old c,cc examples

1 files changed, 61 insertions, 0 deletions

diff --git a/c,cc/vector_addition.cu b/c,cc/vector_addition.cu
new file mode 100644
index 0000000..4f16bc3
--- /dev/null
+++ b/c,cc/vector_addition.cu
@@ -0,0 +1,61 @@
+#include "stdio.h"
+
+
+__global__ void add_arrays_gpu( float *in1, float *in2, float *out, int Ntot)
+{
+  int idx=blockIdx.x*blockDim.x+threadIdx.x;
+  if (idx < Ntot)
+    out[idx]=in1[idx]+in2[idx];
+}
+
+
+int main(void)
+{
+  /* pointers to host memory */
+  float *a, *b, *c;
+  /* pointers to device memory */
+  float *a_d, *b_d, *c_d;
+  int N=100000000;
+  int i;
+
+  /* Allocate arrays a, b and c on host*/
+  a = (float*) malloc(N*sizeof(float));
+  b = (float*) malloc(N*sizeof(float));
+  c = (float*) malloc(N*sizeof(float));
+
+  /* Allocate arrays a_d, b_d and c_d on device*/
+  cudaMalloc ((void **) &a_d, sizeof(float)*N);
+  cudaMalloc ((void **) &b_d, sizeof(float)*N);
+  cudaMalloc ((void **) &c_d, sizeof(float)*N);
+
+  /* Initialize arrays a and b */
+  for (i=0; i<N; i++) {
+    a[i]= (float) i;
+    b[i]=(float) -i;
+  }
+
+
+  /* Copy data from host memory to device memory */
+  cudaMemcpy(a_d, a, sizeof(float)*N, cudaMemcpyHostToDevice);
+  cudaMemcpy(b_d, b, sizeof(float)*N, cudaMemcpyHostToDevice);
+
+  /* Compute the execution configuration */
+  int block_size=256;
+  dim3 dimBlock(block_size);
+  dim3 dimGrid ( (N/dimBlock.x) + (!(N%dimBlock.x)?0:1) );
+
+  /* Add arrays a and b, store result in c */
+  add_arrays_gpu<<<dimGrid,dimBlock>>>(a_d, b_d, c_d, N);
+
+  /* Copy data from deveice memory to host memory */
+  //cudaMemcpy(c, c_d, sizeof(float)*N, cudaMemcpyDeviceToHost);
+
+  /* Print c */
+/*for(i=0; i<N; i++)
+    printf(" c[%d]=%f\n",i,c[i]);*/
+
+  /* Free the memory */
+  free(a); free(b); free(c);
+  cudaFree(a_d); cudaFree(b_d);cudaFree(c_d);
+}
+