[Bug target/98596] registers not reused on RISC-V

[kito at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98596

--- Comment #2 from Kito Cheng <kito at gcc dot gnu.org> ---
Few years ago, Monk and me has write a very detailed cost model for nds32 port,
that way might able to fix the issue and further optimized for the code size
and performance, but...it need lots time to fine tune and run benchmark again
and again, so not sure when it can done.

https://github.com/gcc-mirror/gcc/blob/master/gcc/config/nds32/nds32-cost.c