parse2.cpp revision 605:98cb887364d3
1/*
2 * Copyright 1998-2008 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
28extern int explicit_null_checks_inserted,
29           explicit_null_checks_elided;
30
31//---------------------------------array_load----------------------------------
32void Parse::array_load(BasicType elem_type) {
33  const Type* elem = Type::TOP;
34  Node* adr = array_addressing(elem_type, 0, &elem);
35  if (stopped())  return;     // guaranteed null or range check
36  _sp -= 2;                   // Pop array and index
37  const TypeAryPtr* adr_type = TypeAryPtr::get_array_body_type(elem_type);
38  Node* ld = make_load(control(), adr, elem, elem_type, adr_type);
39  push(ld);
40}
41
42
43//--------------------------------array_store----------------------------------
44void Parse::array_store(BasicType elem_type) {
45  Node* adr = array_addressing(elem_type, 1);
46  if (stopped())  return;     // guaranteed null or range check
47  Node* val = pop();
48  _sp -= 2;                   // Pop array and index
49  const TypeAryPtr* adr_type = TypeAryPtr::get_array_body_type(elem_type);
50  store_to_memory(control(), adr, val, elem_type, adr_type);
51}
52
53
54//------------------------------array_addressing-------------------------------
55// Pull array and index from the stack.  Compute pointer-to-element.
56Node* Parse::array_addressing(BasicType type, int vals, const Type* *result2) {
57  Node *idx   = peek(0+vals);   // Get from stack without popping
58  Node *ary   = peek(1+vals);   // in case of exception
59
60  // Null check the array base, with correct stack contents
61  ary = do_null_check(ary, T_ARRAY);
62  // Compile-time detect of null-exception?
63  if (stopped())  return top();
64
65  const TypeAryPtr* arytype  = _gvn.type(ary)->is_aryptr();
66  const TypeInt*    sizetype = arytype->size();
67  const Type*       elemtype = arytype->elem();
68
69  if (UseUniqueSubclasses && result2 != NULL) {
70    const Type* el = elemtype->make_ptr();
71    if (el && el->isa_instptr()) {
72      const TypeInstPtr* toop = el->is_instptr();
73      if (toop->klass()->as_instance_klass()->unique_concrete_subklass()) {
74        // If we load from "AbstractClass[]" we must see "ConcreteSubClass".
75        const Type* subklass = Type::get_const_type(toop->klass());
76        elemtype = subklass->join(el);
77      }
78    }
79  }
80
81  // Check for big class initializers with all constant offsets
82  // feeding into a known-size array.
83  const TypeInt* idxtype = _gvn.type(idx)->is_int();
84  // See if the highest idx value is less than the lowest array bound,
85  // and if the idx value cannot be negative:
86  bool need_range_check = true;
87  if (idxtype->_hi < sizetype->_lo && idxtype->_lo >= 0) {
88    need_range_check = false;
89    if (C->log() != NULL)   C->log()->elem("observe that='!need_range_check'");
90  }
91
92  if (!arytype->klass()->is_loaded()) {
93    // Only fails for some -Xcomp runs
94    // The class is unloaded.  We have to run this bytecode in the interpreter.
95    uncommon_trap(Deoptimization::Reason_unloaded,
96                  Deoptimization::Action_reinterpret,
97                  arytype->klass(), "!loaded array");
98    return top();
99  }
100
101  // Do the range check
102  if (GenerateRangeChecks && need_range_check) {
103    Node* tst;
104    if (sizetype->_hi <= 0) {
105      // The greatest array bound is negative, so we can conclude that we're
106      // compiling unreachable code, but the unsigned compare trick used below
107      // only works with non-negative lengths.  Instead, hack "tst" to be zero so
108      // the uncommon_trap path will always be taken.
109      tst = _gvn.intcon(0);
110    } else {
111      // Range is constant in array-oop, so we can use the original state of mem
112      Node* len = load_array_length(ary);
113
114      // Test length vs index (standard trick using unsigned compare)
115      Node* chk = _gvn.transform( new (C, 3) CmpUNode(idx, len) );
116      BoolTest::mask btest = BoolTest::lt;
117      tst = _gvn.transform( new (C, 2) BoolNode(chk, btest) );
118    }
119    // Branch to failure if out of bounds
120    { BuildCutout unless(this, tst, PROB_MAX);
121      if (C->allow_range_check_smearing()) {
122        // Do not use builtin_throw, since range checks are sometimes
123        // made more stringent by an optimistic transformation.
124        // This creates "tentative" range checks at this point,
125        // which are not guaranteed to throw exceptions.
126        // See IfNode::Ideal, is_range_check, adjust_check.
127        uncommon_trap(Deoptimization::Reason_range_check,
128                      Deoptimization::Action_make_not_entrant,
129                      NULL, "range_check");
130      } else {
131        // If we have already recompiled with the range-check-widening
132        // heroic optimization turned off, then we must really be throwing
133        // range check exceptions.
134        builtin_throw(Deoptimization::Reason_range_check, idx);
135      }
136    }
137  }
138  // Check for always knowing you are throwing a range-check exception
139  if (stopped())  return top();
140
141  Node* ptr = array_element_address(ary, idx, type, sizetype);
142
143  if (result2 != NULL)  *result2 = elemtype;
144
145  assert(ptr != top(), "top should go hand-in-hand with stopped");
146
147  return ptr;
148}
149
150
151// returns IfNode
152IfNode* Parse::jump_if_fork_int(Node* a, Node* b, BoolTest::mask mask) {
153  Node   *cmp = _gvn.transform( new (C, 3) CmpINode( a, b)); // two cases: shiftcount > 32 and shiftcount <= 32
154  Node   *tst = _gvn.transform( new (C, 2) BoolNode( cmp, mask));
155  IfNode *iff = create_and_map_if( control(), tst, ((mask == BoolTest::eq) ? PROB_STATIC_INFREQUENT : PROB_FAIR), COUNT_UNKNOWN );
156  return iff;
157}
158
159// return Region node
160Node* Parse::jump_if_join(Node* iffalse, Node* iftrue) {
161  Node *region  = new (C, 3) RegionNode(3); // 2 results
162  record_for_igvn(region);
163  region->init_req(1, iffalse);
164  region->init_req(2, iftrue );
165  _gvn.set_type(region, Type::CONTROL);
166  region = _gvn.transform(region);
167  set_control (region);
168  return region;
169}
170
171
172//------------------------------helper for tableswitch-------------------------
173void Parse::jump_if_true_fork(IfNode *iff, int dest_bci_if_true, int prof_table_index) {
174  // True branch, use existing map info
175  { PreserveJVMState pjvms(this);
176    Node *iftrue  = _gvn.transform( new (C, 1) IfTrueNode (iff) );
177    set_control( iftrue );
178    profile_switch_case(prof_table_index);
179    merge_new_path(dest_bci_if_true);
180  }
181
182  // False branch
183  Node *iffalse = _gvn.transform( new (C, 1) IfFalseNode(iff) );
184  set_control( iffalse );
185}
186
187void Parse::jump_if_false_fork(IfNode *iff, int dest_bci_if_true, int prof_table_index) {
188  // True branch, use existing map info
189  { PreserveJVMState pjvms(this);
190    Node *iffalse  = _gvn.transform( new (C, 1) IfFalseNode (iff) );
191    set_control( iffalse );
192    profile_switch_case(prof_table_index);
193    merge_new_path(dest_bci_if_true);
194  }
195
196  // False branch
197  Node *iftrue = _gvn.transform( new (C, 1) IfTrueNode(iff) );
198  set_control( iftrue );
199}
200
201void Parse::jump_if_always_fork(int dest_bci, int prof_table_index) {
202  // False branch, use existing map and control()
203  profile_switch_case(prof_table_index);
204  merge_new_path(dest_bci);
205}
206
207
208extern "C" {
209  static int jint_cmp(const void *i, const void *j) {
210    int a = *(jint *)i;
211    int b = *(jint *)j;
212    return a > b ? 1 : a < b ? -1 : 0;
213  }
214}
215
216
217// Default value for methodData switch indexing. Must be a negative value to avoid
218// conflict with any legal switch index.
219#define NullTableIndex -1
220
221class SwitchRange : public StackObj {
222  // a range of integers coupled with a bci destination
223  jint _lo;                     // inclusive lower limit
224  jint _hi;                     // inclusive upper limit
225  int _dest;
226  int _table_index;             // index into method data table
227
228public:
229  jint lo() const              { return _lo;   }
230  jint hi() const              { return _hi;   }
231  int  dest() const            { return _dest; }
232  int  table_index() const     { return _table_index; }
233  bool is_singleton() const    { return _lo == _hi; }
234
235  void setRange(jint lo, jint hi, int dest, int table_index) {
236    assert(lo <= hi, "must be a non-empty range");
237    _lo = lo, _hi = hi; _dest = dest; _table_index = table_index;
238  }
239  bool adjoinRange(jint lo, jint hi, int dest, int table_index) {
240    assert(lo <= hi, "must be a non-empty range");
241    if (lo == _hi+1 && dest == _dest && table_index == _table_index) {
242      _hi = hi;
243      return true;
244    }
245    return false;
246  }
247
248  void set (jint value, int dest, int table_index) {
249    setRange(value, value, dest, table_index);
250  }
251  bool adjoin(jint value, int dest, int table_index) {
252    return adjoinRange(value, value, dest, table_index);
253  }
254
255  void print(ciEnv* env) {
256    if (is_singleton())
257      tty->print(" {%d}=>%d", lo(), dest());
258    else if (lo() == min_jint)
259      tty->print(" {..%d}=>%d", hi(), dest());
260    else if (hi() == max_jint)
261      tty->print(" {%d..}=>%d", lo(), dest());
262    else
263      tty->print(" {%d..%d}=>%d", lo(), hi(), dest());
264  }
265};
266
267
268//-------------------------------do_tableswitch--------------------------------
269void Parse::do_tableswitch() {
270  Node* lookup = pop();
271
272  // Get information about tableswitch
273  int default_dest = iter().get_dest_table(0);
274  int lo_index     = iter().get_int_table(1);
275  int hi_index     = iter().get_int_table(2);
276  int len          = hi_index - lo_index + 1;
277
278  if (len < 1) {
279    // If this is a backward branch, add safepoint
280    maybe_add_safepoint(default_dest);
281    merge(default_dest);
282    return;
283  }
284
285  // generate decision tree, using trichotomy when possible
286  int rnum = len+2;
287  bool makes_backward_branch = false;
288  SwitchRange* ranges = NEW_RESOURCE_ARRAY(SwitchRange, rnum);
289  int rp = -1;
290  if (lo_index != min_jint) {
291    ranges[++rp].setRange(min_jint, lo_index-1, default_dest, NullTableIndex);
292  }
293  for (int j = 0; j < len; j++) {
294    jint match_int = lo_index+j;
295    int  dest      = iter().get_dest_table(j+3);
296    makes_backward_branch |= (dest <= bci());
297    int  table_index = method_data_update() ? j : NullTableIndex;
298    if (rp < 0 || !ranges[rp].adjoin(match_int, dest, table_index)) {
299      ranges[++rp].set(match_int, dest, table_index);
300    }
301  }
302  jint highest = lo_index+(len-1);
303  assert(ranges[rp].hi() == highest, "");
304  if (highest != max_jint
305      && !ranges[rp].adjoinRange(highest+1, max_jint, default_dest, NullTableIndex)) {
306    ranges[++rp].setRange(highest+1, max_jint, default_dest, NullTableIndex);
307  }
308  assert(rp < len+2, "not too many ranges");
309
310  // Safepoint in case if backward branch observed
311  if( makes_backward_branch && UseLoopSafepoints )
312    add_safepoint();
313
314  jump_switch_ranges(lookup, &ranges[0], &ranges[rp]);
315}
316
317
318//------------------------------do_lookupswitch--------------------------------
319void Parse::do_lookupswitch() {
320  Node *lookup = pop();         // lookup value
321  // Get information about lookupswitch
322  int default_dest = iter().get_dest_table(0);
323  int len          = iter().get_int_table(1);
324
325  if (len < 1) {    // If this is a backward branch, add safepoint
326    maybe_add_safepoint(default_dest);
327    merge(default_dest);
328    return;
329  }
330
331  // generate decision tree, using trichotomy when possible
332  jint* table = NEW_RESOURCE_ARRAY(jint, len*2);
333  {
334    for( int j = 0; j < len; j++ ) {
335      table[j+j+0] = iter().get_int_table(2+j+j);
336      table[j+j+1] = iter().get_dest_table(2+j+j+1);
337    }
338    qsort( table, len, 2*sizeof(table[0]), jint_cmp );
339  }
340
341  int rnum = len*2+1;
342  bool makes_backward_branch = false;
343  SwitchRange* ranges = NEW_RESOURCE_ARRAY(SwitchRange, rnum);
344  int rp = -1;
345  for( int j = 0; j < len; j++ ) {
346    jint match_int   = table[j+j+0];
347    int  dest        = table[j+j+1];
348    int  next_lo     = rp < 0 ? min_jint : ranges[rp].hi()+1;
349    int  table_index = method_data_update() ? j : NullTableIndex;
350    makes_backward_branch |= (dest <= bci());
351    if( match_int != next_lo ) {
352      ranges[++rp].setRange(next_lo, match_int-1, default_dest, NullTableIndex);
353    }
354    if( rp < 0 || !ranges[rp].adjoin(match_int, dest, table_index) ) {
355      ranges[++rp].set(match_int, dest, table_index);
356    }
357  }
358  jint highest = table[2*(len-1)];
359  assert(ranges[rp].hi() == highest, "");
360  if( highest != max_jint
361      && !ranges[rp].adjoinRange(highest+1, max_jint, default_dest, NullTableIndex) ) {
362    ranges[++rp].setRange(highest+1, max_jint, default_dest, NullTableIndex);
363  }
364  assert(rp < rnum, "not too many ranges");
365
366  // Safepoint in case backward branch observed
367  if( makes_backward_branch && UseLoopSafepoints )
368    add_safepoint();
369
370  jump_switch_ranges(lookup, &ranges[0], &ranges[rp]);
371}
372
373//----------------------------create_jump_tables-------------------------------
374bool Parse::create_jump_tables(Node* key_val, SwitchRange* lo, SwitchRange* hi) {
375  // Are jumptables enabled
376  if (!UseJumpTables)  return false;
377
378  // Are jumptables supported
379  if (!Matcher::has_match_rule(Op_Jump))  return false;
380
381  // Don't make jump table if profiling
382  if (method_data_update())  return false;
383
384  // Decide if a guard is needed to lop off big ranges at either (or
385  // both) end(s) of the input set. We'll call this the default target
386  // even though we can't be sure that it is the true "default".
387
388  bool needs_guard = false;
389  int default_dest;
390  int64 total_outlier_size = 0;
391  int64 hi_size = ((int64)hi->hi()) - ((int64)hi->lo()) + 1;
392  int64 lo_size = ((int64)lo->hi()) - ((int64)lo->lo()) + 1;
393
394  if (lo->dest() == hi->dest()) {
395    total_outlier_size = hi_size + lo_size;
396    default_dest = lo->dest();
397  } else if (lo_size > hi_size) {
398    total_outlier_size = lo_size;
399    default_dest = lo->dest();
400  } else {
401    total_outlier_size = hi_size;
402    default_dest = hi->dest();
403  }
404
405  // If a guard test will eliminate very sparse end ranges, then
406  // it is worth the cost of an extra jump.
407  if (total_outlier_size > (MaxJumpTableSparseness * 4)) {
408    needs_guard = true;
409    if (default_dest == lo->dest()) lo++;
410    if (default_dest == hi->dest()) hi--;
411  }
412
413  // Find the total number of cases and ranges
414  int64 num_cases = ((int64)hi->hi()) - ((int64)lo->lo()) + 1;
415  int num_range = hi - lo + 1;
416
417  // Don't create table if: too large, too small, or too sparse.
418  if (num_cases < MinJumpTableSize || num_cases > MaxJumpTableSize)
419    return false;
420  if (num_cases > (MaxJumpTableSparseness * num_range))
421    return false;
422
423  // Normalize table lookups to zero
424  int lowval = lo->lo();
425  key_val = _gvn.transform( new (C, 3) SubINode(key_val, _gvn.intcon(lowval)) );
426
427  // Generate a guard to protect against input keyvals that aren't
428  // in the switch domain.
429  if (needs_guard) {
430    Node*   size = _gvn.intcon(num_cases);
431    Node*   cmp = _gvn.transform( new (C, 3) CmpUNode(key_val, size) );
432    Node*   tst = _gvn.transform( new (C, 2) BoolNode(cmp, BoolTest::ge) );
433    IfNode* iff = create_and_map_if( control(), tst, PROB_FAIR, COUNT_UNKNOWN);
434    jump_if_true_fork(iff, default_dest, NullTableIndex);
435  }
436
437  // Create an ideal node JumpTable that has projections
438  // of all possible ranges for a switch statement
439  // The key_val input must be converted to a pointer offset and scaled.
440  // Compare Parse::array_addressing above.
441#ifdef _LP64
442  // Clean the 32-bit int into a real 64-bit offset.
443  // Otherwise, the jint value 0 might turn into an offset of 0x0800000000.
444  const TypeLong* lkeytype = TypeLong::make(CONST64(0), num_cases-1, Type::WidenMin);
445  key_val       = _gvn.transform( new (C, 2) ConvI2LNode(key_val, lkeytype) );
446#endif
447  // Shift the value by wordsize so we have an index into the table, rather
448  // than a switch value
449  Node *shiftWord = _gvn.MakeConX(wordSize);
450  key_val = _gvn.transform( new (C, 3) MulXNode( key_val, shiftWord));
451
452  // Create the JumpNode
453  Node* jtn = _gvn.transform( new (C, 2) JumpNode(control(), key_val, num_cases) );
454
455  // These are the switch destinations hanging off the jumpnode
456  int i = 0;
457  for (SwitchRange* r = lo; r <= hi; r++) {
458    for (int j = r->lo(); j <= r->hi(); j++, i++) {
459      Node* input = _gvn.transform(new (C, 1) JumpProjNode(jtn, i, r->dest(), j - lowval));
460      {
461        PreserveJVMState pjvms(this);
462        set_control(input);
463        jump_if_always_fork(r->dest(), r->table_index());
464      }
465    }
466  }
467  assert(i == num_cases, "miscount of cases");
468  stop_and_kill_map();  // no more uses for this JVMS
469  return true;
470}
471
472//----------------------------jump_switch_ranges-------------------------------
473void Parse::jump_switch_ranges(Node* key_val, SwitchRange *lo, SwitchRange *hi, int switch_depth) {
474  Block* switch_block = block();
475
476  if (switch_depth == 0) {
477    // Do special processing for the top-level call.
478    assert(lo->lo() == min_jint, "initial range must exhaust Type::INT");
479    assert(hi->hi() == max_jint, "initial range must exhaust Type::INT");
480
481    // Decrement pred-numbers for the unique set of nodes.
482#ifdef ASSERT
483    // Ensure that the block's successors are a (duplicate-free) set.
484    int successors_counted = 0;  // block occurrences in [hi..lo]
485    int unique_successors = switch_block->num_successors();
486    for (int i = 0; i < unique_successors; i++) {
487      Block* target = switch_block->successor_at(i);
488
489      // Check that the set of successors is the same in both places.
490      int successors_found = 0;
491      for (SwitchRange* p = lo; p <= hi; p++) {
492        if (p->dest() == target->start())  successors_found++;
493      }
494      assert(successors_found > 0, "successor must be known");
495      successors_counted += successors_found;
496    }
497    assert(successors_counted == (hi-lo)+1, "no unexpected successors");
498#endif
499
500    // Maybe prune the inputs, based on the type of key_val.
501    jint min_val = min_jint;
502    jint max_val = max_jint;
503    const TypeInt* ti = key_val->bottom_type()->isa_int();
504    if (ti != NULL) {
505      min_val = ti->_lo;
506      max_val = ti->_hi;
507      assert(min_val <= max_val, "invalid int type");
508    }
509    while (lo->hi() < min_val)  lo++;
510    if (lo->lo() < min_val)  lo->setRange(min_val, lo->hi(), lo->dest(), lo->table_index());
511    while (hi->lo() > max_val)  hi--;
512    if (hi->hi() > max_val)  hi->setRange(hi->lo(), max_val, hi->dest(), hi->table_index());
513  }
514
515#ifndef PRODUCT
516  if (switch_depth == 0) {
517    _max_switch_depth = 0;
518    _est_switch_depth = log2_intptr((hi-lo+1)-1)+1;
519  }
520#endif
521
522  assert(lo <= hi, "must be a non-empty set of ranges");
523  if (lo == hi) {
524    jump_if_always_fork(lo->dest(), lo->table_index());
525  } else {
526    assert(lo->hi() == (lo+1)->lo()-1, "contiguous ranges");
527    assert(hi->lo() == (hi-1)->hi()+1, "contiguous ranges");
528
529    if (create_jump_tables(key_val, lo, hi)) return;
530
531    int nr = hi - lo + 1;
532
533    SwitchRange* mid = lo + nr/2;
534    // if there is an easy choice, pivot at a singleton:
535    if (nr > 3 && !mid->is_singleton() && (mid-1)->is_singleton())  mid--;
536
537    assert(lo < mid && mid <= hi, "good pivot choice");
538    assert(nr != 2 || mid == hi,   "should pick higher of 2");
539    assert(nr != 3 || mid == hi-1, "should pick middle of 3");
540
541    Node *test_val = _gvn.intcon(mid->lo());
542
543    if (mid->is_singleton()) {
544      IfNode *iff_ne = jump_if_fork_int(key_val, test_val, BoolTest::ne);
545      jump_if_false_fork(iff_ne, mid->dest(), mid->table_index());
546
547      // Special Case:  If there are exactly three ranges, and the high
548      // and low range each go to the same place, omit the "gt" test,
549      // since it will not discriminate anything.
550      bool eq_test_only = (hi == lo+2 && hi->dest() == lo->dest());
551      if (eq_test_only) {
552        assert(mid == hi-1, "");
553      }
554
555      // if there is a higher range, test for it and process it:
556      if (mid < hi && !eq_test_only) {
557        // two comparisons of same values--should enable 1 test for 2 branches
558        // Use BoolTest::le instead of BoolTest::gt
559        IfNode *iff_le  = jump_if_fork_int(key_val, test_val, BoolTest::le);
560        Node   *iftrue  = _gvn.transform( new (C, 1) IfTrueNode(iff_le) );
561        Node   *iffalse = _gvn.transform( new (C, 1) IfFalseNode(iff_le) );
562        { PreserveJVMState pjvms(this);
563          set_control(iffalse);
564          jump_switch_ranges(key_val, mid+1, hi, switch_depth+1);
565        }
566        set_control(iftrue);
567      }
568
569    } else {
570      // mid is a range, not a singleton, so treat mid..hi as a unit
571      IfNode *iff_ge = jump_if_fork_int(key_val, test_val, BoolTest::ge);
572
573      // if there is a higher range, test for it and process it:
574      if (mid == hi) {
575        jump_if_true_fork(iff_ge, mid->dest(), mid->table_index());
576      } else {
577        Node *iftrue  = _gvn.transform( new (C, 1) IfTrueNode(iff_ge) );
578        Node *iffalse = _gvn.transform( new (C, 1) IfFalseNode(iff_ge) );
579        { PreserveJVMState pjvms(this);
580          set_control(iftrue);
581          jump_switch_ranges(key_val, mid, hi, switch_depth+1);
582        }
583        set_control(iffalse);
584      }
585    }
586
587    // in any case, process the lower range
588    jump_switch_ranges(key_val, lo, mid-1, switch_depth+1);
589  }
590
591  // Decrease pred_count for each successor after all is done.
592  if (switch_depth == 0) {
593    int unique_successors = switch_block->num_successors();
594    for (int i = 0; i < unique_successors; i++) {
595      Block* target = switch_block->successor_at(i);
596      // Throw away the pre-allocated path for each unique successor.
597      target->next_path_num();
598    }
599  }
600
601#ifndef PRODUCT
602  _max_switch_depth = MAX2(switch_depth, _max_switch_depth);
603  if (TraceOptoParse && Verbose && WizardMode && switch_depth == 0) {
604    SwitchRange* r;
605    int nsing = 0;
606    for( r = lo; r <= hi; r++ ) {
607      if( r->is_singleton() )  nsing++;
608    }
609    tty->print(">>> ");
610    _method->print_short_name();
611    tty->print_cr(" switch decision tree");
612    tty->print_cr("    %d ranges (%d singletons), max_depth=%d, est_depth=%d",
613                  hi-lo+1, nsing, _max_switch_depth, _est_switch_depth);
614    if (_max_switch_depth > _est_switch_depth) {
615      tty->print_cr("******** BAD SWITCH DEPTH ********");
616    }
617    tty->print("   ");
618    for( r = lo; r <= hi; r++ ) {
619      r->print(env());
620    }
621    tty->print_cr("");
622  }
623#endif
624}
625
626void Parse::modf() {
627  Node *f2 = pop();
628  Node *f1 = pop();
629  Node* c = make_runtime_call(RC_LEAF, OptoRuntime::modf_Type(),
630                              CAST_FROM_FN_PTR(address, SharedRuntime::frem),
631                              "frem", NULL, //no memory effects
632                              f1, f2);
633  Node* res = _gvn.transform(new (C, 1) ProjNode(c, TypeFunc::Parms + 0));
634
635  push(res);
636}
637
638void Parse::modd() {
639  Node *d2 = pop_pair();
640  Node *d1 = pop_pair();
641  Node* c = make_runtime_call(RC_LEAF, OptoRuntime::Math_DD_D_Type(),
642                              CAST_FROM_FN_PTR(address, SharedRuntime::drem),
643                              "drem", NULL, //no memory effects
644                              d1, top(), d2, top());
645  Node* res_d   = _gvn.transform(new (C, 1) ProjNode(c, TypeFunc::Parms + 0));
646
647#ifdef ASSERT
648  Node* res_top = _gvn.transform(new (C, 1) ProjNode(c, TypeFunc::Parms + 1));
649  assert(res_top == top(), "second value must be top");
650#endif
651
652  push_pair(res_d);
653}
654
655void Parse::l2f() {
656  Node* f2 = pop();
657  Node* f1 = pop();
658  Node* c = make_runtime_call(RC_LEAF, OptoRuntime::l2f_Type(),
659                              CAST_FROM_FN_PTR(address, SharedRuntime::l2f),
660                              "l2f", NULL, //no memory effects
661                              f1, f2);
662  Node* res = _gvn.transform(new (C, 1) ProjNode(c, TypeFunc::Parms + 0));
663
664  push(res);
665}
666
667void Parse::do_irem() {
668  // Must keep both values on the expression-stack during null-check
669  do_null_check(peek(), T_INT);
670  // Compile-time detect of null-exception?
671  if (stopped())  return;
672
673  Node* b = pop();
674  Node* a = pop();
675
676  const Type *t = _gvn.type(b);
677  if (t != Type::TOP) {
678    const TypeInt *ti = t->is_int();
679    if (ti->is_con()) {
680      int divisor = ti->get_con();
681      // check for positive power of 2
682      if (divisor > 0 &&
683          (divisor & ~(divisor-1)) == divisor) {
684        // yes !
685        Node *mask = _gvn.intcon((divisor - 1));
686        // Sigh, must handle negative dividends
687        Node *zero = _gvn.intcon(0);
688        IfNode *ifff = jump_if_fork_int(a, zero, BoolTest::lt);
689        Node *iff = _gvn.transform( new (C, 1) IfFalseNode(ifff) );
690        Node *ift = _gvn.transform( new (C, 1) IfTrueNode (ifff) );
691        Node *reg = jump_if_join(ift, iff);
692        Node *phi = PhiNode::make(reg, NULL, TypeInt::INT);
693        // Negative path; negate/and/negate
694        Node *neg = _gvn.transform( new (C, 3) SubINode(zero, a) );
695        Node *andn= _gvn.transform( new (C, 3) AndINode(neg, mask) );
696        Node *negn= _gvn.transform( new (C, 3) SubINode(zero, andn) );
697        phi->init_req(1, negn);
698        // Fast positive case
699        Node *andx = _gvn.transform( new (C, 3) AndINode(a, mask) );
700        phi->init_req(2, andx);
701        // Push the merge
702        push( _gvn.transform(phi) );
703        return;
704      }
705    }
706  }
707  // Default case
708  push( _gvn.transform( new (C, 3) ModINode(control(),a,b) ) );
709}
710
711// Handle jsr and jsr_w bytecode
712void Parse::do_jsr() {
713  assert(bc() == Bytecodes::_jsr || bc() == Bytecodes::_jsr_w, "wrong bytecode");
714
715  // Store information about current state, tagged with new _jsr_bci
716  int return_bci = iter().next_bci();
717  int jsr_bci    = (bc() == Bytecodes::_jsr) ? iter().get_dest() : iter().get_far_dest();
718
719  // Update method data
720  profile_taken_branch(jsr_bci);
721
722  // The way we do things now, there is only one successor block
723  // for the jsr, because the target code is cloned by ciTypeFlow.
724  Block* target = successor_for_bci(jsr_bci);
725
726  // What got pushed?
727  const Type* ret_addr = target->peek();
728  assert(ret_addr->singleton(), "must be a constant (cloned jsr body)");
729
730  // Effect on jsr on stack
731  push(_gvn.makecon(ret_addr));
732
733  // Flow to the jsr.
734  merge(jsr_bci);
735}
736
737// Handle ret bytecode
738void Parse::do_ret() {
739  // Find to whom we return.
740#if 0 // %%%% MAKE THIS WORK
741  Node* con = local();
742  const TypePtr* tp = con->bottom_type()->isa_ptr();
743  assert(tp && tp->singleton(), "");
744  int return_bci = (int) tp->get_con();
745  merge(return_bci);
746#else
747  assert(block()->num_successors() == 1, "a ret can only go one place now");
748  Block* target = block()->successor_at(0);
749  assert(!target->is_ready(), "our arrival must be expected");
750  profile_ret(target->flow()->start());
751  int pnum = target->next_path_num();
752  merge_common(target, pnum);
753#endif
754}
755
756//--------------------------dynamic_branch_prediction--------------------------
757// Try to gather dynamic branch prediction behavior.  Return a probability
758// of the branch being taken and set the "cnt" field.  Returns a -1.0
759// if we need to use static prediction for some reason.
760float Parse::dynamic_branch_prediction(float &cnt) {
761  ResourceMark rm;
762
763  cnt  = COUNT_UNKNOWN;
764
765  // Use MethodData information if it is available
766  // FIXME: free the ProfileData structure
767  ciMethodData* methodData = method()->method_data();
768  if (!methodData->is_mature())  return PROB_UNKNOWN;
769  ciProfileData* data = methodData->bci_to_data(bci());
770  if (!data->is_JumpData())  return PROB_UNKNOWN;
771
772  // get taken and not taken values
773  int     taken = data->as_JumpData()->taken();
774  int not_taken = 0;
775  if (data->is_BranchData()) {
776    not_taken = data->as_BranchData()->not_taken();
777  }
778
779  // scale the counts to be commensurate with invocation counts:
780  taken = method()->scale_count(taken);
781  not_taken = method()->scale_count(not_taken);
782
783  // Give up if too few counts to be meaningful
784  if (taken + not_taken < 40) {
785    if (C->log() != NULL) {
786      C->log()->elem("branch target_bci='%d' taken='%d' not_taken='%d'", iter().get_dest(), taken, not_taken);
787    }
788    return PROB_UNKNOWN;
789  }
790
791  // Compute frequency that we arrive here
792  int sum = taken + not_taken;
793  // Adjust, if this block is a cloned private block but the
794  // Jump counts are shared.  Taken the private counts for
795  // just this path instead of the shared counts.
796  if( block()->count() > 0 )
797    sum = block()->count();
798  cnt = (float)sum / (float)FreqCountInvocations;
799
800  // Pin probability to sane limits
801  float prob;
802  if( !taken )
803    prob = (0+PROB_MIN) / 2;
804  else if( !not_taken )
805    prob = (1+PROB_MAX) / 2;
806  else {                         // Compute probability of true path
807    prob = (float)taken / (float)(taken + not_taken);
808    if (prob > PROB_MAX)  prob = PROB_MAX;
809    if (prob < PROB_MIN)   prob = PROB_MIN;
810  }
811
812  assert((cnt > 0.0f) && (prob > 0.0f),
813         "Bad frequency assignment in if");
814
815  if (C->log() != NULL) {
816    const char* prob_str = NULL;
817    if (prob >= PROB_MAX)  prob_str = (prob == PROB_MAX) ? "max" : "always";
818    if (prob <= PROB_MIN)  prob_str = (prob == PROB_MIN) ? "min" : "never";
819    char prob_str_buf[30];
820    if (prob_str == NULL) {
821      sprintf(prob_str_buf, "%g", prob);
822      prob_str = prob_str_buf;
823    }
824    C->log()->elem("branch target_bci='%d' taken='%d' not_taken='%d' cnt='%g' prob='%s'",
825                   iter().get_dest(), taken, not_taken, cnt, prob_str);
826  }
827  return prob;
828}
829
830//-----------------------------branch_prediction-------------------------------
831float Parse::branch_prediction(float& cnt,
832                               BoolTest::mask btest,
833                               int target_bci) {
834  float prob = dynamic_branch_prediction(cnt);
835  // If prob is unknown, switch to static prediction
836  if (prob != PROB_UNKNOWN)  return prob;
837
838  prob = PROB_FAIR;                   // Set default value
839  if (btest == BoolTest::eq)          // Exactly equal test?
840    prob = PROB_STATIC_INFREQUENT;    // Assume its relatively infrequent
841  else if (btest == BoolTest::ne)
842    prob = PROB_STATIC_FREQUENT;      // Assume its relatively frequent
843
844  // If this is a conditional test guarding a backwards branch,
845  // assume its a loop-back edge.  Make it a likely taken branch.
846  if (target_bci < bci()) {
847    if (is_osr_parse()) {    // Could be a hot OSR'd loop; force deopt
848      // Since it's an OSR, we probably have profile data, but since
849      // branch_prediction returned PROB_UNKNOWN, the counts are too small.
850      // Let's make a special check here for completely zero counts.
851      ciMethodData* methodData = method()->method_data();
852      if (!methodData->is_empty()) {
853        ciProfileData* data = methodData->bci_to_data(bci());
854        // Only stop for truly zero counts, which mean an unknown part
855        // of the OSR-ed method, and we want to deopt to gather more stats.
856        // If you have ANY counts, then this loop is simply 'cold' relative
857        // to the OSR loop.
858        if (data->as_BranchData()->taken() +
859            data->as_BranchData()->not_taken() == 0 ) {
860          // This is the only way to return PROB_UNKNOWN:
861          return PROB_UNKNOWN;
862        }
863      }
864    }
865    prob = PROB_STATIC_FREQUENT;     // Likely to take backwards branch
866  }
867
868  assert(prob != PROB_UNKNOWN, "must have some guess at this point");
869  return prob;
870}
871
872// The magic constants are chosen so as to match the output of
873// branch_prediction() when the profile reports a zero taken count.
874// It is important to distinguish zero counts unambiguously, because
875// some branches (e.g., _213_javac.Assembler.eliminate) validly produce
876// very small but nonzero probabilities, which if confused with zero
877// counts would keep the program recompiling indefinitely.
878bool Parse::seems_never_taken(float prob) {
879  return prob < PROB_MIN;
880}
881
882//-------------------------------repush_if_args--------------------------------
883// Push arguments of an "if" bytecode back onto the stack by adjusting _sp.
884inline void Parse::repush_if_args() {
885#ifndef PRODUCT
886  if (PrintOpto && WizardMode) {
887    tty->print("defending against excessive implicit null exceptions on %s @%d in ",
888               Bytecodes::name(iter().cur_bc()), iter().cur_bci());
889    method()->print_name(); tty->cr();
890  }
891#endif
892  int bc_depth = - Bytecodes::depth(iter().cur_bc());
893  assert(bc_depth == 1 || bc_depth == 2, "only two kinds of branches");
894  DEBUG_ONLY(sync_jvms());   // argument(n) requires a synced jvms
895  assert(argument(0) != NULL, "must exist");
896  assert(bc_depth == 1 || argument(1) != NULL, "two must exist");
897  _sp += bc_depth;
898}
899
900//----------------------------------do_ifnull----------------------------------
901void Parse::do_ifnull(BoolTest::mask btest, Node *c) {
902  int target_bci = iter().get_dest();
903
904  Block* branch_block = successor_for_bci(target_bci);
905  Block* next_block   = successor_for_bci(iter().next_bci());
906
907  float cnt;
908  float prob = branch_prediction(cnt, btest, target_bci);
909  if (prob == PROB_UNKNOWN) {
910    // (An earlier version of do_ifnull omitted this trap for OSR methods.)
911#ifndef PRODUCT
912    if (PrintOpto && Verbose)
913      tty->print_cr("Never-taken edge stops compilation at bci %d",bci());
914#endif
915    repush_if_args(); // to gather stats on loop
916    // We need to mark this branch as taken so that if we recompile we will
917    // see that it is possible. In the tiered system the interpreter doesn't
918    // do profiling and by the time we get to the lower tier from the interpreter
919    // the path may be cold again. Make sure it doesn't look untaken
920    profile_taken_branch(target_bci, !ProfileInterpreter);
921    uncommon_trap(Deoptimization::Reason_unreached,
922                  Deoptimization::Action_reinterpret,
923                  NULL, "cold");
924    if (EliminateAutoBox) {
925      // Mark the successor blocks as parsed
926      branch_block->next_path_num();
927      next_block->next_path_num();
928    }
929    return;
930  }
931
932  explicit_null_checks_inserted++;
933
934  // Generate real control flow
935  Node   *tst = _gvn.transform( new (C, 2) BoolNode( c, btest ) );
936
937  // Sanity check the probability value
938  assert(prob > 0.0f,"Bad probability in Parser");
939 // Need xform to put node in hash table
940  IfNode *iff = create_and_xform_if( control(), tst, prob, cnt );
941  assert(iff->_prob > 0.0f,"Optimizer made bad probability in parser");
942  // True branch
943  { PreserveJVMState pjvms(this);
944    Node* iftrue  = _gvn.transform( new (C, 1) IfTrueNode (iff) );
945    set_control(iftrue);
946
947    if (stopped()) {            // Path is dead?
948      explicit_null_checks_elided++;
949      if (EliminateAutoBox) {
950        // Mark the successor block as parsed
951        branch_block->next_path_num();
952      }
953    } else {                    // Path is live.
954      // Update method data
955      profile_taken_branch(target_bci);
956      adjust_map_after_if(btest, c, prob, branch_block, next_block);
957      if (!stopped())
958        merge(target_bci);
959    }
960  }
961
962  // False branch
963  Node* iffalse = _gvn.transform( new (C, 1) IfFalseNode(iff) );
964  set_control(iffalse);
965
966  if (stopped()) {              // Path is dead?
967    explicit_null_checks_elided++;
968    if (EliminateAutoBox) {
969      // Mark the successor block as parsed
970      next_block->next_path_num();
971    }
972  } else  {                     // Path is live.
973    // Update method data
974    profile_not_taken_branch();
975    adjust_map_after_if(BoolTest(btest).negate(), c, 1.0-prob,
976                        next_block, branch_block);
977  }
978}
979
980//------------------------------------do_if------------------------------------
981void Parse::do_if(BoolTest::mask btest, Node* c) {
982  int target_bci = iter().get_dest();
983
984  Block* branch_block = successor_for_bci(target_bci);
985  Block* next_block   = successor_for_bci(iter().next_bci());
986
987  float cnt;
988  float prob = branch_prediction(cnt, btest, target_bci);
989  float untaken_prob = 1.0 - prob;
990
991  if (prob == PROB_UNKNOWN) {
992#ifndef PRODUCT
993    if (PrintOpto && Verbose)
994      tty->print_cr("Never-taken edge stops compilation at bci %d",bci());
995#endif
996    repush_if_args(); // to gather stats on loop
997    // We need to mark this branch as taken so that if we recompile we will
998    // see that it is possible. In the tiered system the interpreter doesn't
999    // do profiling and by the time we get to the lower tier from the interpreter
1000    // the path may be cold again. Make sure it doesn't look untaken
1001    profile_taken_branch(target_bci, !ProfileInterpreter);
1002    uncommon_trap(Deoptimization::Reason_unreached,
1003                  Deoptimization::Action_reinterpret,
1004                  NULL, "cold");
1005    if (EliminateAutoBox) {
1006      // Mark the successor blocks as parsed
1007      branch_block->next_path_num();
1008      next_block->next_path_num();
1009    }
1010    return;
1011  }
1012
1013  // Sanity check the probability value
1014  assert(0.0f < prob && prob < 1.0f,"Bad probability in Parser");
1015
1016  bool taken_if_true = true;
1017  // Convert BoolTest to canonical form:
1018  if (!BoolTest(btest).is_canonical()) {
1019    btest         = BoolTest(btest).negate();
1020    taken_if_true = false;
1021    // prob is NOT updated here; it remains the probability of the taken
1022    // path (as opposed to the prob of the path guarded by an 'IfTrueNode').
1023  }
1024  assert(btest != BoolTest::eq, "!= is the only canonical exact test");
1025
1026  Node* tst0 = new (C, 2) BoolNode(c, btest);
1027  Node* tst = _gvn.transform(tst0);
1028  BoolTest::mask taken_btest   = BoolTest::illegal;
1029  BoolTest::mask untaken_btest = BoolTest::illegal;
1030
1031  if (tst->is_Bool()) {
1032    // Refresh c from the transformed bool node, since it may be
1033    // simpler than the original c.  Also re-canonicalize btest.
1034    // This wins when (Bool ne (Conv2B p) 0) => (Bool ne (CmpP p NULL)).
1035    // That can arise from statements like: if (x instanceof C) ...
1036    if (tst != tst0) {
1037      // Canonicalize one more time since transform can change it.
1038      btest = tst->as_Bool()->_test._test;
1039      if (!BoolTest(btest).is_canonical()) {
1040        // Reverse edges one more time...
1041        tst   = _gvn.transform( tst->as_Bool()->negate(&_gvn) );
1042        btest = tst->as_Bool()->_test._test;
1043        assert(BoolTest(btest).is_canonical(), "sanity");
1044        taken_if_true = !taken_if_true;
1045      }
1046      c = tst->in(1);
1047    }
1048    BoolTest::mask neg_btest = BoolTest(btest).negate();
1049    taken_btest   = taken_if_true ?     btest : neg_btest;
1050    untaken_btest = taken_if_true ? neg_btest :     btest;
1051  }
1052
1053  // Generate real control flow
1054  float true_prob = (taken_if_true ? prob : untaken_prob);
1055  IfNode* iff = create_and_map_if(control(), tst, true_prob, cnt);
1056  assert(iff->_prob > 0.0f,"Optimizer made bad probability in parser");
1057  Node* taken_branch   = new (C, 1) IfTrueNode(iff);
1058  Node* untaken_branch = new (C, 1) IfFalseNode(iff);
1059  if (!taken_if_true) {  // Finish conversion to canonical form
1060    Node* tmp      = taken_branch;
1061    taken_branch   = untaken_branch;
1062    untaken_branch = tmp;
1063  }
1064
1065  // Branch is taken:
1066  { PreserveJVMState pjvms(this);
1067    taken_branch = _gvn.transform(taken_branch);
1068    set_control(taken_branch);
1069
1070    if (stopped()) {
1071      if (EliminateAutoBox) {
1072        // Mark the successor block as parsed
1073        branch_block->next_path_num();
1074      }
1075    } else {
1076      // Update method data
1077      profile_taken_branch(target_bci);
1078      adjust_map_after_if(taken_btest, c, prob, branch_block, next_block);
1079      if (!stopped())
1080        merge(target_bci);
1081    }
1082  }
1083
1084  untaken_branch = _gvn.transform(untaken_branch);
1085  set_control(untaken_branch);
1086
1087  // Branch not taken.
1088  if (stopped()) {
1089    if (EliminateAutoBox) {
1090      // Mark the successor block as parsed
1091      next_block->next_path_num();
1092    }
1093  } else {
1094    // Update method data
1095    profile_not_taken_branch();
1096    adjust_map_after_if(untaken_btest, c, untaken_prob,
1097                        next_block, branch_block);
1098  }
1099}
1100
1101//----------------------------adjust_map_after_if------------------------------
1102// Adjust the JVM state to reflect the result of taking this path.
1103// Basically, it means inspecting the CmpNode controlling this
1104// branch, seeing how it constrains a tested value, and then
1105// deciding if it's worth our while to encode this constraint
1106// as graph nodes in the current abstract interpretation map.
1107void Parse::adjust_map_after_if(BoolTest::mask btest, Node* c, float prob,
1108                                Block* path, Block* other_path) {
1109  if (stopped() || !c->is_Cmp() || btest == BoolTest::illegal)
1110    return;                             // nothing to do
1111
1112  bool is_fallthrough = (path == successor_for_bci(iter().next_bci()));
1113
1114  int cop = c->Opcode();
1115  if (seems_never_taken(prob) && cop == Op_CmpP && btest == BoolTest::eq) {
1116    // (An earlier version of do_if omitted '&& btest == BoolTest::eq'.)
1117    //
1118    // If this might possibly turn into an implicit null check,
1119    // and the null has never yet been seen, we need to generate
1120    // an uncommon trap, so as to recompile instead of suffering
1121    // with very slow branches.  (We'll get the slow branches if
1122    // the program ever changes phase and starts seeing nulls here.)
1123    //
1124    // The tests we worry about are of the form (p == null).
1125    // We do not simply inspect for a null constant, since a node may
1126    // optimize to 'null' later on.
1127    repush_if_args();
1128    // We need to mark this branch as taken so that if we recompile we will
1129    // see that it is possible. In the tiered system the interpreter doesn't
1130    // do profiling and by the time we get to the lower tier from the interpreter
1131    // the path may be cold again. Make sure it doesn't look untaken
1132    if (is_fallthrough) {
1133      profile_not_taken_branch(!ProfileInterpreter);
1134    } else {
1135      profile_taken_branch(iter().get_dest(), !ProfileInterpreter);
1136    }
1137    uncommon_trap(Deoptimization::Reason_unreached,
1138                  Deoptimization::Action_reinterpret,
1139                  NULL,
1140                  (is_fallthrough ? "taken always" : "taken never"));
1141    return;
1142  }
1143
1144  Node* val = c->in(1);
1145  Node* con = c->in(2);
1146  const Type* tcon = _gvn.type(con);
1147  const Type* tval = _gvn.type(val);
1148  bool have_con = tcon->singleton();
1149  if (tval->singleton()) {
1150    if (!have_con) {
1151      // Swap, so constant is in con.
1152      con  = val;
1153      tcon = tval;
1154      val  = c->in(2);
1155      tval = _gvn.type(val);
1156      btest = BoolTest(btest).commute();
1157      have_con = true;
1158    } else {
1159      // Do we have two constants?  Then leave well enough alone.
1160      have_con = false;
1161    }
1162  }
1163  if (!have_con)                        // remaining adjustments need a con
1164    return;
1165
1166
1167  int val_in_map = map()->find_edge(val);
1168  if (val_in_map < 0)  return;          // replace_in_map would be useless
1169  {
1170    JVMState* jvms = this->jvms();
1171    if (!(jvms->is_loc(val_in_map) ||
1172          jvms->is_stk(val_in_map)))
1173      return;                           // again, it would be useless
1174  }
1175
1176  // Check for a comparison to a constant, and "know" that the compared
1177  // value is constrained on this path.
1178  assert(tcon->singleton(), "");
1179  ConstraintCastNode* ccast = NULL;
1180  Node* cast = NULL;
1181
1182  switch (btest) {
1183  case BoolTest::eq:                    // Constant test?
1184    {
1185      const Type* tboth = tcon->join(tval);
1186      if (tboth == tval)  break;        // Nothing to gain.
1187      if (tcon->isa_int()) {
1188        ccast = new (C, 2) CastIINode(val, tboth);
1189      } else if (tcon == TypePtr::NULL_PTR) {
1190        // Cast to null, but keep the pointer identity temporarily live.
1191        ccast = new (C, 2) CastPPNode(val, tboth);
1192      } else {
1193        const TypeF* tf = tcon->isa_float_constant();
1194        const TypeD* td = tcon->isa_double_constant();
1195        // Exclude tests vs float/double 0 as these could be
1196        // either +0 or -0.  Just because you are equal to +0
1197        // doesn't mean you ARE +0!
1198        if ((!tf || tf->_f != 0.0) &&
1199            (!td || td->_d != 0.0))
1200          cast = con;                   // Replace non-constant val by con.
1201      }
1202    }
1203    break;
1204
1205  case BoolTest::ne:
1206    if (tcon == TypePtr::NULL_PTR) {
1207      cast = cast_not_null(val, false);
1208    }
1209    break;
1210
1211  default:
1212    // (At this point we could record int range types with CastII.)
1213    break;
1214  }
1215
1216  if (ccast != NULL) {
1217    const Type* tcc = ccast->as_Type()->type();
1218    assert(tcc != tval && tcc->higher_equal(tval), "must improve");
1219    // Delay transform() call to allow recovery of pre-cast value
1220    // at the control merge.
1221    ccast->set_req(0, control());
1222    _gvn.set_type_bottom(ccast);
1223    record_for_igvn(ccast);
1224    cast = ccast;
1225  }
1226
1227  if (cast != NULL) {                   // Here's the payoff.
1228    replace_in_map(val, cast);
1229  }
1230}
1231
1232
1233//------------------------------do_one_bytecode--------------------------------
1234// Parse this bytecode, and alter the Parsers JVM->Node mapping
1235void Parse::do_one_bytecode() {
1236  Node *a, *b, *c, *d;          // Handy temps
1237  BoolTest::mask btest;
1238  int i;
1239
1240  assert(!has_exceptions(), "bytecode entry state must be clear of throws");
1241
1242  if (C->check_node_count(NodeLimitFudgeFactor * 5,
1243                          "out of nodes parsing method")) {
1244    return;
1245  }
1246
1247#ifdef ASSERT
1248  // for setting breakpoints
1249  if (TraceOptoParse) {
1250    tty->print(" @");
1251    dump_bci(bci());
1252  }
1253#endif
1254
1255  switch (bc()) {
1256  case Bytecodes::_nop:
1257    // do nothing
1258    break;
1259  case Bytecodes::_lconst_0:
1260    push_pair(longcon(0));
1261    break;
1262
1263  case Bytecodes::_lconst_1:
1264    push_pair(longcon(1));
1265    break;
1266
1267  case Bytecodes::_fconst_0:
1268    push(zerocon(T_FLOAT));
1269    break;
1270
1271  case Bytecodes::_fconst_1:
1272    push(makecon(TypeF::ONE));
1273    break;
1274
1275  case Bytecodes::_fconst_2:
1276    push(makecon(TypeF::make(2.0f)));
1277    break;
1278
1279  case Bytecodes::_dconst_0:
1280    push_pair(zerocon(T_DOUBLE));
1281    break;
1282
1283  case Bytecodes::_dconst_1:
1284    push_pair(makecon(TypeD::ONE));
1285    break;
1286
1287  case Bytecodes::_iconst_m1:push(intcon(-1)); break;
1288  case Bytecodes::_iconst_0: push(intcon( 0)); break;
1289  case Bytecodes::_iconst_1: push(intcon( 1)); break;
1290  case Bytecodes::_iconst_2: push(intcon( 2)); break;
1291  case Bytecodes::_iconst_3: push(intcon( 3)); break;
1292  case Bytecodes::_iconst_4: push(intcon( 4)); break;
1293  case Bytecodes::_iconst_5: push(intcon( 5)); break;
1294  case Bytecodes::_bipush:   push(intcon( iter().get_byte())); break;
1295  case Bytecodes::_sipush:   push(intcon( iter().get_short())); break;
1296  case Bytecodes::_aconst_null: push(null());  break;
1297  case Bytecodes::_ldc:
1298  case Bytecodes::_ldc_w:
1299  case Bytecodes::_ldc2_w:
1300    // If the constant is unresolved, run this BC once in the interpreter.
1301    if (iter().is_unresolved_string()) {
1302      uncommon_trap(Deoptimization::make_trap_request
1303                    (Deoptimization::Reason_unloaded,
1304                     Deoptimization::Action_reinterpret,
1305                     iter().get_constant_index()),
1306                    NULL, "unresolved_string");
1307      break;
1308    } else {
1309      ciConstant constant = iter().get_constant();
1310      if (constant.basic_type() == T_OBJECT) {
1311        ciObject* c = constant.as_object();
1312        if (c->is_klass()) {
1313          // The constant returned for a klass is the ciKlass for the
1314          // entry.  We want the java_mirror so get it.
1315          ciKlass* klass = c->as_klass();
1316          if (klass->is_loaded()) {
1317            constant = ciConstant(T_OBJECT, klass->java_mirror());
1318          } else {
1319            uncommon_trap(Deoptimization::make_trap_request
1320                          (Deoptimization::Reason_unloaded,
1321                           Deoptimization::Action_reinterpret,
1322                           iter().get_constant_index()),
1323                          NULL, "unresolved_klass");
1324            break;
1325          }
1326        }
1327      }
1328      push_constant(constant);
1329    }
1330
1331    break;
1332
1333  case Bytecodes::_aload_0:
1334    push( local(0) );
1335    break;
1336  case Bytecodes::_aload_1:
1337    push( local(1) );
1338    break;
1339  case Bytecodes::_aload_2:
1340    push( local(2) );
1341    break;
1342  case Bytecodes::_aload_3:
1343    push( local(3) );
1344    break;
1345  case Bytecodes::_aload:
1346    push( local(iter().get_index()) );
1347    break;
1348
1349  case Bytecodes::_fload_0:
1350  case Bytecodes::_iload_0:
1351    push( local(0) );
1352    break;
1353  case Bytecodes::_fload_1:
1354  case Bytecodes::_iload_1:
1355    push( local(1) );
1356    break;
1357  case Bytecodes::_fload_2:
1358  case Bytecodes::_iload_2:
1359    push( local(2) );
1360    break;
1361  case Bytecodes::_fload_3:
1362  case Bytecodes::_iload_3:
1363    push( local(3) );
1364    break;
1365  case Bytecodes::_fload:
1366  case Bytecodes::_iload:
1367    push( local(iter().get_index()) );
1368    break;
1369  case Bytecodes::_lload_0:
1370    push_pair_local( 0 );
1371    break;
1372  case Bytecodes::_lload_1:
1373    push_pair_local( 1 );
1374    break;
1375  case Bytecodes::_lload_2:
1376    push_pair_local( 2 );
1377    break;
1378  case Bytecodes::_lload_3:
1379    push_pair_local( 3 );
1380    break;
1381  case Bytecodes::_lload:
1382    push_pair_local( iter().get_index() );
1383    break;
1384
1385  case Bytecodes::_dload_0:
1386    push_pair_local(0);
1387    break;
1388  case Bytecodes::_dload_1:
1389    push_pair_local(1);
1390    break;
1391  case Bytecodes::_dload_2:
1392    push_pair_local(2);
1393    break;
1394  case Bytecodes::_dload_3:
1395    push_pair_local(3);
1396    break;
1397  case Bytecodes::_dload:
1398    push_pair_local(iter().get_index());
1399    break;
1400  case Bytecodes::_fstore_0:
1401  case Bytecodes::_istore_0:
1402  case Bytecodes::_astore_0:
1403    set_local( 0, pop() );
1404    break;
1405  case Bytecodes::_fstore_1:
1406  case Bytecodes::_istore_1:
1407  case Bytecodes::_astore_1:
1408    set_local( 1, pop() );
1409    break;
1410  case Bytecodes::_fstore_2:
1411  case Bytecodes::_istore_2:
1412  case Bytecodes::_astore_2:
1413    set_local( 2, pop() );
1414    break;
1415  case Bytecodes::_fstore_3:
1416  case Bytecodes::_istore_3:
1417  case Bytecodes::_astore_3:
1418    set_local( 3, pop() );
1419    break;
1420  case Bytecodes::_fstore:
1421  case Bytecodes::_istore:
1422  case Bytecodes::_astore:
1423    set_local( iter().get_index(), pop() );
1424    break;
1425  // long stores
1426  case Bytecodes::_lstore_0:
1427    set_pair_local( 0, pop_pair() );
1428    break;
1429  case Bytecodes::_lstore_1:
1430    set_pair_local( 1, pop_pair() );
1431    break;
1432  case Bytecodes::_lstore_2:
1433    set_pair_local( 2, pop_pair() );
1434    break;
1435  case Bytecodes::_lstore_3:
1436    set_pair_local( 3, pop_pair() );
1437    break;
1438  case Bytecodes::_lstore:
1439    set_pair_local( iter().get_index(), pop_pair() );
1440    break;
1441
1442  // double stores
1443  case Bytecodes::_dstore_0:
1444    set_pair_local( 0, dstore_rounding(pop_pair()) );
1445    break;
1446  case Bytecodes::_dstore_1:
1447    set_pair_local( 1, dstore_rounding(pop_pair()) );
1448    break;
1449  case Bytecodes::_dstore_2:
1450    set_pair_local( 2, dstore_rounding(pop_pair()) );
1451    break;
1452  case Bytecodes::_dstore_3:
1453    set_pair_local( 3, dstore_rounding(pop_pair()) );
1454    break;
1455  case Bytecodes::_dstore:
1456    set_pair_local( iter().get_index(), dstore_rounding(pop_pair()) );
1457    break;
1458
1459  case Bytecodes::_pop:  _sp -= 1;   break;
1460  case Bytecodes::_pop2: _sp -= 2;   break;
1461  case Bytecodes::_swap:
1462    a = pop();
1463    b = pop();
1464    push(a);
1465    push(b);
1466    break;
1467  case Bytecodes::_dup:
1468    a = pop();
1469    push(a);
1470    push(a);
1471    break;
1472  case Bytecodes::_dup_x1:
1473    a = pop();
1474    b = pop();
1475    push( a );
1476    push( b );
1477    push( a );
1478    break;
1479  case Bytecodes::_dup_x2:
1480    a = pop();
1481    b = pop();
1482    c = pop();
1483    push( a );
1484    push( c );
1485    push( b );
1486    push( a );
1487    break;
1488  case Bytecodes::_dup2:
1489    a = pop();
1490    b = pop();
1491    push( b );
1492    push( a );
1493    push( b );
1494    push( a );
1495    break;
1496
1497  case Bytecodes::_dup2_x1:
1498    // before: .. c, b, a
1499    // after:  .. b, a, c, b, a
1500    // not tested
1501    a = pop();
1502    b = pop();
1503    c = pop();
1504    push( b );
1505    push( a );
1506    push( c );
1507    push( b );
1508    push( a );
1509    break;
1510  case Bytecodes::_dup2_x2:
1511    // before: .. d, c, b, a
1512    // after:  .. b, a, d, c, b, a
1513    // not tested
1514    a = pop();
1515    b = pop();
1516    c = pop();
1517    d = pop();
1518    push( b );
1519    push( a );
1520    push( d );
1521    push( c );
1522    push( b );
1523    push( a );
1524    break;
1525
1526  case Bytecodes::_arraylength: {
1527    // Must do null-check with value on expression stack
1528    Node *ary = do_null_check(peek(), T_ARRAY);
1529    // Compile-time detect of null-exception?
1530    if (stopped())  return;
1531    a = pop();
1532    push(load_array_length(a));
1533    break;
1534  }
1535
1536  case Bytecodes::_baload: array_load(T_BYTE);   break;
1537  case Bytecodes::_caload: array_load(T_CHAR);   break;
1538  case Bytecodes::_iaload: array_load(T_INT);    break;
1539  case Bytecodes::_saload: array_load(T_SHORT);  break;
1540  case Bytecodes::_faload: array_load(T_FLOAT);  break;
1541  case Bytecodes::_aaload: array_load(T_OBJECT); break;
1542  case Bytecodes::_laload: {
1543    a = array_addressing(T_LONG, 0);
1544    if (stopped())  return;     // guaranteed null or range check
1545    _sp -= 2;                   // Pop array and index
1546    push_pair( make_load(control(), a, TypeLong::LONG, T_LONG, TypeAryPtr::LONGS));
1547    break;
1548  }
1549  case Bytecodes::_daload: {
1550    a = array_addressing(T_DOUBLE, 0);
1551    if (stopped())  return;     // guaranteed null or range check
1552    _sp -= 2;                   // Pop array and index
1553    push_pair( make_load(control(), a, Type::DOUBLE, T_DOUBLE, TypeAryPtr::DOUBLES));
1554    break;
1555  }
1556  case Bytecodes::_bastore: array_store(T_BYTE);  break;
1557  case Bytecodes::_castore: array_store(T_CHAR);  break;
1558  case Bytecodes::_iastore: array_store(T_INT);   break;
1559  case Bytecodes::_sastore: array_store(T_SHORT); break;
1560  case Bytecodes::_fastore: array_store(T_FLOAT); break;
1561  case Bytecodes::_aastore: {
1562    d = array_addressing(T_OBJECT, 1);
1563    if (stopped())  return;     // guaranteed null or range check
1564    array_store_check();
1565    c = pop();                  // Oop to store
1566    b = pop();                  // index (already used)
1567    a = pop();                  // the array itself
1568    const Type* elemtype  = _gvn.type(a)->is_aryptr()->elem();
1569    const TypeAryPtr* adr_type = TypeAryPtr::OOPS;
1570    Node* store = store_oop_to_array(control(), a, d, adr_type, c, elemtype, T_OBJECT);
1571    break;
1572  }
1573  case Bytecodes::_lastore: {
1574    a = array_addressing(T_LONG, 2);
1575    if (stopped())  return;     // guaranteed null or range check
1576    c = pop_pair();
1577    _sp -= 2;                   // Pop array and index
1578    store_to_memory(control(), a, c, T_LONG, TypeAryPtr::LONGS);
1579    break;
1580  }
1581  case Bytecodes::_dastore: {
1582    a = array_addressing(T_DOUBLE, 2);
1583    if (stopped())  return;     // guaranteed null or range check
1584    c = pop_pair();
1585    _sp -= 2;                   // Pop array and index
1586    c = dstore_rounding(c);
1587    store_to_memory(control(), a, c, T_DOUBLE, TypeAryPtr::DOUBLES);
1588    break;
1589  }
1590  case Bytecodes::_getfield:
1591    do_getfield();
1592    break;
1593
1594  case Bytecodes::_getstatic:
1595    do_getstatic();
1596    break;
1597
1598  case Bytecodes::_putfield:
1599    do_putfield();
1600    break;
1601
1602  case Bytecodes::_putstatic:
1603    do_putstatic();
1604    break;
1605
1606  case Bytecodes::_irem:
1607    do_irem();
1608    break;
1609  case Bytecodes::_idiv:
1610    // Must keep both values on the expression-stack during null-check
1611    do_null_check(peek(), T_INT);
1612    // Compile-time detect of null-exception?
1613    if (stopped())  return;
1614    b = pop();
1615    a = pop();
1616    push( _gvn.transform( new (C, 3) DivINode(control(),a,b) ) );
1617    break;
1618  case Bytecodes::_imul:
1619    b = pop(); a = pop();
1620    push( _gvn.transform( new (C, 3) MulINode(a,b) ) );
1621    break;
1622  case Bytecodes::_iadd:
1623    b = pop(); a = pop();
1624    push( _gvn.transform( new (C, 3) AddINode(a,b) ) );
1625    break;
1626  case Bytecodes::_ineg:
1627    a = pop();
1628    push( _gvn.transform( new (C, 3) SubINode(_gvn.intcon(0),a)) );
1629    break;
1630  case Bytecodes::_isub:
1631    b = pop(); a = pop();
1632    push( _gvn.transform( new (C, 3) SubINode(a,b) ) );
1633    break;
1634  case Bytecodes::_iand:
1635    b = pop(); a = pop();
1636    push( _gvn.transform( new (C, 3) AndINode(a,b) ) );
1637    break;
1638  case Bytecodes::_ior:
1639    b = pop(); a = pop();
1640    push( _gvn.transform( new (C, 3) OrINode(a,b) ) );
1641    break;
1642  case Bytecodes::_ixor:
1643    b = pop(); a = pop();
1644    push( _gvn.transform( new (C, 3) XorINode(a,b) ) );
1645    break;
1646  case Bytecodes::_ishl:
1647    b = pop(); a = pop();
1648    push( _gvn.transform( new (C, 3) LShiftINode(a,b) ) );
1649    break;
1650  case Bytecodes::_ishr:
1651    b = pop(); a = pop();
1652    push( _gvn.transform( new (C, 3) RShiftINode(a,b) ) );
1653    break;
1654  case Bytecodes::_iushr:
1655    b = pop(); a = pop();
1656    push( _gvn.transform( new (C, 3) URShiftINode(a,b) ) );
1657    break;
1658
1659  case Bytecodes::_fneg:
1660    a = pop();
1661    b = _gvn.transform(new (C, 2) NegFNode (a));
1662    push(b);
1663    break;
1664
1665  case Bytecodes::_fsub:
1666    b = pop();
1667    a = pop();
1668    c = _gvn.transform( new (C, 3) SubFNode(a,b) );
1669    d = precision_rounding(c);
1670    push( d );
1671    break;
1672
1673  case Bytecodes::_fadd:
1674    b = pop();
1675    a = pop();
1676    c = _gvn.transform( new (C, 3) AddFNode(a,b) );
1677    d = precision_rounding(c);
1678    push( d );
1679    break;
1680
1681  case Bytecodes::_fmul:
1682    b = pop();
1683    a = pop();
1684    c = _gvn.transform( new (C, 3) MulFNode(a,b) );
1685    d = precision_rounding(c);
1686    push( d );
1687    break;
1688
1689  case Bytecodes::_fdiv:
1690    b = pop();
1691    a = pop();
1692    c = _gvn.transform( new (C, 3) DivFNode(0,a,b) );
1693    d = precision_rounding(c);
1694    push( d );
1695    break;
1696
1697  case Bytecodes::_frem:
1698    if (Matcher::has_match_rule(Op_ModF)) {
1699      // Generate a ModF node.
1700      b = pop();
1701      a = pop();
1702      c = _gvn.transform( new (C, 3) ModFNode(0,a,b) );
1703      d = precision_rounding(c);
1704      push( d );
1705    }
1706    else {
1707      // Generate a call.
1708      modf();
1709    }
1710    break;
1711
1712  case Bytecodes::_fcmpl:
1713    b = pop();
1714    a = pop();
1715    c = _gvn.transform( new (C, 3) CmpF3Node( a, b));
1716    push(c);
1717    break;
1718  case Bytecodes::_fcmpg:
1719    b = pop();
1720    a = pop();
1721
1722    // Same as fcmpl but need to flip the unordered case.  Swap the inputs,
1723    // which negates the result sign except for unordered.  Flip the unordered
1724    // as well by using CmpF3 which implements unordered-lesser instead of
1725    // unordered-greater semantics.  Finally, commute the result bits.  Result
1726    // is same as using a CmpF3Greater except we did it with CmpF3 alone.
1727    c = _gvn.transform( new (C, 3) CmpF3Node( b, a));
1728    c = _gvn.transform( new (C, 3) SubINode(_gvn.intcon(0),c) );
1729    push(c);
1730    break;
1731
1732  case Bytecodes::_f2i:
1733    a = pop();
1734    push(_gvn.transform(new (C, 2) ConvF2INode(a)));
1735    break;
1736
1737  case Bytecodes::_d2i:
1738    a = pop_pair();
1739    b = _gvn.transform(new (C, 2) ConvD2INode(a));
1740    push( b );
1741    break;
1742
1743  case Bytecodes::_f2d:
1744    a = pop();
1745    b = _gvn.transform( new (C, 2) ConvF2DNode(a));
1746    push_pair( b );
1747    break;
1748
1749  case Bytecodes::_d2f:
1750    a = pop_pair();
1751    b = _gvn.transform( new (C, 2) ConvD2FNode(a));
1752    // This breaks _227_mtrt (speed & correctness) and _222_mpegaudio (speed)
1753    //b = _gvn.transform(new (C, 2) RoundFloatNode(0, b) );
1754    push( b );
1755    break;
1756
1757  case Bytecodes::_l2f:
1758    if (Matcher::convL2FSupported()) {
1759      a = pop_pair();
1760      b = _gvn.transform( new (C, 2) ConvL2FNode(a));
1761      // For i486.ad, FILD doesn't restrict precision to 24 or 53 bits.
1762      // Rather than storing the result into an FP register then pushing
1763      // out to memory to round, the machine instruction that implements
1764      // ConvL2D is responsible for rounding.
1765      // c = precision_rounding(b);
1766      c = _gvn.transform(b);
1767      push(c);
1768    } else {
1769      l2f();
1770    }
1771    break;
1772
1773  case Bytecodes::_l2d:
1774    a = pop_pair();
1775    b = _gvn.transform( new (C, 2) ConvL2DNode(a));
1776    // For i486.ad, rounding is always necessary (see _l2f above).
1777    // c = dprecision_rounding(b);
1778    c = _gvn.transform(b);
1779    push_pair(c);
1780    break;
1781
1782  case Bytecodes::_f2l:
1783    a = pop();
1784    b = _gvn.transform( new (C, 2) ConvF2LNode(a));
1785    push_pair(b);
1786    break;
1787
1788  case Bytecodes::_d2l:
1789    a = pop_pair();
1790    b = _gvn.transform( new (C, 2) ConvD2LNode(a));
1791    push_pair(b);
1792    break;
1793
1794  case Bytecodes::_dsub:
1795    b = pop_pair();
1796    a = pop_pair();
1797    c = _gvn.transform( new (C, 3) SubDNode(a,b) );
1798    d = dprecision_rounding(c);
1799    push_pair( d );
1800    break;
1801
1802  case Bytecodes::_dadd:
1803    b = pop_pair();
1804    a = pop_pair();
1805    c = _gvn.transform( new (C, 3) AddDNode(a,b) );
1806    d = dprecision_rounding(c);
1807    push_pair( d );
1808    break;
1809
1810  case Bytecodes::_dmul:
1811    b = pop_pair();
1812    a = pop_pair();
1813    c = _gvn.transform( new (C, 3) MulDNode(a,b) );
1814    d = dprecision_rounding(c);
1815    push_pair( d );
1816    break;
1817
1818  case Bytecodes::_ddiv:
1819    b = pop_pair();
1820    a = pop_pair();
1821    c = _gvn.transform( new (C, 3) DivDNode(0,a,b) );
1822    d = dprecision_rounding(c);
1823    push_pair( d );
1824    break;
1825
1826  case Bytecodes::_dneg:
1827    a = pop_pair();
1828    b = _gvn.transform(new (C, 2) NegDNode (a));
1829    push_pair(b);
1830    break;
1831
1832  case Bytecodes::_drem:
1833    if (Matcher::has_match_rule(Op_ModD)) {
1834      // Generate a ModD node.
1835      b = pop_pair();
1836      a = pop_pair();
1837      // a % b
1838
1839      c = _gvn.transform( new (C, 3) ModDNode(0,a,b) );
1840      d = dprecision_rounding(c);
1841      push_pair( d );
1842    }
1843    else {
1844      // Generate a call.
1845      modd();
1846    }
1847    break;
1848
1849  case Bytecodes::_dcmpl:
1850    b = pop_pair();
1851    a = pop_pair();
1852    c = _gvn.transform( new (C, 3) CmpD3Node( a, b));
1853    push(c);
1854    break;
1855
1856  case Bytecodes::_dcmpg:
1857    b = pop_pair();
1858    a = pop_pair();
1859    // Same as dcmpl but need to flip the unordered case.
1860    // Commute the inputs, which negates the result sign except for unordered.
1861    // Flip the unordered as well by using CmpD3 which implements
1862    // unordered-lesser instead of unordered-greater semantics.
1863    // Finally, negate the result bits.  Result is same as using a
1864    // CmpD3Greater except we did it with CmpD3 alone.
1865    c = _gvn.transform( new (C, 3) CmpD3Node( b, a));
1866    c = _gvn.transform( new (C, 3) SubINode(_gvn.intcon(0),c) );
1867    push(c);
1868    break;
1869
1870
1871    // Note for longs -> lo word is on TOS, hi word is on TOS - 1
1872  case Bytecodes::_land:
1873    b = pop_pair();
1874    a = pop_pair();
1875    c = _gvn.transform( new (C, 3) AndLNode(a,b) );
1876    push_pair(c);
1877    break;
1878  case Bytecodes::_lor:
1879    b = pop_pair();
1880    a = pop_pair();
1881    c = _gvn.transform( new (C, 3) OrLNode(a,b) );
1882    push_pair(c);
1883    break;
1884  case Bytecodes::_lxor:
1885    b = pop_pair();
1886    a = pop_pair();
1887    c = _gvn.transform( new (C, 3) XorLNode(a,b) );
1888    push_pair(c);
1889    break;
1890
1891  case Bytecodes::_lshl:
1892    b = pop();                  // the shift count
1893    a = pop_pair();             // value to be shifted
1894    c = _gvn.transform( new (C, 3) LShiftLNode(a,b) );
1895    push_pair(c);
1896    break;
1897  case Bytecodes::_lshr:
1898    b = pop();                  // the shift count
1899    a = pop_pair();             // value to be shifted
1900    c = _gvn.transform( new (C, 3) RShiftLNode(a,b) );
1901    push_pair(c);
1902    break;
1903  case Bytecodes::_lushr:
1904    b = pop();                  // the shift count
1905    a = pop_pair();             // value to be shifted
1906    c = _gvn.transform( new (C, 3) URShiftLNode(a,b) );
1907    push_pair(c);
1908    break;
1909  case Bytecodes::_lmul:
1910    b = pop_pair();
1911    a = pop_pair();
1912    c = _gvn.transform( new (C, 3) MulLNode(a,b) );
1913    push_pair(c);
1914    break;
1915
1916  case Bytecodes::_lrem:
1917    // Must keep both values on the expression-stack during null-check
1918    assert(peek(0) == top(), "long word order");
1919    do_null_check(peek(1), T_LONG);
1920    // Compile-time detect of null-exception?
1921    if (stopped())  return;
1922    b = pop_pair();
1923    a = pop_pair();
1924    c = _gvn.transform( new (C, 3) ModLNode(control(),a,b) );
1925    push_pair(c);
1926    break;
1927
1928  case Bytecodes::_ldiv:
1929    // Must keep both values on the expression-stack during null-check
1930    assert(peek(0) == top(), "long word order");
1931    do_null_check(peek(1), T_LONG);
1932    // Compile-time detect of null-exception?
1933    if (stopped())  return;
1934    b = pop_pair();
1935    a = pop_pair();
1936    c = _gvn.transform( new (C, 3) DivLNode(control(),a,b) );
1937    push_pair(c);
1938    break;
1939
1940  case Bytecodes::_ladd:
1941    b = pop_pair();
1942    a = pop_pair();
1943    c = _gvn.transform( new (C, 3) AddLNode(a,b) );
1944    push_pair(c);
1945    break;
1946  case Bytecodes::_lsub:
1947    b = pop_pair();
1948    a = pop_pair();
1949    c = _gvn.transform( new (C, 3) SubLNode(a,b) );
1950    push_pair(c);
1951    break;
1952  case Bytecodes::_lcmp:
1953    // Safepoints are now inserted _before_ branches.  The long-compare
1954    // bytecode painfully produces a 3-way value (-1,0,+1) which requires a
1955    // slew of control flow.  These are usually followed by a CmpI vs zero and
1956    // a branch; this pattern then optimizes to the obvious long-compare and
1957    // branch.  However, if the branch is backwards there's a Safepoint
1958    // inserted.  The inserted Safepoint captures the JVM state at the
1959    // pre-branch point, i.e. it captures the 3-way value.  Thus if a
1960    // long-compare is used to control a loop the debug info will force
1961    // computation of the 3-way value, even though the generated code uses a
1962    // long-compare and branch.  We try to rectify the situation by inserting
1963    // a SafePoint here and have it dominate and kill the safepoint added at a
1964    // following backwards branch.  At this point the JVM state merely holds 2
1965    // longs but not the 3-way value.
1966    if( UseLoopSafepoints ) {
1967      switch( iter().next_bc() ) {
1968      case Bytecodes::_ifgt:
1969      case Bytecodes::_iflt:
1970      case Bytecodes::_ifge:
1971      case Bytecodes::_ifle:
1972      case Bytecodes::_ifne:
1973      case Bytecodes::_ifeq:
1974        // If this is a backwards branch in the bytecodes, add Safepoint
1975        maybe_add_safepoint(iter().next_get_dest());
1976      }
1977    }
1978    b = pop_pair();
1979    a = pop_pair();
1980    c = _gvn.transform( new (C, 3) CmpL3Node( a, b ));
1981    push(c);
1982    break;
1983
1984  case Bytecodes::_lneg:
1985    a = pop_pair();
1986    b = _gvn.transform( new (C, 3) SubLNode(longcon(0),a));
1987    push_pair(b);
1988    break;
1989  case Bytecodes::_l2i:
1990    a = pop_pair();
1991    push( _gvn.transform( new (C, 2) ConvL2INode(a)));
1992    break;
1993  case Bytecodes::_i2l:
1994    a = pop();
1995    b = _gvn.transform( new (C, 2) ConvI2LNode(a));
1996    push_pair(b);
1997    break;
1998  case Bytecodes::_i2b:
1999    // Sign extend
2000    a = pop();
2001    a = _gvn.transform( new (C, 3) LShiftINode(a,_gvn.intcon(24)) );
2002    a = _gvn.transform( new (C, 3) RShiftINode(a,_gvn.intcon(24)) );
2003    push( a );
2004    break;
2005  case Bytecodes::_i2s:
2006    a = pop();
2007    a = _gvn.transform( new (C, 3) LShiftINode(a,_gvn.intcon(16)) );
2008    a = _gvn.transform( new (C, 3) RShiftINode(a,_gvn.intcon(16)) );
2009    push( a );
2010    break;
2011  case Bytecodes::_i2c:
2012    a = pop();
2013    push( _gvn.transform( new (C, 3) AndINode(a,_gvn.intcon(0xFFFF)) ) );
2014    break;
2015
2016  case Bytecodes::_i2f:
2017    a = pop();
2018    b = _gvn.transform( new (C, 2) ConvI2FNode(a) ) ;
2019    c = precision_rounding(b);
2020    push (b);
2021    break;
2022
2023  case Bytecodes::_i2d:
2024    a = pop();
2025    b = _gvn.transform( new (C, 2) ConvI2DNode(a));
2026    push_pair(b);
2027    break;
2028
2029  case Bytecodes::_iinc:        // Increment local
2030    i = iter().get_index();     // Get local index
2031    set_local( i, _gvn.transform( new (C, 3) AddINode( _gvn.intcon(iter().get_iinc_con()), local(i) ) ) );
2032    break;
2033
2034  // Exit points of synchronized methods must have an unlock node
2035  case Bytecodes::_return:
2036    return_current(NULL);
2037    break;
2038
2039  case Bytecodes::_ireturn:
2040  case Bytecodes::_areturn:
2041  case Bytecodes::_freturn:
2042    return_current(pop());
2043    break;
2044  case Bytecodes::_lreturn:
2045    return_current(pop_pair());
2046    break;
2047  case Bytecodes::_dreturn:
2048    return_current(pop_pair());
2049    break;
2050
2051  case Bytecodes::_athrow:
2052    // null exception oop throws NULL pointer exception
2053    do_null_check(peek(), T_OBJECT);
2054    if (stopped())  return;
2055    if (JvmtiExport::can_post_exceptions()) {
2056      // "Full-speed throwing" is not necessary here,
2057      // since we're notifying the VM on every throw.
2058      uncommon_trap(Deoptimization::Reason_unhandled,
2059                    Deoptimization::Action_none);
2060      return;
2061    }
2062    // Hook the thrown exception directly to subsequent handlers.
2063    if (BailoutToInterpreterForThrows) {
2064      // Keep method interpreted from now on.
2065      uncommon_trap(Deoptimization::Reason_unhandled,
2066                    Deoptimization::Action_make_not_compilable);
2067      return;
2068    }
2069    add_exception_state(make_exception_state(peek()));
2070    break;
2071
2072  case Bytecodes::_goto:   // fall through
2073  case Bytecodes::_goto_w: {
2074    int target_bci = (bc() == Bytecodes::_goto) ? iter().get_dest() : iter().get_far_dest();
2075
2076    // If this is a backwards branch in the bytecodes, add Safepoint
2077    maybe_add_safepoint(target_bci);
2078
2079    // Update method data
2080    profile_taken_branch(target_bci);
2081
2082    // Merge the current control into the target basic block
2083    merge(target_bci);
2084
2085    // See if we can get some profile data and hand it off to the next block
2086    Block *target_block = block()->successor_for_bci(target_bci);
2087    if (target_block->pred_count() != 1)  break;
2088    ciMethodData* methodData = method()->method_data();
2089    if (!methodData->is_mature())  break;
2090    ciProfileData* data = methodData->bci_to_data(bci());
2091    assert( data->is_JumpData(), "" );
2092    int taken = ((ciJumpData*)data)->taken();
2093    taken = method()->scale_count(taken);
2094    target_block->set_count(taken);
2095    break;
2096  }
2097
2098  case Bytecodes::_ifnull:    btest = BoolTest::eq; goto handle_if_null;
2099  case Bytecodes::_ifnonnull: btest = BoolTest::ne; goto handle_if_null;
2100  handle_if_null:
2101    // If this is a backwards branch in the bytecodes, add Safepoint
2102    maybe_add_safepoint(iter().get_dest());
2103    a = null();
2104    b = pop();
2105    c = _gvn.transform( new (C, 3) CmpPNode(b, a) );
2106    do_ifnull(btest, c);
2107    break;
2108
2109  case Bytecodes::_if_acmpeq: btest = BoolTest::eq; goto handle_if_acmp;
2110  case Bytecodes::_if_acmpne: btest = BoolTest::ne; goto handle_if_acmp;
2111  handle_if_acmp:
2112    // If this is a backwards branch in the bytecodes, add Safepoint
2113    maybe_add_safepoint(iter().get_dest());
2114    a = pop();
2115    b = pop();
2116    c = _gvn.transform( new (C, 3) CmpPNode(b, a) );
2117    do_if(btest, c);
2118    break;
2119
2120  case Bytecodes::_ifeq: btest = BoolTest::eq; goto handle_ifxx;
2121  case Bytecodes::_ifne: btest = BoolTest::ne; goto handle_ifxx;
2122  case Bytecodes::_iflt: btest = BoolTest::lt; goto handle_ifxx;
2123  case Bytecodes::_ifle: btest = BoolTest::le; goto handle_ifxx;
2124  case Bytecodes::_ifgt: btest = BoolTest::gt; goto handle_ifxx;
2125  case Bytecodes::_ifge: btest = BoolTest::ge; goto handle_ifxx;
2126  handle_ifxx:
2127    // If this is a backwards branch in the bytecodes, add Safepoint
2128    maybe_add_safepoint(iter().get_dest());
2129    a = _gvn.intcon(0);
2130    b = pop();
2131    c = _gvn.transform( new (C, 3) CmpINode(b, a) );
2132    do_if(btest, c);
2133    break;
2134
2135  case Bytecodes::_if_icmpeq: btest = BoolTest::eq; goto handle_if_icmp;
2136  case Bytecodes::_if_icmpne: btest = BoolTest::ne; goto handle_if_icmp;
2137  case Bytecodes::_if_icmplt: btest = BoolTest::lt; goto handle_if_icmp;
2138  case Bytecodes::_if_icmple: btest = BoolTest::le; goto handle_if_icmp;
2139  case Bytecodes::_if_icmpgt: btest = BoolTest::gt; goto handle_if_icmp;
2140  case Bytecodes::_if_icmpge: btest = BoolTest::ge; goto handle_if_icmp;
2141  handle_if_icmp:
2142    // If this is a backwards branch in the bytecodes, add Safepoint
2143    maybe_add_safepoint(iter().get_dest());
2144    a = pop();
2145    b = pop();
2146    c = _gvn.transform( new (C, 3) CmpINode( b, a ) );
2147    do_if(btest, c);
2148    break;
2149
2150  case Bytecodes::_tableswitch:
2151    do_tableswitch();
2152    break;
2153
2154  case Bytecodes::_lookupswitch:
2155    do_lookupswitch();
2156    break;
2157
2158  case Bytecodes::_invokestatic:
2159  case Bytecodes::_invokespecial:
2160  case Bytecodes::_invokevirtual:
2161  case Bytecodes::_invokeinterface:
2162    do_call();
2163    break;
2164  case Bytecodes::_checkcast:
2165    do_checkcast();
2166    break;
2167  case Bytecodes::_instanceof:
2168    do_instanceof();
2169    break;
2170  case Bytecodes::_anewarray:
2171    do_anewarray();
2172    break;
2173  case Bytecodes::_newarray:
2174    do_newarray((BasicType)iter().get_index());
2175    break;
2176  case Bytecodes::_multianewarray:
2177    do_multianewarray();
2178    break;
2179  case Bytecodes::_new:
2180    do_new();
2181    break;
2182
2183  case Bytecodes::_jsr:
2184  case Bytecodes::_jsr_w:
2185    do_jsr();
2186    break;
2187
2188  case Bytecodes::_ret:
2189    do_ret();
2190    break;
2191
2192
2193  case Bytecodes::_monitorenter:
2194    do_monitor_enter();
2195    break;
2196
2197  case Bytecodes::_monitorexit:
2198    do_monitor_exit();
2199    break;
2200
2201  case Bytecodes::_breakpoint:
2202    // Breakpoint set concurrently to compile
2203    // %%% use an uncommon trap?
2204    C->record_failure("breakpoint in method");
2205    return;
2206
2207  default:
2208#ifndef PRODUCT
2209    map()->dump(99);
2210#endif
2211    tty->print("\nUnhandled bytecode %s\n", Bytecodes::name(bc()) );
2212    ShouldNotReachHere();
2213  }
2214
2215#ifndef PRODUCT
2216  IdealGraphPrinter *printer = IdealGraphPrinter::printer();
2217  if(printer) {
2218    char buffer[256];
2219    sprintf(buffer, "Bytecode %d: %s", bci(), Bytecodes::name(bc()));
2220    bool old = printer->traverse_outs();
2221    printer->set_traverse_outs(true);
2222    printer->print_method(C, buffer, 4);
2223    printer->set_traverse_outs(old);
2224  }
2225#endif
2226}
2227