Re: [PATCH] target/mips: Fix loongson multimedia condition instructions

[Huacai Chen]

On Sat, Mar 21, 2020 at 7:17 PM Jiaxun Yang <address@hidden> wrote:
>
>
>
> 于 2020年3月21日 GMT+08:00 下午6:57:54, Jiaxun Yang <address@hidden> 写到:
> >
> >
> >于 2020年3月21日 GMT+08:00 下午6:39:21, "Philippe Mathieu-Daudé"
> ><address@hidden> 写到:
> >>On 3/21/20 5:56 AM, Jiaxun Yang wrote:
> >>> Loongson multimedia condition instructions were previously
> >>implemented as
> >>> write 0 to rd due to lack of documentation. So I just confirmed with
> >>Loongson
> >>> about their encoding and implemented them correctly.
> >>
> >>Can you refer to the datasheet in the commit message, or have someone
> >>from Loongson Technology, Lemote Tech or with access to the specs ack
> >>your patch?
> >
> >I just confirmed with Loongson guys on IM.
> >
> >+ Huacai
>
> +Huacai's Gmail as his Lemote mail rejected my bounce.
>
> >
> >Hi Huacai,
> >
> >Could you please acknowledge this change,
> >Thanks.
> >
> >--
> >Jiaxun Yang
Acked-by: Huacai Chen <address@hidden>

> >
> >>
> >>>
> >>> Signed-off-by: Jiaxun Yang <address@hidden>
> >>> ---
> >>>   target/mips/translate.c | 40
> >>++++++++++++++++++++++++++++++++++------
> >>>   1 file changed, 34 insertions(+), 6 deletions(-)
> >>>
> >>> diff --git a/target/mips/translate.c b/target/mips/translate.c
> >>> index d745bd2803..43be8d27b5 100644
> >>> --- a/target/mips/translate.c
> >>> +++ b/target/mips/translate.c
> >>> @@ -5529,6 +5529,8 @@ static void
> >>gen_loongson_multimedia(DisasContext *ctx, int rd, int rs, int rt)
> >>>   {
> >>>       uint32_t opc, shift_max;
> >>>       TCGv_i64 t0, t1;
> >>> +    TCGCond cond;
> >>> +    TCGLabel *lab;
> >>>
> >>>       opc = MASK_LMI(ctx->opcode);
> >>>       switch (opc) {
> >>> @@ -5816,7 +5818,7 @@ static void
> >>gen_loongson_multimedia(DisasContext *ctx, int rd, int rs, int rt)
> >>>       case OPC_DADD_CP2:
> >>>           {
> >>>               TCGv_i64 t2 = tcg_temp_new_i64();
> >>> -            TCGLabel *lab = gen_new_label();
> >>> +            lab = gen_new_label();
> >>>
> >>>               tcg_gen_mov_i64(t2, t0);
> >>>               tcg_gen_add_i64(t0, t1, t2);
> >>> @@ -5837,7 +5839,7 @@ static void
> >>gen_loongson_multimedia(DisasContext *ctx, int rd, int rs, int rt)
> >>>       case OPC_DSUB_CP2:
> >>>           {
> >>>               TCGv_i64 t2 = tcg_temp_new_i64();
> >>> -            TCGLabel *lab = gen_new_label();
> >>> +            lab = gen_new_label();
> >>>
> >>>               tcg_gen_mov_i64(t2, t0);
> >>>               tcg_gen_sub_i64(t0, t1, t2);
> >>> @@ -5862,14 +5864,39 @@ static void
> >>gen_loongson_multimedia(DisasContext *ctx, int rd, int rs, int rt)
> >>>
> >>>       case OPC_SEQU_CP2:
> >>>       case OPC_SEQ_CP2:
> >>> +        cond = TCG_COND_EQ;
> >>> +        goto do_cc_cond;
> >>> +        break;
> >>> +
> >>>       case OPC_SLTU_CP2:
> >>> +        cond = TCG_COND_LTU;
> >>> +        goto do_cc_cond;
> >>> +        break;
> >>> +
> >>>       case OPC_SLT_CP2:
> >>> +        cond = TCG_COND_LT;
> >>> +        goto do_cc_cond;
> >>> +        break;
> >>> +
> >>>       case OPC_SLEU_CP2:
> >>> +        cond = TCG_COND_LEU;
> >>> +        goto do_cc_cond;
> >>> +        break;
> >>> +
> >>>       case OPC_SLE_CP2:
> >>> -        /*
> >>> -         * ??? Document is unclear: Set FCC[CC].  Does that mean
> >the
> >>> -         * FD field is the CC field?
> >>> -         */
> >>> +        cond = TCG_COND_LE;
> >>> +    do_cc_cond:
> >>> +        {
> >>> +            int cc = (ctx->opcode >> 8) & 0x7;
> >>> +            lab = gen_new_label();
> >>> +            tcg_gen_ori_i32(fpu_fcr31, fpu_fcr31, 1 <<
> >>get_fp_bit(cc));
> >>> +            tcg_gen_brcond_i64(cond, t0, t1, lab);
> >>> +            tcg_gen_xori_i32(fpu_fcr31, fpu_fcr31, 1 <<
> >>get_fp_bit(cc));
> >>> +            gen_set_label(lab);
> >>> +        }
> >>> +        goto no_rd;
> >>> +        break;
> >>> +
> >>>       default:
> >>>           MIPS_INVAL("loongson_cp2");
> >>>           generate_exception_end(ctx, EXCP_RI);
> >>> @@ -5878,6 +5905,7 @@ static void
> >>gen_loongson_multimedia(DisasContext *ctx, int rd, int rs, int rt)
> >>>
> >>>       gen_store_fpr64(ctx, t0, rd);
> >>>
> >>> +no_rd:
> >>>       tcg_temp_free_i64(t0);
> >>>       tcg_temp_free_i64(t1);
> >>>   }
> >>>
>
> --
> Jiaxun Yang