The reason for writing out all of the x multiplications like that is that I was hoping the compiler detect such a pattern perform an optimization for me. Mat Godbolt's "Advent of Compiler Optimizations" series mentions some of these cases where the compiler can do more auto-optimizations for the developer.

I did see that, but isn't the vast majority of that page talking about acos() instead?

I did scan some (major) open source games and graphics related project and found a few of them using `std::asin()`. I plan on submitting some patches.

Thanks!

When I was working on this project, I was trying to restrict myself to the architecture of the original Ray Tracing in One Weekend book series. I am aware that things are not as SIMD friendly and that becomes a major bottle neck. While I am confident that an architectural change could yield a massive performance boost, it's something I don't want to spend my time on.

I think it's also more fun sometimes to take existing systems and to try to optimize them given whatever constraints exist. I've had to do that a lot in my day job already.