Re: [PATCH 28/67] target/arm: Convert BFCVT to decodetree

[Richard Henderson]

On 12/3/24 08:05, Peter Maydell wrote:
> On Sun, 1 Dec 2024 at 15:11, Richard Henderson
> <richard.henderson@linaro.org> wrote:
> > Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> > ---
> >   target/arm/tcg/translate-a64.c | 24 ++++++------------------
> >   target/arm/tcg/a64.decode      |  3 +++
> >   2 files changed, 9 insertions(+), 18 deletions(-)
> >
> > @@ -8661,21 +8664,6 @@ static void disas_fp_1src(DisasContext *s, uint32_t insn)
> >           break;
> >
> >       case 0x6:
> > -        switch (type) {
> > -        case 1: /* BFCVT */
>
> Here we decode BFCVT when the 'ftype' field (bits [23:22]) is 0b01...
>
> > -            if (!dc_isar_feature(aa64_bf16, s)) {
> > -                goto do_unallocated;
> > -            }
> > -            if (!fp_access_check(s)) {
> > -                return;
> > -            }
> > -            handle_fp_1src_single(s, opcode, rd, rn);
> > -            break;
> > -        default:
> > -            goto do_unallocated;
> > -        }
> > -        break;
> > -
> >       default:
> >       do_unallocated:
> >           unallocated_encoding(s);
> > diff --git a/target/arm/tcg/a64.decode b/target/arm/tcg/a64.decode
> > index fbfdf96eb3..476989c1b4 100644
> > --- a/target/arm/tcg/a64.decode
> > +++ b/target/arm/tcg/a64.decode
> > @@ -45,6 +45,7 @@
> >   &qrrrr_e        q rd rn rm ra esz
> >
> >   @rr_h           ........ ... ..... ...... rn:5 rd:5     &rr_e esz=1
> > +@rr_s           ........ ... ..... ...... rn:5 rd:5     &rr_e esz=2
> >   @rr_d           ........ ... ..... ...... rn:5 rd:5     &rr_e esz=3
> >   @rr_sd          ........ ... ..... ...... rn:5 rd:5     &rr_e esz=%esz_sd
> >   @rr_hsd         ........ ... ..... ...... rn:5 rd:5     &rr_e esz=%esz_hsd
> > @@ -1337,6 +1338,8 @@ FRINTA_s        00011110 .. 1 001100 10000 ..... .....    
> >   @rr_hsd
> >   FRINTX_s        00011110 .. 1 001110 10000 ..... .....      @rr_hsd
> >   FRINTI_s        00011110 .. 1 001111 10000 ..... .....      @rr_hsd
> >
> > +BFCVT_s         00011110 10 1 000110 10000 ..... .....      @rr_s
>
> ...but this decode pattern has them as 0b10.
>
>
> --- a/target/arm/tcg/a64.decode
> +++ b/target/arm/tcg/a64.decode
> @@ -1338,7 +1338,7 @@ FRINTA_s        00011110 .. 1 001100 10000 .....
> .....      @rr_hsd
>   FRINTX_s        00011110 .. 1 001110 10000 ..... .....      @rr_hsd
>   FRINTI_s        00011110 .. 1 001111 10000 ..... .....      @rr_hsd
>
> -BFCVT_s         00011110 10 1 000110 10000 ..... .....      @rr_s
> +BFCVT_s         00011110 01 1 000110 10000 ..... .....      @rr_s
>
>   # Floating-point Immediate
>
> should fix this.

Yep, thanks.  Fixed.


r~