XAndesBFHCvt provides two builtins functions for converting between
float and bf16. Users can use them to convert bf16 values loaded from
memory to float, perform arithmetic operations, then convert them back
to bf16 and store them to memory.
The load/store and move operations for bf16 will be handled in a later
patch.
clang/lib/CodeGen/CGBuiltin.cpp is over 1MB long (>23k LoC), and can
take minutes to recompile (depending on compiler and host system) when
modified, and 5 seconds for clangd to update for every edit. Splitting
this file was discussed in this thread:
https://discourse.llvm.org/t/splitting-clang-s-cgbuiltin-cpp-over-23k-lines-long-takes-1min-to-compile/
and the idea has received a number of +1 votes, hence this change.
