1 /*
   2  * Copyright (c) 1998, 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "ci/ciMethodData.hpp"
  27 #include "classfile/systemDictionary.hpp"
  28 #include "classfile/vmSymbols.hpp"
  29 #include "compiler/compileLog.hpp"
  30 #include "interpreter/linkResolver.hpp"
  31 #include "memory/universe.inline.hpp"
  32 #include "opto/addnode.hpp"
  33 #include "opto/castnode.hpp"
  34 #include "opto/convertnode.hpp"
  35 #include "opto/divnode.hpp"
  36 #include "opto/idealGraphPrinter.hpp"
  37 #include "opto/matcher.hpp"
  38 #include "opto/memnode.hpp"
  39 #include "opto/mulnode.hpp"
  40 #include "opto/parse.hpp"
  41 #include "opto/runtime.hpp"
  42 #include "runtime/deoptimization.hpp"
  43 #include "runtime/sharedRuntime.hpp"
  44 
  45 extern int explicit_null_checks_inserted,
  46            explicit_null_checks_elided;
  47 
  48 //---------------------------------array_load----------------------------------
  49 void Parse::array_load(BasicType elem_type) {
  50   const Type* elem = Type::TOP;
  51   Node* adr = array_addressing(elem_type, 0, &elem);
  52   if (stopped())  return;     // guaranteed null or range check
  53   dec_sp(2);                  // Pop array and index
  54   const TypeAryPtr* adr_type = TypeAryPtr::get_array_body_type(elem_type);
  55   Node* ld = make_load(control(), adr, elem, elem_type, adr_type, MemNode::unordered);
  56   push(ld);
  57 }
  58 
  59 
  60 //--------------------------------array_store----------------------------------
  61 void Parse::array_store(BasicType elem_type) {
  62   Node* adr = array_addressing(elem_type, 1);
  63   if (stopped())  return;     // guaranteed null or range check
  64   Node* val = pop();
  65   dec_sp(2);                  // Pop array and index
  66   const TypeAryPtr* adr_type = TypeAryPtr::get_array_body_type(elem_type);
  67   store_to_memory(control(), adr, val, elem_type, adr_type, StoreNode::release_if_reference(elem_type));
  68 }
  69 
  70 
  71 //------------------------------array_addressing-------------------------------
  72 // Pull array and index from the stack.  Compute pointer-to-element.
  73 Node* Parse::array_addressing(BasicType type, int vals, const Type* *result2) {
  74   Node *idx   = peek(0+vals);   // Get from stack without popping
  75   Node *ary   = peek(1+vals);   // in case of exception
  76 
  77   // Null check the array base, with correct stack contents
  78   ary = null_check(ary, T_ARRAY);
  79   // Compile-time detect of null-exception?
  80   if (stopped())  return top();
  81 
  82   const TypeAryPtr* arytype  = _gvn.type(ary)->is_aryptr();
  83   const TypeInt*    sizetype = arytype->size();
  84   const Type*       elemtype = arytype->elem();
  85 
  86   if (UseUniqueSubclasses && result2 != NULL) {
  87     const Type* el = elemtype->make_ptr();
  88     if (el && el->isa_instptr()) {
  89       const TypeInstPtr* toop = el->is_instptr();
  90       if (toop->klass()->as_instance_klass()->unique_concrete_subklass()) {
  91         // If we load from "AbstractClass[]" we must see "ConcreteSubClass".
  92         const Type* subklass = Type::get_const_type(toop->klass());
  93         elemtype = subklass->join_speculative(el);
  94       }
  95     }
  96   }
  97 
  98   // Check for big class initializers with all constant offsets
  99   // feeding into a known-size array.
 100   const TypeInt* idxtype = _gvn.type(idx)->is_int();
 101   // See if the highest idx value is less than the lowest array bound,
 102   // and if the idx value cannot be negative:
 103   bool need_range_check = true;
 104   if (idxtype->_hi < sizetype->_lo && idxtype->_lo >= 0) {
 105     need_range_check = false;
 106     if (C->log() != NULL)   C->log()->elem("observe that='!need_range_check'");
 107   }
 108 
 109   ciKlass * arytype_klass = arytype->klass();
 110   if ((arytype_klass != NULL) && (!arytype_klass->is_loaded())) {
 111     // Only fails for some -Xcomp runs
 112     // The class is unloaded.  We have to run this bytecode in the interpreter.
 113     uncommon_trap(Deoptimization::Reason_unloaded,
 114                   Deoptimization::Action_reinterpret,
 115                   arytype->klass(), "!loaded array");
 116     return top();
 117   }
 118 
 119   // Do the range check
 120   if (GenerateRangeChecks && need_range_check) {
 121     Node* tst;
 122     if (sizetype->_hi <= 0) {
 123       // The greatest array bound is negative, so we can conclude that we're
 124       // compiling unreachable code, but the unsigned compare trick used below
 125       // only works with non-negative lengths.  Instead, hack "tst" to be zero so
 126       // the uncommon_trap path will always be taken.
 127       tst = _gvn.intcon(0);
 128     } else {
 129       // Range is constant in array-oop, so we can use the original state of mem
 130       Node* len = load_array_length(ary);
 131 
 132       // Test length vs index (standard trick using unsigned compare)
 133       Node* chk = _gvn.transform( new CmpUNode(idx, len) );
 134       BoolTest::mask btest = BoolTest::lt;
 135       tst = _gvn.transform( new BoolNode(chk, btest) );
 136     }
 137     // Branch to failure if out of bounds
 138     { BuildCutout unless(this, tst, PROB_MAX);
 139       if (C->allow_range_check_smearing()) {
 140         // Do not use builtin_throw, since range checks are sometimes
 141         // made more stringent by an optimistic transformation.
 142         // This creates "tentative" range checks at this point,
 143         // which are not guaranteed to throw exceptions.
 144         // See IfNode::Ideal, is_range_check, adjust_check.
 145         uncommon_trap(Deoptimization::Reason_range_check,
 146                       Deoptimization::Action_make_not_entrant,
 147                       NULL, "range_check");
 148       } else {
 149         // If we have already recompiled with the range-check-widening
 150         // heroic optimization turned off, then we must really be throwing
 151         // range check exceptions.
 152         builtin_throw(Deoptimization::Reason_range_check, idx);
 153       }
 154     }
 155   }
 156   // Check for always knowing you are throwing a range-check exception
 157   if (stopped())  return top();
 158 
 159   Node* ptr = array_element_address(ary, idx, type, sizetype);
 160 
 161   if (result2 != NULL)  *result2 = elemtype;
 162 
 163   assert(ptr != top(), "top should go hand-in-hand with stopped");
 164 
 165   return ptr;
 166 }
 167 
 168 
 169 // returns IfNode
 170 IfNode* Parse::jump_if_fork_int(Node* a, Node* b, BoolTest::mask mask) {
 171   Node   *cmp = _gvn.transform( new CmpINode( a, b)); // two cases: shiftcount > 32 and shiftcount <= 32
 172   Node   *tst = _gvn.transform( new BoolNode( cmp, mask));
 173   IfNode *iff = create_and_map_if( control(), tst, ((mask == BoolTest::eq) ? PROB_STATIC_INFREQUENT : PROB_FAIR), COUNT_UNKNOWN );
 174   return iff;
 175 }
 176 
 177 // return Region node
 178 Node* Parse::jump_if_join(Node* iffalse, Node* iftrue) {
 179   Node *region  = new RegionNode(3); // 2 results
 180   record_for_igvn(region);
 181   region->init_req(1, iffalse);
 182   region->init_req(2, iftrue );
 183   _gvn.set_type(region, Type::CONTROL);
 184   region = _gvn.transform(region);
 185   set_control (region);
 186   return region;
 187 }
 188 
 189 
 190 //------------------------------helper for tableswitch-------------------------
 191 void Parse::jump_if_true_fork(IfNode *iff, int dest_bci_if_true, int prof_table_index) {
 192   // True branch, use existing map info
 193   { PreserveJVMState pjvms(this);
 194     Node *iftrue  = _gvn.transform( new IfTrueNode (iff) );
 195     set_control( iftrue );
 196     profile_switch_case(prof_table_index);
 197     merge_new_path(dest_bci_if_true);
 198   }
 199 
 200   // False branch
 201   Node *iffalse = _gvn.transform( new IfFalseNode(iff) );
 202   set_control( iffalse );
 203 }
 204 
 205 void Parse::jump_if_false_fork(IfNode *iff, int dest_bci_if_true, int prof_table_index) {
 206   // True branch, use existing map info
 207   { PreserveJVMState pjvms(this);
 208     Node *iffalse  = _gvn.transform( new IfFalseNode (iff) );
 209     set_control( iffalse );
 210     profile_switch_case(prof_table_index);
 211     merge_new_path(dest_bci_if_true);
 212   }
 213 
 214   // False branch
 215   Node *iftrue = _gvn.transform( new IfTrueNode(iff) );
 216   set_control( iftrue );
 217 }
 218 
 219 void Parse::jump_if_always_fork(int dest_bci, int prof_table_index) {
 220   // False branch, use existing map and control()
 221   profile_switch_case(prof_table_index);
 222   merge_new_path(dest_bci);
 223 }
 224 
 225 
 226 extern "C" {
 227   static int jint_cmp(const void *i, const void *j) {
 228     int a = *(jint *)i;
 229     int b = *(jint *)j;
 230     return a > b ? 1 : a < b ? -1 : 0;
 231   }
 232 }
 233 
 234 
 235 // Default value for methodData switch indexing. Must be a negative value to avoid
 236 // conflict with any legal switch index.
 237 #define NullTableIndex -1
 238 
 239 class SwitchRange : public StackObj {
 240   // a range of integers coupled with a bci destination
 241   jint _lo;                     // inclusive lower limit
 242   jint _hi;                     // inclusive upper limit
 243   int _dest;
 244   int _table_index;             // index into method data table
 245 
 246 public:
 247   jint lo() const              { return _lo;   }
 248   jint hi() const              { return _hi;   }
 249   int  dest() const            { return _dest; }
 250   int  table_index() const     { return _table_index; }
 251   bool is_singleton() const    { return _lo == _hi; }
 252 
 253   void setRange(jint lo, jint hi, int dest, int table_index) {
 254     assert(lo <= hi, "must be a non-empty range");
 255     _lo = lo, _hi = hi; _dest = dest; _table_index = table_index;
 256   }
 257   bool adjoinRange(jint lo, jint hi, int dest, int table_index) {
 258     assert(lo <= hi, "must be a non-empty range");
 259     if (lo == _hi+1 && dest == _dest && table_index == _table_index) {
 260       _hi = hi;
 261       return true;
 262     }
 263     return false;
 264   }
 265 
 266   void set (jint value, int dest, int table_index) {
 267     setRange(value, value, dest, table_index);
 268   }
 269   bool adjoin(jint value, int dest, int table_index) {
 270     return adjoinRange(value, value, dest, table_index);
 271   }
 272 
 273   void print() {
 274     if (is_singleton())
 275       tty->print(" {%d}=>%d", lo(), dest());
 276     else if (lo() == min_jint)
 277       tty->print(" {..%d}=>%d", hi(), dest());
 278     else if (hi() == max_jint)
 279       tty->print(" {%d..}=>%d", lo(), dest());
 280     else
 281       tty->print(" {%d..%d}=>%d", lo(), hi(), dest());
 282   }
 283 };
 284 
 285 
 286 //-------------------------------do_tableswitch--------------------------------
 287 void Parse::do_tableswitch() {
 288   Node* lookup = pop();
 289 
 290   // Get information about tableswitch
 291   int default_dest = iter().get_dest_table(0);
 292   int lo_index     = iter().get_int_table(1);
 293   int hi_index     = iter().get_int_table(2);
 294   int len          = hi_index - lo_index + 1;
 295 
 296   if (len < 1) {
 297     // If this is a backward branch, add safepoint
 298     maybe_add_safepoint(default_dest);
 299     merge(default_dest);
 300     return;
 301   }
 302 
 303   // generate decision tree, using trichotomy when possible
 304   int rnum = len+2;
 305   bool makes_backward_branch = false;
 306   SwitchRange* ranges = NEW_RESOURCE_ARRAY(SwitchRange, rnum);
 307   int rp = -1;
 308   if (lo_index != min_jint) {
 309     ranges[++rp].setRange(min_jint, lo_index-1, default_dest, NullTableIndex);
 310   }
 311   for (int j = 0; j < len; j++) {
 312     jint match_int = lo_index+j;
 313     int  dest      = iter().get_dest_table(j+3);
 314     makes_backward_branch |= (dest <= bci());
 315     int  table_index = method_data_update() ? j : NullTableIndex;
 316     if (rp < 0 || !ranges[rp].adjoin(match_int, dest, table_index)) {
 317       ranges[++rp].set(match_int, dest, table_index);
 318     }
 319   }
 320   jint highest = lo_index+(len-1);
 321   assert(ranges[rp].hi() == highest, "");
 322   if (highest != max_jint
 323       && !ranges[rp].adjoinRange(highest+1, max_jint, default_dest, NullTableIndex)) {
 324     ranges[++rp].setRange(highest+1, max_jint, default_dest, NullTableIndex);
 325   }
 326   assert(rp < len+2, "not too many ranges");
 327 
 328   // Safepoint in case if backward branch observed
 329   if( makes_backward_branch && UseLoopSafepoints )
 330     add_safepoint();
 331 
 332   jump_switch_ranges(lookup, &ranges[0], &ranges[rp]);
 333 }
 334 
 335 
 336 //------------------------------do_lookupswitch--------------------------------
 337 void Parse::do_lookupswitch() {
 338   Node *lookup = pop();         // lookup value
 339   // Get information about lookupswitch
 340   int default_dest = iter().get_dest_table(0);
 341   int len          = iter().get_int_table(1);
 342 
 343   if (len < 1) {    // If this is a backward branch, add safepoint
 344     maybe_add_safepoint(default_dest);
 345     merge(default_dest);
 346     return;
 347   }
 348 
 349   // generate decision tree, using trichotomy when possible
 350   jint* table = NEW_RESOURCE_ARRAY(jint, len*2);
 351   {
 352     for( int j = 0; j < len; j++ ) {
 353       table[j+j+0] = iter().get_int_table(2+j+j);
 354       table[j+j+1] = iter().get_dest_table(2+j+j+1);
 355     }
 356     qsort( table, len, 2*sizeof(table[0]), jint_cmp );
 357   }
 358 
 359   int rnum = len*2+1;
 360   bool makes_backward_branch = false;
 361   SwitchRange* ranges = NEW_RESOURCE_ARRAY(SwitchRange, rnum);
 362   int rp = -1;
 363   for( int j = 0; j < len; j++ ) {
 364     jint match_int   = table[j+j+0];
 365     int  dest        = table[j+j+1];
 366     int  next_lo     = rp < 0 ? min_jint : ranges[rp].hi()+1;
 367     int  table_index = method_data_update() ? j : NullTableIndex;
 368     makes_backward_branch |= (dest <= bci());
 369     if( match_int != next_lo ) {
 370       ranges[++rp].setRange(next_lo, match_int-1, default_dest, NullTableIndex);
 371     }
 372     if( rp < 0 || !ranges[rp].adjoin(match_int, dest, table_index) ) {
 373       ranges[++rp].set(match_int, dest, table_index);
 374     }
 375   }
 376   jint highest = table[2*(len-1)];
 377   assert(ranges[rp].hi() == highest, "");
 378   if( highest != max_jint
 379       && !ranges[rp].adjoinRange(highest+1, max_jint, default_dest, NullTableIndex) ) {
 380     ranges[++rp].setRange(highest+1, max_jint, default_dest, NullTableIndex);
 381   }
 382   assert(rp < rnum, "not too many ranges");
 383 
 384   // Safepoint in case backward branch observed
 385   if( makes_backward_branch && UseLoopSafepoints )
 386     add_safepoint();
 387 
 388   jump_switch_ranges(lookup, &ranges[0], &ranges[rp]);
 389 }
 390 
 391 //----------------------------create_jump_tables-------------------------------
 392 bool Parse::create_jump_tables(Node* key_val, SwitchRange* lo, SwitchRange* hi) {
 393   // Are jumptables enabled
 394   if (!UseJumpTables)  return false;
 395 
 396   // Are jumptables supported
 397   if (!Matcher::has_match_rule(Op_Jump))  return false;
 398 
 399   // Don't make jump table if profiling
 400   if (method_data_update())  return false;
 401 
 402   // Decide if a guard is needed to lop off big ranges at either (or
 403   // both) end(s) of the input set. We'll call this the default target
 404   // even though we can't be sure that it is the true "default".
 405 
 406   bool needs_guard = false;
 407   int default_dest;
 408   int64_t total_outlier_size = 0;
 409   int64_t hi_size = ((int64_t)hi->hi()) - ((int64_t)hi->lo()) + 1;
 410   int64_t lo_size = ((int64_t)lo->hi()) - ((int64_t)lo->lo()) + 1;
 411 
 412   if (lo->dest() == hi->dest()) {
 413     total_outlier_size = hi_size + lo_size;
 414     default_dest = lo->dest();
 415   } else if (lo_size > hi_size) {
 416     total_outlier_size = lo_size;
 417     default_dest = lo->dest();
 418   } else {
 419     total_outlier_size = hi_size;
 420     default_dest = hi->dest();
 421   }
 422 
 423   // If a guard test will eliminate very sparse end ranges, then
 424   // it is worth the cost of an extra jump.
 425   if (total_outlier_size > (MaxJumpTableSparseness * 4)) {
 426     needs_guard = true;
 427     if (default_dest == lo->dest()) lo++;
 428     if (default_dest == hi->dest()) hi--;
 429   }
 430 
 431   // Find the total number of cases and ranges
 432   int64_t num_cases = ((int64_t)hi->hi()) - ((int64_t)lo->lo()) + 1;
 433   int num_range = hi - lo + 1;
 434 
 435   // Don't create table if: too large, too small, or too sparse.
 436   if (num_cases < MinJumpTableSize || num_cases > MaxJumpTableSize)
 437     return false;
 438   if (num_cases > (MaxJumpTableSparseness * num_range))
 439     return false;
 440 
 441   // Normalize table lookups to zero
 442   int lowval = lo->lo();
 443   key_val = _gvn.transform( new SubINode(key_val, _gvn.intcon(lowval)) );
 444 
 445   // Generate a guard to protect against input keyvals that aren't
 446   // in the switch domain.
 447   if (needs_guard) {
 448     Node*   size = _gvn.intcon(num_cases);
 449     Node*   cmp = _gvn.transform( new CmpUNode(key_val, size) );
 450     Node*   tst = _gvn.transform( new BoolNode(cmp, BoolTest::ge) );
 451     IfNode* iff = create_and_map_if( control(), tst, PROB_FAIR, COUNT_UNKNOWN);
 452     jump_if_true_fork(iff, default_dest, NullTableIndex);
 453   }
 454 
 455   // Create an ideal node JumpTable that has projections
 456   // of all possible ranges for a switch statement
 457   // The key_val input must be converted to a pointer offset and scaled.
 458   // Compare Parse::array_addressing above.
 459 #ifdef _LP64
 460   // Clean the 32-bit int into a real 64-bit offset.
 461   // Otherwise, the jint value 0 might turn into an offset of 0x0800000000.
 462   const TypeLong* lkeytype = TypeLong::make(CONST64(0), num_cases-1, Type::WidenMin);
 463   key_val       = _gvn.transform( new ConvI2LNode(key_val, lkeytype) );
 464 #endif
 465   // Shift the value by wordsize so we have an index into the table, rather
 466   // than a switch value
 467   Node *shiftWord = _gvn.MakeConX(wordSize);
 468   key_val = _gvn.transform( new MulXNode( key_val, shiftWord));
 469 
 470   // Create the JumpNode
 471   Node* jtn = _gvn.transform( new JumpNode(control(), key_val, num_cases) );
 472 
 473   // These are the switch destinations hanging off the jumpnode
 474   int i = 0;
 475   for (SwitchRange* r = lo; r <= hi; r++) {
 476     for (int64_t j = r->lo(); j <= r->hi(); j++, i++) {
 477       Node* input = _gvn.transform(new JumpProjNode(jtn, i, r->dest(), (int)(j - lowval)));
 478       {
 479         PreserveJVMState pjvms(this);
 480         set_control(input);
 481         jump_if_always_fork(r->dest(), r->table_index());
 482       }
 483     }
 484   }
 485   assert(i == num_cases, "miscount of cases");
 486   stop_and_kill_map();  // no more uses for this JVMS
 487   return true;
 488 }
 489 
 490 //----------------------------jump_switch_ranges-------------------------------
 491 void Parse::jump_switch_ranges(Node* key_val, SwitchRange *lo, SwitchRange *hi, int switch_depth) {
 492   Block* switch_block = block();
 493 
 494   if (switch_depth == 0) {
 495     // Do special processing for the top-level call.
 496     assert(lo->lo() == min_jint, "initial range must exhaust Type::INT");
 497     assert(hi->hi() == max_jint, "initial range must exhaust Type::INT");
 498 
 499     // Decrement pred-numbers for the unique set of nodes.
 500 #ifdef ASSERT
 501     // Ensure that the block's successors are a (duplicate-free) set.
 502     int successors_counted = 0;  // block occurrences in [hi..lo]
 503     int unique_successors = switch_block->num_successors();
 504     for (int i = 0; i < unique_successors; i++) {
 505       Block* target = switch_block->successor_at(i);
 506 
 507       // Check that the set of successors is the same in both places.
 508       int successors_found = 0;
 509       for (SwitchRange* p = lo; p <= hi; p++) {
 510         if (p->dest() == target->start())  successors_found++;
 511       }
 512       assert(successors_found > 0, "successor must be known");
 513       successors_counted += successors_found;
 514     }
 515     assert(successors_counted == (hi-lo)+1, "no unexpected successors");
 516 #endif
 517 
 518     // Maybe prune the inputs, based on the type of key_val.
 519     jint min_val = min_jint;
 520     jint max_val = max_jint;
 521     const TypeInt* ti = key_val->bottom_type()->isa_int();
 522     if (ti != NULL) {
 523       min_val = ti->_lo;
 524       max_val = ti->_hi;
 525       assert(min_val <= max_val, "invalid int type");
 526     }
 527     while (lo->hi() < min_val)  lo++;
 528     if (lo->lo() < min_val)  lo->setRange(min_val, lo->hi(), lo->dest(), lo->table_index());
 529     while (hi->lo() > max_val)  hi--;
 530     if (hi->hi() > max_val)  hi->setRange(hi->lo(), max_val, hi->dest(), hi->table_index());
 531   }
 532 
 533 #ifndef PRODUCT
 534   if (switch_depth == 0) {
 535     _max_switch_depth = 0;
 536     _est_switch_depth = log2_intptr((hi-lo+1)-1)+1;
 537   }
 538 #endif
 539 
 540   assert(lo <= hi, "must be a non-empty set of ranges");
 541   if (lo == hi) {
 542     jump_if_always_fork(lo->dest(), lo->table_index());
 543   } else {
 544     assert(lo->hi() == (lo+1)->lo()-1, "contiguous ranges");
 545     assert(hi->lo() == (hi-1)->hi()+1, "contiguous ranges");
 546 
 547     if (create_jump_tables(key_val, lo, hi)) return;
 548 
 549     int nr = hi - lo + 1;
 550 
 551     SwitchRange* mid = lo + nr/2;
 552     // if there is an easy choice, pivot at a singleton:
 553     if (nr > 3 && !mid->is_singleton() && (mid-1)->is_singleton())  mid--;
 554 
 555     assert(lo < mid && mid <= hi, "good pivot choice");
 556     assert(nr != 2 || mid == hi,   "should pick higher of 2");
 557     assert(nr != 3 || mid == hi-1, "should pick middle of 3");
 558 
 559     Node *test_val = _gvn.intcon(mid->lo());
 560 
 561     if (mid->is_singleton()) {
 562       IfNode *iff_ne = jump_if_fork_int(key_val, test_val, BoolTest::ne);
 563       jump_if_false_fork(iff_ne, mid->dest(), mid->table_index());
 564 
 565       // Special Case:  If there are exactly three ranges, and the high
 566       // and low range each go to the same place, omit the "gt" test,
 567       // since it will not discriminate anything.
 568       bool eq_test_only = (hi == lo+2 && hi->dest() == lo->dest());
 569       if (eq_test_only) {
 570         assert(mid == hi-1, "");
 571       }
 572 
 573       // if there is a higher range, test for it and process it:
 574       if (mid < hi && !eq_test_only) {
 575         // two comparisons of same values--should enable 1 test for 2 branches
 576         // Use BoolTest::le instead of BoolTest::gt
 577         IfNode *iff_le  = jump_if_fork_int(key_val, test_val, BoolTest::le);
 578         Node   *iftrue  = _gvn.transform( new IfTrueNode(iff_le) );
 579         Node   *iffalse = _gvn.transform( new IfFalseNode(iff_le) );
 580         { PreserveJVMState pjvms(this);
 581           set_control(iffalse);
 582           jump_switch_ranges(key_val, mid+1, hi, switch_depth+1);
 583         }
 584         set_control(iftrue);
 585       }
 586 
 587     } else {
 588       // mid is a range, not a singleton, so treat mid..hi as a unit
 589       IfNode *iff_ge = jump_if_fork_int(key_val, test_val, BoolTest::ge);
 590 
 591       // if there is a higher range, test for it and process it:
 592       if (mid == hi) {
 593         jump_if_true_fork(iff_ge, mid->dest(), mid->table_index());
 594       } else {
 595         Node *iftrue  = _gvn.transform( new IfTrueNode(iff_ge) );
 596         Node *iffalse = _gvn.transform( new IfFalseNode(iff_ge) );
 597         { PreserveJVMState pjvms(this);
 598           set_control(iftrue);
 599           jump_switch_ranges(key_val, mid, hi, switch_depth+1);
 600         }
 601         set_control(iffalse);
 602       }
 603     }
 604 
 605     // in any case, process the lower range
 606     jump_switch_ranges(key_val, lo, mid-1, switch_depth+1);
 607   }
 608 
 609   // Decrease pred_count for each successor after all is done.
 610   if (switch_depth == 0) {
 611     int unique_successors = switch_block->num_successors();
 612     for (int i = 0; i < unique_successors; i++) {
 613       Block* target = switch_block->successor_at(i);
 614       // Throw away the pre-allocated path for each unique successor.
 615       target->next_path_num();
 616     }
 617   }
 618 
 619 #ifndef PRODUCT
 620   _max_switch_depth = MAX2(switch_depth, _max_switch_depth);
 621   if (TraceOptoParse && Verbose && WizardMode && switch_depth == 0) {
 622     SwitchRange* r;
 623     int nsing = 0;
 624     for( r = lo; r <= hi; r++ ) {
 625       if( r->is_singleton() )  nsing++;
 626     }
 627     tty->print(">>> ");
 628     _method->print_short_name();
 629     tty->print_cr(" switch decision tree");
 630     tty->print_cr("    %d ranges (%d singletons), max_depth=%d, est_depth=%d",
 631                   (int) (hi-lo+1), nsing, _max_switch_depth, _est_switch_depth);
 632     if (_max_switch_depth > _est_switch_depth) {
 633       tty->print_cr("******** BAD SWITCH DEPTH ********");
 634     }
 635     tty->print("   ");
 636     for( r = lo; r <= hi; r++ ) {
 637       r->print();
 638     }
 639     tty->cr();
 640   }
 641 #endif
 642 }
 643 
 644 void Parse::modf() {
 645   Node *f2 = pop();
 646   Node *f1 = pop();
 647   Node* c = make_runtime_call(RC_LEAF, OptoRuntime::modf_Type(),
 648                               CAST_FROM_FN_PTR(address, SharedRuntime::frem),
 649                               "frem", NULL, //no memory effects
 650                               f1, f2);
 651   Node* res = _gvn.transform(new ProjNode(c, TypeFunc::Parms + 0));
 652 
 653   push(res);
 654 }
 655 
 656 void Parse::modd() {
 657   Node *d2 = pop_pair();
 658   Node *d1 = pop_pair();
 659   Node* c = make_runtime_call(RC_LEAF, OptoRuntime::Math_DD_D_Type(),
 660                               CAST_FROM_FN_PTR(address, SharedRuntime::drem),
 661                               "drem", NULL, //no memory effects
 662                               d1, top(), d2, top());
 663   Node* res_d   = _gvn.transform(new ProjNode(c, TypeFunc::Parms + 0));
 664 
 665 #ifdef ASSERT
 666   Node* res_top = _gvn.transform(new ProjNode(c, TypeFunc::Parms + 1));
 667   assert(res_top == top(), "second value must be top");
 668 #endif
 669 
 670   push_pair(res_d);
 671 }
 672 
 673 void Parse::l2f() {
 674   Node* f2 = pop();
 675   Node* f1 = pop();
 676   Node* c = make_runtime_call(RC_LEAF, OptoRuntime::l2f_Type(),
 677                               CAST_FROM_FN_PTR(address, SharedRuntime::l2f),
 678                               "l2f", NULL, //no memory effects
 679                               f1, f2);
 680   Node* res = _gvn.transform(new ProjNode(c, TypeFunc::Parms + 0));
 681 
 682   push(res);
 683 }
 684 
 685 void Parse::do_irem() {
 686   // Must keep both values on the expression-stack during null-check
 687   zero_check_int(peek());
 688   // Compile-time detect of null-exception?
 689   if (stopped())  return;
 690 
 691   Node* b = pop();
 692   Node* a = pop();
 693 
 694   const Type *t = _gvn.type(b);
 695   if (t != Type::TOP) {
 696     const TypeInt *ti = t->is_int();
 697     if (ti->is_con()) {
 698       int divisor = ti->get_con();
 699       // check for positive power of 2
 700       if (divisor > 0 &&
 701           (divisor & ~(divisor-1)) == divisor) {
 702         // yes !
 703         Node *mask = _gvn.intcon((divisor - 1));
 704         // Sigh, must handle negative dividends
 705         Node *zero = _gvn.intcon(0);
 706         IfNode *ifff = jump_if_fork_int(a, zero, BoolTest::lt);
 707         Node *iff = _gvn.transform( new IfFalseNode(ifff) );
 708         Node *ift = _gvn.transform( new IfTrueNode (ifff) );
 709         Node *reg = jump_if_join(ift, iff);
 710         Node *phi = PhiNode::make(reg, NULL, TypeInt::INT);
 711         // Negative path; negate/and/negate
 712         Node *neg = _gvn.transform( new SubINode(zero, a) );
 713         Node *andn= _gvn.transform( new AndINode(neg, mask) );
 714         Node *negn= _gvn.transform( new SubINode(zero, andn) );
 715         phi->init_req(1, negn);
 716         // Fast positive case
 717         Node *andx = _gvn.transform( new AndINode(a, mask) );
 718         phi->init_req(2, andx);
 719         // Push the merge
 720         push( _gvn.transform(phi) );
 721         return;
 722       }
 723     }
 724   }
 725   // Default case
 726   push( _gvn.transform( new ModINode(control(),a,b) ) );
 727 }
 728 
 729 // Handle jsr and jsr_w bytecode
 730 void Parse::do_jsr() {
 731   assert(bc() == Bytecodes::_jsr || bc() == Bytecodes::_jsr_w, "wrong bytecode");
 732 
 733   // Store information about current state, tagged with new _jsr_bci
 734   int return_bci = iter().next_bci();
 735   int jsr_bci    = (bc() == Bytecodes::_jsr) ? iter().get_dest() : iter().get_far_dest();
 736 
 737   // Update method data
 738   profile_taken_branch(jsr_bci);
 739 
 740   // The way we do things now, there is only one successor block
 741   // for the jsr, because the target code is cloned by ciTypeFlow.
 742   Block* target = successor_for_bci(jsr_bci);
 743 
 744   // What got pushed?
 745   const Type* ret_addr = target->peek();
 746   assert(ret_addr->singleton(), "must be a constant (cloned jsr body)");
 747 
 748   // Effect on jsr on stack
 749   push(_gvn.makecon(ret_addr));
 750 
 751   // Flow to the jsr.
 752   merge(jsr_bci);
 753 }
 754 
 755 // Handle ret bytecode
 756 void Parse::do_ret() {
 757   // Find to whom we return.
 758   assert(block()->num_successors() == 1, "a ret can only go one place now");
 759   Block* target = block()->successor_at(0);
 760   assert(!target->is_ready(), "our arrival must be expected");
 761   profile_ret(target->flow()->start());
 762   int pnum = target->next_path_num();
 763   merge_common(target, pnum);
 764 }
 765 
 766 //--------------------------dynamic_branch_prediction--------------------------
 767 // Try to gather dynamic branch prediction behavior.  Return a probability
 768 // of the branch being taken and set the "cnt" field.  Returns a -1.0
 769 // if we need to use static prediction for some reason.
 770 float Parse::dynamic_branch_prediction(float &cnt) {
 771   ResourceMark rm;
 772 
 773   cnt  = COUNT_UNKNOWN;
 774 
 775   // Use MethodData information if it is available
 776   // FIXME: free the ProfileData structure
 777   ciMethodData* methodData = method()->method_data();
 778   if (!methodData->is_mature())  return PROB_UNKNOWN;
 779   ciProfileData* data = methodData->bci_to_data(bci());
 780   if (!data->is_JumpData())  return PROB_UNKNOWN;
 781 
 782   // get taken and not taken values
 783   int     taken = data->as_JumpData()->taken();
 784   int not_taken = 0;
 785   if (data->is_BranchData()) {
 786     not_taken = data->as_BranchData()->not_taken();
 787   }
 788 
 789   // scale the counts to be commensurate with invocation counts:
 790   taken = method()->scale_count(taken);
 791   not_taken = method()->scale_count(not_taken);
 792 
 793   // Give up if too few (or too many, in which case the sum will overflow) counts to be meaningful.
 794   // We also check that individual counters are positive first, overwise the sum can become positive.
 795   if (taken < 0 || not_taken < 0 || taken + not_taken < 40) {
 796     if (C->log() != NULL) {
 797       C->log()->elem("branch target_bci='%d' taken='%d' not_taken='%d'", iter().get_dest(), taken, not_taken);
 798     }
 799     return PROB_UNKNOWN;
 800   }
 801 
 802   // Compute frequency that we arrive here
 803   float sum = taken + not_taken;
 804   // Adjust, if this block is a cloned private block but the
 805   // Jump counts are shared.  Taken the private counts for
 806   // just this path instead of the shared counts.
 807   if( block()->count() > 0 )
 808     sum = block()->count();
 809   cnt = sum / FreqCountInvocations;
 810 
 811   // Pin probability to sane limits
 812   float prob;
 813   if( !taken )
 814     prob = (0+PROB_MIN) / 2;
 815   else if( !not_taken )
 816     prob = (1+PROB_MAX) / 2;
 817   else {                         // Compute probability of true path
 818     prob = (float)taken / (float)(taken + not_taken);
 819     if (prob > PROB_MAX)  prob = PROB_MAX;
 820     if (prob < PROB_MIN)   prob = PROB_MIN;
 821   }
 822 
 823   assert((cnt > 0.0f) && (prob > 0.0f),
 824          "Bad frequency assignment in if");
 825 
 826   if (C->log() != NULL) {
 827     const char* prob_str = NULL;
 828     if (prob >= PROB_MAX)  prob_str = (prob == PROB_MAX) ? "max" : "always";
 829     if (prob <= PROB_MIN)  prob_str = (prob == PROB_MIN) ? "min" : "never";
 830     char prob_str_buf[30];
 831     if (prob_str == NULL) {
 832       sprintf(prob_str_buf, "%g", prob);
 833       prob_str = prob_str_buf;
 834     }
 835     C->log()->elem("branch target_bci='%d' taken='%d' not_taken='%d' cnt='%g' prob='%s'",
 836                    iter().get_dest(), taken, not_taken, cnt, prob_str);
 837   }
 838   return prob;
 839 }
 840 
 841 //-----------------------------branch_prediction-------------------------------
 842 float Parse::branch_prediction(float& cnt,
 843                                BoolTest::mask btest,
 844                                int target_bci) {
 845   float prob = dynamic_branch_prediction(cnt);
 846   // If prob is unknown, switch to static prediction
 847   if (prob != PROB_UNKNOWN)  return prob;
 848 
 849   prob = PROB_FAIR;                   // Set default value
 850   if (btest == BoolTest::eq)          // Exactly equal test?
 851     prob = PROB_STATIC_INFREQUENT;    // Assume its relatively infrequent
 852   else if (btest == BoolTest::ne)
 853     prob = PROB_STATIC_FREQUENT;      // Assume its relatively frequent
 854 
 855   // If this is a conditional test guarding a backwards branch,
 856   // assume its a loop-back edge.  Make it a likely taken branch.
 857   if (target_bci < bci()) {
 858     if (is_osr_parse()) {    // Could be a hot OSR'd loop; force deopt
 859       // Since it's an OSR, we probably have profile data, but since
 860       // branch_prediction returned PROB_UNKNOWN, the counts are too small.
 861       // Let's make a special check here for completely zero counts.
 862       ciMethodData* methodData = method()->method_data();
 863       if (!methodData->is_empty()) {
 864         ciProfileData* data = methodData->bci_to_data(bci());
 865         // Only stop for truly zero counts, which mean an unknown part
 866         // of the OSR-ed method, and we want to deopt to gather more stats.
 867         // If you have ANY counts, then this loop is simply 'cold' relative
 868         // to the OSR loop.
 869         if (data->as_BranchData()->taken() +
 870             data->as_BranchData()->not_taken() == 0 ) {
 871           // This is the only way to return PROB_UNKNOWN:
 872           return PROB_UNKNOWN;
 873         }
 874       }
 875     }
 876     prob = PROB_STATIC_FREQUENT;     // Likely to take backwards branch
 877   }
 878 
 879   assert(prob != PROB_UNKNOWN, "must have some guess at this point");
 880   return prob;
 881 }
 882 
 883 // The magic constants are chosen so as to match the output of
 884 // branch_prediction() when the profile reports a zero taken count.
 885 // It is important to distinguish zero counts unambiguously, because
 886 // some branches (e.g., _213_javac.Assembler.eliminate) validly produce
 887 // very small but nonzero probabilities, which if confused with zero
 888 // counts would keep the program recompiling indefinitely.
 889 bool Parse::seems_never_taken(float prob) const {
 890   return prob < PROB_MIN;
 891 }
 892 
 893 // True if the comparison seems to be the kind that will not change its
 894 // statistics from true to false.  See comments in adjust_map_after_if.
 895 // This question is only asked along paths which are already
 896 // classifed as untaken (by seems_never_taken), so really,
 897 // if a path is never taken, its controlling comparison is
 898 // already acting in a stable fashion.  If the comparison
 899 // seems stable, we will put an expensive uncommon trap
 900 // on the untaken path.
 901 bool Parse::seems_stable_comparison() const {
 902   if (C->too_many_traps(method(), bci(), Deoptimization::Reason_unstable_if)) {
 903     return false;
 904   }
 905   return true;
 906 }
 907 
 908 //-------------------------------repush_if_args--------------------------------
 909 // Push arguments of an "if" bytecode back onto the stack by adjusting _sp.
 910 inline int Parse::repush_if_args() {
 911 #ifndef PRODUCT
 912   if (PrintOpto && WizardMode) {
 913     tty->print("defending against excessive implicit null exceptions on %s @%d in ",
 914                Bytecodes::name(iter().cur_bc()), iter().cur_bci());
 915     method()->print_name(); tty->cr();
 916   }
 917 #endif
 918   int bc_depth = - Bytecodes::depth(iter().cur_bc());
 919   assert(bc_depth == 1 || bc_depth == 2, "only two kinds of branches");
 920   DEBUG_ONLY(sync_jvms());   // argument(n) requires a synced jvms
 921   assert(argument(0) != NULL, "must exist");
 922   assert(bc_depth == 1 || argument(1) != NULL, "two must exist");
 923   inc_sp(bc_depth);
 924   return bc_depth;
 925 }
 926 
 927 //----------------------------------do_ifnull----------------------------------
 928 void Parse::do_ifnull(BoolTest::mask btest, Node *c) {
 929   int target_bci = iter().get_dest();
 930 
 931   Block* branch_block = successor_for_bci(target_bci);
 932   Block* next_block   = successor_for_bci(iter().next_bci());
 933 
 934   float cnt;
 935   float prob = branch_prediction(cnt, btest, target_bci);
 936   if (prob == PROB_UNKNOWN) {
 937     // (An earlier version of do_ifnull omitted this trap for OSR methods.)
 938 #ifndef PRODUCT
 939     if (PrintOpto && Verbose)
 940       tty->print_cr("Never-taken edge stops compilation at bci %d",bci());
 941 #endif
 942     repush_if_args(); // to gather stats on loop
 943     // We need to mark this branch as taken so that if we recompile we will
 944     // see that it is possible. In the tiered system the interpreter doesn't
 945     // do profiling and by the time we get to the lower tier from the interpreter
 946     // the path may be cold again. Make sure it doesn't look untaken
 947     profile_taken_branch(target_bci, !ProfileInterpreter);
 948     uncommon_trap(Deoptimization::Reason_unreached,
 949                   Deoptimization::Action_reinterpret,
 950                   NULL, "cold");
 951     if (C->eliminate_boxing()) {
 952       // Mark the successor blocks as parsed
 953       branch_block->next_path_num();
 954       next_block->next_path_num();
 955     }
 956     return;
 957   }
 958 
 959   explicit_null_checks_inserted++;
 960 
 961   // Generate real control flow
 962   Node   *tst = _gvn.transform( new BoolNode( c, btest ) );
 963 
 964   // Sanity check the probability value
 965   assert(prob > 0.0f,"Bad probability in Parser");
 966  // Need xform to put node in hash table
 967   IfNode *iff = create_and_xform_if( control(), tst, prob, cnt );
 968   assert(iff->_prob > 0.0f,"Optimizer made bad probability in parser");
 969   // True branch
 970   { PreserveJVMState pjvms(this);
 971     Node* iftrue  = _gvn.transform( new IfTrueNode (iff) );
 972     set_control(iftrue);
 973 
 974     if (stopped()) {            // Path is dead?
 975       explicit_null_checks_elided++;
 976       if (C->eliminate_boxing()) {
 977         // Mark the successor block as parsed
 978         branch_block->next_path_num();
 979       }
 980     } else {                    // Path is live.
 981       // Update method data
 982       profile_taken_branch(target_bci);
 983       adjust_map_after_if(btest, c, prob, branch_block, next_block);
 984       if (!stopped()) {
 985         merge(target_bci);
 986       }
 987     }
 988   }
 989 
 990   // False branch
 991   Node* iffalse = _gvn.transform( new IfFalseNode(iff) );
 992   set_control(iffalse);
 993 
 994   if (stopped()) {              // Path is dead?
 995     explicit_null_checks_elided++;
 996     if (C->eliminate_boxing()) {
 997       // Mark the successor block as parsed
 998       next_block->next_path_num();
 999     }
1000   } else  {                     // Path is live.
1001     // Update method data
1002     profile_not_taken_branch();
1003     adjust_map_after_if(BoolTest(btest).negate(), c, 1.0-prob,
1004                         next_block, branch_block);
1005   }
1006 }
1007 
1008 //------------------------------------do_if------------------------------------
1009 void Parse::do_if(BoolTest::mask btest, Node* c) {
1010   int target_bci = iter().get_dest();
1011 
1012   Block* branch_block = successor_for_bci(target_bci);
1013   Block* next_block   = successor_for_bci(iter().next_bci());
1014 
1015   float cnt;
1016   float prob = branch_prediction(cnt, btest, target_bci);
1017   float untaken_prob = 1.0 - prob;
1018 
1019   if (prob == PROB_UNKNOWN) {
1020 #ifndef PRODUCT
1021     if (PrintOpto && Verbose)
1022       tty->print_cr("Never-taken edge stops compilation at bci %d",bci());
1023 #endif
1024     repush_if_args(); // to gather stats on loop
1025     // We need to mark this branch as taken so that if we recompile we will
1026     // see that it is possible. In the tiered system the interpreter doesn't
1027     // do profiling and by the time we get to the lower tier from the interpreter
1028     // the path may be cold again. Make sure it doesn't look untaken
1029     profile_taken_branch(target_bci, !ProfileInterpreter);
1030     uncommon_trap(Deoptimization::Reason_unreached,
1031                   Deoptimization::Action_reinterpret,
1032                   NULL, "cold");
1033     if (C->eliminate_boxing()) {
1034       // Mark the successor blocks as parsed
1035       branch_block->next_path_num();
1036       next_block->next_path_num();
1037     }
1038     return;
1039   }
1040 
1041   // Sanity check the probability value
1042   assert(0.0f < prob && prob < 1.0f,"Bad probability in Parser");
1043 
1044   bool taken_if_true = true;
1045   // Convert BoolTest to canonical form:
1046   if (!BoolTest(btest).is_canonical()) {
1047     btest         = BoolTest(btest).negate();
1048     taken_if_true = false;
1049     // prob is NOT updated here; it remains the probability of the taken
1050     // path (as opposed to the prob of the path guarded by an 'IfTrueNode').
1051   }
1052   assert(btest != BoolTest::eq, "!= is the only canonical exact test");
1053 
1054   Node* tst0 = new BoolNode(c, btest);
1055   Node* tst = _gvn.transform(tst0);
1056   BoolTest::mask taken_btest   = BoolTest::illegal;
1057   BoolTest::mask untaken_btest = BoolTest::illegal;
1058 
1059   if (tst->is_Bool()) {
1060     // Refresh c from the transformed bool node, since it may be
1061     // simpler than the original c.  Also re-canonicalize btest.
1062     // This wins when (Bool ne (Conv2B p) 0) => (Bool ne (CmpP p NULL)).
1063     // That can arise from statements like: if (x instanceof C) ...
1064     if (tst != tst0) {
1065       // Canonicalize one more time since transform can change it.
1066       btest = tst->as_Bool()->_test._test;
1067       if (!BoolTest(btest).is_canonical()) {
1068         // Reverse edges one more time...
1069         tst   = _gvn.transform( tst->as_Bool()->negate(&_gvn) );
1070         btest = tst->as_Bool()->_test._test;
1071         assert(BoolTest(btest).is_canonical(), "sanity");
1072         taken_if_true = !taken_if_true;
1073       }
1074       c = tst->in(1);
1075     }
1076     BoolTest::mask neg_btest = BoolTest(btest).negate();
1077     taken_btest   = taken_if_true ?     btest : neg_btest;
1078     untaken_btest = taken_if_true ? neg_btest :     btest;
1079   }
1080 
1081   // Generate real control flow
1082   float true_prob = (taken_if_true ? prob : untaken_prob);
1083   IfNode* iff = create_and_map_if(control(), tst, true_prob, cnt);
1084   assert(iff->_prob > 0.0f,"Optimizer made bad probability in parser");
1085   Node* taken_branch   = new IfTrueNode(iff);
1086   Node* untaken_branch = new IfFalseNode(iff);
1087   if (!taken_if_true) {  // Finish conversion to canonical form
1088     Node* tmp      = taken_branch;
1089     taken_branch   = untaken_branch;
1090     untaken_branch = tmp;
1091   }
1092 
1093   // Branch is taken:
1094   { PreserveJVMState pjvms(this);
1095     taken_branch = _gvn.transform(taken_branch);
1096     set_control(taken_branch);
1097 
1098     if (stopped()) {
1099       if (C->eliminate_boxing()) {
1100         // Mark the successor block as parsed
1101         branch_block->next_path_num();
1102       }
1103     } else {
1104       // Update method data
1105       profile_taken_branch(target_bci);
1106       adjust_map_after_if(taken_btest, c, prob, branch_block, next_block);
1107       if (!stopped()) {
1108         merge(target_bci);
1109       }
1110     }
1111   }
1112 
1113   untaken_branch = _gvn.transform(untaken_branch);
1114   set_control(untaken_branch);
1115 
1116   // Branch not taken.
1117   if (stopped()) {
1118     if (C->eliminate_boxing()) {
1119       // Mark the successor block as parsed
1120       next_block->next_path_num();
1121     }
1122   } else {
1123     // Update method data
1124     profile_not_taken_branch();
1125     adjust_map_after_if(untaken_btest, c, untaken_prob,
1126                         next_block, branch_block);
1127   }
1128 }
1129 
1130 bool Parse::path_is_suitable_for_uncommon_trap(float prob) const {
1131   // Don't want to speculate on uncommon traps when running with -Xcomp
1132   if (!UseInterpreter) {
1133     return false;
1134   }
1135   return (seems_never_taken(prob) && seems_stable_comparison());
1136 }
1137 
1138 //----------------------------adjust_map_after_if------------------------------
1139 // Adjust the JVM state to reflect the result of taking this path.
1140 // Basically, it means inspecting the CmpNode controlling this
1141 // branch, seeing how it constrains a tested value, and then
1142 // deciding if it's worth our while to encode this constraint
1143 // as graph nodes in the current abstract interpretation map.
1144 void Parse::adjust_map_after_if(BoolTest::mask btest, Node* c, float prob,
1145                                 Block* path, Block* other_path) {
1146   if (stopped() || !c->is_Cmp() || btest == BoolTest::illegal)
1147     return;                             // nothing to do
1148 
1149   bool is_fallthrough = (path == successor_for_bci(iter().next_bci()));
1150 
1151   if (path_is_suitable_for_uncommon_trap(prob)) {
1152     repush_if_args();
1153     uncommon_trap(Deoptimization::Reason_unstable_if,
1154                   Deoptimization::Action_reinterpret,
1155                   NULL,
1156                   (is_fallthrough ? "taken always" : "taken never"));
1157     return;
1158   }
1159 
1160   Node* val = c->in(1);
1161   Node* con = c->in(2);
1162   const Type* tcon = _gvn.type(con);
1163   const Type* tval = _gvn.type(val);
1164   bool have_con = tcon->singleton();
1165   if (tval->singleton()) {
1166     if (!have_con) {
1167       // Swap, so constant is in con.
1168       con  = val;
1169       tcon = tval;
1170       val  = c->in(2);
1171       tval = _gvn.type(val);
1172       btest = BoolTest(btest).commute();
1173       have_con = true;
1174     } else {
1175       // Do we have two constants?  Then leave well enough alone.
1176       have_con = false;
1177     }
1178   }
1179   if (!have_con)                        // remaining adjustments need a con
1180     return;
1181 
1182   sharpen_type_after_if(btest, con, tcon, val, tval);
1183 }
1184 
1185 
1186 static Node* extract_obj_from_klass_load(PhaseGVN* gvn, Node* n) {
1187   Node* ldk;
1188   if (n->is_DecodeNKlass()) {
1189     if (n->in(1)->Opcode() != Op_LoadNKlass) {
1190       return NULL;
1191     } else {
1192       ldk = n->in(1);
1193     }
1194   } else if (n->Opcode() != Op_LoadKlass) {
1195     return NULL;
1196   } else {
1197     ldk = n;
1198   }
1199   assert(ldk != NULL && ldk->is_Load(), "should have found a LoadKlass or LoadNKlass node");
1200 
1201   Node* adr = ldk->in(MemNode::Address);
1202   intptr_t off = 0;
1203   Node* obj = AddPNode::Ideal_base_and_offset(adr, gvn, off);
1204   if (obj == NULL || off != oopDesc::klass_offset_in_bytes()) // loading oopDesc::_klass?
1205     return NULL;
1206   const TypePtr* tp = gvn->type(obj)->is_ptr();
1207   if (tp == NULL || !(tp->isa_instptr() || tp->isa_aryptr())) // is obj a Java object ptr?
1208     return NULL;
1209 
1210   return obj;
1211 }
1212 
1213 void Parse::sharpen_type_after_if(BoolTest::mask btest,
1214                                   Node* con, const Type* tcon,
1215                                   Node* val, const Type* tval) {
1216   // Look for opportunities to sharpen the type of a node
1217   // whose klass is compared with a constant klass.
1218   if (btest == BoolTest::eq && tcon->isa_klassptr()) {
1219     Node* obj = extract_obj_from_klass_load(&_gvn, val);
1220     const TypeOopPtr* con_type = tcon->isa_klassptr()->as_instance_type();
1221     if (obj != NULL && (con_type->isa_instptr() || con_type->isa_aryptr())) {
1222        // Found:
1223        //   Bool(CmpP(LoadKlass(obj._klass), ConP(Foo.klass)), [eq])
1224        // or the narrowOop equivalent.
1225        const Type* obj_type = _gvn.type(obj);
1226        const TypeOopPtr* tboth = obj_type->join_speculative(con_type)->isa_oopptr();
1227        if (tboth != NULL && tboth->klass_is_exact() && tboth != obj_type &&
1228            tboth->higher_equal(obj_type)) {
1229           // obj has to be of the exact type Foo if the CmpP succeeds.
1230           int obj_in_map = map()->find_edge(obj);
1231           JVMState* jvms = this->jvms();
1232           if (obj_in_map >= 0 &&
1233               (jvms->is_loc(obj_in_map) || jvms->is_stk(obj_in_map))) {
1234             TypeNode* ccast = new CheckCastPPNode(control(), obj, tboth);
1235             const Type* tcc = ccast->as_Type()->type();
1236             assert(tcc != obj_type && tcc->higher_equal(obj_type), "must improve");
1237             // Delay transform() call to allow recovery of pre-cast value
1238             // at the control merge.
1239             _gvn.set_type_bottom(ccast);
1240             record_for_igvn(ccast);
1241             // Here's the payoff.
1242             replace_in_map(obj, ccast);
1243           }
1244        }
1245     }
1246   }
1247 
1248   int val_in_map = map()->find_edge(val);
1249   if (val_in_map < 0)  return;          // replace_in_map would be useless
1250   {
1251     JVMState* jvms = this->jvms();
1252     if (!(jvms->is_loc(val_in_map) ||
1253           jvms->is_stk(val_in_map)))
1254       return;                           // again, it would be useless
1255   }
1256 
1257   // Check for a comparison to a constant, and "know" that the compared
1258   // value is constrained on this path.
1259   assert(tcon->singleton(), "");
1260   ConstraintCastNode* ccast = NULL;
1261   Node* cast = NULL;
1262 
1263   switch (btest) {
1264   case BoolTest::eq:                    // Constant test?
1265     {
1266       const Type* tboth = tcon->join_speculative(tval);
1267       if (tboth == tval)  break;        // Nothing to gain.
1268       if (tcon->isa_int()) {
1269         ccast = new CastIINode(val, tboth);
1270       } else if (tcon == TypePtr::NULL_PTR) {
1271         // Cast to null, but keep the pointer identity temporarily live.
1272         ccast = new CastPPNode(val, tboth);
1273       } else {
1274         const TypeF* tf = tcon->isa_float_constant();
1275         const TypeD* td = tcon->isa_double_constant();
1276         // Exclude tests vs float/double 0 as these could be
1277         // either +0 or -0.  Just because you are equal to +0
1278         // doesn't mean you ARE +0!
1279         // Note, following code also replaces Long and Oop values.
1280         if ((!tf || tf->_f != 0.0) &&
1281             (!td || td->_d != 0.0))
1282           cast = con;                   // Replace non-constant val by con.
1283       }
1284     }
1285     break;
1286 
1287   case BoolTest::ne:
1288     if (tcon == TypePtr::NULL_PTR) {
1289       cast = cast_not_null(val, false);
1290     }
1291     break;
1292 
1293   default:
1294     // (At this point we could record int range types with CastII.)
1295     break;
1296   }
1297 
1298   if (ccast != NULL) {
1299     const Type* tcc = ccast->as_Type()->type();
1300     assert(tcc != tval && tcc->higher_equal(tval), "must improve");
1301     // Delay transform() call to allow recovery of pre-cast value
1302     // at the control merge.
1303     ccast->set_req(0, control());
1304     _gvn.set_type_bottom(ccast);
1305     record_for_igvn(ccast);
1306     cast = ccast;
1307   }
1308 
1309   if (cast != NULL) {                   // Here's the payoff.
1310     replace_in_map(val, cast);
1311   }
1312 }
1313 
1314 /**
1315  * Use speculative type to optimize CmpP node: if comparison is
1316  * against the low level class, cast the object to the speculative
1317  * type if any. CmpP should then go away.
1318  *
1319  * @param c  expected CmpP node
1320  * @return   result of CmpP on object casted to speculative type
1321  *
1322  */
1323 Node* Parse::optimize_cmp_with_klass(Node* c) {
1324   // If this is transformed by the _gvn to a comparison with the low
1325   // level klass then we may be able to use speculation
1326   if (c->Opcode() == Op_CmpP &&
1327       (c->in(1)->Opcode() == Op_LoadKlass || c->in(1)->Opcode() == Op_DecodeNKlass) &&
1328       c->in(2)->is_Con()) {
1329     Node* load_klass = NULL;
1330     Node* decode = NULL;
1331     if (c->in(1)->Opcode() == Op_DecodeNKlass) {
1332       decode = c->in(1);
1333       load_klass = c->in(1)->in(1);
1334     } else {
1335       load_klass = c->in(1);
1336     }
1337     if (load_klass->in(2)->is_AddP()) {
1338       Node* addp = load_klass->in(2);
1339       Node* obj = addp->in(AddPNode::Address);
1340       const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
1341       if (obj_type->speculative_type_not_null() != NULL) {
1342         ciKlass* k = obj_type->speculative_type();
1343         inc_sp(2);
1344         obj = maybe_cast_profiled_obj(obj, k);
1345         dec_sp(2);
1346         // Make the CmpP use the casted obj
1347         addp = basic_plus_adr(obj, addp->in(AddPNode::Offset));
1348         load_klass = load_klass->clone();
1349         load_klass->set_req(2, addp);
1350         load_klass = _gvn.transform(load_klass);
1351         if (decode != NULL) {
1352           decode = decode->clone();
1353           decode->set_req(1, load_klass);
1354           load_klass = _gvn.transform(decode);
1355         }
1356         c = c->clone();
1357         c->set_req(1, load_klass);
1358         c = _gvn.transform(c);
1359       }
1360     }
1361   }
1362   return c;
1363 }
1364 
1365 //------------------------------do_one_bytecode--------------------------------
1366 // Parse this bytecode, and alter the Parsers JVM->Node mapping
1367 void Parse::do_one_bytecode() {
1368   Node *a, *b, *c, *d;          // Handy temps
1369   BoolTest::mask btest;
1370   int i;
1371 
1372   assert(!has_exceptions(), "bytecode entry state must be clear of throws");
1373 
1374   if (C->check_node_count(NodeLimitFudgeFactor * 5,
1375                           "out of nodes parsing method")) {
1376     return;
1377   }
1378 
1379 #ifdef ASSERT
1380   // for setting breakpoints
1381   if (TraceOptoParse) {
1382     tty->print(" @");
1383     dump_bci(bci());
1384     tty->cr();
1385   }
1386 #endif
1387 
1388   switch (bc()) {
1389   case Bytecodes::_nop:
1390     // do nothing
1391     break;
1392   case Bytecodes::_lconst_0:
1393     push_pair(longcon(0));
1394     break;
1395 
1396   case Bytecodes::_lconst_1:
1397     push_pair(longcon(1));
1398     break;
1399 
1400   case Bytecodes::_fconst_0:
1401     push(zerocon(T_FLOAT));
1402     break;
1403 
1404   case Bytecodes::_fconst_1:
1405     push(makecon(TypeF::ONE));
1406     break;
1407 
1408   case Bytecodes::_fconst_2:
1409     push(makecon(TypeF::make(2.0f)));
1410     break;
1411 
1412   case Bytecodes::_dconst_0:
1413     push_pair(zerocon(T_DOUBLE));
1414     break;
1415 
1416   case Bytecodes::_dconst_1:
1417     push_pair(makecon(TypeD::ONE));
1418     break;
1419 
1420   case Bytecodes::_iconst_m1:push(intcon(-1)); break;
1421   case Bytecodes::_iconst_0: push(intcon( 0)); break;
1422   case Bytecodes::_iconst_1: push(intcon( 1)); break;
1423   case Bytecodes::_iconst_2: push(intcon( 2)); break;
1424   case Bytecodes::_iconst_3: push(intcon( 3)); break;
1425   case Bytecodes::_iconst_4: push(intcon( 4)); break;
1426   case Bytecodes::_iconst_5: push(intcon( 5)); break;
1427   case Bytecodes::_bipush:   push(intcon(iter().get_constant_u1())); break;
1428   case Bytecodes::_sipush:   push(intcon(iter().get_constant_u2())); break;
1429   case Bytecodes::_aconst_null: push(null());  break;
1430   case Bytecodes::_ldc:
1431   case Bytecodes::_ldc_w:
1432   case Bytecodes::_ldc2_w:
1433     // If the constant is unresolved, run this BC once in the interpreter.
1434     {
1435       ciConstant constant = iter().get_constant();
1436       if (constant.basic_type() == T_OBJECT &&
1437           !constant.as_object()->is_loaded()) {
1438         int index = iter().get_constant_pool_index();
1439         constantTag tag = iter().get_constant_pool_tag(index);
1440         uncommon_trap(Deoptimization::make_trap_request
1441                       (Deoptimization::Reason_unloaded,
1442                        Deoptimization::Action_reinterpret,
1443                        index),
1444                       NULL, tag.internal_name());
1445         break;
1446       }
1447       assert(constant.basic_type() != T_OBJECT || constant.as_object()->is_instance(),
1448              "must be java_mirror of klass");
1449       bool pushed = push_constant(constant, true);
1450       guarantee(pushed, "must be possible to push this constant");
1451     }
1452 
1453     break;
1454 
1455   case Bytecodes::_aload_0:
1456     push( local(0) );
1457     break;
1458   case Bytecodes::_aload_1:
1459     push( local(1) );
1460     break;
1461   case Bytecodes::_aload_2:
1462     push( local(2) );
1463     break;
1464   case Bytecodes::_aload_3:
1465     push( local(3) );
1466     break;
1467   case Bytecodes::_aload:
1468     push( local(iter().get_index()) );
1469     break;
1470 
1471   case Bytecodes::_fload_0:
1472   case Bytecodes::_iload_0:
1473     push( local(0) );
1474     break;
1475   case Bytecodes::_fload_1:
1476   case Bytecodes::_iload_1:
1477     push( local(1) );
1478     break;
1479   case Bytecodes::_fload_2:
1480   case Bytecodes::_iload_2:
1481     push( local(2) );
1482     break;
1483   case Bytecodes::_fload_3:
1484   case Bytecodes::_iload_3:
1485     push( local(3) );
1486     break;
1487   case Bytecodes::_fload:
1488   case Bytecodes::_iload:
1489     push( local(iter().get_index()) );
1490     break;
1491   case Bytecodes::_lload_0:
1492     push_pair_local( 0 );
1493     break;
1494   case Bytecodes::_lload_1:
1495     push_pair_local( 1 );
1496     break;
1497   case Bytecodes::_lload_2:
1498     push_pair_local( 2 );
1499     break;
1500   case Bytecodes::_lload_3:
1501     push_pair_local( 3 );
1502     break;
1503   case Bytecodes::_lload:
1504     push_pair_local( iter().get_index() );
1505     break;
1506 
1507   case Bytecodes::_dload_0:
1508     push_pair_local(0);
1509     break;
1510   case Bytecodes::_dload_1:
1511     push_pair_local(1);
1512     break;
1513   case Bytecodes::_dload_2:
1514     push_pair_local(2);
1515     break;
1516   case Bytecodes::_dload_3:
1517     push_pair_local(3);
1518     break;
1519   case Bytecodes::_dload:
1520     push_pair_local(iter().get_index());
1521     break;
1522   case Bytecodes::_fstore_0:
1523   case Bytecodes::_istore_0:
1524   case Bytecodes::_astore_0:
1525     set_local( 0, pop() );
1526     break;
1527   case Bytecodes::_fstore_1:
1528   case Bytecodes::_istore_1:
1529   case Bytecodes::_astore_1:
1530     set_local( 1, pop() );
1531     break;
1532   case Bytecodes::_fstore_2:
1533   case Bytecodes::_istore_2:
1534   case Bytecodes::_astore_2:
1535     set_local( 2, pop() );
1536     break;
1537   case Bytecodes::_fstore_3:
1538   case Bytecodes::_istore_3:
1539   case Bytecodes::_astore_3:
1540     set_local( 3, pop() );
1541     break;
1542   case Bytecodes::_fstore:
1543   case Bytecodes::_istore:
1544   case Bytecodes::_astore:
1545     set_local( iter().get_index(), pop() );
1546     break;
1547   // long stores
1548   case Bytecodes::_lstore_0:
1549     set_pair_local( 0, pop_pair() );
1550     break;
1551   case Bytecodes::_lstore_1:
1552     set_pair_local( 1, pop_pair() );
1553     break;
1554   case Bytecodes::_lstore_2:
1555     set_pair_local( 2, pop_pair() );
1556     break;
1557   case Bytecodes::_lstore_3:
1558     set_pair_local( 3, pop_pair() );
1559     break;
1560   case Bytecodes::_lstore:
1561     set_pair_local( iter().get_index(), pop_pair() );
1562     break;
1563 
1564   // double stores
1565   case Bytecodes::_dstore_0:
1566     set_pair_local( 0, dstore_rounding(pop_pair()) );
1567     break;
1568   case Bytecodes::_dstore_1:
1569     set_pair_local( 1, dstore_rounding(pop_pair()) );
1570     break;
1571   case Bytecodes::_dstore_2:
1572     set_pair_local( 2, dstore_rounding(pop_pair()) );
1573     break;
1574   case Bytecodes::_dstore_3:
1575     set_pair_local( 3, dstore_rounding(pop_pair()) );
1576     break;
1577   case Bytecodes::_dstore:
1578     set_pair_local( iter().get_index(), dstore_rounding(pop_pair()) );
1579     break;
1580 
1581   case Bytecodes::_pop:  dec_sp(1);   break;
1582   case Bytecodes::_pop2: dec_sp(2);   break;
1583   case Bytecodes::_swap:
1584     a = pop();
1585     b = pop();
1586     push(a);
1587     push(b);
1588     break;
1589   case Bytecodes::_dup:
1590     a = pop();
1591     push(a);
1592     push(a);
1593     break;
1594   case Bytecodes::_dup_x1:
1595     a = pop();
1596     b = pop();
1597     push( a );
1598     push( b );
1599     push( a );
1600     break;
1601   case Bytecodes::_dup_x2:
1602     a = pop();
1603     b = pop();
1604     c = pop();
1605     push( a );
1606     push( c );
1607     push( b );
1608     push( a );
1609     break;
1610   case Bytecodes::_dup2:
1611     a = pop();
1612     b = pop();
1613     push( b );
1614     push( a );
1615     push( b );
1616     push( a );
1617     break;
1618 
1619   case Bytecodes::_dup2_x1:
1620     // before: .. c, b, a
1621     // after:  .. b, a, c, b, a
1622     // not tested
1623     a = pop();
1624     b = pop();
1625     c = pop();
1626     push( b );
1627     push( a );
1628     push( c );
1629     push( b );
1630     push( a );
1631     break;
1632   case Bytecodes::_dup2_x2:
1633     // before: .. d, c, b, a
1634     // after:  .. b, a, d, c, b, a
1635     // not tested
1636     a = pop();
1637     b = pop();
1638     c = pop();
1639     d = pop();
1640     push( b );
1641     push( a );
1642     push( d );
1643     push( c );
1644     push( b );
1645     push( a );
1646     break;
1647 
1648   case Bytecodes::_arraylength: {
1649     // Must do null-check with value on expression stack
1650     Node *ary = null_check(peek(), T_ARRAY);
1651     // Compile-time detect of null-exception?
1652     if (stopped())  return;
1653     a = pop();
1654     push(load_array_length(a));
1655     break;
1656   }
1657 
1658   case Bytecodes::_baload: array_load(T_BYTE);   break;
1659   case Bytecodes::_caload: array_load(T_CHAR);   break;
1660   case Bytecodes::_iaload: array_load(T_INT);    break;
1661   case Bytecodes::_saload: array_load(T_SHORT);  break;
1662   case Bytecodes::_faload: array_load(T_FLOAT);  break;
1663   case Bytecodes::_aaload: array_load(T_OBJECT); break;
1664   case Bytecodes::_laload: {
1665     a = array_addressing(T_LONG, 0);
1666     if (stopped())  return;     // guaranteed null or range check
1667     dec_sp(2);                  // Pop array and index
1668     push_pair(make_load(control(), a, TypeLong::LONG, T_LONG, TypeAryPtr::LONGS, MemNode::unordered));
1669     break;
1670   }
1671   case Bytecodes::_daload: {
1672     a = array_addressing(T_DOUBLE, 0);
1673     if (stopped())  return;     // guaranteed null or range check
1674     dec_sp(2);                  // Pop array and index
1675     push_pair(make_load(control(), a, Type::DOUBLE, T_DOUBLE, TypeAryPtr::DOUBLES, MemNode::unordered));
1676     break;
1677   }
1678   case Bytecodes::_bastore: array_store(T_BYTE);  break;
1679   case Bytecodes::_castore: array_store(T_CHAR);  break;
1680   case Bytecodes::_iastore: array_store(T_INT);   break;
1681   case Bytecodes::_sastore: array_store(T_SHORT); break;
1682   case Bytecodes::_fastore: array_store(T_FLOAT); break;
1683   case Bytecodes::_aastore: {
1684     d = array_addressing(T_OBJECT, 1);
1685     if (stopped())  return;     // guaranteed null or range check
1686     array_store_check();
1687     c = pop();                  // Oop to store
1688     b = pop();                  // index (already used)
1689     a = pop();                  // the array itself
1690     const TypeOopPtr* elemtype  = _gvn.type(a)->is_aryptr()->elem()->make_oopptr();
1691     const TypeAryPtr* adr_type = TypeAryPtr::OOPS;
1692     Node* store = store_oop_to_array(control(), a, d, adr_type, c, elemtype, T_OBJECT, MemNode::release);
1693     break;
1694   }
1695   case Bytecodes::_lastore: {
1696     a = array_addressing(T_LONG, 2);
1697     if (stopped())  return;     // guaranteed null or range check
1698     c = pop_pair();
1699     dec_sp(2);                  // Pop array and index
1700     store_to_memory(control(), a, c, T_LONG, TypeAryPtr::LONGS, MemNode::unordered);
1701     break;
1702   }
1703   case Bytecodes::_dastore: {
1704     a = array_addressing(T_DOUBLE, 2);
1705     if (stopped())  return;     // guaranteed null or range check
1706     c = pop_pair();
1707     dec_sp(2);                  // Pop array and index
1708     c = dstore_rounding(c);
1709     store_to_memory(control(), a, c, T_DOUBLE, TypeAryPtr::DOUBLES, MemNode::unordered);
1710     break;
1711   }
1712   case Bytecodes::_getfield:
1713     do_getfield();
1714     break;
1715 
1716   case Bytecodes::_getstatic:
1717     do_getstatic();
1718     break;
1719 
1720   case Bytecodes::_putfield:
1721     do_putfield();
1722     break;
1723 
1724   case Bytecodes::_putstatic:
1725     do_putstatic();
1726     break;
1727 
1728   case Bytecodes::_irem:
1729     do_irem();
1730     break;
1731   case Bytecodes::_idiv:
1732     // Must keep both values on the expression-stack during null-check
1733     zero_check_int(peek());
1734     // Compile-time detect of null-exception?
1735     if (stopped())  return;
1736     b = pop();
1737     a = pop();
1738     push( _gvn.transform( new DivINode(control(),a,b) ) );
1739     break;
1740   case Bytecodes::_imul:
1741     b = pop(); a = pop();
1742     push( _gvn.transform( new MulINode(a,b) ) );
1743     break;
1744   case Bytecodes::_iadd:
1745     b = pop(); a = pop();
1746     push( _gvn.transform( new AddINode(a,b) ) );
1747     break;
1748   case Bytecodes::_ineg:
1749     a = pop();
1750     push( _gvn.transform( new SubINode(_gvn.intcon(0),a)) );
1751     break;
1752   case Bytecodes::_isub:
1753     b = pop(); a = pop();
1754     push( _gvn.transform( new SubINode(a,b) ) );
1755     break;
1756   case Bytecodes::_iand:
1757     b = pop(); a = pop();
1758     push( _gvn.transform( new AndINode(a,b) ) );
1759     break;
1760   case Bytecodes::_ior:
1761     b = pop(); a = pop();
1762     push( _gvn.transform( new OrINode(a,b) ) );
1763     break;
1764   case Bytecodes::_ixor:
1765     b = pop(); a = pop();
1766     push( _gvn.transform( new XorINode(a,b) ) );
1767     break;
1768   case Bytecodes::_ishl:
1769     b = pop(); a = pop();
1770     push( _gvn.transform( new LShiftINode(a,b) ) );
1771     break;
1772   case Bytecodes::_ishr:
1773     b = pop(); a = pop();
1774     push( _gvn.transform( new RShiftINode(a,b) ) );
1775     break;
1776   case Bytecodes::_iushr:
1777     b = pop(); a = pop();
1778     push( _gvn.transform( new URShiftINode(a,b) ) );
1779     break;
1780 
1781   case Bytecodes::_fneg:
1782     a = pop();
1783     b = _gvn.transform(new NegFNode (a));
1784     push(b);
1785     break;
1786 
1787   case Bytecodes::_fsub:
1788     b = pop();
1789     a = pop();
1790     c = _gvn.transform( new SubFNode(a,b) );
1791     d = precision_rounding(c);
1792     push( d );
1793     break;
1794 
1795   case Bytecodes::_fadd:
1796     b = pop();
1797     a = pop();
1798     c = _gvn.transform( new AddFNode(a,b) );
1799     d = precision_rounding(c);
1800     push( d );
1801     break;
1802 
1803   case Bytecodes::_fmul:
1804     b = pop();
1805     a = pop();
1806     c = _gvn.transform( new MulFNode(a,b) );
1807     d = precision_rounding(c);
1808     push( d );
1809     break;
1810 
1811   case Bytecodes::_fdiv:
1812     b = pop();
1813     a = pop();
1814     c = _gvn.transform( new DivFNode(0,a,b) );
1815     d = precision_rounding(c);
1816     push( d );
1817     break;
1818 
1819   case Bytecodes::_frem:
1820     if (Matcher::has_match_rule(Op_ModF)) {
1821       // Generate a ModF node.
1822       b = pop();
1823       a = pop();
1824       c = _gvn.transform( new ModFNode(0,a,b) );
1825       d = precision_rounding(c);
1826       push( d );
1827     }
1828     else {
1829       // Generate a call.
1830       modf();
1831     }
1832     break;
1833 
1834   case Bytecodes::_fcmpl:
1835     b = pop();
1836     a = pop();
1837     c = _gvn.transform( new CmpF3Node( a, b));
1838     push(c);
1839     break;
1840   case Bytecodes::_fcmpg:
1841     b = pop();
1842     a = pop();
1843 
1844     // Same as fcmpl but need to flip the unordered case.  Swap the inputs,
1845     // which negates the result sign except for unordered.  Flip the unordered
1846     // as well by using CmpF3 which implements unordered-lesser instead of
1847     // unordered-greater semantics.  Finally, commute the result bits.  Result
1848     // is same as using a CmpF3Greater except we did it with CmpF3 alone.
1849     c = _gvn.transform( new CmpF3Node( b, a));
1850     c = _gvn.transform( new SubINode(_gvn.intcon(0),c) );
1851     push(c);
1852     break;
1853 
1854   case Bytecodes::_f2i:
1855     a = pop();
1856     push(_gvn.transform(new ConvF2INode(a)));
1857     break;
1858 
1859   case Bytecodes::_d2i:
1860     a = pop_pair();
1861     b = _gvn.transform(new ConvD2INode(a));
1862     push( b );
1863     break;
1864 
1865   case Bytecodes::_f2d:
1866     a = pop();
1867     b = _gvn.transform( new ConvF2DNode(a));
1868     push_pair( b );
1869     break;
1870 
1871   case Bytecodes::_d2f:
1872     a = pop_pair();
1873     b = _gvn.transform( new ConvD2FNode(a));
1874     // This breaks _227_mtrt (speed & correctness) and _222_mpegaudio (speed)
1875     //b = _gvn.transform(new RoundFloatNode(0, b) );
1876     push( b );
1877     break;
1878 
1879   case Bytecodes::_l2f:
1880     if (Matcher::convL2FSupported()) {
1881       a = pop_pair();
1882       b = _gvn.transform( new ConvL2FNode(a));
1883       // For i486.ad, FILD doesn't restrict precision to 24 or 53 bits.
1884       // Rather than storing the result into an FP register then pushing
1885       // out to memory to round, the machine instruction that implements
1886       // ConvL2D is responsible for rounding.
1887       // c = precision_rounding(b);
1888       c = _gvn.transform(b);
1889       push(c);
1890     } else {
1891       l2f();
1892     }
1893     break;
1894 
1895   case Bytecodes::_l2d:
1896     a = pop_pair();
1897     b = _gvn.transform( new ConvL2DNode(a));
1898     // For i486.ad, rounding is always necessary (see _l2f above).
1899     // c = dprecision_rounding(b);
1900     c = _gvn.transform(b);
1901     push_pair(c);
1902     break;
1903 
1904   case Bytecodes::_f2l:
1905     a = pop();
1906     b = _gvn.transform( new ConvF2LNode(a));
1907     push_pair(b);
1908     break;
1909 
1910   case Bytecodes::_d2l:
1911     a = pop_pair();
1912     b = _gvn.transform( new ConvD2LNode(a));
1913     push_pair(b);
1914     break;
1915 
1916   case Bytecodes::_dsub:
1917     b = pop_pair();
1918     a = pop_pair();
1919     c = _gvn.transform( new SubDNode(a,b) );
1920     d = dprecision_rounding(c);
1921     push_pair( d );
1922     break;
1923 
1924   case Bytecodes::_dadd:
1925     b = pop_pair();
1926     a = pop_pair();
1927     c = _gvn.transform( new AddDNode(a,b) );
1928     d = dprecision_rounding(c);
1929     push_pair( d );
1930     break;
1931 
1932   case Bytecodes::_dmul:
1933     b = pop_pair();
1934     a = pop_pair();
1935     c = _gvn.transform( new MulDNode(a,b) );
1936     d = dprecision_rounding(c);
1937     push_pair( d );
1938     break;
1939 
1940   case Bytecodes::_ddiv:
1941     b = pop_pair();
1942     a = pop_pair();
1943     c = _gvn.transform( new DivDNode(0,a,b) );
1944     d = dprecision_rounding(c);
1945     push_pair( d );
1946     break;
1947 
1948   case Bytecodes::_dneg:
1949     a = pop_pair();
1950     b = _gvn.transform(new NegDNode (a));
1951     push_pair(b);
1952     break;
1953 
1954   case Bytecodes::_drem:
1955     if (Matcher::has_match_rule(Op_ModD)) {
1956       // Generate a ModD node.
1957       b = pop_pair();
1958       a = pop_pair();
1959       // a % b
1960 
1961       c = _gvn.transform( new ModDNode(0,a,b) );
1962       d = dprecision_rounding(c);
1963       push_pair( d );
1964     }
1965     else {
1966       // Generate a call.
1967       modd();
1968     }
1969     break;
1970 
1971   case Bytecodes::_dcmpl:
1972     b = pop_pair();
1973     a = pop_pair();
1974     c = _gvn.transform( new CmpD3Node( a, b));
1975     push(c);
1976     break;
1977 
1978   case Bytecodes::_dcmpg:
1979     b = pop_pair();
1980     a = pop_pair();
1981     // Same as dcmpl but need to flip the unordered case.
1982     // Commute the inputs, which negates the result sign except for unordered.
1983     // Flip the unordered as well by using CmpD3 which implements
1984     // unordered-lesser instead of unordered-greater semantics.
1985     // Finally, negate the result bits.  Result is same as using a
1986     // CmpD3Greater except we did it with CmpD3 alone.
1987     c = _gvn.transform( new CmpD3Node( b, a));
1988     c = _gvn.transform( new SubINode(_gvn.intcon(0),c) );
1989     push(c);
1990     break;
1991 
1992 
1993     // Note for longs -> lo word is on TOS, hi word is on TOS - 1
1994   case Bytecodes::_land:
1995     b = pop_pair();
1996     a = pop_pair();
1997     c = _gvn.transform( new AndLNode(a,b) );
1998     push_pair(c);
1999     break;
2000   case Bytecodes::_lor:
2001     b = pop_pair();
2002     a = pop_pair();
2003     c = _gvn.transform( new OrLNode(a,b) );
2004     push_pair(c);
2005     break;
2006   case Bytecodes::_lxor:
2007     b = pop_pair();
2008     a = pop_pair();
2009     c = _gvn.transform( new XorLNode(a,b) );
2010     push_pair(c);
2011     break;
2012 
2013   case Bytecodes::_lshl:
2014     b = pop();                  // the shift count
2015     a = pop_pair();             // value to be shifted
2016     c = _gvn.transform( new LShiftLNode(a,b) );
2017     push_pair(c);
2018     break;
2019   case Bytecodes::_lshr:
2020     b = pop();                  // the shift count
2021     a = pop_pair();             // value to be shifted
2022     c = _gvn.transform( new RShiftLNode(a,b) );
2023     push_pair(c);
2024     break;
2025   case Bytecodes::_lushr:
2026     b = pop();                  // the shift count
2027     a = pop_pair();             // value to be shifted
2028     c = _gvn.transform( new URShiftLNode(a,b) );
2029     push_pair(c);
2030     break;
2031   case Bytecodes::_lmul:
2032     b = pop_pair();
2033     a = pop_pair();
2034     c = _gvn.transform( new MulLNode(a,b) );
2035     push_pair(c);
2036     break;
2037 
2038   case Bytecodes::_lrem:
2039     // Must keep both values on the expression-stack during null-check
2040     assert(peek(0) == top(), "long word order");
2041     zero_check_long(peek(1));
2042     // Compile-time detect of null-exception?
2043     if (stopped())  return;
2044     b = pop_pair();
2045     a = pop_pair();
2046     c = _gvn.transform( new ModLNode(control(),a,b) );
2047     push_pair(c);
2048     break;
2049 
2050   case Bytecodes::_ldiv:
2051     // Must keep both values on the expression-stack during null-check
2052     assert(peek(0) == top(), "long word order");
2053     zero_check_long(peek(1));
2054     // Compile-time detect of null-exception?
2055     if (stopped())  return;
2056     b = pop_pair();
2057     a = pop_pair();
2058     c = _gvn.transform( new DivLNode(control(),a,b) );
2059     push_pair(c);
2060     break;
2061 
2062   case Bytecodes::_ladd:
2063     b = pop_pair();
2064     a = pop_pair();
2065     c = _gvn.transform( new AddLNode(a,b) );
2066     push_pair(c);
2067     break;
2068   case Bytecodes::_lsub:
2069     b = pop_pair();
2070     a = pop_pair();
2071     c = _gvn.transform( new SubLNode(a,b) );
2072     push_pair(c);
2073     break;
2074   case Bytecodes::_lcmp:
2075     // Safepoints are now inserted _before_ branches.  The long-compare
2076     // bytecode painfully produces a 3-way value (-1,0,+1) which requires a
2077     // slew of control flow.  These are usually followed by a CmpI vs zero and
2078     // a branch; this pattern then optimizes to the obvious long-compare and
2079     // branch.  However, if the branch is backwards there's a Safepoint
2080     // inserted.  The inserted Safepoint captures the JVM state at the
2081     // pre-branch point, i.e. it captures the 3-way value.  Thus if a
2082     // long-compare is used to control a loop the debug info will force
2083     // computation of the 3-way value, even though the generated code uses a
2084     // long-compare and branch.  We try to rectify the situation by inserting
2085     // a SafePoint here and have it dominate and kill the safepoint added at a
2086     // following backwards branch.  At this point the JVM state merely holds 2
2087     // longs but not the 3-way value.
2088     if( UseLoopSafepoints ) {
2089       switch( iter().next_bc() ) {
2090       case Bytecodes::_ifgt:
2091       case Bytecodes::_iflt:
2092       case Bytecodes::_ifge:
2093       case Bytecodes::_ifle:
2094       case Bytecodes::_ifne:
2095       case Bytecodes::_ifeq:
2096         // If this is a backwards branch in the bytecodes, add Safepoint
2097         maybe_add_safepoint(iter().next_get_dest());
2098       }
2099     }
2100     b = pop_pair();
2101     a = pop_pair();
2102     c = _gvn.transform( new CmpL3Node( a, b ));
2103     push(c);
2104     break;
2105 
2106   case Bytecodes::_lneg:
2107     a = pop_pair();
2108     b = _gvn.transform( new SubLNode(longcon(0),a));
2109     push_pair(b);
2110     break;
2111   case Bytecodes::_l2i:
2112     a = pop_pair();
2113     push( _gvn.transform( new ConvL2INode(a)));
2114     break;
2115   case Bytecodes::_i2l:
2116     a = pop();
2117     b = _gvn.transform( new ConvI2LNode(a));
2118     push_pair(b);
2119     break;
2120   case Bytecodes::_i2b:
2121     // Sign extend
2122     a = pop();
2123     a = _gvn.transform( new LShiftINode(a,_gvn.intcon(24)) );
2124     a = _gvn.transform( new RShiftINode(a,_gvn.intcon(24)) );
2125     push( a );
2126     break;
2127   case Bytecodes::_i2s:
2128     a = pop();
2129     a = _gvn.transform( new LShiftINode(a,_gvn.intcon(16)) );
2130     a = _gvn.transform( new RShiftINode(a,_gvn.intcon(16)) );
2131     push( a );
2132     break;
2133   case Bytecodes::_i2c:
2134     a = pop();
2135     push( _gvn.transform( new AndINode(a,_gvn.intcon(0xFFFF)) ) );
2136     break;
2137 
2138   case Bytecodes::_i2f:
2139     a = pop();
2140     b = _gvn.transform( new ConvI2FNode(a) ) ;
2141     c = precision_rounding(b);
2142     push (b);
2143     break;
2144 
2145   case Bytecodes::_i2d:
2146     a = pop();
2147     b = _gvn.transform( new ConvI2DNode(a));
2148     push_pair(b);
2149     break;
2150 
2151   case Bytecodes::_iinc:        // Increment local
2152     i = iter().get_index();     // Get local index
2153     set_local( i, _gvn.transform( new AddINode( _gvn.intcon(iter().get_iinc_con()), local(i) ) ) );
2154     break;
2155 
2156   // Exit points of synchronized methods must have an unlock node
2157   case Bytecodes::_return:
2158     return_current(NULL);
2159     break;
2160 
2161   case Bytecodes::_ireturn:
2162   case Bytecodes::_areturn:
2163   case Bytecodes::_freturn:
2164     return_current(pop());
2165     break;
2166   case Bytecodes::_lreturn:
2167     return_current(pop_pair());
2168     break;
2169   case Bytecodes::_dreturn:
2170     return_current(pop_pair());
2171     break;
2172 
2173   case Bytecodes::_athrow:
2174     // null exception oop throws NULL pointer exception
2175     null_check(peek());
2176     if (stopped())  return;
2177     // Hook the thrown exception directly to subsequent handlers.
2178     if (BailoutToInterpreterForThrows) {
2179       // Keep method interpreted from now on.
2180       uncommon_trap(Deoptimization::Reason_unhandled,
2181                     Deoptimization::Action_make_not_compilable);
2182       return;
2183     }
2184     if (env()->jvmti_can_post_on_exceptions()) {
2185       // check if we must post exception events, take uncommon trap if so (with must_throw = false)
2186       uncommon_trap_if_should_post_on_exceptions(Deoptimization::Reason_unhandled, false);
2187     }
2188     // Here if either can_post_on_exceptions or should_post_on_exceptions is false
2189     add_exception_state(make_exception_state(peek()));
2190     break;
2191 
2192   case Bytecodes::_goto:   // fall through
2193   case Bytecodes::_goto_w: {
2194     int target_bci = (bc() == Bytecodes::_goto) ? iter().get_dest() : iter().get_far_dest();
2195 
2196     // If this is a backwards branch in the bytecodes, add Safepoint
2197     maybe_add_safepoint(target_bci);
2198 
2199     // Update method data
2200     profile_taken_branch(target_bci);
2201 
2202     // Merge the current control into the target basic block
2203     merge(target_bci);
2204 
2205     // See if we can get some profile data and hand it off to the next block
2206     Block *target_block = block()->successor_for_bci(target_bci);
2207     if (target_block->pred_count() != 1)  break;
2208     ciMethodData* methodData = method()->method_data();
2209     if (!methodData->is_mature())  break;
2210     ciProfileData* data = methodData->bci_to_data(bci());
2211     assert( data->is_JumpData(), "" );
2212     int taken = ((ciJumpData*)data)->taken();
2213     taken = method()->scale_count(taken);
2214     target_block->set_count(taken);
2215     break;
2216   }
2217 
2218   case Bytecodes::_ifnull:    btest = BoolTest::eq; goto handle_if_null;
2219   case Bytecodes::_ifnonnull: btest = BoolTest::ne; goto handle_if_null;
2220   handle_if_null:
2221     // If this is a backwards branch in the bytecodes, add Safepoint
2222     maybe_add_safepoint(iter().get_dest());
2223     a = null();
2224     b = pop();
2225     if (!_gvn.type(b)->speculative_maybe_null() &&
2226         !too_many_traps(Deoptimization::Reason_speculate_null_check)) {
2227       inc_sp(1);
2228       Node* null_ctl = top();
2229       b = null_check_oop(b, &null_ctl, true, true, true);
2230       assert(null_ctl->is_top(), "no null control here");
2231       dec_sp(1);
2232     }
2233     c = _gvn.transform( new CmpPNode(b, a) );
2234     do_ifnull(btest, c);
2235     break;
2236 
2237   case Bytecodes::_if_acmpeq: btest = BoolTest::eq; goto handle_if_acmp;
2238   case Bytecodes::_if_acmpne: btest = BoolTest::ne; goto handle_if_acmp;
2239   handle_if_acmp:
2240     // If this is a backwards branch in the bytecodes, add Safepoint
2241     maybe_add_safepoint(iter().get_dest());
2242     a = pop();
2243     b = pop();
2244     c = _gvn.transform( new CmpPNode(b, a) );
2245     c = optimize_cmp_with_klass(c);
2246     do_if(btest, c);
2247     break;
2248 
2249   case Bytecodes::_ifeq: btest = BoolTest::eq; goto handle_ifxx;
2250   case Bytecodes::_ifne: btest = BoolTest::ne; goto handle_ifxx;
2251   case Bytecodes::_iflt: btest = BoolTest::lt; goto handle_ifxx;
2252   case Bytecodes::_ifle: btest = BoolTest::le; goto handle_ifxx;
2253   case Bytecodes::_ifgt: btest = BoolTest::gt; goto handle_ifxx;
2254   case Bytecodes::_ifge: btest = BoolTest::ge; goto handle_ifxx;
2255   handle_ifxx:
2256     // If this is a backwards branch in the bytecodes, add Safepoint
2257     maybe_add_safepoint(iter().get_dest());
2258     a = _gvn.intcon(0);
2259     b = pop();
2260     c = _gvn.transform( new CmpINode(b, a) );
2261     do_if(btest, c);
2262     break;
2263 
2264   case Bytecodes::_if_icmpeq: btest = BoolTest::eq; goto handle_if_icmp;
2265   case Bytecodes::_if_icmpne: btest = BoolTest::ne; goto handle_if_icmp;
2266   case Bytecodes::_if_icmplt: btest = BoolTest::lt; goto handle_if_icmp;
2267   case Bytecodes::_if_icmple: btest = BoolTest::le; goto handle_if_icmp;
2268   case Bytecodes::_if_icmpgt: btest = BoolTest::gt; goto handle_if_icmp;
2269   case Bytecodes::_if_icmpge: btest = BoolTest::ge; goto handle_if_icmp;
2270   handle_if_icmp:
2271     // If this is a backwards branch in the bytecodes, add Safepoint
2272     maybe_add_safepoint(iter().get_dest());
2273     a = pop();
2274     b = pop();
2275     c = _gvn.transform( new CmpINode( b, a ) );
2276     do_if(btest, c);
2277     break;
2278 
2279   case Bytecodes::_tableswitch:
2280     do_tableswitch();
2281     break;
2282 
2283   case Bytecodes::_lookupswitch:
2284     do_lookupswitch();
2285     break;
2286 
2287   case Bytecodes::_invokestatic:
2288   case Bytecodes::_invokedynamic:
2289   case Bytecodes::_invokespecial:
2290   case Bytecodes::_invokevirtual:
2291   case Bytecodes::_invokeinterface:
2292     do_call();
2293     break;
2294   case Bytecodes::_checkcast:
2295     do_checkcast();
2296     break;
2297   case Bytecodes::_instanceof:
2298     do_instanceof();
2299     break;
2300   case Bytecodes::_anewarray:
2301     do_anewarray();
2302     break;
2303   case Bytecodes::_newarray:
2304     do_newarray((BasicType)iter().get_index());
2305     break;
2306   case Bytecodes::_multianewarray:
2307     do_multianewarray();
2308     break;
2309   case Bytecodes::_new:
2310     do_new();
2311     break;
2312 
2313   case Bytecodes::_jsr:
2314   case Bytecodes::_jsr_w:
2315     do_jsr();
2316     break;
2317 
2318   case Bytecodes::_ret:
2319     do_ret();
2320     break;
2321 
2322 
2323   case Bytecodes::_monitorenter:
2324     do_monitor_enter();
2325     break;
2326 
2327   case Bytecodes::_monitorexit:
2328     do_monitor_exit();
2329     break;
2330 
2331   case Bytecodes::_breakpoint:
2332     // Breakpoint set concurrently to compile
2333     // %%% use an uncommon trap?
2334     C->record_failure("breakpoint in method");
2335     return;
2336 
2337   default:
2338 #ifndef PRODUCT
2339     map()->dump(99);
2340 #endif
2341     tty->print("\nUnhandled bytecode %s\n", Bytecodes::name(bc()) );
2342     ShouldNotReachHere();
2343   }
2344 
2345 #ifndef PRODUCT
2346   IdealGraphPrinter *printer = IdealGraphPrinter::printer();
2347   if(printer) {
2348     char buffer[256];
2349     sprintf(buffer, "Bytecode %d: %s", bci(), Bytecodes::name(bc()));
2350     bool old = printer->traverse_outs();
2351     printer->set_traverse_outs(true);
2352     printer->print_method(C, buffer, 4);
2353     printer->set_traverse_outs(old);
2354   }
2355 #endif
2356 }