169 }
 170 
 171 
 172 //------------------------------helper for tableswitch-------------------------
 173 void Parse::jump_if_true_fork(IfNode *iff, int dest_bci_if_true, int prof_table_index) {
 174   // True branch, use existing map info
 175   { PreserveJVMState pjvms(this);
 176     Node *iftrue  = _gvn.transform( new (C, 1) IfTrueNode (iff) );
 177     set_control( iftrue );
 178     profile_switch_case(prof_table_index);
 179     merge_new_path(dest_bci_if_true);
 180   }
 181 
 182   // False branch
 183   Node *iffalse = _gvn.transform( new (C, 1) IfFalseNode(iff) );
 184   set_control( iffalse );
 185 }
 186 
 187 void Parse::jump_if_false_fork(IfNode *iff, int dest_bci_if_true, int prof_table_index) {
 188   // True branch, use existing map info
 189   { PreserveJVMState pjvms(this);
 190     Node *iffalse  = _gvn.transform( new (C, 1) IfFalseNode (iff) );
 191     set_control( iffalse );
 192     profile_switch_case(prof_table_index);
 193     merge_new_path(dest_bci_if_true);
 194   }
 195 
 196   // False branch
 197   Node *iftrue = _gvn.transform( new (C, 1) IfTrueNode(iff) );
 198   set_control( iftrue );
 199 }
 200 
 201 void Parse::jump_if_always_fork(int dest_bci, int prof_table_index) {
 202   // False branch, use existing map and control()
 203   profile_switch_case(prof_table_index);
 204   merge_new_path(dest_bci);
 205 }
 206 
 207 
 208 extern "C" {
 209   static int jint_cmp(const void *i, const void *j) {
 210     int a = *(jint *)i;
 211     int b = *(jint *)j;
 212     return a > b ? 1 : a < b ? -1 : 0;
 213   }
 214 }
 215 
 216 
 217 // Default value for methodData switch indexing. Must be a negative value to avoid
 218 // conflict with any legal switch index.
 219 #define NullTableIndex -1
 220 
 221 class SwitchRange : public StackObj {
 222   // a range of integers coupled with a bci destination
 223   jint _lo;                     // inclusive lower limit
 224   jint _hi;                     // inclusive upper limit
 225   int _dest;
 226   int _table_index;             // index into method data table
 227 
 228 public:
 229   jint lo() const              { return _lo;   }
 230   jint hi() const              { return _hi;   }
 231   int  dest() const            { return _dest; }
 232   int  table_index() const     { return _table_index; }
 233   bool is_singleton() const    { return _lo == _hi; }
 234 
 235   void setRange(jint lo, jint hi, int dest, int table_index) {
 236     assert(lo <= hi, "must be a non-empty range");
 237     _lo = lo, _hi = hi; _dest = dest; _table_index = table_index;
 238   }
 239   bool adjoinRange(jint lo, jint hi, int dest, int table_index) {
 240     assert(lo <= hi, "must be a non-empty range");
 241     if (lo == _hi+1 && dest == _dest && table_index == _table_index) {
 242       _hi = hi;
 243       return true;
 244     }
 245     return false;
 246   }
 247 
 248   void set (jint value, int dest, int table_index) {
 249     setRange(value, value, dest, table_index);
 250   }
 251   bool adjoin(jint value, int dest, int table_index) {
 252     return adjoinRange(value, value, dest, table_index);
 253   }
 254 
 255   void print(ciEnv* env) {
 256     if (is_singleton())
 257       tty->print(" {%d}=>%d", lo(), dest());
 258     else if (lo() == min_jint)
 259       tty->print(" {..%d}=>%d", hi(), dest());
 260     else if (hi() == max_jint)
 261       tty->print(" {%d..}=>%d", lo(), dest());
 262     else
 263       tty->print(" {%d..%d}=>%d", lo(), hi(), dest());
 264   }
 265 };
 266 
 267 
 268 //-------------------------------do_tableswitch--------------------------------
 269 void Parse::do_tableswitch() {
 270   Node* lookup = pop();
 271 
 272   // Get information about tableswitch
 273   int default_dest = iter().get_dest_table(0);
 274   int lo_index     = iter().get_int_table(1);
 275   int hi_index     = iter().get_int_table(2);
 276   int len          = hi_index - lo_index + 1;
 277 
 278   if (len < 1) {
 279     // If this is a backward branch, add safepoint
 280     maybe_add_safepoint(default_dest);
 281     merge(default_dest);
 282     return;
 283   }
 284 
 285   // generate decision tree, using trichotomy when possible
 286   int rnum = len+2;
 287   bool makes_backward_branch = false;
 288   SwitchRange* ranges = NEW_RESOURCE_ARRAY(SwitchRange, rnum);
 289   int rp = -1;
 290   if (lo_index != min_jint) {
 291     ranges[++rp].setRange(min_jint, lo_index-1, default_dest, NullTableIndex);
 292   }
 293   for (int j = 0; j < len; j++) {
 294     jint match_int = lo_index+j;
 295     int  dest      = iter().get_dest_table(j+3);
 296     makes_backward_branch |= (dest <= bci());
 297     int  table_index = method_data_update() ? j : NullTableIndex;
 298     if (rp < 0 || !ranges[rp].adjoin(match_int, dest, table_index)) {
 299       ranges[++rp].set(match_int, dest, table_index);
 300     }
 301   }
 302   jint highest = lo_index+(len-1);
 303   assert(ranges[rp].hi() == highest, "");
 304   if (highest != max_jint
 305       && !ranges[rp].adjoinRange(highest+1, max_jint, default_dest, NullTableIndex)) {
 306     ranges[++rp].setRange(highest+1, max_jint, default_dest, NullTableIndex);
 307   }
 308   assert(rp < len+2, "not too many ranges");
 309 
 310   // Safepoint in case if backward branch observed
 311   if( makes_backward_branch && UseLoopSafepoints )
 312     add_safepoint();
 313 
 314   jump_switch_ranges(lookup, &ranges[0], &ranges[rp]);
 315 }
 316 
 317 
 318 //------------------------------do_lookupswitch--------------------------------
 319 void Parse::do_lookupswitch() {
 320   Node *lookup = pop();         // lookup value
 321   // Get information about lookupswitch
 322   int default_dest = iter().get_dest_table(0);
 323   int len          = iter().get_int_table(1);
 324 
 325   if (len < 1) {    // If this is a backward branch, add safepoint
 326     maybe_add_safepoint(default_dest);
 327     merge(default_dest);
 328     return;
 329   }
 330 
 331   // generate decision tree, using trichotomy when possible
 332   jint* table = NEW_RESOURCE_ARRAY(jint, len*2);
 333   {
 334     for( int j = 0; j < len; j++ ) {
 335       table[j+j+0] = iter().get_int_table(2+j+j);
 336       table[j+j+1] = iter().get_dest_table(2+j+j+1);
 337     }
 338     qsort( table, len, 2*sizeof(table[0]), jint_cmp );
 339   }
 340 
 341   int rnum = len*2+1;
 342   bool makes_backward_branch = false;
 343   SwitchRange* ranges = NEW_RESOURCE_ARRAY(SwitchRange, rnum);
 344   int rp = -1;
 345   for( int j = 0; j < len; j++ ) {
 346     jint match_int   = table[j+j+0];
 347     int  dest        = table[j+j+1];
 348     int  next_lo     = rp < 0 ? min_jint : ranges[rp].hi()+1;
 349     int  table_index = method_data_update() ? j : NullTableIndex;
 350     makes_backward_branch |= (dest <= bci());
 351     if( match_int != next_lo ) {
 352       ranges[++rp].setRange(next_lo, match_int-1, default_dest, NullTableIndex);
 353     }
 354     if( rp < 0 || !ranges[rp].adjoin(match_int, dest, table_index) ) {
 355       ranges[++rp].set(match_int, dest, table_index);
 356     }
 357   }
 358   jint highest = table[2*(len-1)];
 359   assert(ranges[rp].hi() == highest, "");
 360   if( highest != max_jint
 361       && !ranges[rp].adjoinRange(highest+1, max_jint, default_dest, NullTableIndex) ) {
 362     ranges[++rp].setRange(highest+1, max_jint, default_dest, NullTableIndex);
 363   }
 364   assert(rp < rnum, "not too many ranges");
 365 
 366   // Safepoint in case backward branch observed
 367   if( makes_backward_branch && UseLoopSafepoints )
 368     add_safepoint();
 369 
 370   jump_switch_ranges(lookup, &ranges[0], &ranges[rp]);
 371 }
 372 
 373 //----------------------------create_jump_tables-------------------------------
 374 bool Parse::create_jump_tables(Node* key_val, SwitchRange* lo, SwitchRange* hi) {
 375   // Are jumptables enabled
 376   if (!UseJumpTables)  return false;
 377 
 378   // Are jumptables supported
 379   if (!Matcher::has_match_rule(Op_Jump))  return false;
 380 
 381   // Don't make jump table if profiling
 382   if (method_data_update())  return false;
 383 
 384   // Decide if a guard is needed to lop off big ranges at either (or
 385   // both) end(s) of the input set. We'll call this the default target
 386   // even though we can't be sure that it is the true "default".
 387 
 388   bool needs_guard = false;
 389   int default_dest;
 390   int64 total_outlier_size = 0;
 391   int64 hi_size = ((int64)hi->hi()) - ((int64)hi->lo()) + 1;
 392   int64 lo_size = ((int64)lo->hi()) - ((int64)lo->lo()) + 1;
 393 
 394   if (lo->dest() == hi->dest()) {
 395     total_outlier_size = hi_size + lo_size;
 396     default_dest = lo->dest();
 397   } else if (lo_size > hi_size) {
 398     total_outlier_size = lo_size;
 399     default_dest = lo->dest();
 400   } else {
 401     total_outlier_size = hi_size;
 402     default_dest = hi->dest();
 403   }
 404 
 405   // If a guard test will eliminate very sparse end ranges, then
 406   // it is worth the cost of an extra jump.
 407   if (total_outlier_size > (MaxJumpTableSparseness * 4)) {
 408     needs_guard = true;
 409     if (default_dest == lo->dest()) lo++;
 410     if (default_dest == hi->dest()) hi--;
 411   }
 412 
 413   // Find the total number of cases and ranges
 414   int64 num_cases = ((int64)hi->hi()) - ((int64)lo->lo()) + 1;
 415   int num_range = hi - lo + 1;
 416 
 417   // Don't create table if: too large, too small, or too sparse.
 418   if (num_cases < MinJumpTableSize || num_cases > MaxJumpTableSize)
 419     return false;
 420   if (num_cases > (MaxJumpTableSparseness * num_range))
 421     return false;
 422 
 423   // Normalize table lookups to zero
 424   int lowval = lo->lo();
 425   key_val = _gvn.transform( new (C, 3) SubINode(key_val, _gvn.intcon(lowval)) );
 426 
 427   // Generate a guard to protect against input keyvals that aren't
 428   // in the switch domain.
 429   if (needs_guard) {
 430     Node*   size = _gvn.intcon(num_cases);
 431     Node*   cmp = _gvn.transform( new (C, 3) CmpUNode(key_val, size) );
 432     Node*   tst = _gvn.transform( new (C, 2) BoolNode(cmp, BoolTest::ge) );
 433     IfNode* iff = create_and_map_if( control(), tst, PROB_FAIR, COUNT_UNKNOWN);
 434     jump_if_true_fork(iff, default_dest, NullTableIndex);
 435   }
 436 
 437   // Create an ideal node JumpTable that has projections
 438   // of all possible ranges for a switch statement
 439   // The key_val input must be converted to a pointer offset and scaled.
 440   // Compare Parse::array_addressing above.
 441 #ifdef _LP64
 442   // Clean the 32-bit int into a real 64-bit offset.
 443   // Otherwise, the jint value 0 might turn into an offset of 0x0800000000.
 444   const TypeLong* lkeytype = TypeLong::make(CONST64(0), num_cases-1, Type::WidenMin);
 445   key_val       = _gvn.transform( new (C, 2) ConvI2LNode(key_val, lkeytype) );
 446 #endif
 447   // Shift the value by wordsize so we have an index into the table, rather
 448   // than a switch value
 449   Node *shiftWord = _gvn.MakeConX(wordSize);
 450   key_val = _gvn.transform( new (C, 3) MulXNode( key_val, shiftWord));
 451 
 452   // Create the JumpNode
 453   Node* jtn = _gvn.transform( new (C, 2) JumpNode(control(), key_val, num_cases) );
 454 
 455   // These are the switch destinations hanging off the jumpnode
 456   int i = 0;
 457   for (SwitchRange* r = lo; r <= hi; r++) {
 458     for (int j = r->lo(); j <= r->hi(); j++, i++) {
 459       Node* input = _gvn.transform(new (C, 1) JumpProjNode(jtn, i, r->dest(), j - lowval));
 460       {
 461         PreserveJVMState pjvms(this);
 462         set_control(input);
 463         jump_if_always_fork(r->dest(), r->table_index());
 464       }
 465     }
 466   }
 467   assert(i == num_cases, "miscount of cases");
 468   stop_and_kill_map();  // no more uses for this JVMS
 469   return true;
 470 }
 471 
 472 //----------------------------jump_switch_ranges-------------------------------
 473 void Parse::jump_switch_ranges(Node* key_val, SwitchRange *lo, SwitchRange *hi, int switch_depth) {
 474   Block* switch_block = block();
 475 
 476   if (switch_depth == 0) {
 477     // Do special processing for the top-level call.
 478     assert(lo->lo() == min_jint, "initial range must exhaust Type::INT");
 479     assert(hi->hi() == max_jint, "initial range must exhaust Type::INT");
 480 
 481     // Decrement pred-numbers for the unique set of nodes.
 482 #ifdef ASSERT
 483     // Ensure that the block's successors are a (duplicate-free) set.
 484     int successors_counted = 0;  // block occurrences in [hi..lo]
 485     int unique_successors = switch_block->num_successors();
 486     for (int i = 0; i < unique_successors; i++) {
 487       Block* target = switch_block->successor_at(i);
 488 
 489       // Check that the set of successors is the same in both places.
 490       int successors_found = 0;
 491       for (SwitchRange* p = lo; p <= hi; p++) {
 492         if (p->dest() == target->start())  successors_found++;
 493       }
 494       assert(successors_found > 0, "successor must be known");
 495       successors_counted += successors_found;
 496     }
 497     assert(successors_counted == (hi-lo)+1, "no unexpected successors");
 498 #endif
 499 
 500     // Maybe prune the inputs, based on the type of key_val.
 501     jint min_val = min_jint;
 502     jint max_val = max_jint;
 503     const TypeInt* ti = key_val->bottom_type()->isa_int();
 504     if (ti != NULL) {
 505       min_val = ti->_lo;
 506       max_val = ti->_hi;
 507       assert(min_val <= max_val, "invalid int type");
 508     }
 509     while (lo->hi() < min_val)  lo++;
 510     if (lo->lo() < min_val)  lo->setRange(min_val, lo->hi(), lo->dest(), lo->table_index());
 511     while (hi->lo() > max_val)  hi--;
 512     if (hi->hi() > max_val)  hi->setRange(hi->lo(), max_val, hi->dest(), hi->table_index());
 513   }
 514 
 515 #ifndef PRODUCT
 516   if (switch_depth == 0) {
 517     _max_switch_depth = 0;
 518     _est_switch_depth = log2_intptr((hi-lo+1)-1)+1;
 519   }
 520 #endif
 521 
 522   assert(lo <= hi, "must be a non-empty set of ranges");
 523   if (lo == hi) {
 524     jump_if_always_fork(lo->dest(), lo->table_index());
 525   } else {
 526     assert(lo->hi() == (lo+1)->lo()-1, "contiguous ranges");
 527     assert(hi->lo() == (hi-1)->hi()+1, "contiguous ranges");
 528 
 529     if (create_jump_tables(key_val, lo, hi)) return;
 530 
 531     int nr = hi - lo + 1;
 532 
 533     SwitchRange* mid = lo + nr/2;
 534     // if there is an easy choice, pivot at a singleton:
 535     if (nr > 3 && !mid->is_singleton() && (mid-1)->is_singleton())  mid--;
 536 
 537     assert(lo < mid && mid <= hi, "good pivot choice");
 538     assert(nr != 2 || mid == hi,   "should pick higher of 2");
 539     assert(nr != 3 || mid == hi-1, "should pick middle of 3");
 540 
 541     Node *test_val = _gvn.intcon(mid->lo());
 542 
 543     if (mid->is_singleton()) {
 544       IfNode *iff_ne = jump_if_fork_int(key_val, test_val, BoolTest::ne);
 545       jump_if_false_fork(iff_ne, mid->dest(), mid->table_index());
 546 
 547       // Special Case:  If there are exactly three ranges, and the high
 548       // and low range each go to the same place, omit the "gt" test,
 549       // since it will not discriminate anything.
 550       bool eq_test_only = (hi == lo+2 && hi->dest() == lo->dest());
 551       if (eq_test_only) {
 552         assert(mid == hi-1, "");
 553       }
 554 
 555       // if there is a higher range, test for it and process it:
 556       if (mid < hi && !eq_test_only) {
 557         // two comparisons of same values--should enable 1 test for 2 branches
 558         // Use BoolTest::le instead of BoolTest::gt
 559         IfNode *iff_le  = jump_if_fork_int(key_val, test_val, BoolTest::le);
 560         Node   *iftrue  = _gvn.transform( new (C, 1) IfTrueNode(iff_le) );
 561         Node   *iffalse = _gvn.transform( new (C, 1) IfFalseNode(iff_le) );
 562         { PreserveJVMState pjvms(this);
 563           set_control(iffalse);
 564           jump_switch_ranges(key_val, mid+1, hi, switch_depth+1);
 565         }
 566         set_control(iftrue);
 567       }
 568 
 569     } else {
 570       // mid is a range, not a singleton, so treat mid..hi as a unit
 571       IfNode *iff_ge = jump_if_fork_int(key_val, test_val, BoolTest::ge);
 572 
 573       // if there is a higher range, test for it and process it:
 574       if (mid == hi) {
 575         jump_if_true_fork(iff_ge, mid->dest(), mid->table_index());
 576       } else {
 577         Node *iftrue  = _gvn.transform( new (C, 1) IfTrueNode(iff_ge) );
 578         Node *iffalse = _gvn.transform( new (C, 1) IfFalseNode(iff_ge) );
 579         { PreserveJVMState pjvms(this);
 580           set_control(iftrue);
 581           jump_switch_ranges(key_val, mid, hi, switch_depth+1);
 582         }
 583         set_control(iffalse);
 584       }
 585     }
 586 
 587     // in any case, process the lower range
 588     jump_switch_ranges(key_val, lo, mid-1, switch_depth+1);
 589   }
 590 
 591   // Decrease pred_count for each successor after all is done.
 592   if (switch_depth == 0) {
 593     int unique_successors = switch_block->num_successors();
 594     for (int i = 0; i < unique_successors; i++) {
 595       Block* target = switch_block->successor_at(i);
 596       // Throw away the pre-allocated path for each unique successor.
 597       target->next_path_num();
 598     }
 599   }
 600 
 601 #ifndef PRODUCT
 602   _max_switch_depth = MAX2(switch_depth, _max_switch_depth);
 603   if (TraceOptoParse && Verbose && WizardMode && switch_depth == 0) {
 604     SwitchRange* r;
 605     int nsing = 0;
 606     for( r = lo; r <= hi; r++ ) {
 607       if( r->is_singleton() )  nsing++;
 608     }
 609     tty->print(">>> ");
 610     _method->print_short_name();
 611     tty->print_cr(" switch decision tree");
 612     tty->print_cr("    %d ranges (%d singletons), max_depth=%d, est_depth=%d",
 613                   hi-lo+1, nsing, _max_switch_depth, _est_switch_depth);
 614     if (_max_switch_depth > _est_switch_depth) {
 615       tty->print_cr("******** BAD SWITCH DEPTH ********");
 616     }
 617     tty->print("   ");
 618     for( r = lo; r <= hi; r++ ) {
 619       r->print(env());
 620     }
 621     tty->print_cr("");
 622   }
 623 #endif
 624 }
 625 
 626 void Parse::modf() {
 627   Node *f2 = pop();
 628   Node *f1 = pop();
 629   Node* c = make_runtime_call(RC_LEAF, OptoRuntime::modf_Type(),
 630                               CAST_FROM_FN_PTR(address, SharedRuntime::frem),
 631                               "frem", NULL, //no memory effects
 632                               f1, f2);
 633   Node* res = _gvn.transform(new (C, 1) ProjNode(c, TypeFunc::Parms + 0));
 634 
 635   push(res);
 636 }
 637 
 638 void Parse::modd() {
 639   Node *d2 = pop_pair();
 640   Node *d1 = pop_pair();
 641   Node* c = make_runtime_call(RC_LEAF, OptoRuntime::Math_DD_D_Type(),
 642                               CAST_FROM_FN_PTR(address, SharedRuntime::drem),
 643                               "drem", NULL, //no memory effects
 644                               d1, top(), d2, top());
 645   Node* res_d   = _gvn.transform(new (C, 1) ProjNode(c, TypeFunc::Parms + 0));
 646 
 647 #ifdef ASSERT
 648   Node* res_top = _gvn.transform(new (C, 1) ProjNode(c, TypeFunc::Parms + 1));
 649   assert(res_top == top(), "second value must be top");
 650 #endif
 651 
 652   push_pair(res_d);
 653 }
 654 
 655 void Parse::l2f() {
 656   Node* f2 = pop();
 657   Node* f1 = pop();
 658   Node* c = make_runtime_call(RC_LEAF, OptoRuntime::l2f_Type(),
 659                               CAST_FROM_FN_PTR(address, SharedRuntime::l2f),
 660                               "l2f", NULL, //no memory effects
 661                               f1, f2);
 662   Node* res = _gvn.transform(new (C, 1) ProjNode(c, TypeFunc::Parms + 0));
 663 
 664   push(res);
 665 }
 666 
 667 void Parse::do_irem() {
 668   // Must keep both values on the expression-stack during null-check
 669   do_null_check(peek(), T_INT);
 670   // Compile-time detect of null-exception?
 671   if (stopped())  return;
 672 
 673   Node* b = pop();
 674   Node* a = pop();
 675 
 676   const Type *t = _gvn.type(b);
 677   if (t != Type::TOP) {
 678     const TypeInt *ti = t->is_int();
 679     if (ti->is_con()) {
 680       int divisor = ti->get_con();
 681       // check for positive power of 2
 682       if (divisor > 0 &&
 683           (divisor & ~(divisor-1)) == divisor) {
 684         // yes !
 685         Node *mask = _gvn.intcon((divisor - 1));
 686         // Sigh, must handle negative dividends
 687         Node *zero = _gvn.intcon(0);
 688         IfNode *ifff = jump_if_fork_int(a, zero, BoolTest::lt);
 689         Node *iff = _gvn.transform( new (C, 1) IfFalseNode(ifff) );
 690         Node *ift = _gvn.transform( new (C, 1) IfTrueNode (ifff) );
 691         Node *reg = jump_if_join(ift, iff);
 692         Node *phi = PhiNode::make(reg, NULL, TypeInt::INT);
 693         // Negative path; negate/and/negate
 694         Node *neg = _gvn.transform( new (C, 3) SubINode(zero, a) );
 695         Node *andn= _gvn.transform( new (C, 3) AndINode(neg, mask) );
 696         Node *negn= _gvn.transform( new (C, 3) SubINode(zero, andn) );
 697         phi->init_req(1, negn);
 698         // Fast positive case
 699         Node *andx = _gvn.transform( new (C, 3) AndINode(a, mask) );
 700         phi->init_req(2, andx);
 701         // Push the merge
 702         push( _gvn.transform(phi) );
 703         return;
 704       }
 705     }
 706   }
 707   // Default case
 708   push( _gvn.transform( new (C, 3) ModINode(control(),a,b) ) );
 709 }
 710 
 711 // Handle jsr and jsr_w bytecode
 712 void Parse::do_jsr() {
 713   assert(bc() == Bytecodes::_jsr || bc() == Bytecodes::_jsr_w, "wrong bytecode");
 714 
 715   // Store information about current state, tagged with new _jsr_bci
 716   int return_bci = iter().next_bci();
 717   int jsr_bci    = (bc() == Bytecodes::_jsr) ? iter().get_dest() : iter().get_far_dest();
 718 
 719   // Update method data
 720   profile_taken_branch(jsr_bci);
 721 
 722   // The way we do things now, there is only one successor block
 723   // for the jsr, because the target code is cloned by ciTypeFlow.
 724   Block* target = successor_for_bci(jsr_bci);
 725 
 726   // What got pushed?
 727   const Type* ret_addr = target->peek();
 728   assert(ret_addr->singleton(), "must be a constant (cloned jsr body)");
 729 
 730   // Effect on jsr on stack
 731   push(_gvn.makecon(ret_addr));
 732 
 733   // Flow to the jsr.
 734   merge(jsr_bci);
 735 }
 736 
 737 // Handle ret bytecode
 738 void Parse::do_ret() {
 739   // Find to whom we return.
 740 #if 0 // %%%% MAKE THIS WORK
 741   Node* con = local();
 742   const TypePtr* tp = con->bottom_type()->isa_ptr();
 743   assert(tp && tp->singleton(), "");
 744   int return_bci = (int) tp->get_con();
 745   merge(return_bci);
 746 #else
 747   assert(block()->num_successors() == 1, "a ret can only go one place now");
 748   Block* target = block()->successor_at(0);
 749   assert(!target->is_ready(), "our arrival must be expected");
 750   profile_ret(target->flow()->start());
 751   int pnum = target->next_path_num();
 752   merge_common(target, pnum);
 753 #endif
 754 }
 755 
 756 //--------------------------dynamic_branch_prediction--------------------------
 757 // Try to gather dynamic branch prediction behavior.  Return a probability
 758 // of the branch being taken and set the "cnt" field.  Returns a -1.0
 759 // if we need to use static prediction for some reason.
 760 float Parse::dynamic_branch_prediction(float &cnt) {
 761   ResourceMark rm;
 762 
 763   cnt  = COUNT_UNKNOWN;
 764 
 765   // Use MethodData information if it is available
 766   // FIXME: free the ProfileData structure
 767   ciMethodData* methodData = method()->method_data();
 768   if (!methodData->is_mature())  return PROB_UNKNOWN;
 769   ciProfileData* data = methodData->bci_to_data(bci());
 770   if (!data->is_JumpData())  return PROB_UNKNOWN;
 771 
 772   // get taken and not taken values
 773   int     taken = data->as_JumpData()->taken();
 774   int not_taken = 0;
 775   if (data->is_BranchData()) {
 776     not_taken = data->as_BranchData()->not_taken();
 777   }
 778 
 779   // scale the counts to be commensurate with invocation counts:
 780   taken = method()->scale_count(taken);
 781   not_taken = method()->scale_count(not_taken);
 782 
 783   // Give up if too few counts to be meaningful
 784   if (taken + not_taken < 40) {
 785     if (C->log() != NULL) {
 786       C->log()->elem("branch target_bci='%d' taken='%d' not_taken='%d'", iter().get_dest(), taken, not_taken);
 787     }
 788     return PROB_UNKNOWN;
 789   }
 790 
 791   // Compute frequency that we arrive here
 792   int sum = taken + not_taken;
 793   // Adjust, if this block is a cloned private block but the
 794   // Jump counts are shared.  Taken the private counts for
 795   // just this path instead of the shared counts.
 796   if( block()->count() > 0 )
 797     sum = block()->count();
 798   cnt = (float)sum / (float)FreqCountInvocations;
 799 
 800   // Pin probability to sane limits
 801   float prob;
 802   if( !taken )
 803     prob = (0+PROB_MIN) / 2;
 804   else if( !not_taken )
 805     prob = (1+PROB_MAX) / 2;
 806   else {                         // Compute probability of true path
 807     prob = (float)taken / (float)(taken + not_taken);
 808     if (prob > PROB_MAX)  prob = PROB_MAX;
 809     if (prob < PROB_MIN)   prob = PROB_MIN;
 810   }
 811 
 812   assert((cnt > 0.0f) && (prob > 0.0f),
 813          "Bad frequency assignment in if");
 814 
 815   if (C->log() != NULL) {
 816     const char* prob_str = NULL;
 817     if (prob >= PROB_MAX)  prob_str = (prob == PROB_MAX) ? "max" : "always";
 818     if (prob <= PROB_MIN)  prob_str = (prob == PROB_MIN) ? "min" : "never";
 819     char prob_str_buf[30];
 820     if (prob_str == NULL) {
 821       sprintf(prob_str_buf, "%g", prob);
 822       prob_str = prob_str_buf;
 823     }
 824     C->log()->elem("branch target_bci='%d' taken='%d' not_taken='%d' cnt='%g' prob='%s'",
 825                    iter().get_dest(), taken, not_taken, cnt, prob_str);
 826   }
 827   return prob;
 828 }
 829 
 830 //-----------------------------branch_prediction-------------------------------
 831 float Parse::branch_prediction(float& cnt,
 832                                BoolTest::mask btest,
 833                                int target_bci) {
 834   float prob = dynamic_branch_prediction(cnt);
 835   // If prob is unknown, switch to static prediction
 836   if (prob != PROB_UNKNOWN)  return prob;
 837 
 838   prob = PROB_FAIR;                   // Set default value
 839   if (btest == BoolTest::eq)          // Exactly equal test?
 840     prob = PROB_STATIC_INFREQUENT;    // Assume its relatively infrequent
 841   else if (btest == BoolTest::ne)
 842     prob = PROB_STATIC_FREQUENT;      // Assume its relatively frequent
 843 
 844   // If this is a conditional test guarding a backwards branch,
 845   // assume its a loop-back edge.  Make it a likely taken branch.
 846   if (target_bci < bci()) {
 847     if (is_osr_parse()) {    // Could be a hot OSR'd loop; force deopt
 848       // Since it's an OSR, we probably have profile data, but since
 849       // branch_prediction returned PROB_UNKNOWN, the counts are too small.
 850       // Let's make a special check here for completely zero counts.
 851       ciMethodData* methodData = method()->method_data();
 852       if (!methodData->is_empty()) {
 853         ciProfileData* data = methodData->bci_to_data(bci());
 854         // Only stop for truly zero counts, which mean an unknown part
 855         // of the OSR-ed method, and we want to deopt to gather more stats.
 856         // If you have ANY counts, then this loop is simply 'cold' relative
 857         // to the OSR loop.
 858         if (data->as_BranchData()->taken() +
 859             data->as_BranchData()->not_taken() == 0 ) {
 860           // This is the only way to return PROB_UNKNOWN:
 861           return PROB_UNKNOWN;
 862         }
 863       }
 864     }
 865     prob = PROB_STATIC_FREQUENT;     // Likely to take backwards branch
 866   }
 867 
 868   assert(prob != PROB_UNKNOWN, "must have some guess at this point");
 869   return prob;
 870 }
 871 
 872 // The magic constants are chosen so as to match the output of
 873 // branch_prediction() when the profile reports a zero taken count.
 874 // It is important to distinguish zero counts unambiguously, because
 875 // some branches (e.g., _213_javac.Assembler.eliminate) validly produce
 876 // very small but nonzero probabilities, which if confused with zero
 877 // counts would keep the program recompiling indefinitely.
 878 bool Parse::seems_never_taken(float prob) {
 879   return prob < PROB_MIN;
 880 }
 881 
 882 //-------------------------------repush_if_args--------------------------------
 883 // Push arguments of an "if" bytecode back onto the stack by adjusting _sp.
 884 inline void Parse::repush_if_args() {
 885 #ifndef PRODUCT
 886   if (PrintOpto && WizardMode) {
 887     tty->print("defending against excessive implicit null exceptions on %s @%d in ",
 888                Bytecodes::name(iter().cur_bc()), iter().cur_bci());
 889     method()->print_name(); tty->cr();
 890   }
 891 #endif
 892   int bc_depth = - Bytecodes::depth(iter().cur_bc());
 893   assert(bc_depth == 1 || bc_depth == 2, "only two kinds of branches");
 894   DEBUG_ONLY(sync_jvms());   // argument(n) requires a synced jvms
 895   assert(argument(0) != NULL, "must exist");
 896   assert(bc_depth == 1 || argument(1) != NULL, "two must exist");
 897   _sp += bc_depth;
 898 }
 899 
 900 //----------------------------------do_ifnull----------------------------------
 901 void Parse::do_ifnull(BoolTest::mask btest, Node *c) {
 902   int target_bci = iter().get_dest();
 903 
 904   Block* branch_block = successor_for_bci(target_bci);
 905   Block* next_block   = successor_for_bci(iter().next_bci());
 906 
 907   float cnt;
 908   float prob = branch_prediction(cnt, btest, target_bci);
 909   if (prob == PROB_UNKNOWN) {
 910     // (An earlier version of do_ifnull omitted this trap for OSR methods.)
 911 #ifndef PRODUCT
 912     if (PrintOpto && Verbose)
 913       tty->print_cr("Never-taken edge stops compilation at bci %d",bci());
 914 #endif
 915     repush_if_args(); // to gather stats on loop
 916     // We need to mark this branch as taken so that if we recompile we will
 917     // see that it is possible. In the tiered system the interpreter doesn't
 918     // do profiling and by the time we get to the lower tier from the interpreter
 919     // the path may be cold again. Make sure it doesn't look untaken
 920     profile_taken_branch(target_bci, !ProfileInterpreter);
 921     uncommon_trap(Deoptimization::Reason_unreached,
 922                   Deoptimization::Action_reinterpret,
 923                   NULL, "cold");
 924     if (EliminateAutoBox) {
 925       // Mark the successor blocks as parsed
 926       branch_block->next_path_num();
 927       next_block->next_path_num();
 928     }
 929     return;
 930   }
 931 
 932   explicit_null_checks_inserted++;
 933 
 934   // Generate real control flow
 935   Node   *tst = _gvn.transform( new (C, 2) BoolNode( c, btest ) );
 936 
 937   // Sanity check the probability value
 938   assert(prob > 0.0f,"Bad probability in Parser");
 939  // Need xform to put node in hash table
 940   IfNode *iff = create_and_xform_if( control(), tst, prob, cnt );
 941   assert(iff->_prob > 0.0f,"Optimizer made bad probability in parser");
 942   // True branch
 943   { PreserveJVMState pjvms(this);
 944     Node* iftrue  = _gvn.transform( new (C, 1) IfTrueNode (iff) );
 945     set_control(iftrue);
 946 
 947     if (stopped()) {            // Path is dead?
 948       explicit_null_checks_elided++;
 949       if (EliminateAutoBox) {
 950         // Mark the successor block as parsed
 951         branch_block->next_path_num();
 952       }
 953     } else {                    // Path is live.
 954       // Update method data
 955       profile_taken_branch(target_bci);
 956       adjust_map_after_if(btest, c, prob, branch_block, next_block);
 957       if (!stopped())
 958         merge(target_bci);
 959     }
 960   }
 961 
 962   // False branch
 963   Node* iffalse = _gvn.transform( new (C, 1) IfFalseNode(iff) );
 964   set_control(iffalse);
 965 
 966   if (stopped()) {              // Path is dead?
 967     explicit_null_checks_elided++;
 968     if (EliminateAutoBox) {
 969       // Mark the successor block as parsed
 970       next_block->next_path_num();
 971     }
 972   } else  {                     // Path is live.
 973     // Update method data
 974     profile_not_taken_branch();
 975     adjust_map_after_if(BoolTest(btest).negate(), c, 1.0-prob,
 976                         next_block, branch_block);
 977   }
 978 }
 979 
 980 //------------------------------------do_if------------------------------------
 981 void Parse::do_if(BoolTest::mask btest, Node* c) {
 982   int target_bci = iter().get_dest();
 983 
 984   Block* branch_block = successor_for_bci(target_bci);
 985   Block* next_block   = successor_for_bci(iter().next_bci());
 986 
 987   float cnt;
 988   float prob = branch_prediction(cnt, btest, target_bci);
 989   float untaken_prob = 1.0 - prob;
 990 
 991   if (prob == PROB_UNKNOWN) {
 992 #ifndef PRODUCT
 993     if (PrintOpto && Verbose)
 994       tty->print_cr("Never-taken edge stops compilation at bci %d",bci());
 995 #endif
 996     repush_if_args(); // to gather stats on loop
 997     // We need to mark this branch as taken so that if we recompile we will
 998     // see that it is possible. In the tiered system the interpreter doesn't
 999     // do profiling and by the time we get to the lower tier from the interpreter
1000     // the path may be cold again. Make sure it doesn't look untaken
1001     profile_taken_branch(target_bci, !ProfileInterpreter);
1002     uncommon_trap(Deoptimization::Reason_unreached,
1003                   Deoptimization::Action_reinterpret,
1004                   NULL, "cold");
1005     if (EliminateAutoBox) {
1006       // Mark the successor blocks as parsed
1007       branch_block->next_path_num();
1008       next_block->next_path_num();
1009     }
1010     return;
1011   }
1012 
1013   // Sanity check the probability value
1014   assert(0.0f < prob && prob < 1.0f,"Bad probability in Parser");
1015 
1016   bool taken_if_true = true;
1017   // Convert BoolTest to canonical form:
1018   if (!BoolTest(btest).is_canonical()) {
1019     btest         = BoolTest(btest).negate();
1020     taken_if_true = false;
1021     // prob is NOT updated here; it remains the probability of the taken
1022     // path (as opposed to the prob of the path guarded by an 'IfTrueNode').
1023   }
1024   assert(btest != BoolTest::eq, "!= is the only canonical exact test");
1025 
1026   Node* tst0 = new (C, 2) BoolNode(c, btest);
1027   Node* tst = _gvn.transform(tst0);
1028   BoolTest::mask taken_btest   = BoolTest::illegal;
1029   BoolTest::mask untaken_btest = BoolTest::illegal;
1030 
1031   if (tst->is_Bool()) {
1032     // Refresh c from the transformed bool node, since it may be
1033     // simpler than the original c.  Also re-canonicalize btest.
1034     // This wins when (Bool ne (Conv2B p) 0) => (Bool ne (CmpP p NULL)).
1035     // That can arise from statements like: if (x instanceof C) ...
1036     if (tst != tst0) {
1037       // Canonicalize one more time since transform can change it.
1038       btest = tst->as_Bool()->_test._test;
1039       if (!BoolTest(btest).is_canonical()) {
1040         // Reverse edges one more time...
1041         tst   = _gvn.transform( tst->as_Bool()->negate(&_gvn) );
1042         btest = tst->as_Bool()->_test._test;
1043         assert(BoolTest(btest).is_canonical(), "sanity");
1044         taken_if_true = !taken_if_true;
1045       }
1046       c = tst->in(1);
1047     }
1048     BoolTest::mask neg_btest = BoolTest(btest).negate();
1049     taken_btest   = taken_if_true ?     btest : neg_btest;
1050     untaken_btest = taken_if_true ? neg_btest :     btest;
1051   }
1052 
1053   // Generate real control flow
1054   float true_prob = (taken_if_true ? prob : untaken_prob);
1055   IfNode* iff = create_and_map_if(control(), tst, true_prob, cnt);
1056   assert(iff->_prob > 0.0f,"Optimizer made bad probability in parser");
1057   Node* taken_branch   = new (C, 1) IfTrueNode(iff);
1058   Node* untaken_branch = new (C, 1) IfFalseNode(iff);
1059   if (!taken_if_true) {  // Finish conversion to canonical form
1060     Node* tmp      = taken_branch;
1061     taken_branch   = untaken_branch;
1062     untaken_branch = tmp;
1063   }
1064 
1065   // Branch is taken:
1066   { PreserveJVMState pjvms(this);
1067     taken_branch = _gvn.transform(taken_branch);
1068     set_control(taken_branch);
1069 
1070     if (stopped()) {
1071       if (EliminateAutoBox) {
1072         // Mark the successor block as parsed
1073         branch_block->next_path_num();
1074       }
1075     } else {
1076       // Update method data
1077       profile_taken_branch(target_bci);
1078       adjust_map_after_if(taken_btest, c, prob, branch_block, next_block);
1079       if (!stopped())
1080         merge(target_bci);
1081     }
1082   }
1083 
1084   untaken_branch = _gvn.transform(untaken_branch);
1085   set_control(untaken_branch);
1086 
1087   // Branch not taken.
1088   if (stopped()) {
1089     if (EliminateAutoBox) {
1090       // Mark the successor block as parsed
1091       next_block->next_path_num();
1092     }
1093   } else {
1094     // Update method data
1095     profile_not_taken_branch();
1096     adjust_map_after_if(untaken_btest, c, untaken_prob,
1097                         next_block, branch_block);
1098   }
1099 }
1100 
1101 //----------------------------adjust_map_after_if------------------------------
1102 // Adjust the JVM state to reflect the result of taking this path.
1103 // Basically, it means inspecting the CmpNode controlling this
1104 // branch, seeing how it constrains a tested value, and then
1105 // deciding if it's worth our while to encode this constraint
1106 // as graph nodes in the current abstract interpretation map.
1107 void Parse::adjust_map_after_if(BoolTest::mask btest, Node* c, float prob,
1108                                 Block* path, Block* other_path) {
1109   if (stopped() || !c->is_Cmp() || btest == BoolTest::illegal)
1110     return;                             // nothing to do
1111 
1112   bool is_fallthrough = (path == successor_for_bci(iter().next_bci()));
1113 
1114   int cop = c->Opcode();
1115   if (seems_never_taken(prob) && cop == Op_CmpP && btest == BoolTest::eq) {
1116     // (An earlier version of do_if omitted '&& btest == BoolTest::eq'.)
1117     //
1118     // If this might possibly turn into an implicit null check,
1119     // and the null has never yet been seen, we need to generate
1120     // an uncommon trap, so as to recompile instead of suffering
1121     // with very slow branches.  (We'll get the slow branches if
1122     // the program ever changes phase and starts seeing nulls here.)
1123     //
1124     // The tests we worry about are of the form (p == null).
1125     // We do not simply inspect for a null constant, since a node may
1126     // optimize to 'null' later on.
1127     repush_if_args();
1128     // We need to mark this branch as taken so that if we recompile we will
1129     // see that it is possible. In the tiered system the interpreter doesn't
1130     // do profiling and by the time we get to the lower tier from the interpreter
1131     // the path may be cold again. Make sure it doesn't look untaken
1132     if (is_fallthrough) {
1133       profile_not_taken_branch(!ProfileInterpreter);
1134     } else {
1135       profile_taken_branch(iter().get_dest(), !ProfileInterpreter);
1136     }
1137     uncommon_trap(Deoptimization::Reason_unreached,
1138                   Deoptimization::Action_reinterpret,
1139                   NULL,
1140                   (is_fallthrough ? "taken always" : "taken never"));
1141     return;
1142   }
1143 
1144   Node* val = c->in(1);
1145   Node* con = c->in(2);
1146   const Type* tcon = _gvn.type(con);
1147   const Type* tval = _gvn.type(val);
1148   bool have_con = tcon->singleton();
1149   if (tval->singleton()) {
1150     if (!have_con) {
1151       // Swap, so constant is in con.
1152       con  = val;
1153       tcon = tval;
1154       val  = c->in(2);
1155       tval = _gvn.type(val);
1156       btest = BoolTest(btest).commute();
1157       have_con = true;
1158     } else {
1159       // Do we have two constants?  Then leave well enough alone.
1160       have_con = false;
1161     }
1162   }
1163   if (!have_con)                        // remaining adjustments need a con
1164     return;
1165 
1166 
1167   int val_in_map = map()->find_edge(val);
1168   if (val_in_map < 0)  return;          // replace_in_map would be useless
1169   {
1170     JVMState* jvms = this->jvms();
1171     if (!(jvms->is_loc(val_in_map) ||
1172           jvms->is_stk(val_in_map)))
1173       return;                           // again, it would be useless
1174   }
1175 
1176   // Check for a comparison to a constant, and "know" that the compared
1177   // value is constrained on this path.
1178   assert(tcon->singleton(), "");
1179   ConstraintCastNode* ccast = NULL;
1180   Node* cast = NULL;
1181 
1182   switch (btest) {
1183   case BoolTest::eq:                    // Constant test?
1184     {
1185       const Type* tboth = tcon->join(tval);
1186       if (tboth == tval)  break;        // Nothing to gain.
1187       if (tcon->isa_int()) {
1188         ccast = new (C, 2) CastIINode(val, tboth);
1189       } else if (tcon == TypePtr::NULL_PTR) {
1190         // Cast to null, but keep the pointer identity temporarily live.
1191         ccast = new (C, 2) CastPPNode(val, tboth);
1192       } else {
1193         const TypeF* tf = tcon->isa_float_constant();
1194         const TypeD* td = tcon->isa_double_constant();
1195         // Exclude tests vs float/double 0 as these could be
1196         // either +0 or -0.  Just because you are equal to +0
1197         // doesn't mean you ARE +0!
1198         if ((!tf || tf->_f != 0.0) &&
1199             (!td || td->_d != 0.0))
1200           cast = con;                   // Replace non-constant val by con.
1201       }
1202     }
1203     break;
1204 
1205   case BoolTest::ne:
1206     if (tcon == TypePtr::NULL_PTR) {
1207       cast = cast_not_null(val, false);
1208     }
1209     break;
1210 
1211   default:
1212     // (At this point we could record int range types with CastII.)
1213     break;
1214   }
1215 
1216   if (ccast != NULL) {
1217     const Type* tcc = ccast->as_Type()->type();
1218     assert(tcc != tval && tcc->higher_equal(tval), "must improve");
1219     // Delay transform() call to allow recovery of pre-cast value
1220     // at the control merge.
1221     ccast->set_req(0, control());
1222     _gvn.set_type_bottom(ccast);
1223     record_for_igvn(ccast);
1224     cast = ccast;
1225   }
1226 
1227   if (cast != NULL) {                   // Here's the payoff.
1228     replace_in_map(val, cast);
1229   }
1230 }
1231 
1232 
1233 //------------------------------do_one_bytecode--------------------------------
1234 // Parse this bytecode, and alter the Parsers JVM->Node mapping
1235 void Parse::do_one_bytecode() {
1236   Node *a, *b, *c, *d;          // Handy temps
1237   BoolTest::mask btest;
1238   int i;
1239 
1240   assert(!has_exceptions(), "bytecode entry state must be clear of throws");
1241 
1242   if (C->check_node_count(NodeLimitFudgeFactor * 5,
1243                           "out of nodes parsing method")) {
1244     return;
1245   }
1246 
1247 #ifdef ASSERT
1248   // for setting breakpoints
1249   if (TraceOptoParse) {
1250     tty->print(" @");
1251     dump_bci(bci());
1252   }
1253 #endif
1254 
1255   switch (bc()) {
1256   case Bytecodes::_nop:
1257     // do nothing
1258     break;
1259   case Bytecodes::_lconst_0:
1260     push_pair(longcon(0));
1261     break;
1262 
1263   case Bytecodes::_lconst_1:
1264     push_pair(longcon(1));
1265     break;
1266 
1267   case Bytecodes::_fconst_0:
1268     push(zerocon(T_FLOAT));
1269     break;
1270 
1271   case Bytecodes::_fconst_1:
1272     push(makecon(TypeF::ONE));
1273     break;
1274 
1275   case Bytecodes::_fconst_2:
1276     push(makecon(TypeF::make(2.0f)));
1277     break;
1278 
1279   case Bytecodes::_dconst_0:
1280     push_pair(zerocon(T_DOUBLE));
1281     break;
1282 
1283   case Bytecodes::_dconst_1:
1284     push_pair(makecon(TypeD::ONE));
1285     break;
1286 
1287   case Bytecodes::_iconst_m1:push(intcon(-1)); break;
1288   case Bytecodes::_iconst_0: push(intcon( 0)); break;
1289   case Bytecodes::_iconst_1: push(intcon( 1)); break;
1290   case Bytecodes::_iconst_2: push(intcon( 2)); break;
1291   case Bytecodes::_iconst_3: push(intcon( 3)); break;
1292   case Bytecodes::_iconst_4: push(intcon( 4)); break;
1293   case Bytecodes::_iconst_5: push(intcon( 5)); break;
1294   case Bytecodes::_bipush:   push(intcon( iter().get_byte())); break;
1295   case Bytecodes::_sipush:   push(intcon( iter().get_short())); break;
1296   case Bytecodes::_aconst_null: push(null());  break;
1297   case Bytecodes::_ldc:
1298   case Bytecodes::_ldc_w:
1299   case Bytecodes::_ldc2_w:
1300     // If the constant is unresolved, run this BC once in the interpreter.
1301     if (iter().is_unresolved_string()) {
1302       uncommon_trap(Deoptimization::make_trap_request
1303                     (Deoptimization::Reason_unloaded,
1304                      Deoptimization::Action_reinterpret,
1305                      iter().get_constant_index()),
1306                     NULL, "unresolved_string");
1307       break;
1308     } else {
1309       ciConstant constant = iter().get_constant();
1310       if (constant.basic_type() == T_OBJECT) {
1311         ciObject* c = constant.as_object();
1312         if (c->is_klass()) {
1313           // The constant returned for a klass is the ciKlass for the
1314           // entry.  We want the java_mirror so get it.
1315           ciKlass* klass = c->as_klass();
1316           if (klass->is_loaded()) {
1317             constant = ciConstant(T_OBJECT, klass->java_mirror());
1318           } else {
1319             uncommon_trap(Deoptimization::make_trap_request
1320                           (Deoptimization::Reason_unloaded,
1321                            Deoptimization::Action_reinterpret,
1322                            iter().get_constant_index()),
1323                           NULL, "unresolved_klass");
1324             break;
1325           }
1326         }
1327       }
1328       bool pushed = push_constant(constant, true);
1329       guarantee(pushed, "must be possible to push this constant");
1330     }
1331 
1332     break;
1333 
1334   case Bytecodes::_aload_0:
1335     push( local(0) );
1336     break;
1337   case Bytecodes::_aload_1:
1338     push( local(1) );
1339     break;
1340   case Bytecodes::_aload_2:
1341     push( local(2) );
1342     break;
1343   case Bytecodes::_aload_3:
1344     push( local(3) );
1345     break;
1346   case Bytecodes::_aload:
1347     push( local(iter().get_index()) );
1348     break;
1349 
1350   case Bytecodes::_fload_0:
1351   case Bytecodes::_iload_0:
1352     push( local(0) );
1353     break;
1354   case Bytecodes::_fload_1:
1355   case Bytecodes::_iload_1:
1356     push( local(1) );
1357     break;
1358   case Bytecodes::_fload_2:
1359   case Bytecodes::_iload_2:
1360     push( local(2) );
1361     break;
1362   case Bytecodes::_fload_3:
1363   case Bytecodes::_iload_3:
1364     push( local(3) );
1365     break;
1366   case Bytecodes::_fload:
1367   case Bytecodes::_iload:
1368     push( local(iter().get_index()) );
1369     break;
1370   case Bytecodes::_lload_0:
1371     push_pair_local( 0 );
1372     break;
1373   case Bytecodes::_lload_1:
1374     push_pair_local( 1 );
1375     break;
1376   case Bytecodes::_lload_2:
1377     push_pair_local( 2 );
1378     break;
1379   case Bytecodes::_lload_3:
1380     push_pair_local( 3 );
1381     break;
1382   case Bytecodes::_lload:
1383     push_pair_local( iter().get_index() );
1384     break;
1385 
1386   case Bytecodes::_dload_0:
1387     push_pair_local(0);
1388     break;
1389   case Bytecodes::_dload_1:
1390     push_pair_local(1);
1391     break;
1392   case Bytecodes::_dload_2:
1393     push_pair_local(2);
1394     break;
1395   case Bytecodes::_dload_3:
1396     push_pair_local(3);
1397     break;
1398   case Bytecodes::_dload:
1399     push_pair_local(iter().get_index());
1400     break;
1401   case Bytecodes::_fstore_0:
1402   case Bytecodes::_istore_0:
1403   case Bytecodes::_astore_0:
1404     set_local( 0, pop() );
1405     break;
1406   case Bytecodes::_fstore_1:
1407   case Bytecodes::_istore_1:
1408   case Bytecodes::_astore_1:
1409     set_local( 1, pop() );
1410     break;
1411   case Bytecodes::_fstore_2:
1412   case Bytecodes::_istore_2:
1413   case Bytecodes::_astore_2:
1414     set_local( 2, pop() );
1415     break;
1416   case Bytecodes::_fstore_3:
1417   case Bytecodes::_istore_3:
1418   case Bytecodes::_astore_3:
1419     set_local( 3, pop() );
1420     break;
1421   case Bytecodes::_fstore:
1422   case Bytecodes::_istore:
1423   case Bytecodes::_astore:
1424     set_local( iter().get_index(), pop() );
1425     break;
1426   // long stores
1427   case Bytecodes::_lstore_0:
1428     set_pair_local( 0, pop_pair() );
1429     break;
1430   case Bytecodes::_lstore_1:
1431     set_pair_local( 1, pop_pair() );
1432     break;
1433   case Bytecodes::_lstore_2:
1434     set_pair_local( 2, pop_pair() );
1435     break;
1436   case Bytecodes::_lstore_3:
1437     set_pair_local( 3, pop_pair() );
1438     break;
1439   case Bytecodes::_lstore:
1440     set_pair_local( iter().get_index(), pop_pair() );
1441     break;
1442 
1443   // double stores
1444   case Bytecodes::_dstore_0:
1445     set_pair_local( 0, dstore_rounding(pop_pair()) );
1446     break;
1447   case Bytecodes::_dstore_1:
1448     set_pair_local( 1, dstore_rounding(pop_pair()) );
1449     break;
1450   case Bytecodes::_dstore_2:
1451     set_pair_local( 2, dstore_rounding(pop_pair()) );
1452     break;
1453   case Bytecodes::_dstore_3:
1454     set_pair_local( 3, dstore_rounding(pop_pair()) );
1455     break;
1456   case Bytecodes::_dstore:
1457     set_pair_local( iter().get_index(), dstore_rounding(pop_pair()) );
1458     break;
1459 
1460   case Bytecodes::_pop:  _sp -= 1;   break;
1461   case Bytecodes::_pop2: _sp -= 2;   break;
1462   case Bytecodes::_swap:
1463     a = pop();
1464     b = pop();
1465     push(a);
1466     push(b);
1467     break;
1468   case Bytecodes::_dup:
1469     a = pop();
1470     push(a);
1471     push(a);
1472     break;
1473   case Bytecodes::_dup_x1:
1474     a = pop();
1475     b = pop();
1476     push( a );
1477     push( b );
1478     push( a );
1479     break;
1480   case Bytecodes::_dup_x2:
1481     a = pop();
1482     b = pop();
1483     c = pop();
1484     push( a );
1485     push( c );
1486     push( b );
1487     push( a );
1488     break;
1489   case Bytecodes::_dup2:
1490     a = pop();
1491     b = pop();
1492     push( b );
1493     push( a );
1494     push( b );
1495     push( a );
1496     break;
1497 
1498   case Bytecodes::_dup2_x1:
1499     // before: .. c, b, a
1500     // after:  .. b, a, c, b, a
1501     // not tested
1502     a = pop();
1503     b = pop();
1504     c = pop();
1505     push( b );
1506     push( a );
1507     push( c );
1508     push( b );
1509     push( a );
1510     break;
1511   case Bytecodes::_dup2_x2:
1512     // before: .. d, c, b, a
1513     // after:  .. b, a, d, c, b, a
1514     // not tested
1515     a = pop();
1516     b = pop();
1517     c = pop();
1518     d = pop();
1519     push( b );
1520     push( a );
1521     push( d );
1522     push( c );
1523     push( b );
1524     push( a );
1525     break;
1526 
1527   case Bytecodes::_arraylength: {
1528     // Must do null-check with value on expression stack
1529     Node *ary = do_null_check(peek(), T_ARRAY);
1530     // Compile-time detect of null-exception?
1531     if (stopped())  return;
1532     a = pop();
1533     push(load_array_length(a));
1534     break;
1535   }
1536 
1537   case Bytecodes::_baload: array_load(T_BYTE);   break;
1538   case Bytecodes::_caload: array_load(T_CHAR);   break;
1539   case Bytecodes::_iaload: array_load(T_INT);    break;
1540   case Bytecodes::_saload: array_load(T_SHORT);  break;
1541   case Bytecodes::_faload: array_load(T_FLOAT);  break;
1542   case Bytecodes::_aaload: array_load(T_OBJECT); break;
1543   case Bytecodes::_laload: {
1544     a = array_addressing(T_LONG, 0);
1545     if (stopped())  return;     // guaranteed null or range check
1546     _sp -= 2;                   // Pop array and index
1547     push_pair( make_load(control(), a, TypeLong::LONG, T_LONG, TypeAryPtr::LONGS));
1548     break;
1549   }
1550   case Bytecodes::_daload: {
1551     a = array_addressing(T_DOUBLE, 0);
1552     if (stopped())  return;     // guaranteed null or range check
1553     _sp -= 2;                   // Pop array and index
1554     push_pair( make_load(control(), a, Type::DOUBLE, T_DOUBLE, TypeAryPtr::DOUBLES));
1555     break;
1556   }
1557   case Bytecodes::_bastore: array_store(T_BYTE);  break;
1558   case Bytecodes::_castore: array_store(T_CHAR);  break;
1559   case Bytecodes::_iastore: array_store(T_INT);   break;
1560   case Bytecodes::_sastore: array_store(T_SHORT); break;
1561   case Bytecodes::_fastore: array_store(T_FLOAT); break;
1562   case Bytecodes::_aastore: {
1563     d = array_addressing(T_OBJECT, 1);
1564     if (stopped())  return;     // guaranteed null or range check
1565     array_store_check();
1566     c = pop();                  // Oop to store
1567     b = pop();                  // index (already used)
1568     a = pop();                  // the array itself
1569     const TypeOopPtr* elemtype  = _gvn.type(a)->is_aryptr()->elem()->make_oopptr();
1570     const TypeAryPtr* adr_type = TypeAryPtr::OOPS;
1571     Node* store = store_oop_to_array(control(), a, d, adr_type, c, elemtype, T_OBJECT);
1572     break;
1573   }
1574   case Bytecodes::_lastore: {
1575     a = array_addressing(T_LONG, 2);
1576     if (stopped())  return;     // guaranteed null or range check
1577     c = pop_pair();
1578     _sp -= 2;                   // Pop array and index
1579     store_to_memory(control(), a, c, T_LONG, TypeAryPtr::LONGS);
1580     break;
1581   }
1582   case Bytecodes::_dastore: {
1583     a = array_addressing(T_DOUBLE, 2);
1584     if (stopped())  return;     // guaranteed null or range check
1585     c = pop_pair();
1586     _sp -= 2;                   // Pop array and index
1587     c = dstore_rounding(c);
1588     store_to_memory(control(), a, c, T_DOUBLE, TypeAryPtr::DOUBLES);
1589     break;
1590   }
1591   case Bytecodes::_getfield:
1592     do_getfield();
1593     break;
1594 
1595   case Bytecodes::_getstatic:
1596     do_getstatic();
1597     break;
1598 
1599   case Bytecodes::_putfield:
1600     do_putfield();
1601     break;
1602 
1603   case Bytecodes::_putstatic:
1604     do_putstatic();
1605     break;
1606 
1607   case Bytecodes::_irem:
1608     do_irem();
1609     break;
1610   case Bytecodes::_idiv:
1611     // Must keep both values on the expression-stack during null-check
1612     do_null_check(peek(), T_INT);
1613     // Compile-time detect of null-exception?
1614     if (stopped())  return;
1615     b = pop();
1616     a = pop();
1617     push( _gvn.transform( new (C, 3) DivINode(control(),a,b) ) );
1618     break;
1619   case Bytecodes::_imul:
1620     b = pop(); a = pop();
1621     push( _gvn.transform( new (C, 3) MulINode(a,b) ) );
1622     break;
1623   case Bytecodes::_iadd:
1624     b = pop(); a = pop();
1625     push( _gvn.transform( new (C, 3) AddINode(a,b) ) );
1626     break;
1627   case Bytecodes::_ineg:
1628     a = pop();
1629     push( _gvn.transform( new (C, 3) SubINode(_gvn.intcon(0),a)) );
1630     break;
1631   case Bytecodes::_isub:
1632     b = pop(); a = pop();
1633     push( _gvn.transform( new (C, 3) SubINode(a,b) ) );
1634     break;
1635   case Bytecodes::_iand:
1636     b = pop(); a = pop();
1637     push( _gvn.transform( new (C, 3) AndINode(a,b) ) );
1638     break;
1639   case Bytecodes::_ior:
1640     b = pop(); a = pop();
1641     push( _gvn.transform( new (C, 3) OrINode(a,b) ) );
1642     break;
1643   case Bytecodes::_ixor:
1644     b = pop(); a = pop();
1645     push( _gvn.transform( new (C, 3) XorINode(a,b) ) );
1646     break;
1647   case Bytecodes::_ishl:
1648     b = pop(); a = pop();
1649     push( _gvn.transform( new (C, 3) LShiftINode(a,b) ) );
1650     break;
1651   case Bytecodes::_ishr:
1652     b = pop(); a = pop();
1653     push( _gvn.transform( new (C, 3) RShiftINode(a,b) ) );
1654     break;
1655   case Bytecodes::_iushr:
1656     b = pop(); a = pop();
1657     push( _gvn.transform( new (C, 3) URShiftINode(a,b) ) );
1658     break;
1659 
1660   case Bytecodes::_fneg:
1661     a = pop();
1662     b = _gvn.transform(new (C, 2) NegFNode (a));
1663     push(b);
1664     break;
1665 
1666   case Bytecodes::_fsub:
1667     b = pop();
1668     a = pop();
1669     c = _gvn.transform( new (C, 3) SubFNode(a,b) );
1670     d = precision_rounding(c);
1671     push( d );
1672     break;
1673 
1674   case Bytecodes::_fadd:
1675     b = pop();
1676     a = pop();
1677     c = _gvn.transform( new (C, 3) AddFNode(a,b) );
1678     d = precision_rounding(c);
1679     push( d );
1680     break;
1681 
1682   case Bytecodes::_fmul:
1683     b = pop();
1684     a = pop();
1685     c = _gvn.transform( new (C, 3) MulFNode(a,b) );
1686     d = precision_rounding(c);
1687     push( d );
1688     break;
1689 
1690   case Bytecodes::_fdiv:
1691     b = pop();
1692     a = pop();
1693     c = _gvn.transform( new (C, 3) DivFNode(0,a,b) );
1694     d = precision_rounding(c);
1695     push( d );
1696     break;
1697 
1698   case Bytecodes::_frem:
1699     if (Matcher::has_match_rule(Op_ModF)) {
1700       // Generate a ModF node.
1701       b = pop();
1702       a = pop();
1703       c = _gvn.transform( new (C, 3) ModFNode(0,a,b) );
1704       d = precision_rounding(c);
1705       push( d );
1706     }
1707     else {
1708       // Generate a call.
1709       modf();
1710     }
1711     break;
1712 
1713   case Bytecodes::_fcmpl:
1714     b = pop();
1715     a = pop();
1716     c = _gvn.transform( new (C, 3) CmpF3Node( a, b));
1717     push(c);
1718     break;
1719   case Bytecodes::_fcmpg:
1720     b = pop();
1721     a = pop();
1722 
1723     // Same as fcmpl but need to flip the unordered case.  Swap the inputs,
1724     // which negates the result sign except for unordered.  Flip the unordered
1725     // as well by using CmpF3 which implements unordered-lesser instead of
1726     // unordered-greater semantics.  Finally, commute the result bits.  Result
1727     // is same as using a CmpF3Greater except we did it with CmpF3 alone.
1728     c = _gvn.transform( new (C, 3) CmpF3Node( b, a));
1729     c = _gvn.transform( new (C, 3) SubINode(_gvn.intcon(0),c) );
1730     push(c);
1731     break;
1732 
1733   case Bytecodes::_f2i:
1734     a = pop();
1735     push(_gvn.transform(new (C, 2) ConvF2INode(a)));
1736     break;
1737 
1738   case Bytecodes::_d2i:
1739     a = pop_pair();
1740     b = _gvn.transform(new (C, 2) ConvD2INode(a));
1741     push( b );
1742     break;
1743 
1744   case Bytecodes::_f2d:
1745     a = pop();
1746     b = _gvn.transform( new (C, 2) ConvF2DNode(a));
1747     push_pair( b );
1748     break;
1749 
1750   case Bytecodes::_d2f:
1751     a = pop_pair();
1752     b = _gvn.transform( new (C, 2) ConvD2FNode(a));
1753     // This breaks _227_mtrt (speed & correctness) and _222_mpegaudio (speed)
1754     //b = _gvn.transform(new (C, 2) RoundFloatNode(0, b) );
1755     push( b );
1756     break;
1757 
1758   case Bytecodes::_l2f:
1759     if (Matcher::convL2FSupported()) {
1760       a = pop_pair();
1761       b = _gvn.transform( new (C, 2) ConvL2FNode(a));
1762       // For i486.ad, FILD doesn't restrict precision to 24 or 53 bits.
1763       // Rather than storing the result into an FP register then pushing
1764       // out to memory to round, the machine instruction that implements
1765       // ConvL2D is responsible for rounding.
1766       // c = precision_rounding(b);
1767       c = _gvn.transform(b);
1768       push(c);
1769     } else {
1770       l2f();
1771     }
1772     break;
1773 
1774   case Bytecodes::_l2d:
1775     a = pop_pair();
1776     b = _gvn.transform( new (C, 2) ConvL2DNode(a));
1777     // For i486.ad, rounding is always necessary (see _l2f above).
1778     // c = dprecision_rounding(b);
1779     c = _gvn.transform(b);
1780     push_pair(c);
1781     break;
1782 
1783   case Bytecodes::_f2l:
1784     a = pop();
1785     b = _gvn.transform( new (C, 2) ConvF2LNode(a));
1786     push_pair(b);
1787     break;
1788 
1789   case Bytecodes::_d2l:
1790     a = pop_pair();
1791     b = _gvn.transform( new (C, 2) ConvD2LNode(a));
1792     push_pair(b);
1793     break;
1794 
1795   case Bytecodes::_dsub:
1796     b = pop_pair();
1797     a = pop_pair();
1798     c = _gvn.transform( new (C, 3) SubDNode(a,b) );
1799     d = dprecision_rounding(c);
1800     push_pair( d );
1801     break;
1802 
1803   case Bytecodes::_dadd:
1804     b = pop_pair();
1805     a = pop_pair();
1806     c = _gvn.transform( new (C, 3) AddDNode(a,b) );
1807     d = dprecision_rounding(c);
1808     push_pair( d );
1809     break;
1810 
1811   case Bytecodes::_dmul:
1812     b = pop_pair();
1813     a = pop_pair();
1814     c = _gvn.transform( new (C, 3) MulDNode(a,b) );
1815     d = dprecision_rounding(c);
1816     push_pair( d );
1817     break;
1818 
1819   case Bytecodes::_ddiv:
1820     b = pop_pair();
1821     a = pop_pair();
1822     c = _gvn.transform( new (C, 3) DivDNode(0,a,b) );
1823     d = dprecision_rounding(c);
1824     push_pair( d );
1825     break;
1826 
1827   case Bytecodes::_dneg:
1828     a = pop_pair();
1829     b = _gvn.transform(new (C, 2) NegDNode (a));
1830     push_pair(b);
1831     break;
1832 
1833   case Bytecodes::_drem:
1834     if (Matcher::has_match_rule(Op_ModD)) {
1835       // Generate a ModD node.
1836       b = pop_pair();
1837       a = pop_pair();
1838       // a % b
1839 
1840       c = _gvn.transform( new (C, 3) ModDNode(0,a,b) );
1841       d = dprecision_rounding(c);
1842       push_pair( d );
1843     }
1844     else {
1845       // Generate a call.
1846       modd();
1847     }
1848     break;
1849 
1850   case Bytecodes::_dcmpl:
1851     b = pop_pair();
1852     a = pop_pair();
1853     c = _gvn.transform( new (C, 3) CmpD3Node( a, b));
1854     push(c);
1855     break;
1856 
1857   case Bytecodes::_dcmpg:
1858     b = pop_pair();
1859     a = pop_pair();
1860     // Same as dcmpl but need to flip the unordered case.
1861     // Commute the inputs, which negates the result sign except for unordered.
1862     // Flip the unordered as well by using CmpD3 which implements
1863     // unordered-lesser instead of unordered-greater semantics.
1864     // Finally, negate the result bits.  Result is same as using a
1865     // CmpD3Greater except we did it with CmpD3 alone.
1866     c = _gvn.transform( new (C, 3) CmpD3Node( b, a));
1867     c = _gvn.transform( new (C, 3) SubINode(_gvn.intcon(0),c) );
1868     push(c);
1869     break;
1870 
1871 
1872     // Note for longs -> lo word is on TOS, hi word is on TOS - 1
1873   case Bytecodes::_land:
1874     b = pop_pair();
1875     a = pop_pair();
1876     c = _gvn.transform( new (C, 3) AndLNode(a,b) );
1877     push_pair(c);
1878     break;
1879   case Bytecodes::_lor:
1880     b = pop_pair();
1881     a = pop_pair();
1882     c = _gvn.transform( new (C, 3) OrLNode(a,b) );
1883     push_pair(c);
1884     break;
1885   case Bytecodes::_lxor:
1886     b = pop_pair();
1887     a = pop_pair();
1888     c = _gvn.transform( new (C, 3) XorLNode(a,b) );
1889     push_pair(c);
1890     break;
1891 
1892   case Bytecodes::_lshl:
1893     b = pop();                  // the shift count
1894     a = pop_pair();             // value to be shifted
1895     c = _gvn.transform( new (C, 3) LShiftLNode(a,b) );
1896     push_pair(c);
1897     break;
1898   case Bytecodes::_lshr:
1899     b = pop();                  // the shift count
1900     a = pop_pair();             // value to be shifted
1901     c = _gvn.transform( new (C, 3) RShiftLNode(a,b) );
1902     push_pair(c);
1903     break;
1904   case Bytecodes::_lushr:
1905     b = pop();                  // the shift count
1906     a = pop_pair();             // value to be shifted
1907     c = _gvn.transform( new (C, 3) URShiftLNode(a,b) );
1908     push_pair(c);
1909     break;
1910   case Bytecodes::_lmul:
1911     b = pop_pair();
1912     a = pop_pair();
1913     c = _gvn.transform( new (C, 3) MulLNode(a,b) );
1914     push_pair(c);
1915     break;
1916 
1917   case Bytecodes::_lrem:
1918     // Must keep both values on the expression-stack during null-check
1919     assert(peek(0) == top(), "long word order");
1920     do_null_check(peek(1), T_LONG);
1921     // Compile-time detect of null-exception?
1922     if (stopped())  return;
1923     b = pop_pair();
1924     a = pop_pair();
1925     c = _gvn.transform( new (C, 3) ModLNode(control(),a,b) );
1926     push_pair(c);
1927     break;
1928 
1929   case Bytecodes::_ldiv:
1930     // Must keep both values on the expression-stack during null-check
1931     assert(peek(0) == top(), "long word order");
1932     do_null_check(peek(1), T_LONG);
1933     // Compile-time detect of null-exception?
1934     if (stopped())  return;
1935     b = pop_pair();
1936     a = pop_pair();
1937     c = _gvn.transform( new (C, 3) DivLNode(control(),a,b) );
1938     push_pair(c);
1939     break;
1940 
1941   case Bytecodes::_ladd:
1942     b = pop_pair();
1943     a = pop_pair();
1944     c = _gvn.transform( new (C, 3) AddLNode(a,b) );
1945     push_pair(c);
1946     break;
1947   case Bytecodes::_lsub:
1948     b = pop_pair();
1949     a = pop_pair();
1950     c = _gvn.transform( new (C, 3) SubLNode(a,b) );
1951     push_pair(c);
1952     break;
1953   case Bytecodes::_lcmp:
1954     // Safepoints are now inserted _before_ branches.  The long-compare
1955     // bytecode painfully produces a 3-way value (-1,0,+1) which requires a
1956     // slew of control flow.  These are usually followed by a CmpI vs zero and
1957     // a branch; this pattern then optimizes to the obvious long-compare and
1958     // branch.  However, if the branch is backwards there's a Safepoint
1959     // inserted.  The inserted Safepoint captures the JVM state at the
1960     // pre-branch point, i.e. it captures the 3-way value.  Thus if a
1961     // long-compare is used to control a loop the debug info will force
1962     // computation of the 3-way value, even though the generated code uses a
1963     // long-compare and branch.  We try to rectify the situation by inserting
1964     // a SafePoint here and have it dominate and kill the safepoint added at a
1965     // following backwards branch.  At this point the JVM state merely holds 2
1966     // longs but not the 3-way value.
1967     if( UseLoopSafepoints ) {
1968       switch( iter().next_bc() ) {
1969       case Bytecodes::_ifgt:
1970       case Bytecodes::_iflt:
1971       case Bytecodes::_ifge:
1972       case Bytecodes::_ifle:
1973       case Bytecodes::_ifne:
1974       case Bytecodes::_ifeq:
1975         // If this is a backwards branch in the bytecodes, add Safepoint
1976         maybe_add_safepoint(iter().next_get_dest());
1977       }
1978     }
1979     b = pop_pair();
1980     a = pop_pair();
1981     c = _gvn.transform( new (C, 3) CmpL3Node( a, b ));
1982     push(c);
1983     break;
1984 
1985   case Bytecodes::_lneg:
1986     a = pop_pair();
1987     b = _gvn.transform( new (C, 3) SubLNode(longcon(0),a));
1988     push_pair(b);
1989     break;
1990   case Bytecodes::_l2i:
1991     a = pop_pair();
1992     push( _gvn.transform( new (C, 2) ConvL2INode(a)));
1993     break;
1994   case Bytecodes::_i2l:
1995     a = pop();
1996     b = _gvn.transform( new (C, 2) ConvI2LNode(a));
1997     push_pair(b);
1998     break;
1999   case Bytecodes::_i2b:
2000     // Sign extend
2001     a = pop();
2002     a = _gvn.transform( new (C, 3) LShiftINode(a,_gvn.intcon(24)) );
2003     a = _gvn.transform( new (C, 3) RShiftINode(a,_gvn.intcon(24)) );
2004     push( a );
2005     break;
2006   case Bytecodes::_i2s:
2007     a = pop();
2008     a = _gvn.transform( new (C, 3) LShiftINode(a,_gvn.intcon(16)) );
2009     a = _gvn.transform( new (C, 3) RShiftINode(a,_gvn.intcon(16)) );
2010     push( a );
2011     break;
2012   case Bytecodes::_i2c:
2013     a = pop();
2014     push( _gvn.transform( new (C, 3) AndINode(a,_gvn.intcon(0xFFFF)) ) );
2015     break;
2016 
2017   case Bytecodes::_i2f:
2018     a = pop();
2019     b = _gvn.transform( new (C, 2) ConvI2FNode(a) ) ;
2020     c = precision_rounding(b);
2021     push (b);
2022     break;
2023 
2024   case Bytecodes::_i2d:
2025     a = pop();
2026     b = _gvn.transform( new (C, 2) ConvI2DNode(a));
2027     push_pair(b);
2028     break;
2029 
2030   case Bytecodes::_iinc:        // Increment local
2031     i = iter().get_index();     // Get local index
2032     set_local( i, _gvn.transform( new (C, 3) AddINode( _gvn.intcon(iter().get_iinc_con()), local(i) ) ) );
2033     break;
2034 
2035   // Exit points of synchronized methods must have an unlock node
2036   case Bytecodes::_return:
2037     return_current(NULL);
2038     break;
2039 
2040   case Bytecodes::_ireturn:
2041   case Bytecodes::_areturn:
2042   case Bytecodes::_freturn:
2043     return_current(pop());
2044     break;
2045   case Bytecodes::_lreturn:
2046     return_current(pop_pair());
2047     break;
2048   case Bytecodes::_dreturn:
2049     return_current(pop_pair());
2050     break;
2051 
2052   case Bytecodes::_athrow:
2053     // null exception oop throws NULL pointer exception
2054     do_null_check(peek(), T_OBJECT);
2055     if (stopped())  return;
2056     if (env()->jvmti_can_post_exceptions()) {
2057 
2058           if (CheckExceptionEventsNeeded) {
2059                 // if the exception capability is set, then we will generate a
2060                 // runtime call to see if we actually need to report exception
2061                 // events.  If we don't need to report exception events, we will
2062                 // take the normal fast path provided by add_exception_events.
2063                 // If exception event reporting is enabled, we will take the
2064                 // uncommon_trap in the BuildCutout below.
2065                 
2066                 // call C++ runtime routine to determine whether we need to
2067                 // report exception events
2068                 Node* c = make_runtime_call(RC_LEAF, OptoRuntime::must_post_exception_events_Type(),
2069                                                                         CAST_FROM_FN_PTR(address, JvmtiExport::must_post_exception_events_jrt_leaf),
2070                                                                         "must_post_exception_events", NULL   //no memory effects
2071                   );
2072                 
2073                 Node* need_exc_bool = _gvn.transform(new (C, 1) ProjNode(c, TypeFunc::Parms + 0));
2074                 
2075                 // Test the result returned by the runtime call vs. 0
2076                 Node* zero = _gvn.intcon(0);
2077                 Node* chk = _gvn.transform( new (C, 3) CmpINode(need_exc_bool, zero) );
2078                 BoolTest::mask btesteq = BoolTest::eq;
2079                 Node* tst = _gvn.transform( new (C, 2) BoolNode(chk, btesteq) );
2080                 
2081                 // Branch to slow_path if runtime call returned true
2082                 { BuildCutout unless(this, tst, PROB_MAX);
2083                   // "Full-speed throwing" is not necessary here,
2084                   // since we're notifying the VM on every throw.
2085                   uncommon_trap(Deoptimization::Reason_unhandled,
2086                                                 Deoptimization::Action_none);
2087                 }
2088                 // this is the fast path
2089                 add_exception_state(make_exception_state(peek()));
2090                 return;
2091           }
2092           else {
2093                 // CheckExceptionEventsNeeded=false
2094                 // this is the code that always generated the slow path
2095                 // "Full-speed throwing" is not necessary here,
2096                 // since we're notifying the VM on every throw.
2097                 uncommon_trap(Deoptimization::Reason_unhandled,
2098                                           Deoptimization::Action_none);
2099                 return;
2100           }
2101     }
2102     // Hook the thrown exception directly to subsequent handlers.
2103     if (BailoutToInterpreterForThrows) {
2104       // Keep method interpreted from now on.
2105       uncommon_trap(Deoptimization::Reason_unhandled,
2106                     Deoptimization::Action_make_not_compilable);
2107       return;
2108     }
2109     add_exception_state(make_exception_state(peek()));
2110     break;
2111 
2112   case Bytecodes::_goto:   // fall through
2113   case Bytecodes::_goto_w: {
2114     int target_bci = (bc() == Bytecodes::_goto) ? iter().get_dest() : iter().get_far_dest();
2115 
2116     // If this is a backwards branch in the bytecodes, add Safepoint
2117     maybe_add_safepoint(target_bci);
2118 
2119     // Update method data
2120     profile_taken_branch(target_bci);
2121 
2122     // Merge the current control into the target basic block
2123     merge(target_bci);
2124 
2125     // See if we can get some profile data and hand it off to the next block
2126     Block *target_block = block()->successor_for_bci(target_bci);
2127     if (target_block->pred_count() != 1)  break;
2128     ciMethodData* methodData = method()->method_data();
2129     if (!methodData->is_mature())  break;
2130     ciProfileData* data = methodData->bci_to_data(bci());
2131     assert( data->is_JumpData(), "" );
2132     int taken = ((ciJumpData*)data)->taken();
2133     taken = method()->scale_count(taken);
2134     target_block->set_count(taken);
2135     break;
2136   }
2137 
2138   case Bytecodes::_ifnull:    btest = BoolTest::eq; goto handle_if_null;
2139   case Bytecodes::_ifnonnull: btest = BoolTest::ne; goto handle_if_null;
2140   handle_if_null:
2141     // If this is a backwards branch in the bytecodes, add Safepoint
2142     maybe_add_safepoint(iter().get_dest());
2143     a = null();
2144     b = pop();
2145     c = _gvn.transform( new (C, 3) CmpPNode(b, a) );
2146     do_ifnull(btest, c);
2147     break;
2148 
2149   case Bytecodes::_if_acmpeq: btest = BoolTest::eq; goto handle_if_acmp;
2150   case Bytecodes::_if_acmpne: btest = BoolTest::ne; goto handle_if_acmp;
2151   handle_if_acmp:
2152     // If this is a backwards branch in the bytecodes, add Safepoint
2153     maybe_add_safepoint(iter().get_dest());
2154     a = pop();
2155     b = pop();
2156     c = _gvn.transform( new (C, 3) CmpPNode(b, a) );
2157     do_if(btest, c);
2158     break;
2159 
2160   case Bytecodes::_ifeq: btest = BoolTest::eq; goto handle_ifxx;
2161   case Bytecodes::_ifne: btest = BoolTest::ne; goto handle_ifxx;
2162   case Bytecodes::_iflt: btest = BoolTest::lt; goto handle_ifxx;
2163   case Bytecodes::_ifle: btest = BoolTest::le; goto handle_ifxx;
2164   case Bytecodes::_ifgt: btest = BoolTest::gt; goto handle_ifxx;
2165   case Bytecodes::_ifge: btest = BoolTest::ge; goto handle_ifxx;
2166   handle_ifxx:
2167     // If this is a backwards branch in the bytecodes, add Safepoint
2168     maybe_add_safepoint(iter().get_dest());
2169     a = _gvn.intcon(0);
2170     b = pop();
2171     c = _gvn.transform( new (C, 3) CmpINode(b, a) );
2172     do_if(btest, c);
2173     break;
2174 
2175   case Bytecodes::_if_icmpeq: btest = BoolTest::eq; goto handle_if_icmp;
2176   case Bytecodes::_if_icmpne: btest = BoolTest::ne; goto handle_if_icmp;
2177   case Bytecodes::_if_icmplt: btest = BoolTest::lt; goto handle_if_icmp;
2178   case Bytecodes::_if_icmple: btest = BoolTest::le; goto handle_if_icmp;
2179   case Bytecodes::_if_icmpgt: btest = BoolTest::gt; goto handle_if_icmp;
2180   case Bytecodes::_if_icmpge: btest = BoolTest::ge; goto handle_if_icmp;
2181   handle_if_icmp:
2182     // If this is a backwards branch in the bytecodes, add Safepoint
2183     maybe_add_safepoint(iter().get_dest());
2184     a = pop();
2185     b = pop();
2186     c = _gvn.transform( new (C, 3) CmpINode( b, a ) );
2187     do_if(btest, c);
2188     break;
2189 
2190   case Bytecodes::_tableswitch:
2191     do_tableswitch();
2192     break;
2193 
2194   case Bytecodes::_lookupswitch:
2195     do_lookupswitch();
2196     break;
2197 
2198   case Bytecodes::_invokestatic:
2199   case Bytecodes::_invokedynamic:
2200   case Bytecodes::_invokespecial:
2201   case Bytecodes::_invokevirtual:
2202   case Bytecodes::_invokeinterface:
2203     do_call();
2204     break;
2205   case Bytecodes::_checkcast:
2206     do_checkcast();
2207     break;
2208   case Bytecodes::_instanceof:
2209     do_instanceof();
2210     break;
2211   case Bytecodes::_anewarray:
2212     do_anewarray();
2213     break;
2214   case Bytecodes::_newarray:
2215     do_newarray((BasicType)iter().get_index());
2216     break;
2217   case Bytecodes::_multianewarray:
2218     do_multianewarray();
2219     break;
2220   case Bytecodes::_new:
2221     do_new();
2222     break;
2223 
2224   case Bytecodes::_jsr:
2225   case Bytecodes::_jsr_w:
2226     do_jsr();
2227     break;
2228 
2229   case Bytecodes::_ret:
2230     do_ret();
2231     break;
2232 
2233 
2234   case Bytecodes::_monitorenter:
2235     do_monitor_enter();
2236     break;
2237 
2238   case Bytecodes::_monitorexit:
2239     do_monitor_exit();
2240     break;
2241 
2242   case Bytecodes::_breakpoint:
2243     // Breakpoint set concurrently to compile
2244     // %%% use an uncommon trap?
2245     C->record_failure("breakpoint in method");
2246     return;
2247 
2248   default:
2249 #ifndef PRODUCT
2250     map()->dump(99);
2251 #endif
2252     tty->print("\nUnhandled bytecode %s\n", Bytecodes::name(bc()) );
2253     ShouldNotReachHere();
2254   }
2255 
2256 #ifndef PRODUCT
2257   IdealGraphPrinter *printer = IdealGraphPrinter::printer();
2258   if(printer) {
2259     char buffer[256];
2260     sprintf(buffer, "Bytecode %d: %s", bci(), Bytecodes::name(bc()));
2261     bool old = printer->traverse_outs();
2262     printer->set_traverse_outs(true);
2263     printer->print_method(C, buffer, 4);
2264     printer->set_traverse_outs(old);
2265   }
2266 #endif
2267 }