https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97417
--- Comment #25 from Kito Cheng <kito at gcc dot gnu.org> --- Seem like you have add code to gcc/optabs.h and gcc/optabs.c, however those functions are RISC-V specific, so I would suggest you put in riscv.c and riscv-protos.h.