hotspot/src/share/vm/c1/c1_ValueStack.cpp
author iveresov
Thu, 02 Dec 2010 17:21:12 -0800
changeset 7432 f06f1253c317
parent 7397 5b173b4ca846
child 13391 30245956af37
permissions -rw-r--r--
7003554: (tiered) assert(is_null_object() || handle() != NULL) failed: cannot embed null pointer Summary: C1 with profiling doesn't check whether the MDO has been really allocated, which can silently fail if the perm gen is full. The solution is to check if the allocation failed and bailout out of inlining or compilation. Reviewed-by: kvn, never

/*
 * Copyright (c) 1999, 2010, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

#include "precompiled.hpp"
#include "c1/c1_IR.hpp"
#include "c1/c1_InstructionPrinter.hpp"
#include "c1/c1_ValueStack.hpp"


// Implementation of ValueStack

ValueStack::ValueStack(IRScope* scope, ValueStack* caller_state)
: _scope(scope)
, _caller_state(caller_state)
, _bci(-99)
, _kind(Parsing)
, _locals(scope->method()->max_locals(), NULL)
, _stack(scope->method()->max_stack())
, _locks()
{
  verify();
}


ValueStack::ValueStack(ValueStack* copy_from, Kind kind, int bci)
  : _scope(copy_from->scope())
  , _caller_state(copy_from->caller_state())
  , _bci(bci)
  , _kind(kind)
  , _locals()
  , _stack()
  , _locks(copy_from->locks_size())
{
  assert(kind != EmptyExceptionState || !Compilation::current()->env()->jvmti_can_access_local_variables(), "need locals");
  if (kind != EmptyExceptionState) {
    // only allocate space if we need to copy the locals-array
    _locals = Values(copy_from->locals_size());
    _locals.appendAll(&copy_from->_locals);
  }

  if (kind != ExceptionState && kind != EmptyExceptionState) {
    if (kind == Parsing) {
      // stack will be modified, so reserve enough space to avoid resizing
      _stack = Values(scope()->method()->max_stack());
    } else {
      // stack will not be modified, so do not waste space
      _stack = Values(copy_from->stack_size());
    }
    _stack.appendAll(&copy_from->_stack);
  }

  _locks.appendAll(&copy_from->_locks);

  verify();
}


bool ValueStack::is_same(ValueStack* s) {
  if (scope() != s->scope()) return false;
  if (caller_state() != s->caller_state()) return false;

  if (locals_size() != s->locals_size()) return false;
  if (stack_size() != s->stack_size()) return false;
  if (locks_size() != s->locks_size()) return false;

  // compare each stack element with the corresponding stack element of s
  int index;
  Value value;
  for_each_stack_value(this, index, value) {
    if (value->type()->tag() != s->stack_at(index)->type()->tag()) return false;
  }
  for_each_lock_value(this, index, value) {
    if (value != s->lock_at(index)) return false;
  }
  return true;
}

void ValueStack::clear_locals() {
  for (int i = _locals.length() - 1; i >= 0; i--) {
    _locals.at_put(i, NULL);
  }
}


void ValueStack::pin_stack_for_linear_scan() {
  for_each_state_value(this, v,
    if (v->as_Constant() == NULL && v->as_Local() == NULL) {
      v->pin(Instruction::PinStackForStateSplit);
    }
  );
}


// apply function to all values of a list; factored out from values_do(f)
void ValueStack::apply(Values list, ValueVisitor* f) {
  for (int i = 0; i < list.length(); i++) {
    Value* va = list.adr_at(i);
    Value v0 = *va;
    if (v0 != NULL && !v0->type()->is_illegal()) {
      f->visit(va);
#ifdef ASSERT
      Value v1 = *va;
      assert(v1->type()->is_illegal() || v0->type()->tag() == v1->type()->tag(), "types must match");
      assert(!v1->type()->is_double_word() || list.at(i + 1) == NULL, "hi-word of doubleword value must be NULL");
#endif
      if (v0->type()->is_double_word()) i++;
    }
  }
}


void ValueStack::values_do(ValueVisitor* f) {
  ValueStack* state = this;
  for_each_state(state) {
    apply(state->_locals, f);
    apply(state->_stack, f);
    apply(state->_locks, f);
  }
}


Values* ValueStack::pop_arguments(int argument_size) {
  assert(stack_size() >= argument_size, "stack too small or too many arguments");
  int base = stack_size() - argument_size;
  Values* args = new Values(argument_size);
  for (int i = base; i < stack_size();) args->push(stack_at_inc(i));
  truncate_stack(base);
  return args;
}


int ValueStack::total_locks_size() const {
  int num_locks = 0;
  const ValueStack* state = this;
  for_each_state(state) {
    num_locks += state->locks_size();
  }
  return num_locks;
}

int ValueStack::lock(Value obj) {
  _locks.push(obj);
  int num_locks = total_locks_size();
  scope()->set_min_number_of_locks(num_locks);
  return num_locks - 1;
}


int ValueStack::unlock() {
  _locks.pop();
  return total_locks_size();
}


void ValueStack::setup_phi_for_stack(BlockBegin* b, int index) {
  assert(stack_at(index)->as_Phi() == NULL || stack_at(index)->as_Phi()->block() != b, "phi function already created");

  ValueType* t = stack_at(index)->type();
  Value phi = new Phi(t, b, -index - 1);
  _stack[index] = phi;

  assert(!t->is_double_word() || _stack.at(index + 1) == NULL, "hi-word of doubleword value must be NULL");
}

void ValueStack::setup_phi_for_local(BlockBegin* b, int index) {
  assert(local_at(index)->as_Phi() == NULL || local_at(index)->as_Phi()->block() != b, "phi function already created");

  ValueType* t = local_at(index)->type();
  Value phi = new Phi(t, b, index);
  store_local(index, phi);
}

#ifndef PRODUCT

void ValueStack::print() {
  scope()->method()->print_name();
  if (stack_is_empty()) {
    tty->print_cr("empty stack");
  } else {
    InstructionPrinter ip;
    for (int i = 0; i < stack_size();) {
      Value t = stack_at_inc(i);
      tty->print("%2d  ", i);
      tty->print("%c%d ", t->type()->tchar(), t->id());
      ip.print_instr(t);
      tty->cr();
    }
  }
  if (!no_active_locks()) {
    InstructionPrinter ip;
    for (int i = 0; i < locks_size(); i++) {
      Value t = lock_at(i);
      tty->print("lock %2d  ", i);
      if (t == NULL) {
        tty->print("this");
      } else {
        tty->print("%c%d ", t->type()->tchar(), t->id());
        ip.print_instr(t);
      }
      tty->cr();
    }
  }
  if (locals_size() > 0) {
    InstructionPrinter ip;
    for (int i = 0; i < locals_size();) {
      Value l = _locals[i];
      tty->print("local %d ", i);
      if (l == NULL) {
        tty->print("null");
        i ++;
      } else {
        tty->print("%c%d ", l->type()->tchar(), l->id());
        ip.print_instr(l);
        if (l->type()->is_illegal() || l->type()->is_single_word()) i ++; else i += 2;
      }
      tty->cr();
    }
  }

  if (caller_state() != NULL) {
    caller_state()->print();
  }
}


void ValueStack::verify() {
  assert(scope() != NULL, "scope must exist");
  if (caller_state() != NULL) {
    assert(caller_state()->scope() == scope()->caller(), "invalid caller scope");
    caller_state()->verify();
  }

  if (kind() == Parsing) {
    assert(bci() == -99, "bci not defined during parsing");
  } else {
    assert(bci() >= -1, "bci out of range");
    assert(bci() < scope()->method()->code_size(), "bci out of range");
    assert(bci() == SynchronizationEntryBCI || Bytecodes::is_defined(scope()->method()->java_code_at_bci(bci())), "make sure bci points at a real bytecode");
    assert(scope()->method()->liveness_at_bci(bci()).is_valid(), "liveness at bci must be valid");
  }

  int i;
  for (i = 0; i < stack_size(); i++) {
    Value v = _stack.at(i);
    if (v == NULL) {
      assert(_stack.at(i - 1)->type()->is_double_word(), "only hi-words are NULL on stack");
    } else if (v->type()->is_double_word()) {
      assert(_stack.at(i + 1) == NULL, "hi-word must be NULL");
    }
  }

  for (i = 0; i < locals_size(); i++) {
    Value v = _locals.at(i);
    if (v != NULL && v->type()->is_double_word()) {
      assert(_locals.at(i + 1) == NULL, "hi-word must be NULL");
    }
  }

  for_each_state_value(this, v,
    assert(v != NULL, "just test if state-iteration succeeds");
  );
}
#endif // PRODUCT