--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/c1/c1_Instruction.cpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,1006 @@
+/*
+ * Copyright 1999-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+#include "incls/_precompiled.incl"
+#include "incls/_c1_Instruction.cpp.incl"
+
+
+// Implementation of Instruction
+
+
+int Instruction::_next_id = 0;
+
+#ifdef ASSERT
+void Instruction::create_hi_word() {
+  assert(type()->is_double_word() && _hi_word == NULL, "only double word has high word");
+  _hi_word = new HiWord(this);
+}
+#endif
+
+Instruction::Condition Instruction::mirror(Condition cond) {
+  switch (cond) {
+    case eql: return eql;
+    case neq: return neq;
+    case lss: return gtr;
+    case leq: return geq;
+    case gtr: return lss;
+    case geq: return leq;
+  }
+  ShouldNotReachHere();
+  return eql;
+}
+
+
+Instruction::Condition Instruction::negate(Condition cond) {
+  switch (cond) {
+    case eql: return neq;
+    case neq: return eql;
+    case lss: return geq;
+    case leq: return gtr;
+    case gtr: return leq;
+    case geq: return lss;
+  }
+  ShouldNotReachHere();
+  return eql;
+}
+
+
+Instruction* Instruction::prev(BlockBegin* block) {
+  Instruction* p = NULL;
+  Instruction* q = block;
+  while (q != this) {
+    assert(q != NULL, "this is not in the block's instruction list");
+    p = q; q = q->next();
+  }
+  return p;
+}
+
+
+#ifndef PRODUCT
+void Instruction::print() {
+  InstructionPrinter ip;
+  print(ip);
+}
+
+
+void Instruction::print_line() {
+  InstructionPrinter ip;
+  ip.print_line(this);
+}
+
+
+void Instruction::print(InstructionPrinter& ip) {
+  ip.print_head();
+  ip.print_line(this);
+  tty->cr();
+}
+#endif // PRODUCT
+
+
+// perform constant and interval tests on index value
+bool AccessIndexed::compute_needs_range_check() {
+  Constant* clength = length()->as_Constant();
+  Constant* cindex = index()->as_Constant();
+  if (clength && cindex) {
+    IntConstant* l = clength->type()->as_IntConstant();
+    IntConstant* i = cindex->type()->as_IntConstant();
+    if (l && i && i->value() < l->value() && i->value() >= 0) {
+      return false;
+    }
+  }
+  return true;
+}
+
+
+ciType* LoadIndexed::exact_type() const {
+  ciType* array_type = array()->exact_type();
+  if (array_type == NULL) {
+    return NULL;
+  }
+  assert(array_type->is_array_klass(), "what else?");
+  ciArrayKlass* ak = (ciArrayKlass*)array_type;
+
+  if (ak->element_type()->is_instance_klass()) {
+    ciInstanceKlass* ik = (ciInstanceKlass*)ak->element_type();
+    if (ik->is_loaded() && ik->is_final()) {
+      return ik;
+    }
+  }
+  return NULL;
+}
+
+
+ciType* LoadIndexed::declared_type() const {
+  ciType* array_type = array()->declared_type();
+  if (array_type == NULL) {
+    return NULL;
+  }
+  assert(array_type->is_array_klass(), "what else?");
+  ciArrayKlass* ak = (ciArrayKlass*)array_type;
+  return ak->element_type();
+}
+
+
+ciType* LoadField::declared_type() const {
+  return field()->type();
+}
+
+
+ciType* LoadField::exact_type() const {
+  ciType* type = declared_type();
+  // for primitive arrays, the declared type is the exact type
+  if (type->is_type_array_klass()) {
+    return type;
+  }
+  if (type->is_instance_klass()) {
+    ciInstanceKlass* ik = (ciInstanceKlass*)type;
+    if (ik->is_loaded() && ik->is_final()) {
+      return type;
+    }
+  }
+  return NULL;
+}
+
+
+ciType* NewTypeArray::exact_type() const {
+  return ciTypeArrayKlass::make(elt_type());
+}
+
+
+ciType* NewObjectArray::exact_type() const {
+  return ciObjArrayKlass::make(klass());
+}
+
+
+ciType* NewInstance::exact_type() const {
+  return klass();
+}
+
+
+ciType* CheckCast::declared_type() const {
+  return klass();
+}
+
+ciType* CheckCast::exact_type() const {
+  if (klass()->is_instance_klass()) {
+    ciInstanceKlass* ik = (ciInstanceKlass*)klass();
+    if (ik->is_loaded() && ik->is_final()) {
+      return ik;
+    }
+  }
+  return NULL;
+}
+
+
+void ArithmeticOp::other_values_do(void f(Value*)) {
+  if (lock_stack() != NULL) lock_stack()->values_do(f);
+}
+
+void NullCheck::other_values_do(void f(Value*)) {
+  lock_stack()->values_do(f);
+}
+
+void AccessArray::other_values_do(void f(Value*)) {
+  if (lock_stack() != NULL) lock_stack()->values_do(f);
+}
+
+
+// Implementation of AccessField
+
+void AccessField::other_values_do(void f(Value*)) {
+  if (state_before() != NULL) state_before()->values_do(f);
+  if (lock_stack() != NULL) lock_stack()->values_do(f);
+}
+
+
+// Implementation of StoreIndexed
+
+IRScope* StoreIndexed::scope() const {
+  return lock_stack()->scope();
+}
+
+
+// Implementation of ArithmeticOp
+
+bool ArithmeticOp::is_commutative() const {
+  switch (op()) {
+    case Bytecodes::_iadd: // fall through
+    case Bytecodes::_ladd: // fall through
+    case Bytecodes::_fadd: // fall through
+    case Bytecodes::_dadd: // fall through
+    case Bytecodes::_imul: // fall through
+    case Bytecodes::_lmul: // fall through
+    case Bytecodes::_fmul: // fall through
+    case Bytecodes::_dmul: return true;
+  }
+  return false;
+}
+
+
+bool ArithmeticOp::can_trap() const {
+  switch (op()) {
+    case Bytecodes::_idiv: // fall through
+    case Bytecodes::_ldiv: // fall through
+    case Bytecodes::_irem: // fall through
+    case Bytecodes::_lrem: return true;
+  }
+  return false;
+}
+
+
+// Implementation of LogicOp
+
+bool LogicOp::is_commutative() const {
+#ifdef ASSERT
+  switch (op()) {
+    case Bytecodes::_iand: // fall through
+    case Bytecodes::_land: // fall through
+    case Bytecodes::_ior : // fall through
+    case Bytecodes::_lor : // fall through
+    case Bytecodes::_ixor: // fall through
+    case Bytecodes::_lxor: break;
+    default              : ShouldNotReachHere();
+  }
+#endif
+  // all LogicOps are commutative
+  return true;
+}
+
+
+// Implementation of CompareOp
+
+void CompareOp::other_values_do(void f(Value*)) {
+  if (state_before() != NULL) state_before()->values_do(f);
+}
+
+
+// Implementation of IfOp
+
+bool IfOp::is_commutative() const {
+  return cond() == eql || cond() == neq;
+}
+
+
+// Implementation of StateSplit
+
+void StateSplit::substitute(BlockList& list, BlockBegin* old_block, BlockBegin* new_block) {
+  NOT_PRODUCT(bool assigned = false;)
+  for (int i = 0; i < list.length(); i++) {
+    BlockBegin** b = list.adr_at(i);
+    if (*b == old_block) {
+      *b = new_block;
+      NOT_PRODUCT(assigned = true;)
+    }
+  }
+  assert(assigned == true, "should have assigned at least once");
+}
+
+
+IRScope* StateSplit::scope() const {
+  return _state->scope();
+}
+
+
+void StateSplit::state_values_do(void f(Value*)) {
+  if (state() != NULL) state()->values_do(f);
+}
+
+
+void BlockBegin::state_values_do(void f(Value*)) {
+  StateSplit::state_values_do(f);
+
+  if (is_set(BlockBegin::exception_entry_flag)) {
+    for (int i = 0; i < number_of_exception_states(); i++) {
+      exception_state_at(i)->values_do(f);
+    }
+  }
+}
+
+
+void MonitorEnter::state_values_do(void f(Value*)) {
+  StateSplit::state_values_do(f);
+  _lock_stack_before->values_do(f);
+}
+
+
+void Intrinsic::state_values_do(void f(Value*)) {
+  StateSplit::state_values_do(f);
+  if (lock_stack() != NULL) lock_stack()->values_do(f);
+}
+
+
+// Implementation of Invoke
+
+
+Invoke::Invoke(Bytecodes::Code code, ValueType* result_type, Value recv, Values* args,
+               int vtable_index, ciMethod* target)
+  : StateSplit(result_type)
+  , _code(code)
+  , _recv(recv)
+  , _args(args)
+  , _vtable_index(vtable_index)
+  , _target(target)
+{
+  set_flag(TargetIsLoadedFlag,   target->is_loaded());
+  set_flag(TargetIsFinalFlag,    target_is_loaded() && target->is_final_method());
+  set_flag(TargetIsStrictfpFlag, target_is_loaded() && target->is_strict());
+
+  assert(args != NULL, "args must exist");
+#ifdef ASSERT
+  values_do(assert_value);
+#endif // ASSERT
+
+  // provide an initial guess of signature size.
+  _signature = new BasicTypeList(number_of_arguments() + (has_receiver() ? 1 : 0));
+  if (has_receiver()) {
+    _signature->append(as_BasicType(receiver()->type()));
+  }
+  for (int i = 0; i < number_of_arguments(); i++) {
+    ValueType* t = argument_at(i)->type();
+    BasicType bt = as_BasicType(t);
+    _signature->append(bt);
+  }
+}
+
+
+// Implementation of Contant
+intx Constant::hash() const {
+  if (_state == NULL) {
+    switch (type()->tag()) {
+    case intTag:
+      return HASH2(name(), type()->as_IntConstant()->value());
+    case longTag:
+      {
+        jlong temp = type()->as_LongConstant()->value();
+        return HASH3(name(), high(temp), low(temp));
+      }
+    case floatTag:
+      return HASH2(name(), jint_cast(type()->as_FloatConstant()->value()));
+    case doubleTag:
+      {
+        jlong temp = jlong_cast(type()->as_DoubleConstant()->value());
+        return HASH3(name(), high(temp), low(temp));
+      }
+    case objectTag:
+      assert(type()->as_ObjectType()->is_loaded(), "can't handle unloaded values");
+      return HASH2(name(), type()->as_ObjectType()->constant_value());
+    }
+  }
+  return 0;
+}
+
+bool Constant::is_equal(Value v) const {
+  if (v->as_Constant() == NULL) return false;
+
+  switch (type()->tag()) {
+    case intTag:
+      {
+        IntConstant* t1 =    type()->as_IntConstant();
+        IntConstant* t2 = v->type()->as_IntConstant();
+        return (t1 != NULL && t2 != NULL &&
+                t1->value() == t2->value());
+      }
+    case longTag:
+      {
+        LongConstant* t1 =    type()->as_LongConstant();
+        LongConstant* t2 = v->type()->as_LongConstant();
+        return (t1 != NULL && t2 != NULL &&
+                t1->value() == t2->value());
+      }
+    case floatTag:
+      {
+        FloatConstant* t1 =    type()->as_FloatConstant();
+        FloatConstant* t2 = v->type()->as_FloatConstant();
+        return (t1 != NULL && t2 != NULL &&
+                jint_cast(t1->value()) == jint_cast(t2->value()));
+      }
+    case doubleTag:
+      {
+        DoubleConstant* t1 =    type()->as_DoubleConstant();
+        DoubleConstant* t2 = v->type()->as_DoubleConstant();
+        return (t1 != NULL && t2 != NULL &&
+                jlong_cast(t1->value()) == jlong_cast(t2->value()));
+      }
+    case objectTag:
+      {
+        ObjectType* t1 =    type()->as_ObjectType();
+        ObjectType* t2 = v->type()->as_ObjectType();
+        return (t1 != NULL && t2 != NULL &&
+                t1->is_loaded() && t2->is_loaded() &&
+                t1->constant_value() == t2->constant_value());
+      }
+  }
+  return false;
+}
+
+
+BlockBegin* Constant::compare(Instruction::Condition cond, Value right,
+                              BlockBegin* true_sux, BlockBegin* false_sux) {
+  Constant* rc = right->as_Constant();
+  // other is not a constant
+  if (rc == NULL) return NULL;
+
+  ValueType* lt = type();
+  ValueType* rt = rc->type();
+  // different types
+  if (lt->base() != rt->base()) return NULL;
+  switch (lt->tag()) {
+  case intTag: {
+    int x = lt->as_IntConstant()->value();
+    int y = rt->as_IntConstant()->value();
+    switch (cond) {
+    case If::eql: return x == y ? true_sux : false_sux;
+    case If::neq: return x != y ? true_sux : false_sux;
+    case If::lss: return x <  y ? true_sux : false_sux;
+    case If::leq: return x <= y ? true_sux : false_sux;
+    case If::gtr: return x >  y ? true_sux : false_sux;
+    case If::geq: return x >= y ? true_sux : false_sux;
+    }
+    break;
+  }
+  case longTag: {
+    jlong x = lt->as_LongConstant()->value();
+    jlong y = rt->as_LongConstant()->value();
+    switch (cond) {
+    case If::eql: return x == y ? true_sux : false_sux;
+    case If::neq: return x != y ? true_sux : false_sux;
+    case If::lss: return x <  y ? true_sux : false_sux;
+    case If::leq: return x <= y ? true_sux : false_sux;
+    case If::gtr: return x >  y ? true_sux : false_sux;
+    case If::geq: return x >= y ? true_sux : false_sux;
+    }
+    break;
+  }
+  case objectTag: {
+    ciObject* xvalue = lt->as_ObjectType()->constant_value();
+    ciObject* yvalue = rt->as_ObjectType()->constant_value();
+    assert(xvalue != NULL && yvalue != NULL, "not constants");
+    if (xvalue->is_loaded() && yvalue->is_loaded()) {
+      switch (cond) {
+      case If::eql: return xvalue == yvalue ? true_sux : false_sux;
+      case If::neq: return xvalue != yvalue ? true_sux : false_sux;
+      }
+    }
+    break;
+  }
+  }
+  return NULL;
+}
+
+
+void Constant::other_values_do(void f(Value*)) {
+  if (state() != NULL) state()->values_do(f);
+}
+
+
+// Implementation of NewArray
+
+void NewArray::other_values_do(void f(Value*)) {
+  if (state_before() != NULL) state_before()->values_do(f);
+}
+
+
+// Implementation of TypeCheck
+
+void TypeCheck::other_values_do(void f(Value*)) {
+  if (state_before() != NULL) state_before()->values_do(f);
+}
+
+
+// Implementation of BlockBegin
+
+int BlockBegin::_next_block_id = 0;
+
+
+void BlockBegin::set_end(BlockEnd* end) {
+  assert(end != NULL, "should not reset block end to NULL");
+  BlockEnd* old_end = _end;
+  if (end == old_end) {
+    return;
+  }
+  // Must make the predecessors/successors match up with the
+  // BlockEnd's notion.
+  int i, n;
+  if (old_end != NULL) {
+    // disconnect from the old end
+    old_end->set_begin(NULL);
+
+    // disconnect this block from it's current successors
+    for (i = 0; i < _successors.length(); i++) {
+      _successors.at(i)->remove_predecessor(this);
+    }
+  }
+  _end = end;
+
+  _successors.clear();
+  // Now reset successors list based on BlockEnd
+  n = end->number_of_sux();
+  for (i = 0; i < n; i++) {
+    BlockBegin* sux = end->sux_at(i);
+    _successors.append(sux);
+    sux->_predecessors.append(this);
+  }
+  _end->set_begin(this);
+}
+
+
+void BlockBegin::disconnect_edge(BlockBegin* from, BlockBegin* to) {
+  // disconnect any edges between from and to
+#ifndef PRODUCT
+  if (PrintIR && Verbose) {
+    tty->print_cr("Disconnected edge B%d -> B%d", from->block_id(), to->block_id());
+  }
+#endif
+  for (int s = 0; s < from->number_of_sux();) {
+    BlockBegin* sux = from->sux_at(s);
+    if (sux == to) {
+      int index = sux->_predecessors.index_of(from);
+      if (index >= 0) {
+        sux->_predecessors.remove_at(index);
+      }
+      from->_successors.remove_at(s);
+    } else {
+      s++;
+    }
+  }
+}
+
+
+void BlockBegin::disconnect_from_graph() {
+  // disconnect this block from all other blocks
+  for (int p = 0; p < number_of_preds(); p++) {
+    pred_at(p)->remove_successor(this);
+  }
+  for (int s = 0; s < number_of_sux(); s++) {
+    sux_at(s)->remove_predecessor(this);
+  }
+}
+
+void BlockBegin::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) {
+  // modify predecessors before substituting successors
+  for (int i = 0; i < number_of_sux(); i++) {
+    if (sux_at(i) == old_sux) {
+      // remove old predecessor before adding new predecessor
+      // otherwise there is a dead predecessor in the list
+      new_sux->remove_predecessor(old_sux);
+      new_sux->add_predecessor(this);
+    }
+  }
+  old_sux->remove_predecessor(this);
+  end()->substitute_sux(old_sux, new_sux);
+}
+
+
+
+// In general it is not possible to calculate a value for the field "depth_first_number"
+// of the inserted block, without recomputing the values of the other blocks
+// in the CFG. Therefore the value of "depth_first_number" in BlockBegin becomes meaningless.
+BlockBegin* BlockBegin::insert_block_between(BlockBegin* sux) {
+  // Try to make the bci close to a block with a single pred or sux,
+  // since this make the block layout algorithm work better.
+  int bci = -1;
+  if (sux->number_of_preds() == 1) {
+    bci = sux->bci();
+  } else {
+    bci = end()->bci();
+  }
+
+  BlockBegin* new_sux = new BlockBegin(bci);
+
+  // mark this block (special treatment when block order is computed)
+  new_sux->set(critical_edge_split_flag);
+
+  // This goto is not a safepoint.
+  Goto* e = new Goto(sux, false);
+  new_sux->set_next(e, bci);
+  new_sux->set_end(e);
+  // setup states
+  ValueStack* s = end()->state();
+  new_sux->set_state(s->copy());
+  e->set_state(s->copy());
+  assert(new_sux->state()->locals_size() == s->locals_size(), "local size mismatch!");
+  assert(new_sux->state()->stack_size() == s->stack_size(), "stack size mismatch!");
+  assert(new_sux->state()->locks_size() == s->locks_size(), "locks size mismatch!");
+
+  // link predecessor to new block
+  end()->substitute_sux(sux, new_sux);
+
+  // The ordering needs to be the same, so remove the link that the
+  // set_end call above added and substitute the new_sux for this
+  // block.
+  sux->remove_predecessor(new_sux);
+
+  // the successor could be the target of a switch so it might have
+  // multiple copies of this predecessor, so substitute the new_sux
+  // for the first and delete the rest.
+  bool assigned = false;
+  BlockList& list = sux->_predecessors;
+  for (int i = 0; i < list.length(); i++) {
+    BlockBegin** b = list.adr_at(i);
+    if (*b == this) {
+      if (assigned) {
+        list.remove_at(i);
+        // reprocess this index
+        i--;
+      } else {
+        assigned = true;
+        *b = new_sux;
+      }
+      // link the new block back to it's predecessors.
+      new_sux->add_predecessor(this);
+    }
+  }
+  assert(assigned == true, "should have assigned at least once");
+  return new_sux;
+}
+
+
+void BlockBegin::remove_successor(BlockBegin* pred) {
+  int idx;
+  while ((idx = _successors.index_of(pred)) >= 0) {
+    _successors.remove_at(idx);
+  }
+}
+
+
+void BlockBegin::add_predecessor(BlockBegin* pred) {
+  _predecessors.append(pred);
+}
+
+
+void BlockBegin::remove_predecessor(BlockBegin* pred) {
+  int idx;
+  while ((idx = _predecessors.index_of(pred)) >= 0) {
+    _predecessors.remove_at(idx);
+  }
+}
+
+
+void BlockBegin::add_exception_handler(BlockBegin* b) {
+  assert(b != NULL && (b->is_set(exception_entry_flag)), "exception handler must exist");
+  // add only if not in the list already
+  if (!_exception_handlers.contains(b)) _exception_handlers.append(b);
+}
+
+int BlockBegin::add_exception_state(ValueStack* state) {
+  assert(is_set(exception_entry_flag), "only for xhandlers");
+  if (_exception_states == NULL) {
+    _exception_states = new ValueStackStack(4);
+  }
+  _exception_states->append(state);
+  return _exception_states->length() - 1;
+}
+
+
+void BlockBegin::iterate_preorder(boolArray& mark, BlockClosure* closure) {
+  if (!mark.at(block_id())) {
+    mark.at_put(block_id(), true);
+    closure->block_do(this);
+    BlockEnd* e = end(); // must do this after block_do because block_do may change it!
+    { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_preorder(mark, closure); }
+    { for (int i = e->number_of_sux            () - 1; i >= 0; i--) e->sux_at           (i)->iterate_preorder(mark, closure); }
+  }
+}
+
+
+void BlockBegin::iterate_postorder(boolArray& mark, BlockClosure* closure) {
+  if (!mark.at(block_id())) {
+    mark.at_put(block_id(), true);
+    BlockEnd* e = end();
+    { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_postorder(mark, closure); }
+    { for (int i = e->number_of_sux            () - 1; i >= 0; i--) e->sux_at           (i)->iterate_postorder(mark, closure); }
+    closure->block_do(this);
+  }
+}
+
+
+void BlockBegin::iterate_preorder(BlockClosure* closure) {
+  boolArray mark(number_of_blocks(), false);
+  iterate_preorder(mark, closure);
+}
+
+
+void BlockBegin::iterate_postorder(BlockClosure* closure) {
+  boolArray mark(number_of_blocks(), false);
+  iterate_postorder(mark, closure);
+}
+
+
+void BlockBegin::block_values_do(void f(Value*)) {
+  for (Instruction* n = this; n != NULL; n = n->next()) n->values_do(f);
+}
+
+
+#ifndef PRODUCT
+  #define TRACE_PHI(code) if (PrintPhiFunctions) { code; }
+#else
+  #define TRACE_PHI(coce)
+#endif
+
+
+bool BlockBegin::try_merge(ValueStack* new_state) {
+  TRACE_PHI(tty->print_cr("********** try_merge for block B%d", block_id()));
+
+  // local variables used for state iteration
+  int index;
+  Value new_value, existing_value;
+
+  ValueStack* existing_state = state();
+  if (existing_state == NULL) {
+    TRACE_PHI(tty->print_cr("first call of try_merge for this block"));
+
+    if (is_set(BlockBegin::was_visited_flag)) {
+      // this actually happens for complicated jsr/ret structures
+      return false; // BAILOUT in caller
+    }
+
+    // copy state because it is altered
+    new_state = new_state->copy();
+
+    // Use method liveness to invalidate dead locals
+    MethodLivenessResult liveness = new_state->scope()->method()->liveness_at_bci(bci());
+    if (liveness.is_valid()) {
+      assert((int)liveness.size() == new_state->locals_size(), "error in use of liveness");
+
+      for_each_local_value(new_state, index, new_value) {
+        if (!liveness.at(index) || new_value->type()->is_illegal()) {
+          new_state->invalidate_local(index);
+          TRACE_PHI(tty->print_cr("invalidating dead local %d", index));
+        }
+      }
+    }
+
+    if (is_set(BlockBegin::parser_loop_header_flag)) {
+      TRACE_PHI(tty->print_cr("loop header block, initializing phi functions"));
+
+      for_each_stack_value(new_state, index, new_value) {
+        new_state->setup_phi_for_stack(this, index);
+        TRACE_PHI(tty->print_cr("creating phi-function %c%d for stack %d", new_state->stack_at(index)->type()->tchar(), new_state->stack_at(index)->id(), index));
+      }
+
+      BitMap requires_phi_function = new_state->scope()->requires_phi_function();
+
+      for_each_local_value(new_state, index, new_value) {
+        bool requires_phi = requires_phi_function.at(index) || (new_value->type()->is_double_word() && requires_phi_function.at(index + 1));
+        if (requires_phi || !SelectivePhiFunctions) {
+          new_state->setup_phi_for_local(this, index);
+          TRACE_PHI(tty->print_cr("creating phi-function %c%d for local %d", new_state->local_at(index)->type()->tchar(), new_state->local_at(index)->id(), index));
+        }
+      }
+    }
+
+    // initialize state of block
+    set_state(new_state);
+
+  } else if (existing_state->is_same_across_scopes(new_state)) {
+    TRACE_PHI(tty->print_cr("exisiting state found"));
+
+    // Inlining may cause the local state not to match up, so walk up
+    // the new state until we get to the same scope as the
+    // existing and then start processing from there.
+    while (existing_state->scope() != new_state->scope()) {
+      new_state = new_state->caller_state();
+      assert(new_state != NULL, "could not match up scopes");
+
+      assert(false, "check if this is necessary");
+    }
+
+    assert(existing_state->scope() == new_state->scope(), "not matching");
+    assert(existing_state->locals_size() == new_state->locals_size(), "not matching");
+    assert(existing_state->stack_size() == new_state->stack_size(), "not matching");
+
+    if (is_set(BlockBegin::was_visited_flag)) {
+      TRACE_PHI(tty->print_cr("loop header block, phis must be present"));
+
+      if (!is_set(BlockBegin::parser_loop_header_flag)) {
+        // this actually happens for complicated jsr/ret structures
+        return false; // BAILOUT in caller
+      }
+
+      for_each_local_value(existing_state, index, existing_value) {
+        Value new_value = new_state->local_at(index);
+        if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) {
+          // The old code invalidated the phi function here
+          // Because dead locals are replaced with NULL, this is a very rare case now, so simply bail out
+          return false; // BAILOUT in caller
+        }
+      }
+
+#ifdef ASSERT
+      // check that all necessary phi functions are present
+      for_each_stack_value(existing_state, index, existing_value) {
+        assert(existing_value->as_Phi() != NULL && existing_value->as_Phi()->block() == this, "phi function required");
+      }
+      for_each_local_value(existing_state, index, existing_value) {
+        assert(existing_value == new_state->local_at(index) || (existing_value->as_Phi() != NULL && existing_value->as_Phi()->as_Phi()->block() == this), "phi function required");
+      }
+#endif
+
+    } else {
+      TRACE_PHI(tty->print_cr("creating phi functions on demand"));
+
+      // create necessary phi functions for stack
+      for_each_stack_value(existing_state, index, existing_value) {
+        Value new_value = new_state->stack_at(index);
+        Phi* existing_phi = existing_value->as_Phi();
+
+        if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) {
+          existing_state->setup_phi_for_stack(this, index);
+          TRACE_PHI(tty->print_cr("creating phi-function %c%d for stack %d", existing_state->stack_at(index)->type()->tchar(), existing_state->stack_at(index)->id(), index));
+        }
+      }
+
+      // create necessary phi functions for locals
+      for_each_local_value(existing_state, index, existing_value) {
+        Value new_value = new_state->local_at(index);
+        Phi* existing_phi = existing_value->as_Phi();
+
+        if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) {
+          existing_state->invalidate_local(index);
+          TRACE_PHI(tty->print_cr("invalidating local %d because of type mismatch", index));
+        } else if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) {
+          existing_state->setup_phi_for_local(this, index);
+          TRACE_PHI(tty->print_cr("creating phi-function %c%d for local %d", existing_state->local_at(index)->type()->tchar(), existing_state->local_at(index)->id(), index));
+        }
+      }
+    }
+
+    assert(existing_state->caller_state() == new_state->caller_state(), "caller states must be equal");
+
+  } else {
+    assert(false, "stack or locks not matching (invalid bytecodes)");
+    return false;
+  }
+
+  TRACE_PHI(tty->print_cr("********** try_merge for block B%d successful", block_id()));
+
+  return true;
+}
+
+
+#ifndef PRODUCT
+void BlockBegin::print_block() {
+  InstructionPrinter ip;
+  print_block(ip, false);
+}
+
+
+void BlockBegin::print_block(InstructionPrinter& ip, bool live_only) {
+  ip.print_instr(this); tty->cr();
+  ip.print_stack(this->state()); tty->cr();
+  ip.print_inline_level(this);
+  ip.print_head();
+  for (Instruction* n = next(); n != NULL; n = n->next()) {
+    if (!live_only || n->is_pinned() || n->use_count() > 0) {
+      ip.print_line(n);
+    }
+  }
+  tty->cr();
+}
+#endif // PRODUCT
+
+
+// Implementation of BlockList
+
+void BlockList::iterate_forward (BlockClosure* closure) {
+  const int l = length();
+  for (int i = 0; i < l; i++) closure->block_do(at(i));
+}
+
+
+void BlockList::iterate_backward(BlockClosure* closure) {
+  for (int i = length() - 1; i >= 0; i--) closure->block_do(at(i));
+}
+
+
+void BlockList::blocks_do(void f(BlockBegin*)) {
+  for (int i = length() - 1; i >= 0; i--) f(at(i));
+}
+
+
+void BlockList::values_do(void f(Value*)) {
+  for (int i = length() - 1; i >= 0; i--) at(i)->block_values_do(f);
+}
+
+
+#ifndef PRODUCT
+void BlockList::print(bool cfg_only, bool live_only) {
+  InstructionPrinter ip;
+  for (int i = 0; i < length(); i++) {
+    BlockBegin* block = at(i);
+    if (cfg_only) {
+      ip.print_instr(block); tty->cr();
+    } else {
+      block->print_block(ip, live_only);
+    }
+  }
+}
+#endif // PRODUCT
+
+
+// Implementation of BlockEnd
+
+void BlockEnd::set_begin(BlockBegin* begin) {
+  BlockList* sux = NULL;
+  if (begin != NULL) {
+    sux = begin->successors();
+  } else if (_begin != NULL) {
+    // copy our sux list
+    BlockList* sux = new BlockList(_begin->number_of_sux());
+    for (int i = 0; i < _begin->number_of_sux(); i++) {
+      sux->append(_begin->sux_at(i));
+    }
+  }
+  _sux = sux;
+  _begin = begin;
+}
+
+
+void BlockEnd::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) {
+  substitute(*_sux, old_sux, new_sux);
+}
+
+
+void BlockEnd::other_values_do(void f(Value*)) {
+  if (state_before() != NULL) state_before()->values_do(f);
+}
+
+
+// Implementation of Phi
+
+// Normal phi functions take their operands from the last instruction of the
+// predecessor. Special handling is needed for xhanlder entries because there
+// the state of arbitrary instructions are needed.
+
+Value Phi::operand_at(int i) const {
+  ValueStack* state;
+  if (_block->is_set(BlockBegin::exception_entry_flag)) {
+    state = _block->exception_state_at(i);
+  } else {
+    state = _block->pred_at(i)->end()->state();
+  }
+  assert(state != NULL, "");
+
+  if (is_local()) {
+    return state->local_at(local_index());
+  } else {
+    return state->stack_at(stack_index());
+  }
+}
+
+
+int Phi::operand_count() const {
+  if (_block->is_set(BlockBegin::exception_entry_flag)) {
+    return _block->number_of_exception_states();
+  } else {
+    return _block->number_of_preds();
+  }
+}
+
+
+// Implementation of Throw
+
+void Throw::state_values_do(void f(Value*)) {
+  BlockEnd::state_values_do(f);
+}