Re: [PATCH v2 03/14] tcg/loongarch64: Lower cmp_vec to vseq/vsle/vslt

[Richard Henderson]

On 9/1/23 10:28, Jiajie Chen wrote:
> On 2023/9/2 01:24, Richard Henderson wrote:
> > On 9/1/23 02:30, Jiajie Chen wrote:
> > > Signed-off-by: Jiajie Chen <c@jia.je>
> > > ---
> > >   tcg/loongarch64/tcg-target-con-set.h |  1 +
> > >   tcg/loongarch64/tcg-target.c.inc     | 60 ++++++++++++++++++++++++++++
> > >   2 files changed, 61 insertions(+)
> >
> > Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
> >
> >
> > > diff --git a/tcg/loongarch64/tcg-target-con-set.h 
> > > b/tcg/loongarch64/tcg-target-con-set.h
> > > index 37b3f80bf9..d04916db25 100644
> > > --- a/tcg/loongarch64/tcg-target-con-set.h
> > > +++ b/tcg/loongarch64/tcg-target-con-set.h
> > > @@ -31,4 +31,5 @@ C_O1_I2(r, 0, rZ)
> > >   C_O1_I2(r, rZ, ri)
> > >   C_O1_I2(r, rZ, rJ)
> > >   C_O1_I2(r, rZ, rZ)
> > > +C_O1_I2(w, w, wJ)
> >
> > Notes for improvement: 'J' is a signed 32-bit immediate.
>
>
> I was wondering about the behavior of 'J' on i128 types: in tcg_target_const_match(), the 
> argument type is int, so will the higher bits be truncated?

The argument is int64_t val.

The only constants that we allow for vectors are dupi, so all higher parts are the same as 
the lower part.

> Besides, tcg_target_const_match() does not know the vector element width.

No, it hadn't been required so far -- there are very few vector instructions that allow 
immediates.


r~