[Bug middle-end/68291] [6 regression] ICE in emit_move_insn, at expr.c:3540

["ebotcazou at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68291

--- Comment #8 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
> Eric, apologies for the slow response, I'm in the middle of an all-week trip
> with little Internet access.

No problem.

> I think the best course of action is to adjust gimple_can_coalesce_p so that
> it returns false for RESULT_DECLs for which promote_ssa_mode returns
> BLKmode, and then adjust the block you quoted to assign a group rtx to the
> result decl, like the original code (still present a few lines below) used
> to do when hard_function_value returned a non-REG.  I don't think we can
> allow coalescing in this case, because IIRC expanders can't deal with these
> parallels in general.

Thanks for the tip.  In fact it appears that the patch I'm about to attach is
sufficient to fix all the regressions on SPARC 64-bit, so I'm not sure if we
want to fiddle with gimple_can_coalesce_p in the end.