I'm having trouble locating the builtin functions for the SHA extensions. The 5.4 and 6.3 docs do not list them. (See, for example, https://gcc.gnu.org/onlinedocs/gcc-6.3.0/gcc/x86-Built-in-Functions.html#x86-Built-in-Functions). What are the builtin functions for the various SHA extensions, like _mm_sha256rnds2_epu32?
