performance measurements
Each table row shows performance measurements for this Java 7 program with a particular command-line input value N.
| N | CPU secs | Elapsed secs | Memory KB | Code B | ≈ CPU Load |
|---|---|---|---|---|---|
| 10 | 0.53 | 0.54 | 14,300 | 1633 | 0% 0% 4% 100% |
| 11 | 3.34 | 3.34 | 15,708 | 1633 | 0% 1% 1% 100% |
| 12 | 41.34 | 41.35 | 15,688 | 1633 | 0% 0% 0% 100% |
Read the ↓ make, command line, and program output logs to see how this program was run.
Read fannkuch-redux benchmark to see what this program should do.
notes
java version "1.7.0_11"
Java(TM) SE Runtime Environment (build 1.7.0_11-b21)
Java HotSpot(TM) Server VM (build 23.6-b04, mixed mode)
fannkuch-redux Java 7 #3 program source code
/* * The Computer Language Benchmarks Game * http://benchmarksgame.alioth.debian.org/ * * Contributed by Oleg Mazurov, October 2010 * * This version is submitted for comparison purpose only. * It's intended to show the effect of array bound check elimination in Java. */ import java.util.concurrent.atomic.AtomicInteger; public final class fannkuchredux implements Runnable { private static final int NCHUNKS = 240; private static int CHUNKSZ; private static int NTASKS; private static int n; private static int[] Fact; private static int[] maxFlips; private static int[] chkSums; private static AtomicInteger taskId; int[] p, pp, count; public fannkuchredux() { p = new int[n]; pp = new int[n]; count = new int[n+1]; } void runTask( int task ) { int idxMin = task*CHUNKSZ; int idxMax = Math.min( Fact[n], idxMin+CHUNKSZ ); // first permutation for ( int i=0; i<n; ++i ) { p[i] = i; } for ( int i=n-1, idx=idxMin; i>0; --i ) { int d = idx / Fact[i]; count[i] = d; idx = idx % Fact[i]; System.arraycopy( p, 0, pp, 0, i+1 ); for ( int j=0; j<=i; ++j ) { p[j] = j+d <= i ? pp[j+d] : pp[j+d-i-1]; } } int p0=0,p1=0,p2=0,p3=0,p4=0,p5=0,p6=0,p7=0,p8=0,p9=0,p10=0,p11=0; switch ( n ) { case 12: p11 = p[11]; case 11: p10 = p[10]; case 10: p9 = p[9]; case 9: p8 = p[8]; case 8: p7 = p[7]; case 7: p6 = p[6]; case 6: p5 = p[5]; case 5: p4 = p[4]; case 4: p3 = p[3]; case 3: p2 = p[2]; case 2: p1 = p[1]; case 1: p0 = p[0]; } int maxflips = 0; int chksum = 0; for ( int i=idxMin; i<idxMax; ++i ) { // count flips if ( p0 != 0 ) { int pp0 = p0, pp1 = p1, pp2 = p2, pp3 = p3, pp4 = p4, pp5 = p5, pp6 = p6, pp7 = p7, pp8 = p8, pp9 = p9, pp10 = p10, pp11 = p11; int flips = 1; for ( ;; ++flips ) { int t = pp0; switch ( t ) { case 1: pp0 = pp1; pp1 = t; break; case 2: pp0 = pp2; pp2 = t; break; case 3: pp0 = pp3; pp3 = t; t = pp2; pp2 = pp1; pp1 = t; break; case 4: pp0 = pp4; pp4 = t; t = pp3; pp3 = pp1; pp1 = t; break; case 5: pp0 = pp5; pp5 = t; t = pp4; pp4 = pp1; pp1 = t; t = pp3; pp3 = pp2; pp2 = t; break; case 6: pp0 = pp6; pp6 = t; t = pp5; pp5 = pp1; pp1 = t; t = pp4; pp4 = pp2; pp2 = t; break; case 7: pp0 = pp7; pp7 = t; t = pp6; pp6 = pp1; pp1 = t; t = pp5; pp5 = pp2; pp2 = t; t = pp4; pp4 = pp3; pp3 = t; break; case 8: pp0 = pp8; pp8 = t; t = pp7; pp7 = pp1; pp1 = t; t = pp6; pp6 = pp2; pp2 = t; t = pp5; pp5 = pp3; pp3 = t; break; case 9: pp0 = pp9; pp9 = t; t = pp8; pp8 = pp1; pp1 = t; t = pp7; pp7 = pp2; pp2 = t; t = pp6; pp6 = pp3; pp3 = t; t = pp5; pp5 = pp4; pp4 = t; break; case 10: pp0 = pp10; pp10 = t; t = pp9; pp9 = pp1; pp1 = t; t = pp8; pp8 = pp2; pp2 = t; t = pp7; pp7 = pp3; pp3 = t; t = pp6; pp6 = pp4; pp4 = t; break; case 11: pp0 = pp11; pp11 = t; t = pp10; pp10 = pp1; pp1 = t; t = pp9; pp9 = pp2; pp2 = t; t = pp8; pp8 = pp3; pp3 = t; t = pp7; pp7 = pp4; pp4 = t; t = pp6; pp6 = pp5; pp5 = t; break; } if ( pp0 == 0 ) break; } maxflips = Math.max( maxflips, flips ); chksum += (i&1)==0 ? flips : -flips; } // next permutation int t = p0; p0 = p1; p1 = t; int k=1; while ( ++count[k] > k ) { count[k++] = 0; switch ( k ) { case 11: t = p11; p11 = p0; p0 = t; case 10: t = p10; p10 = p0; p0 = t; case 9: t = p9; p9 = p0; p0 = t; case 8: t = p8; p8 = p0; p0 = t; case 7: t = p7; p7 = p0; p0 = t; case 6: t = p6; p6 = p0; p0 = t; case 5: t = p5; p5 = p0; p0 = t; case 4: t = p4; p4 = p0; p0 = t; case 3: t = p3; p3 = p0; p0 = t; case 2: t = p2; p2 = p0; p0 = p1; p1 = t; } } } maxFlips[task] = maxflips; chkSums[task] = chksum; } public void run() { int task; while ( ( task = taskId.getAndIncrement() ) < NTASKS ) { runTask( task ); } } static void printResult( int n, int res, int chk ) { System.out.println( chk+"\nPfannkuchen("+n+") = "+res ); } public static void main( String[] args ) { // Inititalize n = args.length > 0 ? Integer.parseInt( args[0] ) : 12; if ( n <= 0 || n > 12 ) { // 13! won't fit into int printResult( n, -1, -1 ); return; } Fact = new int[n+1]; Fact[0] = 1; for ( int i=1; i<Fact.length; ++i ) { Fact[i] = Fact[i-1] * i; } CHUNKSZ = (Fact[n] + NCHUNKS - 1) / NCHUNKS; NTASKS = (Fact[n] + CHUNKSZ - 1) / CHUNKSZ; maxFlips = new int[NTASKS]; chkSums = new int[NTASKS]; taskId = new AtomicInteger(0); // Go parallel int nthreads = Runtime.getRuntime().availableProcessors()-1; Thread[] threads = new Thread[nthreads]; for ( int i=0; i<nthreads; ++i ) { threads[i] = new Thread( new fannkuchredux() ); threads[i].start(); } new fannkuchredux().run(); for ( Thread t : threads ) { try { t.join(); } catch ( InterruptedException e ) {} } // Reduce the results int res = 0; for ( int v : maxFlips ) { res = Math.max( res, v ); } int chk = 0; for ( int v : chkSums ) { chk += v; } printResult( n, res, chk ); } }
make, command-line, and program output logs
Mon, 21 Jan 2013 06:38:16 GMT MAKE: mv fannkuchredux.java-3.java fannkuchredux.java /usr/local/src/jdk1.7.0_11/bin/javac fannkuchredux.java 0.57s to complete and log all make actions COMMAND LINE: /usr/local/src/jdk1.7.0_11/bin/java -server -XX:+TieredCompilation -XX:+AggressiveOpts fannkuchredux 12 PROGRAM OUTPUT: 3968050 Pfannkuchen(12) = 65