Re: [PATCH 11/12] target/loongarch: Use generic hrev64_i32() in REVB.2H opcode

[Philippe Mathieu-Daudé]

On 22/8/23 15:30, Philippe Mathieu-Daudé wrote:
> On 22/8/23 14:52, Philippe Mathieu-Daudé wrote:
> > Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> > ---
> >   target/loongarch/insn_trans/trans_bit.c.inc | 15 +--------------
> >   1 file changed, 1 insertion(+), 14 deletions(-)
> >
> > diff --git a/target/loongarch/insn_trans/trans_bit.c.inc 
> > b/target/loongarch/insn_trans/trans_bit.c.inc
> > index c04806dc21..9d564a0999 100644
> > --- a/target/loongarch/insn_trans/trans_bit.c.inc
> > +++ b/target/loongarch/insn_trans/trans_bit.c.inc
> > @@ -111,19 +111,6 @@ static void gen_revb_2w(TCGv dest, TCGv src1)
> >       tcg_gen_rotri_i64(dest, dest, 32);
> >   }
> > -static void gen_revb_2h(TCGv dest, TCGv src1)
> > -{
> > -    TCGv mask = tcg_constant_tl(0x00FF00FF);
> > -    TCGv t0 = tcg_temp_new();
> > -    TCGv t1 = tcg_temp_new();
> > -
> > -    tcg_gen_shri_tl(t0, src1, 8);
> > -    tcg_gen_and_tl(t0, t0, mask);
> > -    tcg_gen_and_tl(t1, src1, mask);
> > -    tcg_gen_shli_tl(t1, t1, 8);

Looking at 
https://loongson.github.io/LoongArch-Documentation/LoongArch-Vol1-EN.html#_revb_2h4h2wd
the sign extension is missing, so the next line:

> > -    tcg_gen_or_tl(dest, t0, t1);

should be replaced by smth like:

        tcg_gen_or_tl(t0, t0, t1);
        tcg_gen_ext32s_tl(dest, t0);

> > -}