/* * Copyright 1993-2010 NVIDIA Corporation. All rights reserved. * * Please refer to the NVIDIA end user license agreement (EULA) associated * with this source code for terms and conditions that govern your use of * this software. Any use, reproduction, disclosure, or distribution of * this software and related documentation outside the terms of the EULA * is strictly prohibited. * */
/* Vector addition: C = A + B. * * This sample is a very basic sample that implements element by element * vector addition. It is the same as the sample illustrating Chapter 3 * of the programming guide with some additions like error checking. * */
// Includes#include <stdio.h>#include <cutil_inline.h>
// Variablesfloat* h_A;float* h_B;float* h_C;float* d_A;float* d_B;float* d_C;bool noprompt = false;
// Functionsvoid Cleanup(void);void RandomInit(float*, int);void ParseArguments(int, char**);
// Device code__global__ void VecAdd(const float* A, const float* B, float* C, int N){ int i = blockDim.x * blockIdx.x + threadIdx.x; if (i < N) C[i] = A[i] + B[i];}
// Host codeint main(int argc, char** argv){ printf("Vector addition/n"); int N = 50000; size_t size = N * sizeof(float); ParseArguments(argc, argv);
// Allocate input vectors h_A and h_B in host memory h_A = (float*)malloc(size); if (h_A == 0) Cleanup(); h_B = (float*)malloc(size); if (h_B == 0) Cleanup(); h_C = (float*)malloc(size); if (h_C == 0) Cleanup(); // Initialize input vectors RandomInit(h_A, N); RandomInit(h_B, N);
// Allocate vectors in device memory cutilSafeCall( cudaMalloc((void**)&d_A, size) ); cutilSafeCall( cudaMalloc((void**)&d_B, size) ); cutilSafeCall( cudaMalloc((void**)&d_C, size) );
// Copy vectors from host memory to device memory cutilSafeCall( cudaMemcpy(d_A, h_A, size, cudaMemcpyHostToDevice) ); cutilSafeCall( cudaMemcpy(d_B, h_B, size, cudaMemcpyHostToDevice) );
// Invoke kernel int threadsPerBlock = 256; int blocksPerGrid = (N + threadsPerBlock - 1) / threadsPerBlock; VecAdd<<<blocksPerGrid, threadsPerBlock>>>(d_A, d_B, d_C, N); cutilCheckMsg("kernel launch failure");#ifdef _DEBUG cutilSafeCall( cudaThreadSynchronize() );#endif
// Copy result from device memory to host memory // h_C contains the result in host memory cutilSafeCall( cudaMemcpy(h_C, d_C, size, cudaMemcpyDeviceToHost) ); // Verify result int i; for (i = 0; i < N; ++i) { float sum = h_A[i] + h_B[i]; if (fabs(h_C[i] - sum) > 1e-5) break; } printf("%s /n", (i == N) ? "PASSED" : "FAILED"); Cleanup();}
void Cleanup(void){ // Free device memory if (d_A) cudaFree(d_A); if (d_B) cudaFree(d_B); if (d_C) cudaFree(d_C);
// Free host memory if (h_A) free(h_A); if (h_B) free(h_B); if (h_C) free(h_C); cutilSafeCall( cudaThreadExit() ); if (!noprompt) { printf("/nPress ENTER to exit.../n"); fflush( stdout); fflush( stderr); getchar(); }
exit(0);}
// Allocates an array with random float entries.void RandomInit(float* data, int n){ for (int i = 0; i < n; ++i) data[i] = rand() / (float)RAND_MAX;}
// Parse program argumentsvoid ParseArguments(int argc, char** argv){ for (int i = 0; i < argc; ++i) if (strcmp(argv[i], "--noprompt") == 0 || strcmp(argv[i], "-noprompt") == 0) { noprompt = true; break; }}
