cubla sample-code

cublasSscal 

//Example 1. Application Using C and CUBLAS: 1-based indexing



#include <stdlib.h>

#include <math.h>

#include <cuda_runtime.h>

#include "cublas_v2.h"

#include <stdio.h>

#define M 6

#define N 5

#define IDX2F(i,j,ld) ((((j)-1)*(ld))+((i)-1))

static __inline__ void modify (cublasHandle_t handle, float*m, int ldm, int

    n, int p, int q, float alpha, float beta){

        cublasSscal (handle, n-p+1, &alpha, &m[IDX2F(p,q,ldm)], ldm);

        cublasSscal (handle, ldm-p+1, &beta, &m[IDX2F(p,q,ldm)], 1);

}

int main (void){

    cudaError_t cudaStat; 

    cublasStatus_t stat;

    cublasHandle_t handle;

    int i, j;

    float* devPtrA;

    float* a = 0;

    a = (float*)malloc (M * N * sizeof(*a));

    if(!a) {

        printf("host memory allocation failed");

        return EXIT_FAILURE;

    }

    for(j = 1; j <= N; j++) {

        for(i = 1; i <= M; i++) {

            a[IDX2F(i,j,M)] = (float)((i-1) * M + j);

            printf("%7.0f",a[IDX2F(i,j,M)]);

        }printf("\n");

    }printf("\n");

    cudaStat = cudaMalloc ((void**)&devPtrA, M*N*sizeof(*a));

    if(cudaStat != cudaSuccess) {

        printf ("device memory allocation failed");

        return EXIT_FAILURE;

    }

    stat = cublasCreate(&handle);

    if(stat != CUBLAS_STATUS_SUCCESS) {

        printf ("CUBLAS initialization failed\n");

        return EXIT_FAILURE;

    }

    stat = cublasSetMatrix (M, N, sizeof(*a), a, M, devPtrA, M);

    if(stat != CUBLAS_STATUS_SUCCESS) {

        printf ("data download failed");

        cudaFree (devPtrA);

        cublasDestroy(handle);

        return EXIT_FAILURE;

    }

    modify (handle, devPtrA, M, N, 2, 3, 16.0f, 12.0f);

    stat = cublasGetMatrix (M, N, sizeof(*a), devPtrA, M, a, M);

    if(stat != CUBLAS_STATUS_SUCCESS) {

        printf("data upload failed");

        cudaFree (devPtrA);

        cublasDestroy(handle); 

        return EXIT_FAILURE;

    } 

    cudaFree (devPtrA);

    cublasDestroy(handle);

    for(j = 1; j <= N; j++) {

        for(i = 1; i <= M; i++) {

            printf ("%7.0f", a[IDX2F(i,j,M)]);

        }

        printf ("\n");

    }

    free(a);

    return EXIT_SUCCESS;

}