CUDA矩陣相乘函數實作

__global__ void matrix_mul_gpu(int* M, int* N, int* P, int width)
{
    int i = threadIdx.x + blockDim.x * blockIdx.x;
    int j = threadIdx.y + blockDim.y * blockIdx.y;

    int sum = 0;
    for (int k = 0; k < width; k++)
    {
        int a = M[j * width + k];
        int b = N[k * width + i];
        sum += a * b;
    }
    P[j * width + i] = sum;
}