> x87 is just a really weird and funky instruction set that's best left in the gutter of history
hmmm, can you use the long doubles in sse or avx? They are glorious, and as far as I see from playing with godbolt, they still require dirtying your hands with the x87 stack.
The 80bit float? Not as far as I'm aware. However, it's fairly trivial to represent a 127bit float with 2 64bit floats. And with the nature of AVX/SSE, you don't really take much of a performance hit for doing that as you are often operating on both parts of the double with the same instruction.
