Re: [PATCH v8 04/14] target/riscv: rvk: add support for zbkx extension

[Alistair Francis]

On Tue, Mar 1, 2022 at 10:06 PM Weiwei Li <liweiwei@iscas.ac.cn> wrote:
>
>  - add xperm4 and xperm8 instructions
>
> Signed-off-by: Weiwei Li <liweiwei@iscas.ac.cn>
> Signed-off-by: Junqiang Wang <wangjunqiang@iscas.ac.cn>
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

Acked-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
>  target/riscv/bitmanip_helper.c          | 27 +++++++++++++++++++++++++
>  target/riscv/helper.h                   |  2 ++
>  target/riscv/insn32.decode              |  4 ++++
>  target/riscv/insn_trans/trans_rvb.c.inc | 18 +++++++++++++++++
>  4 files changed, 51 insertions(+)
>
> diff --git a/target/riscv/bitmanip_helper.c b/target/riscv/bitmanip_helper.c
> index e003e8b25b..b99c4a39a1 100644
> --- a/target/riscv/bitmanip_helper.c
> +++ b/target/riscv/bitmanip_helper.c
> @@ -102,3 +102,30 @@ target_ulong HELPER(zip)(target_ulong rs1)
>      x = do_shuf_stage(x, shuf_masks[0], shuf_masks[0] >> 1, 1);
>      return x;
>  }
> +
> +static inline target_ulong do_xperm(target_ulong rs1, target_ulong rs2,
> +                                    uint32_t sz_log2)
> +{
> +    target_ulong r = 0;
> +    target_ulong sz = 1LL << sz_log2;
> +    target_ulong mask = (1LL << sz) - 1;
> +    target_ulong pos;
> +
> +    for (int i = 0; i < TARGET_LONG_BITS; i += sz) {
> +        pos = ((rs2 >> i) & mask) << sz_log2;
> +        if (pos < sizeof(target_ulong) * 8) {
> +            r |= ((rs1 >> pos) & mask) << i;
> +        }
> +    }
> +    return r;
> +}
> +
> +target_ulong HELPER(xperm4)(target_ulong rs1, target_ulong rs2)
> +{
> +    return do_xperm(rs1, rs2, 2);
> +}
> +
> +target_ulong HELPER(xperm8)(target_ulong rs1, target_ulong rs2)
> +{
> +    return do_xperm(rs1, rs2, 3);
> +}
> diff --git a/target/riscv/helper.h b/target/riscv/helper.h
> index 7331d32dbf..a1d28b257f 100644
> --- a/target/riscv/helper.h
> +++ b/target/riscv/helper.h
> @@ -69,6 +69,8 @@ DEF_HELPER_FLAGS_2(clmulr, TCG_CALL_NO_RWG_SE, tl, tl, tl)
>  DEF_HELPER_FLAGS_1(brev8, TCG_CALL_NO_RWG_SE, tl, tl)
>  DEF_HELPER_FLAGS_1(unzip, TCG_CALL_NO_RWG_SE, tl, tl)
>  DEF_HELPER_FLAGS_1(zip, TCG_CALL_NO_RWG_SE, tl, tl)
> +DEF_HELPER_FLAGS_2(xperm4, TCG_CALL_NO_RWG_SE, tl, tl, tl)
> +DEF_HELPER_FLAGS_2(xperm8, TCG_CALL_NO_RWG_SE, tl, tl, tl)
>
>  /* Floating Point - Half Precision */
>  DEF_HELPER_FLAGS_3(fadd_h, TCG_CALL_NO_RWG, i64, env, i64, i64)
> diff --git a/target/riscv/insn32.decode b/target/riscv/insn32.decode
> index 3a49acab37..75ffac9c81 100644
> --- a/target/riscv/insn32.decode
> +++ b/target/riscv/insn32.decode
> @@ -776,6 +776,10 @@ clmulh     0000101 .......... 011 ..... 0110011 @r
>  # *** RV32 extra Zbc Standard Extension ***
>  clmulr     0000101 .......... 010 ..... 0110011 @r
>
> +# *** RV32 Zbkx Standard Extension ***
> +xperm4     0010100 .......... 010 ..... 0110011 @r
> +xperm8     0010100 .......... 100 ..... 0110011 @r
> +
>  # *** RV32 Zbs Standard Extension ***
>  bclr       0100100 .......... 001 ..... 0110011 @r
>  bclri      01001. ........... 001 ..... 0010011 @sh
> diff --git a/target/riscv/insn_trans/trans_rvb.c.inc 
> b/target/riscv/insn_trans/trans_rvb.c.inc
> index 1980bfe971..54927ba763 100644
> --- a/target/riscv/insn_trans/trans_rvb.c.inc
> +++ b/target/riscv/insn_trans/trans_rvb.c.inc
> @@ -48,6 +48,12 @@
>      }                                            \
>  } while (0)
>
> +#define REQUIRE_ZBKX(ctx) do {                   \
> +    if (!ctx->cfg_ptr->ext_zbkx) {               \
> +        return false;                            \
> +    }                                            \
> +} while (0)
> +
>  static void gen_clz(TCGv ret, TCGv arg1)
>  {
>      tcg_gen_clzi_tl(ret, arg1, TARGET_LONG_BITS);
> @@ -574,3 +580,15 @@ static bool trans_zip(DisasContext *ctx, arg_zip *a)
>      REQUIRE_ZBKB(ctx);
>      return gen_unary(ctx, a, EXT_NONE, gen_helper_zip);
>  }
> +
> +static bool trans_xperm4(DisasContext *ctx, arg_xperm4 *a)
> +{
> +    REQUIRE_ZBKX(ctx);
> +    return gen_arith(ctx, a, EXT_NONE, gen_helper_xperm4, NULL);
> +}
> +
> +static bool trans_xperm8(DisasContext *ctx, arg_xperm8 *a)
> +{
> +    REQUIRE_ZBKX(ctx);
> +    return gen_arith(ctx, a, EXT_NONE, gen_helper_xperm8, NULL);
> +}
> --
> 2.17.1
>
>