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

[gaosong]

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. :-)

Thanks.
Song Gao