6667615: (Escape Analysis) extend MDO to cache arguments escape state
authorkvn
Tue, 11 Mar 2008 19:00:38 -0700
changeset 218 a0e996680b05
parent 217 c646ef2f5d58
child 219 ac2d788217ca
6667615: (Escape Analysis) extend MDO to cache arguments escape state Summary: Use MDO to cache arguments escape state determined by the byte code escape analyzer. Reviewed-by: never
hotspot/src/share/vm/ci/bcEscapeAnalyzer.cpp
hotspot/src/share/vm/ci/bcEscapeAnalyzer.hpp
hotspot/src/share/vm/ci/ciMethodData.cpp
hotspot/src/share/vm/ci/ciMethodData.hpp
hotspot/src/share/vm/classfile/vmSymbols.cpp
hotspot/src/share/vm/classfile/vmSymbols.hpp
hotspot/src/share/vm/oops/methodDataOop.cpp
hotspot/src/share/vm/oops/methodDataOop.hpp
--- a/hotspot/src/share/vm/ci/bcEscapeAnalyzer.cpp	Tue Mar 11 11:25:13 2008 -0700
+++ b/hotspot/src/share/vm/ci/bcEscapeAnalyzer.cpp	Tue Mar 11 19:00:38 2008 -0700
@@ -104,7 +104,7 @@
 };
 
 void BCEscapeAnalyzer::set_returned(ArgumentMap vars) {
-  for (int i = 0; i <= _arg_size; i++) {
+  for (int i = 0; i < _arg_size; i++) {
     if (vars.contains(i))
       _arg_returned.set_bit(i);
   }
@@ -112,10 +112,9 @@
   _return_allocated = _return_allocated && vars.contains_allocated() && !(vars.contains_unknown() || vars.contains_vars());
 }
 
-
 // return true if any element of vars is an argument
 bool BCEscapeAnalyzer::is_argument(ArgumentMap vars) {
-  for (int i = 0; i <= _arg_size; i++) {
+  for (int i = 0; i < _arg_size; i++) {
     if (vars.contains(i))
       return true;
   }
@@ -126,7 +125,7 @@
 bool BCEscapeAnalyzer::is_arg_stack(ArgumentMap vars){
   if (_conservative)
     return true;
-  for (int i = 0; i <= _arg_size; i++) {
+  for (int i = 0; i < _arg_size; i++) {
     if (vars.contains(i) && _arg_stack.at(i))
       return true;
   }
@@ -134,12 +133,13 @@
 }
 
 void BCEscapeAnalyzer::clear_bits(ArgumentMap vars, BitMap &bm) {
-  for (int i = 0; i <= _arg_size; i++) {
+  for (int i = 0; i < _arg_size; i++) {
     if (vars.contains(i)) {
       bm.clear_bit(i);
     }
   }
 }
+
 void BCEscapeAnalyzer::set_method_escape(ArgumentMap vars) {
   clear_bits(vars, _arg_local);
 }
@@ -155,6 +155,17 @@
   clear_bits(vars, _dirty);
 }
 
+void BCEscapeAnalyzer::set_modified(ArgumentMap vars, int offs, int size) {
+
+  for (int i = 0; i < _arg_size; i++) {
+    if (vars.contains(i)) {
+      set_arg_modified(i, offs, size);
+    }
+  }
+  if (vars.contains_unknown())
+    _unknown_modified = true;
+}
+
 bool BCEscapeAnalyzer::is_recursive_call(ciMethod* callee) {
   for (BCEscapeAnalyzer* scope = this; scope != NULL; scope = scope->_parent) {
     if (scope->method() == callee) {
@@ -164,6 +175,40 @@
   return false;
 }
 
+bool BCEscapeAnalyzer::is_arg_modified(int arg, int offset, int size_in_bytes) {
+  if (offset == OFFSET_ANY)
+    return _arg_modified[arg] != 0;
+  assert(arg >= 0 && arg < _arg_size, "must be an argument.");
+  bool modified = false;
+  int l = offset / HeapWordSize;
+  int h = round_to(offset + size_in_bytes, HeapWordSize) / HeapWordSize;
+  if (l > ARG_OFFSET_MAX)
+    l = ARG_OFFSET_MAX;
+  if (h > ARG_OFFSET_MAX+1)
+    h = ARG_OFFSET_MAX + 1;
+  for (int i = l; i < h; i++) {
+    modified = modified || (_arg_modified[arg] & (1 << i)) != 0;
+  }
+  return modified;
+}
+
+void BCEscapeAnalyzer::set_arg_modified(int arg, int offset, int size_in_bytes) {
+  if (offset == OFFSET_ANY) {
+    _arg_modified[arg] =  (uint) -1;
+    return;
+  }
+  assert(arg >= 0 && arg < _arg_size, "must be an argument.");
+  int l = offset / HeapWordSize;
+  int h = round_to(offset + size_in_bytes, HeapWordSize) / HeapWordSize;
+  if (l > ARG_OFFSET_MAX)
+    l = ARG_OFFSET_MAX;
+  if (h > ARG_OFFSET_MAX+1)
+    h = ARG_OFFSET_MAX + 1;
+  for (int i = l; i < h; i++) {
+    _arg_modified[arg] |= (1 << i);
+  }
+}
+
 void BCEscapeAnalyzer::invoke(StateInfo &state, Bytecodes::Code code, ciMethod* target, ciKlass* holder) {
   int i;
 
@@ -197,6 +242,7 @@
     for (i = 0; i < arg_size; i++) {
       set_method_escape(state.raw_pop());
     }
+    _unknown_modified = true;  // assume the worst since we don't analyze the called method
     return;
   }
 
@@ -224,6 +270,11 @@
       ArgumentMap arg = state.raw_pop();
       if (!is_argument(arg))
         continue;
+      for (int j = 0; j < _arg_size; j++) {
+        if (arg.contains(j)) {
+          _arg_modified[j] |= analyzer._arg_modified[i];
+        }
+      }
       if (!is_arg_stack(arg)) {
         // arguments have already been recognized as escaping
       } else if (analyzer.is_arg_stack(i) && !analyzer.is_arg_returned(i)) {
@@ -233,6 +284,7 @@
         set_global_escape(arg);
       }
     }
+    _unknown_modified = _unknown_modified || analyzer.has_non_arg_side_affects();
 
     // record dependencies if at least one parameter retained stack-allocatable
     if (must_record_dependencies) {
@@ -250,8 +302,10 @@
       ArgumentMap arg = state.raw_pop();
       if (!is_argument(arg))
         continue;
+      set_modified(arg, OFFSET_ANY, type2size[T_INT]*HeapWordSize);
       set_global_escape(arg);
     }
+    _unknown_modified = true;  // assume the worst since we don't know the called method
   }
 }
 
@@ -421,6 +475,7 @@
         state.spop();
         ArgumentMap arr = state.apop();
         set_method_escape(arr);
+        set_modified(arr, OFFSET_ANY, type2size[T_INT]*HeapWordSize);
         break;
       }
       case Bytecodes::_lastore:
@@ -430,6 +485,7 @@
         state.spop();
         ArgumentMap arr = state.apop();
         set_method_escape(arr);
+        set_modified(arr, OFFSET_ANY, type2size[T_LONG]*HeapWordSize);
         break;
       }
       case Bytecodes::_aastore:
@@ -437,6 +493,7 @@
         set_global_escape(state.apop());
         state.spop();
         ArgumentMap arr = state.apop();
+        set_modified(arr, OFFSET_ANY, type2size[T_OBJECT]*HeapWordSize);
         break;
       }
       case Bytecodes::_pop:
@@ -762,6 +819,7 @@
           if (s.cur_bc() != Bytecodes::_putstatic) {
             ArgumentMap p = state.apop();
             set_method_escape(p);
+            set_modified(p, will_link ? field->offset() : OFFSET_ANY, type2size[field_type]*HeapWordSize);
           }
         }
         break;
@@ -872,7 +930,7 @@
 }
 
 void BCEscapeAnalyzer::merge_block_states(StateInfo *blockstates, ciBlock *dest, StateInfo *s_state) {
-  StateInfo *d_state = blockstates+dest->index();
+  StateInfo *d_state = blockstates + dest->index();
   int nlocals = _method->max_locals();
 
   // exceptions may cause transfer of control to handlers in the middle of a
@@ -916,6 +974,7 @@
     }
     for (int i = 0; i < s_state->_stack_height; i++) {
       ArgumentMap t;
+      //extra_vars |= !d_state->_vars[i] & s_state->_vars[i];
       t.clear();
       t = s_state->_stack[i];
       t.set_difference(d_state->_stack[i]);
@@ -933,7 +992,7 @@
 
   int datacount = (numblocks + 1) * (stkSize + numLocals);
   int datasize = datacount * sizeof(ArgumentMap);
-  StateInfo *blockstates = (StateInfo *) arena->Amalloc(_methodBlocks->num_blocks() * sizeof(StateInfo));
+  StateInfo *blockstates = (StateInfo *) arena->Amalloc(numblocks * sizeof(StateInfo));
   ArgumentMap *statedata  = (ArgumentMap *) arena->Amalloc(datasize);
   for (int i = 0; i < datacount; i++) ::new ((void*)&statedata[i]) ArgumentMap();
   ArgumentMap *dp = statedata;
@@ -961,33 +1020,35 @@
   ArgumentMap allVars;   // all oop arguments to method
   ciSignature* sig = method()->signature();
   int j = 0;
+  ciBlock* first_blk = _methodBlocks->block_containing(0);
+  int fb_i = first_blk->index();
   if (!method()->is_static()) {
     // record information for "this"
-    blockstates[0]._vars[j].set(j);
+    blockstates[fb_i]._vars[j].set(j);
     allVars.add(j);
     j++;
   }
   for (int i = 0; i < sig->count(); i++) {
     ciType* t = sig->type_at(i);
     if (!t->is_primitive_type()) {
-      blockstates[0]._vars[j].set(j);
+      blockstates[fb_i]._vars[j].set(j);
       allVars.add(j);
     }
     j += t->size();
   }
-  blockstates[0]._initialized = true;
+  blockstates[fb_i]._initialized = true;
   assert(j == _arg_size, "just checking");
 
   ArgumentMap unknown_map;
   unknown_map.add_unknown();
 
-  worklist.push(_methodBlocks->block_containing(0));
+  worklist.push(first_blk);
   while(worklist.length() > 0) {
     ciBlock *blk = worklist.pop();
-    StateInfo *blkState = blockstates+blk->index();
+    StateInfo *blkState = blockstates + blk->index();
     if (blk->is_handler() || blk->is_ret_target()) {
       // for an exception handler or a target of a ret instruction, we assume the worst case,
-      // that any variable or stack slot could contain any argument
+      // that any variable could contain any argument
       for (int i = 0; i < numLocals; i++) {
         state._vars[i] = allVars;
       }
@@ -997,6 +1058,7 @@
         state._stack_height = blkState->_stack_height;
       }
       for (int i = 0; i < state._stack_height; i++) {
+// ??? should this be unknown_map ???
         state._stack[i] = allVars;
       }
     } else {
@@ -1053,6 +1115,7 @@
   vmIntrinsics::ID iid = method()->intrinsic_id();
 
   if (iid == vmIntrinsics::_getClass ||
+      iid ==  vmIntrinsics::_fillInStackTrace ||
       iid == vmIntrinsics::_hashCode)
     return iid;
   else
@@ -1060,12 +1123,16 @@
 }
 
 bool BCEscapeAnalyzer::compute_escape_for_intrinsic(vmIntrinsics::ID iid) {
-  ArgumentMap empty;
-  empty.clear();
+  ArgumentMap arg;
+  arg.clear();
   switch (iid) {
   case vmIntrinsics::_getClass:
     _return_local = false;
     break;
+  case vmIntrinsics::_fillInStackTrace:
+    arg.set(0); // 'this'
+    set_returned(arg);
+    break;
   case vmIntrinsics::_hashCode:
     // initialized state is correct
     break;
@@ -1109,15 +1176,21 @@
     _return_allocated = true;
   }
   _allocated_escapes = false;
+  _unknown_modified = false;
 }
 
 void BCEscapeAnalyzer::clear_escape_info() {
   ciSignature* sig = method()->signature();
   int arg_count = sig->count();
   ArgumentMap var;
+  if (!method()->is_static()) {
+    arg_count++;  // allow for "this"
+  }
   for (int i = 0; i < arg_count; i++) {
+    set_arg_modified(i, OFFSET_ANY, 4);
     var.clear();
     var.set(i);
+    set_modified(var, OFFSET_ANY, 4);
     set_global_escape(var);
   }
   _arg_local.clear();
@@ -1126,6 +1199,7 @@
   _return_local = false;
   _return_allocated = false;
   _allocated_escapes = true;
+  _unknown_modified = true;
 }
 
 
@@ -1205,8 +1279,17 @@
     } else {
       tty->print_cr("     non-local return values");
     }
+    tty->print("     modified args: ");
+    for (int i = 0; i < _arg_size; i++) {
+      if (_arg_modified[i] == 0)
+        tty->print("    0");
+      else
+        tty->print("    0x%x", _arg_modified[i]);
+    }
     tty->cr();
     tty->print("     flags: ");
+    if (_unknown_modified)
+      tty->print(" unknown_modified");
     if (_return_allocated)
       tty->print(" return_allocated");
     tty->cr();
@@ -1228,6 +1311,7 @@
       if (_arg_returned.at(i)) {
         methodData()->set_arg_returned(i);
       }
+      methodData()->set_arg_modified(i, _arg_modified[i]);
     }
     if (_return_local) {
       methodData()->set_eflag(methodDataOopDesc::return_local);
@@ -1244,6 +1328,7 @@
     _arg_local.at_put(i, methodData()->is_arg_local(i));
     _arg_stack.at_put(i, methodData()->is_arg_stack(i));
     _arg_returned.at_put(i, methodData()->is_arg_returned(i));
+    _arg_modified[i] = methodData()->arg_modified(i);
   }
   _return_local = methodData()->eflag_set(methodDataOopDesc::return_local);
 
@@ -1261,6 +1346,12 @@
       tty->print_cr("     non-local return values");
     }
     tty->print("     modified args: ");
+    for (int i = 0; i < _arg_size; i++) {
+      if (_arg_modified[i] == 0)
+        tty->print("    0");
+      else
+        tty->print("    0x%x", _arg_modified[i]);
+    }
     tty->cr();
   }
 #endif
@@ -1281,6 +1372,7 @@
     , _return_local(false)
     , _return_allocated(false)
     , _allocated_escapes(false)
+    , _unknown_modified(false)
     , _dependencies()
     , _parent(parent)
     , _level(parent == NULL ? 0 : parent->level() + 1) {
@@ -1290,6 +1382,8 @@
     _arg_returned.clear();
     _dirty.clear();
     Arena* arena = CURRENT_ENV->arena();
+    _arg_modified = (uint *) arena->Amalloc(_arg_size * sizeof(uint));
+    Copy::zero_to_bytes(_arg_modified, _arg_size * sizeof(uint));
 
     if (methodData() == NULL)
       return;
--- a/hotspot/src/share/vm/ci/bcEscapeAnalyzer.hpp	Tue Mar 11 11:25:13 2008 -0700
+++ b/hotspot/src/share/vm/ci/bcEscapeAnalyzer.hpp	Tue Mar 11 19:00:38 2008 -0700
@@ -46,9 +46,12 @@
   BitMap            _arg_stack;
   BitMap            _arg_returned;
   BitMap            _dirty;
+  enum{ ARG_OFFSET_MAX = 31};
+  uint              *_arg_modified;
 
   bool              _return_local;
   bool              _allocated_escapes;
+  bool              _unknown_modified;
   bool              _return_allocated;
 
   ciObjectList     _dependencies;
@@ -80,6 +83,7 @@
   void set_method_escape(ArgumentMap vars);
   void set_global_escape(ArgumentMap vars);
   void set_dirty(ArgumentMap vars);
+  void set_modified(ArgumentMap vars, int offs, int size);
 
   bool is_recursive_call(ciMethod* callee);
   void add_dependence(ciKlass *klass, ciMethod *meth);
@@ -140,6 +144,13 @@
     return !_conservative && _return_allocated && !_allocated_escapes;
   }
 
+  // Tracking of argument modification
+
+  enum {OFFSET_ANY = -1};
+  bool is_arg_modified(int arg, int offset, int size_in_bytes);
+  void set_arg_modified(int arg, int offset, int size_in_bytes);
+  bool has_non_arg_side_affects()    { return _unknown_modified; }
+
   // Copy dependencies from this analysis into "deps"
   void copy_dependencies(Dependencies *deps);
 };
--- a/hotspot/src/share/vm/ci/ciMethodData.cpp	Tue Mar 11 11:25:13 2008 -0700
+++ b/hotspot/src/share/vm/ci/ciMethodData.cpp	Tue Mar 11 19:00:38 2008 -0700
@@ -42,6 +42,8 @@
   // Set an initial hint. Don't use set_hint_di() because
   // first_di() may be out of bounds if data_size is 0.
   _hint_di = first_di();
+  // Initialize the escape information (to "don't know.");
+  _eflags = _arg_local = _arg_stack = _arg_returned = 0;
 }
 
 // ------------------------------------------------------------------
@@ -59,6 +61,8 @@
   // Set an initial hint. Don't use set_hint_di() because
   // first_di() may be out of bounds if data_size is 0.
   _hint_di = first_di();
+  // Initialize the escape information (to "don't know.");
+  _eflags = _arg_local = _arg_stack = _arg_returned = 0;
 }
 
 void ciMethodData::load_data() {
@@ -142,6 +146,8 @@
     return new ciBranchData(data_layout);
   case DataLayout::multi_branch_data_tag:
     return new ciMultiBranchData(data_layout);
+  case DataLayout::arg_info_data_tag:
+    return new ciArgInfoData(data_layout);
   };
 }
 
@@ -172,6 +178,9 @@
       _saw_free_extra_data = true;  // observed an empty slot (common case)
       return NULL;
     }
+    if (dp->tag() == DataLayout::arg_info_data_tag) {
+      break; // ArgInfoData is at the end of extra data section.
+    }
     if (dp->bci() == bci) {
       assert(dp->tag() == DataLayout::bit_data_tag, "sane");
       return new ciBitData(dp);
@@ -217,8 +226,14 @@
 void ciMethodData::clear_escape_info() {
   VM_ENTRY_MARK;
   methodDataOop mdo = get_methodDataOop();
-  if (mdo != NULL)
+  if (mdo != NULL) {
     mdo->clear_escape_info();
+    ArgInfoData *aid = arg_info();
+    int arg_count = (aid == NULL) ? 0 : aid->number_of_args();
+    for (int i = 0; i < arg_count; i++) {
+      set_arg_modified(i, 0);
+    }
+  }
   _eflags = _arg_local = _arg_stack = _arg_returned = 0;
 }
 
@@ -231,6 +246,10 @@
     mdo->set_arg_local(_arg_local);
     mdo->set_arg_stack(_arg_stack);
     mdo->set_arg_returned(_arg_returned);
+    int arg_count = mdo->method()->size_of_parameters();
+    for (int i = 0; i < arg_count; i++) {
+      mdo->set_arg_modified(i, arg_modified(i));
+    }
   }
 }
 
@@ -262,6 +281,14 @@
   set_nth_bit(_arg_returned, i);
 }
 
+void ciMethodData::set_arg_modified(int arg, uint val) {
+  ArgInfoData *aid = arg_info();
+  if (aid == NULL)
+    return;
+  assert(arg >= 0 && arg < aid->number_of_args(), "valid argument number");
+  aid->set_arg_modified(arg, val);
+}
+
 bool ciMethodData::is_arg_local(int i) const {
   return is_set_nth_bit(_arg_local, i);
 }
@@ -274,6 +301,14 @@
   return is_set_nth_bit(_arg_returned, i);
 }
 
+uint ciMethodData::arg_modified(int arg) const {
+  ArgInfoData *aid = arg_info();
+  if (aid == NULL)
+    return 0;
+  assert(arg >= 0 && arg < aid->number_of_args(), "valid argument number");
+  return aid->arg_modified(arg);
+}
+
 ByteSize ciMethodData::offset_of_slot(ciProfileData* data, ByteSize slot_offset_in_data) {
   // Get offset within methodDataOop of the data array
   ByteSize data_offset = methodDataOopDesc::data_offset();
@@ -287,6 +322,18 @@
   return in_ByteSize(offset);
 }
 
+ciArgInfoData *ciMethodData::arg_info() const {
+  // Should be last, have to skip all traps.
+  DataLayout* dp  = data_layout_at(data_size());
+  DataLayout* end = data_layout_at(data_size() + extra_data_size());
+  for (; dp < end; dp = methodDataOopDesc::next_extra(dp)) {
+    if (dp->tag() == DataLayout::arg_info_data_tag)
+      return new ciArgInfoData(dp);
+  }
+  return NULL;
+}
+
+
 // Implementation of the print method.
 void ciMethodData::print_impl(outputStream* st) {
   ciObject::print_impl(st);
@@ -305,6 +352,22 @@
     st->fill_to(6);
     data->print_data_on(st);
   }
+  st->print_cr("--- Extra data:");
+  DataLayout* dp  = data_layout_at(data_size());
+  DataLayout* end = data_layout_at(data_size() + extra_data_size());
+  for (; dp < end; dp = methodDataOopDesc::next_extra(dp)) {
+    if (dp->tag() == DataLayout::no_tag)  continue;
+    if (dp->tag() == DataLayout::bit_data_tag) {
+      data = new BitData(dp);
+    } else {
+      assert(dp->tag() == DataLayout::arg_info_data_tag, "must be BitData or ArgInfo");
+      data = new ciArgInfoData(dp);
+      dp = end; // ArgInfoData is at the end of extra data section.
+    }
+    st->print("%d", dp_to_di(data->dp()));
+    st->fill_to(6);
+    data->print_data_on(st);
+  }
 }
 
 void ciReceiverTypeData::print_receiver_data_on(outputStream* st) {
--- a/hotspot/src/share/vm/ci/ciMethodData.hpp	Tue Mar 11 11:25:13 2008 -0700
+++ b/hotspot/src/share/vm/ci/ciMethodData.hpp	Tue Mar 11 19:00:38 2008 -0700
@@ -30,6 +30,7 @@
 class ciBranchData;
 class ciArrayData;
 class ciMultiBranchData;
+class ciArgInfoData;
 
 typedef ProfileData ciProfileData;
 
@@ -121,6 +122,11 @@
   ciMultiBranchData(DataLayout* layout) : MultiBranchData(layout) {};
 };
 
+class ciArgInfoData : public ArgInfoData {
+public:
+  ciArgInfoData(DataLayout* layout) : ArgInfoData(layout) {};
+};
+
 // ciMethodData
 //
 // This class represents a methodDataOop in the HotSpot virtual
@@ -163,9 +169,9 @@
   ciMethodData();
 
   // Accessors
-  int data_size() { return _data_size; }
-  int extra_data_size() { return _extra_data_size; }
-  intptr_t * data() { return _data; }
+  int data_size() const { return _data_size; }
+  int extra_data_size() const { return _extra_data_size; }
+  intptr_t * data() const { return _data; }
 
   methodDataOop get_methodDataOop() const {
     if (handle() == NULL) return NULL;
@@ -178,7 +184,7 @@
 
   void print_impl(outputStream* st);
 
-  DataLayout* data_layout_at(int data_index) {
+  DataLayout* data_layout_at(int data_index) const {
     assert(data_index % sizeof(intptr_t) == 0, "unaligned");
     return (DataLayout*) (((address)_data) + data_index);
   }
@@ -207,6 +213,8 @@
   // What is the index of the first data entry?
   int first_di() { return 0; }
 
+  ciArgInfoData *arg_info() const;
+
 public:
   bool is_method_data()  { return true; }
   bool is_empty() { return _state == empty_state; }
@@ -270,10 +278,12 @@
   void set_arg_local(int i);
   void set_arg_stack(int i);
   void set_arg_returned(int i);
+  void set_arg_modified(int arg, uint val);
 
   bool is_arg_local(int i) const;
   bool is_arg_stack(int i) const;
   bool is_arg_returned(int i) const;
+  uint arg_modified(int arg) const;
 
   // Code generation helper
   ByteSize offset_of_slot(ciProfileData* data, ByteSize slot_offset_in_data);
--- a/hotspot/src/share/vm/classfile/vmSymbols.cpp	Tue Mar 11 11:25:13 2008 -0700
+++ b/hotspot/src/share/vm/classfile/vmSymbols.cpp	Tue Mar 11 19:00:38 2008 -0700
@@ -318,6 +318,11 @@
   const int neg = JVM_ACC_SYNCHRONIZED;
   return (flags & (req | neg)) == req;
 }
+inline bool match_F_RNY(jshort flags) {
+  const int req = JVM_ACC_NATIVE | JVM_ACC_SYNCHRONIZED;
+  const int neg = JVM_ACC_STATIC;
+  return (flags & (req | neg)) == req;
+}
 
 // These are for forming case labels:
 #define ID3(x, y, z) (( jint)(z) +                                  \
@@ -359,6 +364,7 @@
   case F_RN: fname = "native ";        break;
   case F_SN: fname = "native static "; break;
   case F_S:  fname = "static ";        break;
+  case F_RNY:fname = "native synchronized "; break;
   }
   const char* kptr = strrchr(kname, '/');
   if (kptr != NULL)  kname = kptr + 1;
@@ -485,7 +491,7 @@
   if (PrintMiscellaneous && (WizardMode || Verbose)) {
     tty->print_cr("*** misidentified method; %s(%d) should be %s(%d):",
                   declared_name, declared_id, actual_name, actual_id);
-    m->print_short_name(tty);
+    mh()->print_short_name(tty);
     tty->cr();
   }
 }
--- a/hotspot/src/share/vm/classfile/vmSymbols.hpp	Tue Mar 11 11:25:13 2008 -0700
+++ b/hotspot/src/share/vm/classfile/vmSymbols.hpp	Tue Mar 11 19:00:38 2008 -0700
@@ -584,6 +584,8 @@
    do_name(     attemptUpdate_name,                                 "attemptUpdate")                                    \
    do_signature(attemptUpdate_signature,                            "(JJ)Z")                                            \
                                                                                                                         \
+  do_intrinsic(_fillInStackTrace,         java_lang_Throwable, fillInStackTrace_name, void_throwable_signature,  F_RNY) \
+                                                                                                                        \
   /* support for sun.misc.Unsafe */                                                                                     \
   do_class(sun_misc_Unsafe,               "sun/misc/Unsafe")                                                            \
                                                                                                                         \
@@ -871,7 +873,8 @@
     F_R,                        // !static        !synchronized (R="regular")
     F_S,                        //  static        !synchronized
     F_RN,                       // !static native !synchronized
-    F_SN                        //  static native !synchronized
+    F_SN,                       //  static native !synchronized
+    F_RNY                       // !static native  synchronized
   };
 
 public:
--- a/hotspot/src/share/vm/oops/methodDataOop.cpp	Tue Mar 11 11:25:13 2008 -0700
+++ b/hotspot/src/share/vm/oops/methodDataOop.cpp	Tue Mar 11 19:00:38 2008 -0700
@@ -32,7 +32,7 @@
 
 // Some types of data layouts need a length field.
 bool DataLayout::needs_array_len(u1 tag) {
-  return (tag == multi_branch_data_tag);
+  return (tag == multi_branch_data_tag) || (tag == arg_info_data_tag);
 }
 
 // Perform generic initialization of the data.  More specific
@@ -404,6 +404,17 @@
 }
 #endif
 
+#ifndef PRODUCT
+void ArgInfoData::print_data_on(outputStream* st) {
+  print_shared(st, "ArgInfoData");
+  int nargs = number_of_args();
+  for (int i = 0; i < nargs; i++) {
+    st->print("  0x%x", arg_modified(i));
+  }
+  st->cr();
+}
+
+#endif
 // ==================================================================
 // methodDataOop
 //
@@ -508,6 +519,9 @@
   int extra_data_count = compute_extra_data_count(data_size, empty_bc_count);
   object_size += extra_data_count * DataLayout::compute_size_in_bytes(0);
 
+  // Add a cell to record information about modified arguments.
+  int arg_size = method->size_of_parameters();
+  object_size += DataLayout::compute_size_in_bytes(arg_size+1);
   return object_size;
 }
 
@@ -626,6 +640,8 @@
     return new BranchData(data_layout);
   case DataLayout::multi_branch_data_tag:
     return new MultiBranchData(data_layout);
+  case DataLayout::arg_info_data_tag:
+    return new ArgInfoData(data_layout);
   };
 }
 
@@ -681,7 +697,17 @@
 
   // Add some extra DataLayout cells (at least one) to track stray traps.
   int extra_data_count = compute_extra_data_count(data_size, empty_bc_count);
-  object_size += extra_data_count * DataLayout::compute_size_in_bytes(0);
+  int extra_size = extra_data_count * DataLayout::compute_size_in_bytes(0);
+
+  // Add a cell to record information about modified arguments.
+  // Set up _args_modified array after traps cells so that
+  // the code for traps cells works.
+  DataLayout *dp = data_layout_at(data_size + extra_size);
+
+  int arg_size = method->size_of_parameters();
+  dp->initialize(DataLayout::arg_info_data_tag, 0, arg_size+1);
+
+  object_size += extra_size + DataLayout::compute_size_in_bytes(arg_size+1);
 
   // Set an initial hint. Don't use set_hint_di() because
   // first_di() may be out of bounds if data_size is 0.
@@ -764,6 +790,10 @@
     // No need for "OrderAccess::load_acquire" ops,
     // since the data structure is monotonic.
     if (dp->tag() == DataLayout::no_tag)  break;
+    if (dp->tag() == DataLayout::arg_info_data_tag) {
+      dp = end; // ArgInfoData is at the end of extra data section.
+      break;
+    }
     if (dp->bci() == bci) {
       assert(dp->tag() == DataLayout::bit_data_tag, "sane");
       return new BitData(dp);
@@ -785,6 +815,16 @@
   return NULL;
 }
 
+ArgInfoData *methodDataOopDesc::arg_info() {
+  DataLayout* dp    = extra_data_base();
+  DataLayout* end   = extra_data_limit();
+  for (; dp < end; dp = next_extra(dp)) {
+    if (dp->tag() == DataLayout::arg_info_data_tag)
+      return new ArgInfoData(dp);
+  }
+  return NULL;
+}
+
 #ifndef PRODUCT
 void methodDataOopDesc::print_data_on(outputStream* st) {
   ResourceMark rm;
@@ -794,15 +834,20 @@
     st->fill_to(6);
     data->print_data_on(st);
   }
+  st->print_cr("--- Extra data:");
   DataLayout* dp    = extra_data_base();
   DataLayout* end   = extra_data_limit();
   for (; dp < end; dp = next_extra(dp)) {
     // No need for "OrderAccess::load_acquire" ops,
     // since the data structure is monotonic.
-    if (dp->tag() == DataLayout::no_tag)  break;
-    if (dp == extra_data_base())
-      st->print_cr("--- Extra data:");
-    data = new BitData(dp);
+    if (dp->tag() == DataLayout::no_tag)  continue;
+    if (dp->tag() == DataLayout::bit_data_tag) {
+      data = new BitData(dp);
+    } else {
+      assert(dp->tag() == DataLayout::arg_info_data_tag, "must be BitData or ArgInfo");
+      data = new ArgInfoData(dp);
+      dp = end; // ArgInfoData is at the end of extra data section.
+    }
     st->print("%d", dp_to_di(data->dp()));
     st->fill_to(6);
     data->print_data_on(st);
--- a/hotspot/src/share/vm/oops/methodDataOop.hpp	Tue Mar 11 11:25:13 2008 -0700
+++ b/hotspot/src/share/vm/oops/methodDataOop.hpp	Tue Mar 11 19:00:38 2008 -0700
@@ -101,7 +101,8 @@
     virtual_call_data_tag,
     ret_data_tag,
     branch_data_tag,
-    multi_branch_data_tag
+    multi_branch_data_tag,
+    arg_info_data_tag
   };
 
   enum {
@@ -245,6 +246,7 @@
 class     BranchData;
 class   ArrayData;
 class     MultiBranchData;
+class     ArgInfoData;
 
 
 // ProfileData
@@ -376,6 +378,8 @@
   virtual bool is_BranchData()      { return false; }
   virtual bool is_ArrayData()       { return false; }
   virtual bool is_MultiBranchData() { return false; }
+  virtual bool is_ArgInfoData()     { return false; }
+
 
   BitData* as_BitData() {
     assert(is_BitData(), "wrong type");
@@ -413,6 +417,10 @@
     assert(is_MultiBranchData(), "wrong type");
     return is_MultiBranchData() ? (MultiBranchData*)this : NULL;
   }
+  ArgInfoData* as_ArgInfoData() {
+    assert(is_ArgInfoData(), "wrong type");
+    return is_ArgInfoData() ? (ArgInfoData*)this : NULL;
+  }
 
 
   // Subclass specific initialization
@@ -1047,6 +1055,33 @@
 #endif
 };
 
+class ArgInfoData : public ArrayData {
+
+public:
+  ArgInfoData(DataLayout* layout) : ArrayData(layout) {
+    assert(layout->tag() == DataLayout::arg_info_data_tag, "wrong type");
+  }
+
+  virtual bool is_ArgInfoData() { return true; }
+
+
+  int number_of_args() {
+    return array_len();
+  }
+
+  uint arg_modified(int arg) {
+    return array_uint_at(arg);
+  }
+
+  void set_arg_modified(int arg, uint val) {
+    array_set_int_at(arg, val);
+  }
+
+#ifndef PRODUCT
+  void print_data_on(outputStream* st);
+#endif
+};
+
 // methodDataOop
 //
 // A methodDataOop holds information which has been collected about
@@ -1183,6 +1218,9 @@
   // Find or create an extra ProfileData:
   ProfileData* bci_to_extra_data(int bci, bool create_if_missing);
 
+  // return the argument info cell
+  ArgInfoData *arg_info();
+
 public:
   static int header_size() {
     return sizeof(methodDataOopDesc)/wordSize;
@@ -1222,11 +1260,18 @@
   intx arg_local()                               { return _arg_local; }
   intx arg_stack()                               { return _arg_stack; }
   intx arg_returned()                            { return _arg_returned; }
+  uint arg_modified(int a)                       { ArgInfoData *aid = arg_info();
+                                                   assert(a >= 0 && a < aid->number_of_args(), "valid argument number");
+                                                   return aid->arg_modified(a); }
 
   void set_eflags(intx v)                        { _eflags = v; }
   void set_arg_local(intx v)                     { _arg_local = v; }
   void set_arg_stack(intx v)                     { _arg_stack = v; }
   void set_arg_returned(intx v)                  { _arg_returned = v; }
+  void set_arg_modified(int a, uint v)           { ArgInfoData *aid = arg_info();
+                                                   assert(a >= 0 && a < aid->number_of_args(), "valid argument number");
+
+                                                   aid->set_arg_modified(a, v); }
 
   void clear_escape_info()                       { _eflags = _arg_local = _arg_stack = _arg_returned = 0; }