1 /*
2 * Copyright (c) 1997, 2021, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "compiler/compiler_globals.hpp"
27 #include "interpreter/invocationCounter.hpp"
28
init()29 void InvocationCounter::init() {
30 _counter = 0; // reset all the bits, including the sticky carry
31 }
32
set(uint count,uint flag)33 void InvocationCounter::set(uint count, uint flag) {
34 _counter = (count << number_of_noncount_bits) | (flag & carry_mask);
35 }
36
set(uint count)37 void InvocationCounter::set(uint count) {
38 uint carry = (_counter & carry_mask); // the carry bit is sticky
39 _counter = (count << number_of_noncount_bits) | carry;
40 }
41
update(uint new_count)42 void InvocationCounter::update(uint new_count) {
43 // Don't make the method look like it's never been executed
44 uint counter = raw_counter();
45 uint c = extract_count(counter);
46 uint f = extract_carry(counter);
47 // prevent from going to zero, to distinguish from never-executed methods
48 if (c > 0 && new_count == 0) new_count = 1;
49 set(new_count, f);
50 }
51
set_carry_on_overflow()52 void InvocationCounter::set_carry_on_overflow() {
53 if (!carry() && count() > InvocationCounter::count_limit / 2) {
54 set_carry();
55 }
56 }
57
reset()58 void InvocationCounter::reset() {
59 update(0);
60 }
61
decay()62 void InvocationCounter::decay() {
63 update(count() >> 1);
64 }
65
print()66 void InvocationCounter::print() {
67 uint counter = raw_counter();
68 tty->print_cr("invocation count: up = %d, limit = %d, carry = %s",
69 extract_count(counter), limit(),
70 extract_carry(counter) ? "true" : "false");
71 }
72