Re: [PATCH v4 29/31] target/ppc: Implement cfuged instruction

[Richard Henderson]

On 5/13/21 7:24 AM, Matheus K. Ferst wrote:
> > > +static bool trans_CFUGED(DisasContext *ctx, arg_X *a)
> > > +{
> > > +    REQUIRE_64BIT(ctx);
> > > +    REQUIRE_INSNS_FLAGS2(ctx, ISA310);
> > > +#if defined(TARGET_PPC64)
> > > +    gen_helper_cfuged(cpu_gpr[a->ra], cpu_gpr[a->rt], cpu_gpr[a->rb]);
> > > +#else
> > > +    gen_invalid(ctx);
> > > +#endif
> > > +    return true;
> > > +}
> >
> > Given that this helper will also be used by vcfuged, there's no point in 
> > hiding it in a TARGET_PPC64 block, and thus you can drop the ifdefs.
> >
> >
> > r~
>
> If I remove it, the build for ppc will fail, because cpu_gpr is declared as 
> TCGv, and the helper uses i64 to match {get,set}_cpu_vsr{l,h}. REQUIRE_64BIT 
> makes the helper call unreachable for ppc, but it's a runtime check. At build 
> time, the compiler will check the types anyway, and give us an error.

Hmm, yes.  Just change the gen_invalid above to qemu_build_not_reached().


r~