Re: [RFC PATCH v2 18/44] target/loongarch: Implement vsat

[Richard Henderson]

On 4/3/23 19:11, gaosong wrote:
> 在 2023/4/4 上午4:13, Richard Henderson 写道:
> > On 4/3/23 05:55, gaosong wrote:
> > > Hi, Richard
> > >
> > > 在 2023/4/1 下午1:03, Richard Henderson 写道:
> > > > On 3/27/23 20:06, Song Gao wrote:
> > > > > +static void gen_vsat_s(unsigned vece, TCGv_vec t, TCGv_vec a, int64_t imm)
> > > > > +{
> > > > > +    TCGv_vec t1;
> > > > > +    int64_t max  = (1l << imm) - 1;
> > > >
> > > > This needed 1ull, but better to just use
> > > >
> > > >     max = MAKE_64BIT_MASK(0, imm - 1); 
> > > For the signed  version use ll?
> > > I think use MAKE_64BIT_MASK(0, imm -1 )  for the signed version is not suitable.
> >
> > int64_t max = MAKE_64BIT_MASK(0, imm);
> > int64_t min = ~max // or -1 - max
> The same problem with imm = 0,
> MAKE_64BIT_MASK(0, 0) is always  0xffffffffffffffff. :-)

Huh.  Well that's a bug.


r~