Re: [PATCH v1 2/6] target/loongarch: Add set_vec_extctx to set LSX/LASX instructions extctx_flags

[gaosong]

在 2023/10/29 上午5:40, Richard Henderson 写道:
> On 10/9/23 20:36, Song Gao wrote:
> > Signed-off-by: Song Gao <gaosong@loongson.cn>
> > ---
> >   target/loongarch/insn_trans/trans_vec.c.inc | 12 ++++++++++++
> >   target/loongarch/internals.h                |  2 ++
> >   2 files changed, 14 insertions(+)
> >
> > diff --git a/target/loongarch/insn_trans/trans_vec.c.inc 
> > b/target/loongarch/insn_trans/trans_vec.c.inc
> > index 98f856bb29..aef16ef44a 100644
> > --- a/target/loongarch/insn_trans/trans_vec.c.inc
> > +++ b/target/loongarch/insn_trans/trans_vec.c.inc
> > @@ -23,8 +23,20 @@ static bool check_vec(DisasContext *ctx, uint32_t 
> > oprsz)
> >     #else
> >   +static void set_vec_extctx(DisasContext *ctx, uint32_t oprsz)
> > +{
> > +    if (oprsz == 16) {
> > +        ctx->extctx_flags |= EXTCTX_FLAGS_LSX;
> > +    }
> > +
> > +    if (oprsz == 32) {
> > +        ctx->extctx_flags |= EXTCTX_FLAGS_LASX;
> > +    }
> > +}
> > +
> >   static bool check_vec(DisasContext *ctx, uint32_t oprsz)
> >   {
> > +    set_vec_extctx(ctx, oprsz);
> >       return true;
> >   }
>
> This doesn't do anything.  Nothing copies the changed value back to env.
> Anyway, I think this is the wrong way to go about it.
Oh, It is on patch1.

@@ -294,6 +296,7 @@ static void 
loongarch_tr_translate_insn(DisasContextBase *dcbase, CPUState *cs)
         generate_exception(ctx, EXCCODE_INE);
     }

+    env->extctx_flags |= ctx->extctx_flags;
     ctx->base.pc_next += 4;


Thanks.
Song Gao
> If you want to track what the program is using, you should do it 
> exactly like the real kernel: disable the execution unit, have the 
> program trap, and the enable the execution unit when the trap occurs.  
> At this point, CSR_EUEN enable bits contain exactly which units have 
> been used by the program.
>
>
> r~