[Bug target/117565] RISC-V: Make ABI implicit for non-default march

[rguenth at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117565

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
You usually do not get a choice when choosing a multilib - when you avoid the
multilib setting by -march=rv32gc you get what you deserve and have to specify
a (valid) ABI manually as well.

For a rv64gc configured compiler I'd have expected -m32 to select the platform
32bit ABI, so -march=rv32gc -m32 should get you the arch specification and an
ABI for 32 bit operation.