Re: [PATCH v2 01/26] s390x/tcg: Fix FP CONVERT TO (LOGICAL) FIXED NaN handling

[David Hildenbrand]

On 02.06.21 11:50, David Hildenbrand wrote:
> On 01.06.21 23:27, Richard Henderson wrote:
> > On 5/17/21 7:27 AM, David Hildenbrand wrote:
> > > @@ -634,6 +664,9 @@ uint64_t HELPER(clfxb)(CPUS390XState *env, uint64_t h, 
> > > uint64_t l, uint32_t m34)
> > >    
> > >        s390_restore_bfp_rounding_mode(env, old_mode);
> > >        handle_exceptions(env, xxc_from_m34(m34), GETPC());
> > > +    if (float128_is_any_nan(make_float128(h, l))) {
> > > +        return 0;
> > > +    }
> >
> > I wonder if handle_exceptions should return s390_exc.
> > Then you can test
> >
> >      exc = handle_exceptions(...);
> >      if (unlikely(exc & S390_IEEE_MASK_INVALID)) {
> >        ret = 0;
> >      }
> >      return ret;
>
> I'll give it a thought if that makes things easier.

Looking at partsN(float_to_uint), we also raise float_flag_invalid in 
other cases, for example with float_class_inf. So IIUC, your proposal 
would also set "ret = 0" in case our input is +inf, which would be wrong.


--
Thanks,

David / dhildenb