The log file for the shader demonstrating implicit truncation of vector type.

ShaderLog

/***** Used Parameters *****
 * EffectName: EffectMain
 * CompilerParameters.DebugKey: True
 * MaterialParameters.UseTransparentMask: False
 * MaterialParameters.NormalMap: NullValue
 * MaterialParameters.AmbientMap: NullValue
 * Lighting.CastShadows: True
 * CompilerParameters.GraphicsPlatformKey: Direct3D11
 * MaterialParameters.AlbedoSpecular: NullValue
 * CompilerParameters.GraphicsProfileKey: Level_11_1
 * MaterialParameters.UseTransparent: False
 * MaterialParameters.AlbedoDiffuse: NullValue
 * MaterialParameters.HasSkinningPosition: False
 ***************************/
SamplerState Sampler_id46;
Texture2D VisibilityMap_id40;
Texture2DArray TextureArray_id39;
struct PS_STREAMS 
{
    float4 Position_id13;
    float2 TexCoord_id44;
    float TexIndex_id45;
    float4 ColorTarget_id1;
};
struct PS_OUTPUT 
{
    float4 ColorTarget_id1 : SV_Target0;
};
struct VS_STREAMS 
{
    float4 Position_id13;
    float3 vNormal_id36;
    float2 TexCoord_id44;
    float TexIndex_id45;
    float4 PositionWS_id14;
    float4 PositionH_id15;
    float4 vPositionVS_id35;
    float3 vNormalVS_id38;
    float4 ShadingPosition_id0;
};
struct VS_OUTPUT 
{
    float4 ShadingPosition_id0 : SV_Position;
    float4 Position_id13 : POSITION;
    float2 TexCoord_id44 : TEXCOORD0;
    float TexIndex_id45 : TEXINDEX;
};
struct VS_INPUT 
{
    float4 Position_id13 : POSITION;
    float3 vNormal_id36 : NORMAL;
    float2 TexCoord_id44 : TEXCOORD0;
    float TexIndex_id45 : TEXINDEX;
};
cbuffer OpenglFlags 
{
    float ParadoxFlipRendertarget;
};
cbuffer PerFrame 
{
    float4x4 ViewProjection_id26;
};
cbuffer PerObject 
{
    float4x4 World_id30;
    float4x4 WorldView_id32;
    float4x4 WorldViewInverse_id33;
};
cbuffer Globals 
{
    uint Ticks_id41;
};
void PostTransformPosition_id4()
{
}
void PreTransformPosition_id2()
{
}
float4 Compute_id26(inout PS_STREAMS streams)
{
    uint v = VisibilityMap_id40.Load(int3(streams.Position_id13.xy, 0));
    if (v == 0)
        return float4(0, 0, 0, 1);
    float4 diffuseColor = TextureArray_id39.Sample(Sampler_id46, float3(streams.TexCoord_id44, streams.TexIndex_id45));
    if (v < Ticks_id41)
    {
        float4 aLighting = float4(0.1, 0.1, 0.1, 1);
        return diffuseColor * aLighting;
    }
    return diffuseColor;
}
float4 Compute_id27()
{
    return 0;
}
void PostTransformPosition_id8(inout VS_STREAMS streams)
{
    PostTransformPosition_id4();
    streams.ShadingPosition_id0 = mul(streams.PositionWS_id14, ViewProjection_id26);
    streams.PositionH_id15 = streams.ShadingPosition_id0;
}
void TransformPosition_id3()
{
}
void PreTransformPosition_id7(inout VS_STREAMS streams)
{
    PreTransformPosition_id2();
    streams.PositionWS_id14 = mul(streams.Position_id13, World_id30);
}
float4 DiffuseAlbedo_id9(inout PS_STREAMS streams)
{
    return Compute_id26(streams);
}
float4 Shading_id17()
{
    return Compute_id27();
}
void BaseTransformVS_id5(inout VS_STREAMS streams)
{
    PreTransformPosition_id7(streams);
    TransformPosition_id3();
    PostTransformPosition_id8(streams);
}
float4 Shading_id19(inout PS_STREAMS streams)
{
    return Shading_id17() + DiffuseAlbedo_id9(streams);
}
void PSMain_id1()
{
}
void VSMain_id6(inout VS_STREAMS streams)
{
    BaseTransformVS_id5(streams);
}
void PSMain_id18(inout PS_STREAMS streams)
{
    PSMain_id1();
    streams.ColorTarget_id1 = Shading_id19(streams);
}
void GenerateNormalVS_PS_id23()
{
}
void GenerateNormalVS_VS_id25(inout VS_STREAMS streams)
{
    streams.vNormalVS_id38 = mul((float3x3)WorldViewInverse_id33, streams.vNormal_id36);
}
void VSMain_id20(inout VS_STREAMS streams)
{
    VSMain_id6(streams);
    streams.vPositionVS_id35 = mul(streams.Position_id13, WorldView_id32);
}
PS_OUTPUT PSMain(VS_OUTPUT input)
{
    PS_STREAMS streams = (PS_STREAMS)0;
    streams.Position_id13 = input.Position_id13;
    streams.TexCoord_id44 = input.TexCoord_id44;
    streams.TexIndex_id45 = input.TexIndex_id45;
    GenerateNormalVS_PS_id23();
    PSMain_id18(streams);
    PS_OUTPUT output = (PS_OUTPUT)0;
    output.ColorTarget_id1 = streams.ColorTarget_id1;
    return output;
}
VS_OUTPUT VSMain(VS_INPUT input)
{
    VS_STREAMS streams = (VS_STREAMS)0;
    streams.Position_id13 = input.Position_id13;
    streams.vNormal_id36 = input.vNormal_id36;
    streams.TexCoord_id44 = input.TexCoord_id44;
    streams.TexIndex_id45 = input.TexIndex_id45;
    VSMain_id20(streams);
    GenerateNormalVS_VS_id25(streams);
    VS_OUTPUT output = (VS_OUTPUT)0;
    output.ShadingPosition_id0 = streams.ShadingPosition_id0;
    output.Position_id13 = streams.Position_id13;
    output.TexCoord_id44 = streams.TexCoord_id44;
    output.TexIndex_id45 = streams.TexIndex_id45;
    return output;
}

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