https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118940
--- Comment #9 from Hongtao Liu <liuhongt at gcc dot gnu.org> ---
>
> > Because I think the operands usage is broken.
>
> Additionally, by removing the do{ ... } while(0) wrap from
> bigint_test_exec(), the issue disappears. I believe that if it is the
> operands usage issue, the result should be the same no matter whether it is
> wrapped in a do{ ... } while(0).
I think it just happened to hit the RA limitation, and it doesn't look like a
performance/functionality regression either.
