Does the "dot" intrinsic take into cosideration the .w component of a float4 register?
For example,
const float4 a = (float4)(1.0f,2.0f,3.0f,4.0f);
const float4 b = (float4)(1.0f,1.0f,1.0f,1.0f);
what's the result of dot(a,b)? 10 or 6?
And what's more efficient?
1. const float k = dot(a,b)
or
2. const float k = a.x*b.x + a.y*b.y + a.z*b.z
thx