diff --git a/src/additional/ecpufn/ecpufn.c b/src/additional/ecpufn/ecpufn.c
index d687b60..c125324 100644
--- a/src/additional/ecpufn/ecpufn.c
+++ b/src/additional/ecpufn/ecpufn.c
@@ -77,7 +77,12 @@ void ecpu_conv2d_f32(const f32 *in, f32 *out, i32 ix, i32 iy,
 #endif
 #ifdef ALT_CONV2D_F32_K3SX
 	case 3:
-		ALT_CONV2D_F32_K3SX(in, out, ix, iy, ox, oy, sx, sy, k, kw);
+		if (sx == sy && sx == 1)
+			ALT_CONV2D_F32_K3S1(
+				in, out, ix, iy, ox, oy, sx, sy, k, kw);
+		else
+			ALT_CONV2D_F32_K3SX(
+				in, out, ix, iy, ox, oy, sx, sy, k, kw);
 		break;
 #endif
 	default:
@@ -129,6 +134,59 @@ void sse_conv2d_f32_k2sx(const f32 *in, f32 *out, i32 ix, i32 iy,
 	}
 }
 
+void sse_conv2d_f32_k3s1(const f32 *in, f32 *out, i32 ix, i32 iy,
+	i32 ox, i32 oy, i32 sx, i32 sy, const f32 *k, i32 kw)
+{
+	i32 i, j, u, off;
+	__m128 vkl[3];
+	__m128 vkh[3];
+	__m128 blk, accl, acch;
+	f32 *resl = (f32*)&(accl);
+	f32 *resh = (f32*)&(acch);
+	for (u = 0; u < kw; ++u) {
+		memcpy(((f32*)&(vkl[u])) + 0, k + u * kw, sizeof(f32) * kw);
+		memcpy(((f32*)&(vkh[u])) + 1, k + u * kw, sizeof(f32) * kw);
+	}
+	for (i = 0; i <= iy - kw - sy; i += sy) {
+		for (j = 0; j < ix - kw; j += 2) {
+			accl = _mm_setzero_ps();
+			acch = _mm_setzero_ps();
+			off = i * ix + j;
+			for (u = 0; u < kw; ++u) {
+				blk = _mm_loadu_ps(in + off);
+				accl += blk * vkl[u];
+				acch += blk * vkh[u];
+				off += ix;
+			}
+			*out++ = (resl[0] + resl[1] + resl[2]);
+			*out++ = (resh[1] + resh[2] + resh[3]);
+		}
+		if (j == ix - kw) {
+			accl = _mm_setzero_ps();
+			off = i * ix + j;
+			for (u = 0; u < kw; ++u) {
+				blk = _mm_loadu_ps(in + off);
+				accl += blk * vkl[u];
+				off  += ix;
+			}
+			*out++ = (resl[0] + resl[1] + resl[2]);
+		}
+	}
+	if (iy - kw >= i) {
+		off = i * ix;
+		for (j = -1; j <= ix - kw - 1; ++j) {
+			acch = _mm_setzero_ps();
+			off = i * ix + j;
+			for (u = 0; u < kw; ++u) {
+				blk = _mm_loadu_ps(in + off);
+				acch += blk * vkh[u];
+				off  += ix;
+			}
+			*out++ = (resh[1] + resh[2] + resh[3]);
+		}
+	}
+}
+
 void sse_conv2d_f32_k3sx(const f32 *in, f32 *out, i32 ix, i32 iy,
 	i32 ox, i32 oy, i32 sx, i32 sy, const f32 *k, i32 kw)
 {
diff --git a/src/additional/ecpufn/ecpufn.h b/src/additional/ecpufn/ecpufn.h
index 170a29f..d0a4245 100644
--- a/src/additional/ecpufn/ecpufn.h
+++ b/src/additional/ecpufn/ecpufn.h
@@ -43,6 +43,7 @@ ECPU_CONV2D_DECLARATION  (f64);
 #if defined(__x86_64) && defined(__SSE__)
   #define ALT_CONV2D_F32_K1S1  sse_conv2d_f32_k1s1
   #define ALT_CONV2D_F32_K2SX  sse_conv2d_f32_k2sx
+  #define ALT_CONV2D_F32_K3S1  sse_conv2d_f32_k3s1
   #define ALT_CONV2D_F32_K3SX  sse_conv2d_f32_k3sx
 #endif
 
@@ -50,10 +51,9 @@ void sse_conv2d_f32_k1s1(const f32 *in, f32 *out, i32 ix, i32 iy,
 	i32 ox, i32 oy, i32 sx, i32 sy, const f32 *k, i32 kw);
 void sse_conv2d_f32_k2sx(const f32 *in, f32 *out, i32 ix, i32 iy,
 	i32 ox, i32 oy, i32 sx, i32 sy, const f32 *k, i32 kw);
-void sse_conv2d_f32_k3sx(const f32 *in, f32 *out, i32 ix, i32 iy,
+void sse_conv2d_f32_k3s1(const f32 *in, f32 *out, i32 ix, i32 iy,
 	i32 ox, i32 oy, i32 sx, i32 sy, const f32 *k, i32 kw);
-
-void avx_conv2d_f32_k3sx(const f32 *in, f32 *out, i32 ix, i32 iy,
+void sse_conv2d_f32_k3sx(const f32 *in, f32 *out, i32 ix, i32 iy,
 	i32 ox, i32 oy, i32 sx, i32 sy, const f32 *k, i32 kw);
 
 /* void ecpu_dot_prod_xxx(xxx *in, xxx *out, xxx *w, i32 iw); */