Re: [RFC PATCH v2 33/44] target/loongarch: Implement vfrstp

[gaosong]

在 2023/4/2 下午1:17, Richard Henderson 写道:
> On 3/27/23 20:06, Song Gao wrote:
> > This patch includes:
> > - VFRSTP[I].{B/H}.
> >
> > Signed-off-by: Song Gao<gaosong@loongson.cn>
> > ---
> >   target/loongarch/disas.c                    |  5 +++
> >   target/loongarch/helper.h                   |  5 +++
> >   target/loongarch/insn_trans/trans_lsx.c.inc |  5 +++
> >   target/loongarch/insns.decode               |  5 +++
> >   target/loongarch/lsx_helper.c               | 41 +++++++++++++++++++++
> >   5 files changed, 61 insertions(+)
>
> This one's obscure.  Find first negative element in Vj,
> store that value in Vd element indexed by Vk?
Yes,  but the value is  the first negative element index  or  max index + 1.

e.g   vfrstp.b  vd, vj, vk.
    idx = 0;
    for  i in range(16);
        if Vj->B[i]  < 0; break;
        idx = idx +1;
    m = Vk->B(0) % 16;
    Vd->B(m) = idx;

Thanks.
Song Gao