91 lines
No EOL
2.7 KiB
Text
91 lines
No EOL
2.7 KiB
Text
#include <stdio.h>
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#include <stdlib.h>
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#include <cuda_runtime.h>
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#define N 4096
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#define FILE_A "matrix_A.bin"
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#define FILE_B "matrix_B.bin"
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// 主機端讀取矩陣檔案
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void load_matrix(const char *filename, double *matrix) {
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FILE *file = fopen(filename, "rb");
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if (!file) {
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perror("無法讀取檔案");
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exit(EXIT_FAILURE);
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}
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fread(matrix, sizeof(double), N * N, file);
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fclose(file);
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}
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// CUDA 核函數：每個執行緒計算 C 中一個元素
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__global__ void matrixMultiply(const double *A, const double *B, double *C, int n) {
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int row = blockIdx.y * blockDim.y + threadIdx.y; // 計算矩陣行索引
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int col = blockIdx.x * blockDim.x + threadIdx.x; // 計算矩陣列索引
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if (row < n && col < n) {
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double sum = 0;
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for (int k = 0; k < n; k++) {
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sum += A[row * n + k] * B[k * n + col];
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}
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C[row * n + col] = sum;
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}
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}
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int main() {
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double *h_A = (double *)malloc(N * N * sizeof(double));
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double *h_B = (double *)malloc(N * N * sizeof(double));
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double *h_C = (double *)malloc(N * N * sizeof(double));
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if (!h_A || !h_B || !h_C) {
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perror("記憶體配置失敗");
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exit(EXIT_FAILURE);
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}
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// 從檔案載入矩陣
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load_matrix(FILE_A, h_A);
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load_matrix(FILE_B, h_B);
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// 配置裝置記憶體
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double *d_A, *d_B, *d_C;
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cudaMalloc((void**)&d_A, N * N * sizeof(double));
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cudaMalloc((void**)&d_B, N * N * sizeof(double));
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cudaMalloc((void**)&d_C, N * N * sizeof(double));
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// 將主機資料複製到裝置
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cudaMemcpy(d_A, h_A, N * N * sizeof(double), cudaMemcpyHostToDevice);
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cudaMemcpy(d_B, h_B, N * N * sizeof(double), cudaMemcpyHostToDevice);
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// 定義區塊與網格大小 (這裡選擇 16x16 的區塊)
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dim3 threadsPerBlock(16, 16);
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dim3 blocksPerGrid((N + threadsPerBlock.x - 1) / threadsPerBlock.x,
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(N + threadsPerBlock.y - 1) / threadsPerBlock.y);
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// 使用 cudaEvent 計時
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cudaEvent_t start, stop;
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cudaEventCreate(&start);
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cudaEventCreate(&stop);
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cudaEventRecord(start);
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// 執行 CUDA 核函數
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matrixMultiply<<<blocksPerGrid, threadsPerBlock>>>(d_A, d_B, d_C, N);
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cudaDeviceSynchronize();
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cudaEventRecord(stop);
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cudaEventSynchronize(stop);
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float milliseconds = 0;
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cudaEventElapsedTime(&milliseconds, start, stop);
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printf("矩陣乘法完成，花費時間: %f 秒\n", milliseconds / 1000.0);
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// 將結果從裝置複製回主機
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cudaMemcpy(h_C, d_C, N * N * sizeof(double), cudaMemcpyDeviceToHost);
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// 釋放記憶體
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cudaFree(d_A);
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cudaFree(d_B);
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cudaFree(d_C);
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free(h_A);
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free(h_B);
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free(h_C);
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return 0;
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} |