aaa/matrix_multiplication.c

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <arm_neon.h>

#define SIZE 512

// 基础矩阵乘法
void matmul(float** A, float** B, float** C, int n) {
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            C[i][j] = 0;
            for (int k = 0; k < n; k++) {
                C[i][j] += A[i][k] * B[k][j];
            }
        }
    }
}

// NEON 优化矩阵乘法
void matmul_optimized(float** A, float** B, float** C, int n) {
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            float32x4_t sum = vmovq_n_f32(0);
            for (int k = 0; k <= n - 4; k += 4) {
                float32x4_t vecA = vld1q_f32(&A[i][k]);
                float32x4_t vecB = vld1q_f32(&B[k][j]);
                sum = vmlaq_f32(sum, vecA, vecB);
            }
            C[i][j] = vgetq_lane_f32(sum, 0) + vgetq_lane_f32(sum, 1) +
                      vgetq_lane_f32(sum, 2) + vgetq_lane_f32(sum, 3);
            for (int k = (n / 4) * 4; k < n; k++) {
                C[i][j] += A[i][k] * B[k][j];
            }
        }
    }
}

int main() {
    float** A = (float**)malloc(SIZE * sizeof(float*));
    float** B = (float**)malloc(SIZE * sizeof(float*));
    float** C = (float**)malloc(SIZE * sizeof(float*));

    for (int i = 0; i < SIZE; i++) {
        A[i] = (float*)malloc(SIZE * sizeof(float));
        B[i] = (float*)malloc(SIZE * sizeof(float));
        C[i] = (float*)malloc(SIZE * sizeof(float));
    }

    srand(time(NULL));
    for (int i = 0; i < SIZE; i++) {
        for (int j = 0; j < SIZE; j++) {
            A[i][j] = rand() % 100;
            B[i][j] = rand() % 100;
        }
    }

    clock_t start, end;

    // 基础矩阵乘法
    start = clock();
    matmul(A, B, C, SIZE);
    end = clock();
    printf("基础矩阵乘法时间: %f 秒\n", (double)(end - start) / CLOCKS_PER_SEC);

    // NEON 优化矩阵乘法
    start = clock();
    matmul_optimized(A, B, C, SIZE);
    end = clock();
    printf("NEON 优化矩阵乘法时间: %f 秒\n", (double)(end - start) / CLOCKS_PER_SEC);

    for (int i = 0; i < SIZE; i++) {
        free(A[i]);
        free(B[i]);
        free(C[i]);
    }
    free(A);
    free(B);
    free(C);

    return 0;
}