稀疏矩阵 part 4

▶ 各种稀疏矩阵数据结构下 y(n,1) = A(n,m) * x(m,1) 的实现，GPU版本

● MAT 乘法

__global__ void dotGPU(const MAT *a, const MAT *x, MAT *y)
{
    int id = blockIdx.x * blockDim.x + threadIdx.x;
    if (id < a->row)
    {
        format sum = 0;
        for (int i = 0; i < a->col; i++)
            sum += a->data[id * a->col + i] * x->data[i];
        y->data[id] = sum;
    }
    if (id == 0)
    {
        y->row = a->row;
        y->col = x->col;
        COUNT_MAT(y);
    }
    return;
}

● CSR 乘法

__global__ void dotGPU(const CSR *a, const MAT *x, MAT *y)
{
    int id = blockIdx.x * blockDim.x + threadIdx.x;
    if (id < a->row)
    {
        format sum = 0;
        for (int j = a->ptr[id]; j < a->ptr[id + 1]; j++)
            sum += a->data[j] * x->data[a->index[j]];
        y->data[id] = sum;
    }
    if (id == 0)
    {
        y->row = a->row;
        y->col = x->col;
        COUNT_MAT(y);
    }
    return;
}

● ELL 乘法

__global__ void dotGPU(const ELL *a, const MAT *x, MAT *y)
{
    int id = blockIdx.x * blockDim.x + threadIdx.x;
    if (id < a->col)
    {
        format sum = 0;
        for (int j = 0; j < a->row; j++)            
            sum += a->data[id + j * a->col] * (a->index[id + j * a->col] < 0 ? 0 : x->data[a->index[id + j * a->col]]);
        y->data[id] = sum;
    }
    if (id == 0)
    {
        y->row = a->col;
        y->col = x->col;
        COUNT_MAT(y);
    }
    return;
}

● COO 乘法

__global__ void dotGPU(const ELL *a, const MAT *x, MAT *y)// GPU ELL乘法
{
    int id = blockIdx.x * blockDim.x + threadIdx.x;
    if (id < a->col)
    {
        format sum = 0;
        for (int j = 0; j < a->row; j++)            
            sum += a->data[id + j * a->col] * (a->index[id + j * a->col] < 0 ? 0 : x->data[a->index[id + j * a->col]]);
        y->data[id] = sum;
    }
    if (id == 0)
    {
        y->row = a->col;
        y->col = x->col;
        COUNT_MAT(y);
    }
    return;
}

● DIA 乘法，留坑