Hi,
I am using cuBLAS for the first time. I am trying to compile the SDK example (given at the end of this post) I have saved this in file named cublasExample.c .I am facing some problems in successfully compiling the code.
1- How do I compile this? Shall I use gcc cublasExample.c -o output ?
2- when I used gcc its giving lots of errors. Using NVCC gave me the following output:
/tmp/tmpxft_0000163a_00000000-1_cublasExample.o: In function `main':
cublasExample.c:(.text+0x10d): undefined reference to `cublasInit'
cublasExample.c:(.text+0x2b4): undefined reference to `cublasAlloc'
cublasExample.c:(.text+0x308): undefined reference to `cublasAlloc'
cublasExample.c:(.text+0x35c): undefined reference to `cublasAlloc'
cublasExample.c:(.text+0x3c7): undefined reference to `cublasSetVector'
cublasExample.c:(.text+0x432): undefined reference to `cublasSetVector'
cublasExample.c:(.text+0x49d): undefined reference to `cublasSetVector'
cublasExample.c:(.text+0x511): undefined reference to `cublasGetError'
cublasExample.c:(.text+0x578): undefined reference to `cublasSgemm'
cublasExample.c:(.text+0x57d): undefined reference to `cublasGetError'
cublasExample.c:(.text+0x630): undefined reference to `cublasGetVector'
cublasExample.c:(.text+0x7c4): undefined reference to `cublasFree'
cublasExample.c:(.text+0x809): undefined reference to `cublasFree'
cublasExample.c:(.text+0x84e): undefined reference to `cublasFree'
cublasExample.c:(.text+0x88d): undefined reference to `cublasShutdown'
collect2: ld returned 1 exit status
Please help me in solving this issue.
cublasExample.c which I am trying to compile
/* Includes, system */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/* Includes, cuda */
#include "cublas.h"
/* Matrix size */
#define N (275)
/* Host implementation of a simple version of sgemm */
static void simple_sgemm(int n, float alpha, const float *A, const float *B,
float beta, float *C)
{
int i;
int j;
int k;
for (i = 0; i < n; ++i) {
for (j = 0; j < n; ++j) {
float prod = 0;
for (k = 0; k < n; ++k) {
prod += A[k * n + i] * B[j * n + k];
}
C[j * n + i] = alpha * prod + beta * C[j * n + i];
}
}
}
/* Main */
int main(int argc, char** argv)
{
cublasStatus status;
float* h_A;
float* h_B;
float* h_C;
float* h_C_ref;
float* d_A = 0;
float* d_B = 0;
float* d_C = 0;
float alpha = 1.0f;
float beta = 0.0f;
int n2 = N * N;
int i;
float error_norm;
float ref_norm;
float diff;
/* Initialize CUBLAS */
printf("simpleCUBLAS test running..\n");
status = cublasInit();
if (status != CUBLAS_STATUS_SUCCESS) {
fprintf (stderr, "!!!! CUBLAS initialization error\n");
return EXIT_FAILURE;
}
/* Allocate host memory for the matrices */
h_A = (float*)malloc(n2 * sizeof(h_A[0]));
if (h_A == 0) {
fprintf (stderr, "!!!! host memory allocation error (A)\n");
return EXIT_FAILURE;
}
h_B = (float*)malloc(n2 * sizeof(h_B[0]));
if (h_B == 0) {
fprintf (stderr, "!!!! host memory allocation error (B)\n");
return EXIT_FAILURE;
}
h_C = (float*)malloc(n2 * sizeof(h_C[0]));
if (h_C == 0) {
fprintf (stderr, "!!!! host memory allocation error (C)\n");
return EXIT_FAILURE;
}
/* Fill the matrices with test data */
for (i = 0; i < n2; i++) {
h_A[i] = rand() / (float)RAND_MAX;
h_B[i] = rand() / (float)RAND_MAX;
h_C[i] = rand() / (float)RAND_MAX;
}
/* Allocate device memory for the matrices */
status = cublasAlloc(n2, sizeof(d_A[0]), (void**)&d_A);
if (status != CUBLAS_STATUS_SUCCESS) {
fprintf (stderr, "!!!! device memory allocation error (A)\n");
return EXIT_FAILURE;
}
status = cublasAlloc(n2, sizeof(d_B[0]), (void**)&d_B);
if (status != CUBLAS_STATUS_SUCCESS) {
fprintf (stderr, "!!!! device memory allocation error (B)\n");
return EXIT_FAILURE;
}
status = cublasAlloc(n2, sizeof(d_C[0]), (void**)&d_C);
if (status != CUBLAS_STATUS_SUCCESS) {
fprintf (stderr, "!!!! device memory allocation error (C)\n");
return EXIT_FAILURE;
}
/* Initialize the device matrices with the host matrices */
status = cublasSetVector(n2, sizeof(h_A[0]), h_A, 1, d_A, 1);
if (status != CUBLAS_STATUS_SUCCESS) {
fprintf (stderr, "!!!! device access error (write A)\n");
return EXIT_FAILURE;
}
status = cublasSetVector(n2, sizeof(h_B[0]), h_B, 1, d_B, 1);
if (status != CUBLAS_STATUS_SUCCESS) {
fprintf (stderr, "!!!! device access error (write B)\n");
return EXIT_FAILURE;
}
status = cublasSetVector(n2, sizeof(h_C[0]), h_C, 1, d_C, 1);
if (status != CUBLAS_STATUS_SUCCESS) {
fprintf (stderr, "!!!! device access error (write C)\n");
return EXIT_FAILURE;
}
/* Performs operation using plain C code */
simple_sgemm(N, alpha, h_A, h_B, beta, h_C);
h_C_ref = h_C;
/* Clear last error */
cublasGetError();
/* Performs operation using cublas */
cublasSgemm('n', 'n', N, N, N, alpha, d_A, N, d_B, N, beta, d_C, N);
status = cublasGetError();
if (status != CUBLAS_STATUS_SUCCESS) {
fprintf (stderr, "!!!! kernel execution error.\n");
return EXIT_FAILURE;
}
/* Allocate host memory for reading back the result from device memory */
h_C = (float*)malloc(n2 * sizeof(h_C[0]));
if (h_C == 0) {
fprintf (stderr, "!!!! host memory allocation error (C)\n");
return EXIT_FAILURE;
}
/* Read the result back */
status = cublasGetVector(n2, sizeof(h_C[0]), d_C, 1, h_C, 1);
if (status != CUBLAS_STATUS_SUCCESS) {
fprintf (stderr, "!!!! device access error (read C)\n");
return EXIT_FAILURE;
}
/* Check result against reference */
error_norm = 0;
ref_norm = 0;
for (i = 0; i < n2; ++i) {
diff = h_C_ref[i] - h_C[i];
error_norm += diff * diff;
ref_norm += h_C_ref[i] * h_C_ref[i];
}
error_norm = (float)sqrt((double)error_norm);
ref_norm = (float)sqrt((double)ref_norm);
if (fabs(ref_norm) < 1e-7) {
fprintf (stderr, "!!!! reference norm is 0\n");
return EXIT_FAILURE;
}
printf( "Test %s\n", (error_norm / ref_norm < 1e-6f) ? "PASSED" : "FAILED");
/* Memory clean up */
free(h_A);
free(h_B);
free(h_C);
free(h_C_ref);
status = cublasFree(d_A);
if (status != CUBLAS_STATUS_SUCCESS) {
fprintf (stderr, "!!!! memory free error (A)\n");
return EXIT_FAILURE;
}
status = cublasFree(d_B);
if (status != CUBLAS_STATUS_SUCCESS) {
fprintf (stderr, "!!!! memory free error (B)\n");
return EXIT_FAILURE;
}
status = cublasFree(d_C);
if (status != CUBLAS_STATUS_SUCCESS) {
fprintf (stderr, "!!!! memory free error (C)\n");
return EXIT_FAILURE;
}
/* Shutdown */
status = cublasShutdown();
if (status != CUBLAS_STATUS_SUCCESS) {
fprintf (stderr, "!!!! shutdown error (A)\n");
return EXIT_FAILURE;
}
if (argc > 1) {
if (!strcmp(argv[1], "-noprompt") ||
!strcmp(argv[1], "-qatest") )
{
return EXIT_SUCCESS;
}
}
else
{
printf("\nPress ENTER to exit...\n");
getchar();
}
return EXIT_SUCCESS;
}
