According to Jeff's review feedback, the issues regarding UNSPEC's implementation of round, ceil, nearbyint, etc. still need to be determined: https://gcc.gnu.org/pipermail/gcc-patches/2023-May/617706.html
source: https://github.com/majin2020/gcc-mirror/commit/93d7a2d995cee588d494d1839f56e8151c6cb057
