On Fri, 11 Aug 2023 16:30:29 PDT (-0700), gcc-patches@gcc.gnu.org wrote:
On 8/9/23 16:39, Tsukasa OI wrote:
On 2023/08/10 5:05, Jeff Law wrote:
I'd tend to think we do not want to expose the intrinsic unless the
right extensions are enabled -- even though the encoding is a no-op and
we could emit it as a .insn.
I think that makes sense. The only reason I implemented the
no-'Zihintpause' version is because GCC 13 implemented the built-in
unconditionally. If the compatibility breakage is considered minimum (I
don't know, though), I'm ready to submit 'Zihintpause'-only version of
this patch set.
While it's a compatibility break I don't think we have a need to
preserve this kind of compatibility. I suspect anyone using
__builtin_riscv_pause was probably already turning on Zihintpause and if
they weren't they should have been :-0
I agree it's fine to just call this a bug: the builtin wasn't doing
anything on non-Zihintpause systems anyway, so it's not like it could
have been all that useful.
I'm sure we'll kick this around in the Tuesday meeting and hopefully
make a decision about the desired direction. You're obviously welcome
to join if you're inclined. Let me know if you need an invite.
jeff
