/*
This file is part of JOP, the Java Optimized Processor
see <http://www.jopdesign.com/>
Copyright (C) 2001-2008, Martin Schoeberl (martin@jopdesign.com)
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program 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 for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package wcet;
import com.jopdesign.sys.*;
public class SimpleMethod2 {
static int ts, te, to;
/**
* @param args
*/
public static void main(String[] args) {
ts = Native.rdMem(Const.IO_CNT);
te = Native.rdMem(Const.IO_CNT);
to = te-ts;
// measurement + return takes 22+22+21=65 cycles
// WCET measured: 211
// WCET analysed: 278-65 = 213
// diff is 2 cycles:
// As the invokestatic of the native methods get substituted
// by the special bytecode, the method length gets shorter (1 byte
// for the special bytecode instead of 3 bytes for the
// invokestatic). Therefore, foo() is now 5 words instead of the
// original 6 words. That means the miss from the xxx() return is 2
// cycles less then in the original, analyzed method.
measure();
// System.out.println(te-ts-to);
}
public static void measure() {
ts = Native.rdMem(Const.IO_CNT);
foo();
te = Native.rdMem(Const.IO_CNT);
}
static int foo() {
xxx();
return 123;
}
static int xxx() {
return 456;
}
}