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