1 files changed, 66 insertions, 0 deletions
diff --git a/examples/cuda-chill/nbody.c b/examples/cuda-chill/nbody.c
new file mode 100644
index 0000000..57899b6
--- /dev/null
+++ b/examples/cuda-chill/nbody.c
@@ -0,0 +1,66 @@
+#define NBODIES 16384
+#define SOFTENINGSQUARED 0.01f
+#define DELTATIME 0.001f
+#define DAMPING 1.0f
+
+#define NBLOCKSY 1
+#define NBLOCKSX (NBODIES/NTHREADSX)
+#define NTHREADSY 1 
+#define NTHREADSX 64
+
+#define BLOCKSIZE 128
+
+#define SHARED 1
+#define TIMER 1
+#define VERIFY 1
+
+extern float sqrtf(float);
+
+void nbody_cpu(float* oldpos,float* oldpos1, float *newpos, float *oldvel, float *newvel, float *force)
+{
+    float r0,r1,r2;
+    float invDist, invDistCube, mass, invMass;
+    unsigned int i,j;
+    for(i = 0; i < NBODIES; ++i) {
+        //force[i*4  ] = 0;
+        //force[i*4+1] = 0;
+        //force[i*4+2] = 0;
+        //force[i*4+3] = 0;
+        for(j = 0; j < NBODIES; ++j) {
+	    r0 = oldpos[j*4]-oldpos1[i*4];
+	    r1 = oldpos[j*4+1]-oldpos1[i*4+1];
+	    r2 = oldpos[j*4+2]-oldpos1[i*4+2];
+
+	    invDist = 1.0/sqrtf(r0 * r0 + r1 * r1 + r2 * r2 + SOFTENINGSQUARED);
+	    invDistCube =  invDist * invDist * invDist;
+	    mass = oldpos1[i*4+3];
+
+	    force[i*4] = force[i*4] + r0 * mass * invDistCube;
+	    force[i*4+1] = force[i*4+1] + r1 * mass * invDistCube;
+	    force[i*4+2] = force[i*4+2] + r2 * mass * invDistCube;
+
+        }
+    }
+
+/*    for (i = 0; i < NBODIES; ++i) {
+        invMass = oldvel[4*i+3];
+
+        oldvel[4*i] += (force[4*i] * invMass) * DELTATIME * DAMPING;
+        oldvel[4*i+1] += (force[4*i+1] * invMass) * DELTATIME * DAMPING;
+        oldvel[4*i+2] += (force[4*i+2] * invMass) * DELTATIME * DAMPING;
+
+        oldpos[4*i] += oldvel[4*i] * DELTATIME;
+        oldpos[4*i+1] += oldvel[4*i+1] * DELTATIME;
+        oldpos[4*i+2] += oldvel[4*i+2] * DELTATIME;
+
+        newpos[4*i+0] = oldpos[4*i];
+        newpos[4*i+1] = oldpos[4*i+1];
+        newpos[4*i+2] = oldpos[4*i+2];
+        newpos[4*i+3] = oldpos[4*i+3];
+
+        newvel[4*i+0] = oldvel[4*i];
+        newvel[4*i+1] = oldvel[4*i+1];
+        newvel[4*i+2] = oldvel[4*i+2];
+        newvel[4*i+3] = oldvel[4*i+3];
+    }*/
+}