1 files changed, 229 insertions, 0 deletions
diff --git a/BenchmarkFramework/app/src/main/java/art_benchmarks/benchmarksgame/nbody.java b/BenchmarkFramework/app/src/main/java/art_benchmarks/benchmarksgame/nbody.java
new file mode 100644
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+++ b/BenchmarkFramework/app/src/main/java/art_benchmarks/benchmarksgame/nbody.java
@@ -0,0 +1,229 @@
+/*
+ * This benchmark has been ported from "The Computer Language Benchmarks Game" suite and slightly
+ * modified to fit the benchmarking framework.
+ *
+ * The original file is `nbody/nbody.java` from the archive available at
+ * http://benchmarksgame.alioth.debian.org/download/benchmarksgame-sourcecode.zip.
+ * See LICENSE file in the same folder (BSD 3-clause)
+ *
+ * The Computer Language Benchmarks Game
+ * http://benchmarksgame.alioth.debian.org/
+ *
+ * contributed by Mark C. Lewis
+ * modified slightly by Chad Whipkey
+ *
+ * Same program, different command-line:
+ *     -XX:MaxMetaspaceSize=3m -XX:InitialCodeCacheSize=2048K -XX:ReservedCodeCacheSize=2048K
+ */
+
+/*
+ * Description:     Double-precision N-body simulation.
+ * Main Focus:      TODO
+ *
+ */
+
+package art_benchmarks.benchmarksgame;
+
+// CHECKSTYLE.OFF: .*
+final class NBodySystem {
+   private Body[] bodies;
+
+   public NBodySystem(){
+      bodies = new Body[]{
+            Body.sun(),
+            Body.jupiter(),
+            Body.saturn(),
+            Body.uranus(),
+            Body.neptune()
+         };
+
+      double px = 0.0;
+      double py = 0.0;
+      double pz = 0.0;
+      for(int i=0; i < bodies.length; ++i) {
+         px += bodies[i].vx * bodies[i].mass;
+         py += bodies[i].vy * bodies[i].mass;
+         pz += bodies[i].vz * bodies[i].mass;
+      }
+      bodies[0].offsetMomentum(px,py,pz);
+   }
+
+   public void advance(double dt) {
+
+      for(int i=0; i < bodies.length; ++i) {
+            Body iBody = bodies[i];
+         for(int j=i+1; j < bodies.length; ++j) {
+                double dx = iBody.x - bodies[j].x;
+            double dy = iBody.y - bodies[j].y;
+            double dz = iBody.z - bodies[j].z;
+
+                double dSquared = dx * dx + dy * dy + dz * dz;
+                double distance = Math.sqrt(dSquared);
+                double mag = dt / (dSquared * distance);
+
+            iBody.vx -= dx * bodies[j].mass * mag;
+            iBody.vy -= dy * bodies[j].mass * mag;
+            iBody.vz -= dz * bodies[j].mass * mag;
+
+            bodies[j].vx += dx * iBody.mass * mag;
+            bodies[j].vy += dy * iBody.mass * mag;
+            bodies[j].vz += dz * iBody.mass * mag;
+         }
+      }
+
+        for ( Body body : bodies) {
+         body.x += dt * body.vx;
+         body.y += dt * body.vy;
+         body.z += dt * body.vz;
+      }
+   }
+
+   public double energy(){
+      double dx, dy, dz, distance;
+      double e = 0.0;
+
+      for (int i=0; i < bodies.length; ++i) {
+            Body iBody = bodies[i];
+            e += 0.5 * iBody.mass *
+                 ( iBody.vx * iBody.vx
+                   + iBody.vy * iBody.vy
+                   + iBody.vz * iBody.vz );
+
+         for (int j=i+1; j < bodies.length; ++j) {
+                Body jBody = bodies[j];
+                dx = iBody.x - jBody.x;
+            dy = iBody.y - jBody.y;
+            dz = iBody.z - jBody.z;
+
+            distance = Math.sqrt(dx*dx + dy*dy + dz*dz);
+            e -= (iBody.mass * jBody.mass) / distance;
+         }
+      }
+      return e;
+   }
+}
+
+
+final class Body {
+   static final double PI = 3.141592653589793;
+   static final double SOLAR_MASS = 4 * PI * PI;
+   static final double DAYS_PER_YEAR = 365.24;
+
+   public double x, y, z, vx, vy, vz, mass;
+
+   public Body(){}
+
+   static Body jupiter(){
+      Body p = new Body();
+      p.x = 4.84143144246472090e+00;
+      p.y = -1.16032004402742839e+00;
+      p.z = -1.03622044471123109e-01;
+      p.vx = 1.66007664274403694e-03 * DAYS_PER_YEAR;
+      p.vy = 7.69901118419740425e-03 * DAYS_PER_YEAR;
+      p.vz = -6.90460016972063023e-05 * DAYS_PER_YEAR;
+      p.mass = 9.54791938424326609e-04 * SOLAR_MASS;
+      return p;
+   }
+
+   static Body saturn(){
+      Body p = new Body();
+      p.x = 8.34336671824457987e+00;
+      p.y = 4.12479856412430479e+00;
+      p.z = -4.03523417114321381e-01;
+      p.vx = -2.76742510726862411e-03 * DAYS_PER_YEAR;
+      p.vy = 4.99852801234917238e-03 * DAYS_PER_YEAR;
+      p.vz = 2.30417297573763929e-05 * DAYS_PER_YEAR;
+      p.mass = 2.85885980666130812e-04 * SOLAR_MASS;
+      return p;
+   }
+
+   static Body uranus(){
+      Body p = new Body();
+      p.x = 1.28943695621391310e+01;
+      p.y = -1.51111514016986312e+01;
+      p.z = -2.23307578892655734e-01;
+      p.vx = 2.96460137564761618e-03 * DAYS_PER_YEAR;
+      p.vy = 2.37847173959480950e-03 * DAYS_PER_YEAR;
+      p.vz = -2.96589568540237556e-05 * DAYS_PER_YEAR;
+      p.mass = 4.36624404335156298e-05 * SOLAR_MASS;
+      return p;
+   }
+
+   static Body neptune(){
+      Body p = new Body();
+      p.x = 1.53796971148509165e+01;
+      p.y = -2.59193146099879641e+01;
+      p.z = 1.79258772950371181e-01;
+      p.vx = 2.68067772490389322e-03 * DAYS_PER_YEAR;
+      p.vy = 1.62824170038242295e-03 * DAYS_PER_YEAR;
+      p.vz = -9.51592254519715870e-05 * DAYS_PER_YEAR;
+      p.mass = 5.15138902046611451e-05 * SOLAR_MASS;
+      return p;
+   }
+
+   static Body sun(){
+      Body p = new Body();
+      p.mass = SOLAR_MASS;
+      return p;
+   }
+
+   Body offsetMomentum(double px, double py, double pz){
+      vx = -px / SOLAR_MASS;
+      vy = -py / SOLAR_MASS;
+      vz = -pz / SOLAR_MASS;
+      return this;
+   }
+}
+
+public final class nbody {
+  // CHECKSTYLE.ON: .*
+  private NBodySystem bodies;
+
+  public nbody() {
+    bodies = new NBodySystem();
+  }
+
+  private static final int PREDEFINED_N_STEPS = 1000;
+
+  public void solve() {
+    for (int i = 0; i < PREDEFINED_N_STEPS; ++i) {
+      bodies.advance(0.01);
+    }
+  }
+
+  public void timeNBody(int iters) {
+    for (int j = 0; j < iters; ++j) {
+      solve();
+    }
+  }
+
+  public boolean verifyNBody() {
+    bodies = new NBodySystem();
+    solve();
+
+    double expected = -0.169087605234606;
+    double found = bodies.energy();
+
+    if (Math.abs(expected - found) > 0.000000001) {
+      System.out.println("ERROR: Expected " + expected + " but found " + found);
+      return false;
+    }
+
+    return true;
+  }
+
+  public static void main(String[] args) {
+    int rc = 0;
+    nbody obj = new nbody();
+
+    final long before = System.currentTimeMillis();
+    obj.timeNBody(1000);
+    final long after = System.currentTimeMillis();
+
+    if (!obj.verifyNBody()) {
+      rc++;
+    }
+    System.out.println("art_benchmarks/benchmarksgame/nbody: " + (after - before));
+    System.exit(rc);
+  }
+}