我尝试使用与 magmablas_sgeadd_q 内核类似的格式，但是我没有得到正确的输出，而且每次运行它时，我都会得到不同的输出。我使用的代码如下：
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <cuda_runtime.h>
#define BLK_X 2
#define BLK_Y 1
__global__ void matrixAdd2( const float *dA, const float *dB, float *dC, int m, int n)
{
int ldda = m;
int lddb = m;
int ind = blockIdx.x*BLK_X + threadIdx.x;
int iby = blockIdx.y*BLK_Y;
/* check if full block-column */
bool full = (iby + BLK_Y <= n);
/* do only rows inside matrix */
if ( ind < m ) {
dA += ind + iby*ldda;
dB += ind + iby*lddb;
if ( full )
{
// full block-column
#pragma unroll
for( int j=0; j < BLK_Y; ++j )
{
dC[j*lddb] = dA[j*ldda] + dB[j*lddb];
printf("A is %f, B is %f, C is %f \n",dA[j*ldda],dB[j*lddb],dC[j*lddb]);
}
}
else
{
// partial block-column
for( int j=0; j < BLK_Y && iby+j < n; ++j )
{
dC[j*lddb] = dA[j*ldda] + dB[j*lddb];
printf("parital: A is %f, B is %f, C is %f \n",dA[j*ldda],dB[j*lddb],dC[j*lddb]);
}
}
}
}
int main ( void )
{
int m = 4; // a - mxn matrix
int n = 2; // b - mxn matrix
size_t size = m * n * sizeof(float);
printf("Matrix addition of %d rows and %d columns \n", m, n);
// allocate matrices on the host
float *h_A = (float *)malloc(size); // a- mxn matrix on the host
float *h_B = (float *)malloc(size); // b- mxn matrix on the host
float *h_C = (float *)malloc(size); // b- mxn matrix on the host
// Initialize the host input matrixs
for (int i = 0; i < m; ++i)
{
for (int j = 0; j < n ; j ++)
{
h_A[i*m+j] = rand()/(float)RAND_MAX;
h_B[i*m+j] = rand()/(float)RAND_MAX;
}
}
// Allocate the device input matrix A
float *d_A = NULL;
err = cudaMalloc((void **)&d_A, size);; // d_a - mxn matrix a on the device
// Allocate the device input matrix B
float *d_B = NULL;
err = cudaMalloc((void **)&d_B, size);
// Allocate the device output matrix C
float *d_C = NULL;
err = cudaMalloc((void **)&d_C, size);
// Copy the host input matrixs A and B in host memory to the device input matrixs in device memory
printf("Copy input data from the host memory to the CUDA device\n");
err = cudaMemcpy(d_A, h_A, size, cudaMemcpyHostToDevice);
err = cudaMemcpy(d_B, h_B, size, cudaMemcpyHostToDevice);
// defining number of threads and blocks
dim3 threads( BLK_X, 1 );
dim3 grid((int)ceil(m/BLK_X),(int)ceil(n/BLK_Y) );
// Launching kernel
matrixAdd2<<<grid, threads, 0>>>(d_A, d_B, d_C, m, n);
// Copy the device result matrix in device memory to the host result matrix in host memory.
printf("Copy output data from the CUDA device to the host memory\n");
err = cudaMemcpy(h_C, d_C, size, cudaMemcpyDeviceToHost);
//print A matrix
printf("Matrix A");
for (int i = 0; i < m; i++)
{
for (int j = 0; j < n; j++)
{
printf(" %f", h_A[i*m+j]);
}
printf("\n");
}
// print B matrix if required
printf("Matrix B");
for (int i = 0; i < m; i++)
{
for (int j = 0; j < n; j++)
{
printf(" %f", h_B[i*m+j]);
}
printf("\n");
}
//Error checkng
printf("Matrix C ");
for (int i = 0; i < m; i++)
{
for (int j = 0; j < n; j++)
{
printf("%f", h_C[i*m+j]);
if(h_C[i*m+j] == h_A[i*m+j] + h_B[i*m+j] )
{
flag = flag + 1;
}
}
printf("\n");
}
if(flag==m*n)
{
printf("Test PASSED\n");
}
// Free device global memory
err = cudaFree(d_A);
err = cudaFree(d_B);
err = cudaFree(d_C);
// Free host memory
free(h_A);
free(h_B);
free(h_C);
err = cudaDeviceReset();
printf("Done\n");
return 0;
}
我得到的输出：
4 行 2 列的矩阵加法 将输入数据从主机内存复制到 CUDA 设备 CUDA 内核启动 4 块 2 线程 将输出数据从 CUDA 设备复制到主机内存 A为 0.000000，B 为 0.364784，C 为 0.364784 A IS 0.000000，B为0.952230，C为0.9522230 A IS 0.000000，B IS 0.000000，C IS 0.000000 A IS 0.000000，B IS 0.000000，B IS 0.000000，C IS 0.000000 A IS 0.840188，B IS 0.840188，B IS 0.394383，C IS 0.394383，C IS 1.234571 A IS 0.78830999，B IS 0.7883099，BB 0.798440，C 是 1.581539 A是 0.911647，B 是 0.197551，C 是 1.109199 A是 0.335223，B 是 0.768230，C 是 1.103452
矩阵 A
0.840188 0.783099 0.911647 0.335223 0.277775 0.477397 0.364784 0.952230
矩阵 B
0.394383 0.798440 0.197551 0.768230 0.553970 0.628871 0.000000 0.000000
矩阵 C
0.0000000.000000 0.0000000.000000 0.0000000.000000 0.0000000.000000
如果您发现代码有问题，请告诉我。
谢谢