Lightmaped model still compute normal？

Unity Engine
1

I profile my game use Adreno Profiler and find lightmaped static model’s vertex data have normal attribute.
3103889--234419--upload_2017-6-11_17-50-28.png
Lighting mode is Subtractive. Non-Directional. Directional Light is baked.novertexlights is set to surfaceshader. So there should no normal used in somewhere.
When I use Unity4.7，the normal data not used on mobile.

The surface shader is very simple

        struct Input {
            float2 uv_MainTex;
        };

        void surf(Input IN, inout SurfaceOutput o) {
            fixed4 c = tex2D(_MainTex, IN.uv_MainTex);
            o.Albedo = c.rgb;
            o.Alpha = c.a;
        }

        inline fixed4 LightingTestLambert(SurfaceOutput s, fixed3 lightDir, fixed atten)
        {
            fixed diff = max(0, dot(s.Normal, lightDir));

            fixed4 c;
            c.rgb = s.Albedo * _LightColor0.rgb * (diff * atten);
            c.a = s.Alpha;
            return c;
        }

And I looked generated code， even no normal used， worldNormal always compute.
3103889--234424--upload_2017-6-11_18-33-49.png

Is there anyway I can save this operate and not export normal data when build apk.

3103889--234422--upload_2017-6-11_18-28-3.png
3103889--234423--upload_2017-6-11_18-31-42.png

2

You’d probably have to write your own shader. Not much you can change about this any other way.

Edit: With shader I mean a shader with all separate passes instead of generated from a surface shader.

3

Thank you.
I just update project from 4.7 to 5.6, so want to confirm when Unity change this.
Have to write every pass is annoying, so sad…