Why does this keep getting downvoted? This is fundamentally true, and good advice borne of experience. At least somebody would care to weight in as to why they disagree?
I am not 100% sure nor did I downvote, but it doesn't look like a counter-argument at all.
> Due to how SIMD works, it's quite likely both paths of the conditional statement get executed, so its a wash
It's not just quite likely, it's what IQ is showing in the disassembly. For a ternary op like this one with trivial expressions on each side, the GPU evals both and then masks the result given the result of the condition.
> a step function doesnt change this, but that means the code is already in the correct form to replace it with smoothstep, which means you can interpolate between the two variations, which does look good.
A smoothstep does smooth interpolation of two values. It seems unrelated to the issue in the post. step() relates to the ternary op in the sense that both can be used to express conditionals. The post explains why you wouldn't necessarily want to use step() vs ternary op. smoothstep is related to step in some sense, but not in a way that relates to the article? i.e., going from step() to smoothstep() will entirely change the semantics of the program precisely because of the 'smooth' part.
Step vs ternary op vs if statement are equivalent - you are correct in that. What I'm saying is not about optimization or assembly - optimization doesn't matter when the end result looks bad.
What I'm saying that no matter how you express it in code, abrupt transitions of values introduce aliasing (or 'edge shimmer'), which looks unpleaseant. The way you get rid of it by smoothly blending between 2 values with smoothstep for example.
