src/hotspot/share/interpreter/invocationCounter.cpp

/*
 * Copyright (c) 1997, 2021, 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 "compiler/compiler_globals.hpp"
#include "interpreter/invocationCounter.hpp"

void InvocationCounter::init() {
  _counter = 0;  // reset all the bits, including the sticky carry
}

void InvocationCounter::set(uint count, uint flag) {
  _counter = (count << number_of_noncount_bits) | (flag & carry_mask);
}

void InvocationCounter::set(uint count) {
  uint carry = (_counter & carry_mask);    // the carry bit is sticky
  _counter = (count << number_of_noncount_bits) | carry;
}

void InvocationCounter::update(uint new_count) {
  // Don't make the method look like it's never been executed
  uint counter = raw_counter();
  uint c = extract_count(counter);
  uint f = extract_carry(counter);
  // prevent from going to zero, to distinguish from never-executed methods
  if (c > 0 && new_count == 0) new_count = 1;
  set(new_count, f);
}

void InvocationCounter::set_carry_on_overflow() {
  if (!carry() && count() > InvocationCounter::count_limit / 2) {
    set_carry();
  }
}

void InvocationCounter::reset() {
  update(0);
}

void InvocationCounter::print() {
  uint counter = raw_counter();
  tty->print_cr("invocation count: up = %d, limit = %d, carry = %s",
                                   extract_count(counter), limit(),
                                   extract_carry(counter) ? "true" : "false");
}