Re: [RFC PATCH v5 02/14] target/riscv: rvk: add support for zbkb extension

[Alistair Francis]

On Wed, Jan 19, 2022 at 9:52 PM Weiwei Li <liweiwei@iscas.ac.cn> wrote:
>
>  - reuse partial instructions of zbb extension, update extension check for 
> them
>  - add brev8, pack, packh, packw, unzip, zip instructions
>
> Signed-off-by: Weiwei Li <liweiwei@iscas.ac.cn>
> Signed-off-by: Junqiang Wang <wangjunqiang@iscas.ac.cn>

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

Alistair

> ---
>  target/riscv/bitmanip_helper.c          |  53 +++++++++++
>  target/riscv/helper.h                   |   3 +
>  target/riscv/insn32.decode              |  45 ++++++----
>  target/riscv/insn_trans/trans_rvb.c.inc | 115 +++++++++++++++++++++---
>  target/riscv/translate.c                |   7 ++
>  5 files changed, 195 insertions(+), 28 deletions(-)
>
> diff --git a/target/riscv/bitmanip_helper.c b/target/riscv/bitmanip_helper.c
> index f1b5e5549f..e003e8b25b 100644
> --- a/target/riscv/bitmanip_helper.c
> +++ b/target/riscv/bitmanip_helper.c
> @@ -49,3 +49,56 @@ target_ulong HELPER(clmulr)(target_ulong rs1, target_ulong 
> rs2)
>
>      return result;
>  }
> +
> +static inline target_ulong do_swap(target_ulong x, uint64_t mask, int shift)
> +{
> +    return ((x & mask) << shift) | ((x & ~mask) >> shift);
> +}
> +
> +target_ulong HELPER(brev8)(target_ulong rs1)
> +{
> +    target_ulong x = rs1;
> +
> +    x = do_swap(x, 0x5555555555555555ull, 1);
> +    x = do_swap(x, 0x3333333333333333ull, 2);
> +    x = do_swap(x, 0x0f0f0f0f0f0f0f0full, 4);
> +    return x;
> +}
> +
> +static const uint64_t shuf_masks[] = {
> +    dup_const(MO_8, 0x44),
> +    dup_const(MO_8, 0x30),
> +    dup_const(MO_16, 0x0f00),
> +    dup_const(MO_32, 0xff0000)
> +};
> +
> +static inline target_ulong do_shuf_stage(target_ulong src, uint64_t maskL,
> +                                         uint64_t maskR, int shift)
> +{
> +    target_ulong x = src & ~(maskL | maskR);
> +
> +    x |= ((src << shift) & maskL) | ((src >> shift) & maskR);
> +    return x;
> +}
> +
> +target_ulong HELPER(unzip)(target_ulong rs1)
> +{
> +    target_ulong x = rs1;
> +
> +    x = do_shuf_stage(x, shuf_masks[0], shuf_masks[0] >> 1, 1);
> +    x = do_shuf_stage(x, shuf_masks[1], shuf_masks[1] >> 2, 2);
> +    x = do_shuf_stage(x, shuf_masks[2], shuf_masks[2] >> 4, 4);
> +    x = do_shuf_stage(x, shuf_masks[3], shuf_masks[3] >> 8, 8);
> +    return x;
> +}
> +
> +target_ulong HELPER(zip)(target_ulong rs1)
> +{
> +    target_ulong x = rs1;
> +
> +    x = do_shuf_stage(x, shuf_masks[3], shuf_masks[3] >> 8, 8);
> +    x = do_shuf_stage(x, shuf_masks[2], shuf_masks[2] >> 4, 4);
> +    x = do_shuf_stage(x, shuf_masks[1], shuf_masks[1] >> 2, 2);
> +    x = do_shuf_stage(x, shuf_masks[0], shuf_masks[0] >> 1, 1);
> +    return x;
> +}
> diff --git a/target/riscv/helper.h b/target/riscv/helper.h
> index 6cf6d6ce98..547dfa86bc 100644
> --- a/target/riscv/helper.h
> +++ b/target/riscv/helper.h
> @@ -66,6 +66,9 @@ DEF_HELPER_FLAGS_1(fclass_d, TCG_CALL_NO_RWG_SE, tl, i64)
>  /* Bitmanip */
>  DEF_HELPER_FLAGS_2(clmul, TCG_CALL_NO_RWG_SE, tl, tl, tl)
>  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)
>
>  /* 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 5bbedc254c..bf080cb489 100644
> --- a/target/riscv/insn32.decode
> +++ b/target/riscv/insn32.decode
> @@ -717,8 +717,22 @@ sh2add_uw  0010000 .......... 100 ..... 0111011 @r
>  sh3add_uw  0010000 .......... 110 ..... 0111011 @r
>  slli_uw    00001 ............ 001 ..... 0011011 @sh
>
> -# *** RV32 Zbb Standard Extension ***
> +# *** RV32 Zbb/Zbkb Standard Extension ***
>  andn       0100000 .......... 111 ..... 0110011 @r
> +rol        0110000 .......... 001 ..... 0110011 @r
> +ror        0110000 .......... 101 ..... 0110011 @r
> +rori       01100 ............ 101 ..... 0010011 @sh
> +# The encoding for rev8 differs between RV32 and RV64.
> +# rev8_32 denotes the RV32 variant.
> +rev8_32    011010 011000 ..... 101 ..... 0010011 @r2
> +# The encoding for zext.h differs between RV32 and RV64.
> +# zext_h_32 denotes the RV32 variant.
> +{
> +  zext_h_32  0000100 00000 ..... 100 ..... 0110011 @r2
> +  pack       0000100 ..... ..... 100 ..... 0110011 @r
> +}
> +xnor       0100000 .......... 100 ..... 0110011 @r
> +# *** RV32 extra Zbb Standard Extension ***
>  clz        011000 000000 ..... 001 ..... 0010011 @r2
>  cpop       011000 000010 ..... 001 ..... 0010011 @r2
>  ctz        011000 000001 ..... 001 ..... 0010011 @r2
> @@ -728,23 +742,15 @@ min        0000101 .......... 100 ..... 0110011 @r
>  minu       0000101 .......... 101 ..... 0110011 @r
>  orc_b      001010 000111 ..... 101 ..... 0010011 @r2
>  orn        0100000 .......... 110 ..... 0110011 @r
> -# The encoding for rev8 differs between RV32 and RV64.
> -# rev8_32 denotes the RV32 variant.
> -rev8_32    011010 011000 ..... 101 ..... 0010011 @r2
> -rol        0110000 .......... 001 ..... 0110011 @r
> -ror        0110000 .......... 101 ..... 0110011 @r
> -rori       01100 ............ 101 ..... 0010011 @sh
>  sext_b     011000 000100 ..... 001 ..... 0010011 @r2
>  sext_h     011000 000101 ..... 001 ..... 0010011 @r2
> -xnor       0100000 .......... 100 ..... 0110011 @r
> -# The encoding for zext.h differs between RV32 and RV64.
> -# zext_h_32 denotes the RV32 variant.
> -zext_h_32  0000100 00000 ..... 100 ..... 0110011 @r2
> +# *** RV32 extra Zbkb Standard Extension ***
> +brev8      0110100 00111 ..... 101 ..... 0010011 @r2  #grevi
> +packh      0000100  .......... 111 ..... 0110011 @r
> +unzip      0000100 01111 ..... 101 ..... 0010011 @r2  #unshfl
> +zip        0000100 01111 ..... 001 ..... 0010011 @r2  #shfl
>
> -# *** RV64 Zbb Standard Extension (in addition to RV32 Zbb) ***
> -clzw       0110000 00000 ..... 001 ..... 0011011 @r2
> -ctzw       0110000 00001 ..... 001 ..... 0011011 @r2
> -cpopw      0110000 00010 ..... 001 ..... 0011011 @r2
> +# *** RV64 Zbb/Zbkb Standard Extension (in addition to RV32 Zbb/Zbkb) ***
>  # The encoding for rev8 differs between RV32 and RV64.
>  # When executing on RV64, the encoding used in RV32 is an illegal
>  # instruction, so we use different handler functions to differentiate.
> @@ -755,7 +761,14 @@ rorw       0110000 .......... 101 ..... 0111011 @r
>  # The encoding for zext.h differs between RV32 and RV64.
>  # When executing on RV64, the encoding used in RV32 is an illegal
>  # instruction, so we use different handler functions to differentiate.
> -zext_h_64  0000100 00000 ..... 100 ..... 0111011 @r2
> +{
> +  zext_h_64  0000100 00000 ..... 100 ..... 0111011 @r2
> +  packw      0000100 ..... ..... 100 ..... 0111011 @r
> +}
> +# *** RV64 extra Zbb Standard Extension (in addition to RV32 Zbb) ***
> +clzw       0110000 00000 ..... 001 ..... 0011011 @r2
> +ctzw       0110000 00001 ..... 001 ..... 0011011 @r2
> +cpopw      0110000 00010 ..... 001 ..... 0011011 @r2
>
>  # *** RV32 Zbc Standard Extension ***
>  clmul      0000101 .......... 001 ..... 0110011 @r
> diff --git a/target/riscv/insn_trans/trans_rvb.c.inc 
> b/target/riscv/insn_trans/trans_rvb.c.inc
> index 810431a1d6..7590c0538e 100644
> --- a/target/riscv/insn_trans/trans_rvb.c.inc
> +++ b/target/riscv/insn_trans/trans_rvb.c.inc
> @@ -1,5 +1,5 @@
>  /*
> - * RISC-V translation routines for the Zb[abcs] Standard Extension.
> + * RISC-V translation routines for the Zb[abcs] and Zbk[bcx] Standard 
> Extension.
>   *
>   * Copyright (c) 2020 Kito Cheng, kito.cheng@sifive.com
>   * Copyright (c) 2020 Frank Chang, frank.chang@sifive.com
> @@ -42,6 +42,12 @@
>      }                                            \
>  } while (0)
>
> +#define REQUIRE_ZBKB(ctx) do {                   \
> +    if (!RISCV_CPU(ctx->cs)->cfg.ext_zbkb) {     \
> +        return false;                            \
> +    }                                            \
> +} while (0)
> +
>  static void gen_clz(TCGv ret, TCGv arg1)
>  {
>      tcg_gen_clzi_tl(ret, arg1, TARGET_LONG_BITS);
> @@ -85,19 +91,19 @@ static bool trans_cpop(DisasContext *ctx, arg_cpop *a)
>
>  static bool trans_andn(DisasContext *ctx, arg_andn *a)
>  {
> -    REQUIRE_ZBB(ctx);
> +    REQUIRE_EITHER_EXT(ctx, zbb, zbkb);
>      return gen_logic(ctx, a, tcg_gen_andc_tl);
>  }
>
>  static bool trans_orn(DisasContext *ctx, arg_orn *a)
>  {
> -    REQUIRE_ZBB(ctx);
> +    REQUIRE_EITHER_EXT(ctx, zbb, zbkb);
>      return gen_logic(ctx, a, tcg_gen_orc_tl);
>  }
>
>  static bool trans_xnor(DisasContext *ctx, arg_xnor *a)
>  {
> -    REQUIRE_ZBB(ctx);
> +    REQUIRE_EITHER_EXT(ctx, zbb, zbkb);
>      return gen_logic(ctx, a, tcg_gen_eqv_tl);
>  }
>
> @@ -247,7 +253,7 @@ static void gen_rorw(TCGv ret, TCGv arg1, TCGv arg2)
>
>  static bool trans_ror(DisasContext *ctx, arg_ror *a)
>  {
> -    REQUIRE_ZBB(ctx);
> +    REQUIRE_EITHER_EXT(ctx, zbb, zbkb);
>      return gen_shift_per_ol(ctx, a, EXT_NONE, tcg_gen_rotr_tl, gen_rorw, 
> NULL);
>  }
>
> @@ -264,7 +270,7 @@ static void gen_roriw(TCGv ret, TCGv arg1, target_long 
> shamt)
>
>  static bool trans_rori(DisasContext *ctx, arg_rori *a)
>  {
> -    REQUIRE_ZBB(ctx);
> +    REQUIRE_EITHER_EXT(ctx, zbb, zbkb);
>      return gen_shift_imm_fn_per_ol(ctx, a, EXT_NONE,
>                                     tcg_gen_rotri_tl, gen_roriw, NULL);
>  }
> @@ -289,7 +295,7 @@ static void gen_rolw(TCGv ret, TCGv arg1, TCGv arg2)
>
>  static bool trans_rol(DisasContext *ctx, arg_rol *a)
>  {
> -    REQUIRE_ZBB(ctx);
> +    REQUIRE_EITHER_EXT(ctx, zbb, zbkb);
>      return gen_shift_per_ol(ctx, a, EXT_NONE, tcg_gen_rotl_tl, gen_rolw, 
> NULL);
>  }
>
> @@ -301,14 +307,14 @@ static void gen_rev8_32(TCGv ret, TCGv src1)
>  static bool trans_rev8_32(DisasContext *ctx, arg_rev8_32 *a)
>  {
>      REQUIRE_32BIT(ctx);
> -    REQUIRE_ZBB(ctx);
> +    REQUIRE_EITHER_EXT(ctx, zbb, zbkb);
>      return gen_unary(ctx, a, EXT_NONE, gen_rev8_32);
>  }
>
>  static bool trans_rev8_64(DisasContext *ctx, arg_rev8_64 *a)
>  {
>      REQUIRE_64BIT(ctx);
> -    REQUIRE_ZBB(ctx);
> +    REQUIRE_EITHER_EXT(ctx, zbb, zbkb);
>      return gen_unary(ctx, a, EXT_NONE, tcg_gen_bswap_tl);
>  }
>
> @@ -403,7 +409,7 @@ static bool trans_cpopw(DisasContext *ctx, arg_cpopw *a)
>  static bool trans_rorw(DisasContext *ctx, arg_rorw *a)
>  {
>      REQUIRE_64BIT(ctx);
> -    REQUIRE_ZBB(ctx);
> +    REQUIRE_EITHER_EXT(ctx, zbb, zbkb);
>      ctx->ol = MXL_RV32;
>      return gen_shift(ctx, a, EXT_NONE, gen_rorw, NULL);
>  }
> @@ -411,7 +417,7 @@ static bool trans_rorw(DisasContext *ctx, arg_rorw *a)
>  static bool trans_roriw(DisasContext *ctx, arg_roriw *a)
>  {
>      REQUIRE_64BIT(ctx);
> -    REQUIRE_ZBB(ctx);
> +    REQUIRE_EITHER_EXT(ctx, zbb, zbkb);
>      ctx->ol = MXL_RV32;
>      return gen_shift_imm_fn(ctx, a, EXT_NONE, gen_roriw, NULL);
>  }
> @@ -419,7 +425,7 @@ static bool trans_roriw(DisasContext *ctx, arg_roriw *a)
>  static bool trans_rolw(DisasContext *ctx, arg_rolw *a)
>  {
>      REQUIRE_64BIT(ctx);
> -    REQUIRE_ZBB(ctx);
> +    REQUIRE_EITHER_EXT(ctx, zbb, zbkb);
>      ctx->ol = MXL_RV32;
>      return gen_shift(ctx, a, EXT_NONE, gen_rolw, NULL);
>  }
> @@ -504,3 +510,88 @@ static bool trans_clmulr(DisasContext *ctx, arg_clmulh 
> *a)
>      REQUIRE_ZBC(ctx);
>      return gen_arith(ctx, a, EXT_NONE, gen_helper_clmulr, NULL);
>  }
> +
> +static void gen_pack(TCGv ret, TCGv src1, TCGv src2)
> +{
> +    tcg_gen_deposit_tl(ret, src1, src2,
> +                       TARGET_LONG_BITS / 2,
> +                       TARGET_LONG_BITS / 2);
> +}
> +
> +static void gen_packh(TCGv ret, TCGv src1, TCGv src2)
> +{
> +    TCGv t = tcg_temp_new();
> +
> +    tcg_gen_ext8u_tl(t, src2);
> +    tcg_gen_deposit_tl(ret, src1, t, 8, TARGET_LONG_BITS - 8);
> +    tcg_temp_free(t);
> +}
> +
> +static void gen_packw(TCGv ret, TCGv src1, TCGv src2)
> +{
> +    TCGv t = tcg_temp_new();
> +
> +    tcg_gen_ext16s_tl(t, src2);
> +    tcg_gen_deposit_tl(ret, src1, t, 16, 48);
> +    tcg_temp_free(t);
> +}
> +
> +static bool trans_brev8(DisasContext *ctx, arg_brev8 *a)
> +{
> +    REQUIRE_ZBKB(ctx);
> +
> +    TCGv dest = dest_gpr(ctx, a->rd);
> +    TCGv src1 = get_gpr(ctx, a->rs1, EXT_NONE);
> +
> +    gen_helper_brev8(dest, src1);
> +    gen_set_gpr(ctx, a->rd, dest);
> +
> +    return true;
> +}
> +
> +static bool trans_pack(DisasContext *ctx, arg_pack *a)
> +{
> +    REQUIRE_ZBKB(ctx);
> +    return gen_arith(ctx, a, EXT_NONE, gen_pack, NULL);
> +}
> +
> +static bool trans_packh(DisasContext *ctx, arg_packh *a)
> +{
> +    REQUIRE_ZBKB(ctx);
> +    return gen_arith(ctx, a, EXT_NONE, gen_packh, NULL);
> +}
> +
> +static bool trans_packw(DisasContext *ctx, arg_packw *a)
> +{
> +    REQUIRE_64BIT(ctx);
> +    REQUIRE_ZBKB(ctx);
> +    return gen_arith(ctx, a, EXT_NONE, gen_packw, NULL);
> +}
> +
> +static bool trans_unzip(DisasContext *ctx, arg_unzip *a)
> +{
> +    REQUIRE_ZBKB(ctx);
> +    REQUIRE_32BIT(ctx);
> +
> +    TCGv dest = dest_gpr(ctx, a->rd);
> +    TCGv src1 = get_gpr(ctx, a->rs1, EXT_NONE);
> +
> +    gen_helper_unzip(dest, src1);
> +    gen_set_gpr(ctx, a->rd, dest);
> +
> +    return true;
> +}
> +
> +static bool trans_zip(DisasContext *ctx, arg_zip *a)
> +{
> +    REQUIRE_ZBKB(ctx);
> +    REQUIRE_32BIT(ctx);
> +
> +    TCGv dest = dest_gpr(ctx, a->rd);
> +    TCGv src1 = get_gpr(ctx, a->rs1, EXT_NONE);
> +
> +    gen_helper_zip(dest, src1);
> +    gen_set_gpr(ctx, a->rd, dest);
> +
> +    return true;
> +}
> diff --git a/target/riscv/translate.c b/target/riscv/translate.c
> index 615048ec87..f3e37ddcd2 100644
> --- a/target/riscv/translate.c
> +++ b/target/riscv/translate.c
> @@ -525,6 +525,13 @@ EX_SH(12)
>      }                                  \
>  } while (0)
>
> +#define REQUIRE_EITHER_EXT(ctx, A, B) do {       \
> +    if (!RISCV_CPU(ctx->cs)->cfg.ext_##A &&      \
> +        !RISCV_CPU(ctx->cs)->cfg.ext_##B) {      \
> +        return false;                            \
> +    }                                            \
> +} while (0)
> +
>  static int ex_rvc_register(DisasContext *ctx, int reg)
>  {
>      return 8 + reg;
> --
> 2.17.1
>
>