diff --git a/cxy_opt/3.c b/cxy_opt/3.c
new file mode 100644
index 0000000..4f546e7
--- /dev/null
+++ b/cxy_opt/3.c
@@ -0,0 +1,61 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <string.h>
+#include <arm_neon.h>
+#include "render.h"
+#define IDX(n) ((n) % 3)
+
+void applySeparableGaussianBlur(float src[][MAT_SIZE], float dst[][MAT_SIZE], 
+	 float kx[], float ky[]);
+int main() {
+	float inputImage[MAT_SIZE][MAT_SIZE];
+	Render(inputImage);
+	float kernel[3][3] = {
+		{1.0f/16, 2.0f/16, 1.0f/16},
+		{2.0f/16, 4.0f/16, 2.0f/16},
+		{1.0f/16, 2.0f/16, 1.0f/16}
+	};
+	float kx[4] = {1.0f/4, 1.0f/2, 1.0f/4, 0.0f}; // 防止越界多定义一个
+	float ky[4] = {1.0f/4, 1.0f/2, 1.0f/4, 0.0f};
+	float outputImage[MAT_SIZE][MAT_SIZE] = {0};
+	clock_t start = clock();
+	applySeparableGaussianBlur(inputImage, outputImage, kx, ky);
+	clock_t end   = clock();
+	printf("Time: %lf s\n", (double)(end-start) / CLOCKS_PER_SEC);
+	Print(outputImage);
+}
+
+void applySeparableGaussianBlur(float src[][MAT_SIZE], float dst[][MAT_SIZE], 
+		float kx[], float ky[]) {
+	int i, j;
+	float buf[3][MAT_SIZE];
+	float32x4_t kx_vec = vld1q_f32(kx);
+	float32x4_t ky_vec = vld1q_f32(ky);
+	// 计算前两行的行内卷积
+	float32x4_t* left, *mid, *right, *result;
+	for(i=0; i<2; i++)
+	for(j=1; j<MAT_SIZE-1; j+=4) {
+		left   = (float32x4_t*)&src[i][j-1];
+		mid    = (float32x4_t*)&src[i][j];
+		right  = (float32x4_t*)&src[i][j+1];
+		result = (float32x4_t*)&buf[i][j];
+		*result  = vmulq_lane_f32(*left,  vget_low_f32(kx_vec), 0);
+		*result += vmulq_lane_f32(*mid,   vget_low_f32(kx_vec), 1);
+		*result += vmulq_lane_f32(*right, vget_high_f32(kx_vec), 0);
+	}
+	// 利用buf进行累计
+	for(i=1; i<MAT_SIZE-1; i++) {
+		for(j=1; j<MAT_SIZE-1; j+=4) {
+			left   = (float32x4_t*)&src[i+1][j-1];
+			mid    = (float32x4_t*)&src[i+1][j];
+			right  = (float32x4_t*)&src[i+1][j+1];
+			result = (float32x4_t*)&buf[IDX(i+1)][j];
+			*result  = vmulq_lane_f32(*left,  vget_low_f32(kx_vec), 0);
+			*result += vmulq_lane_f32(*mid,   vget_low_f32(kx_vec), 1);
+			*result += vmulq_lane_f32(*right, vget_high_f32(kx_vec), 0);
+		}
+		for(j=1; j<MAT_SIZE-1; j++)
+			dst[i][j] = buf[IDX(i-1)][j]*ky[0]+buf[IDX(i)][j]*ky[1]+buf[IDX(i+1)][j]*ky[2];
+	}
+}