SymmColumnVec_32f16s asymm

NEON speedup: 9.46x
Auto-vect speedup: 1x

Test kernel: [-0.9432, -1.1528, 0, 1.1528, 0.9432]

modules/imgproc/src/filter.cpp

@@ -2873,7 +2873,53 @@ struct SymmColumnVec_32f16s
         }
         else
         {
-            return 0;
+            float32x2_t k32;
+            k32 = vdup_n_f32(0);
+            k32 = vld1_lane_f32(ky + 1, k32, 1);
+
+            for( ; i <= width - 8; i += 8 )
+            {
+                float32x4_t x1l, x1h, x2l, x2h;
+                float32x4_t accl, acch;
+
+                S = src[1] + i;
+                S2 = src[-1] + i;
+
+                x1l = vld1q_f32(S);
+                x1h = vld1q_f32(S + 4);
+                x2l = vld1q_f32(S2);
+                x2h = vld1q_f32(S2 + 4);
+
+                accl = acch = d4;
+                accl = vmlaq_lane_f32(accl, vsubq_f32(x1l, x2l), k32, 1);
+                acch = vmlaq_lane_f32(acch, vsubq_f32(x1h, x2h), k32, 1);
+
+                for( k = 2; k <= ksize2; k++ )
+                {
+                    S = src[k] + i;
+                    S2 = src[-k] + i;
+
+                    float32x4_t x3l, x3h, x4l, x4h;
+                    x3l = vld1q_f32(S);
+                    x3h = vld1q_f32(S + 4);
+                    x4l = vld1q_f32(S2);
+                    x4h = vld1q_f32(S2 + 4);
+
+                    accl = vmlaq_n_f32(accl, vsubq_f32(x3l, x4l), ky[k]);
+                    acch = vmlaq_n_f32(acch, vsubq_f32(x3h, x4h), ky[k]);
+                }
+
+                int32x4_t s32l, s32h;
+                s32l = vcvtq_s32_f32(accl);
+                s32h = vcvtq_s32_f32(acch);
+
+                int16x4_t s16l, s16h;
+                s16l = vqmovn_s32(s32l);
+                s16h = vqmovn_s32(s32h);
+
+                vst1_s16((int16_t *)(dst + i), s16l);
+                vst1_s16((int16_t *)(dst + i + 4), s16h);
+            }
         }
 
         return i;