Re: [PATCH] target/riscv: Add support for Zicond extension

[Frank Chang <frank.chang@sifive.com>]

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Reviewed-by: Frank Chang <frank.chang@sifive.com>

On Tue, Feb 21, 2023 at 5:10 PM Weiwei Li <liweiwei@iscas.ac.cn> wrote:

> The spec can be found in https://github.com/riscv/riscv-zicond.
> Two instructions are added:
>  - czero.eqz: Moves zero to a register rd, if the condition rs2 is
>    equal to zero, otherwise moves rs1 to rd.
>  - czero.nez: Moves zero to a register rd, if the condition rs2 is
>    nonzero, otherwise moves rs1 to rd.
>
> Signed-off-by: Weiwei Li <liweiwei@iscas.ac.cn>
> Signed-off-by: Junqiang Wang <wangjunqiang@iscas.ac.cn>
> ---
>  target/riscv/cpu.c                           |  2 +
>  target/riscv/cpu.h                           |  1 +
>  target/riscv/insn32.decode                   |  4 ++
>  target/riscv/insn_trans/trans_rvzicond.c.inc | 49 ++++++++++++++++++++
>  target/riscv/translate.c                     |  1 +
>  5 files changed, 57 insertions(+)
>  create mode 100644 target/riscv/insn_trans/trans_rvzicond.c.inc
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 0dd2f0c753..80b92930ae 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -74,6 +74,7 @@ struct isa_ext_data {
>  static const struct isa_ext_data isa_edata_arr[] = {
>      ISA_EXT_DATA_ENTRY(h, false, PRIV_VERSION_1_12_0, ext_h),
>      ISA_EXT_DATA_ENTRY(v, false, PRIV_VERSION_1_12_0, ext_v),
> +    ISA_EXT_DATA_ENTRY(zicond, true, PRIV_VERSION_1_12_0, ext_zicond),
>      ISA_EXT_DATA_ENTRY(zicsr, true, PRIV_VERSION_1_10_0, ext_icsr),
>      ISA_EXT_DATA_ENTRY(zifencei, true, PRIV_VERSION_1_10_0, ext_ifencei),
>      ISA_EXT_DATA_ENTRY(zihintpause, true, PRIV_VERSION_1_10_0,
> ext_zihintpause),
> @@ -1143,6 +1144,7 @@ static Property riscv_cpu_extensions[] = {
>      DEFINE_PROP_BOOL("xventanacondops", RISCVCPU,
> cfg.ext_XVentanaCondOps, false),
>
>      /* These are experimental so mark with 'x-' */
> +    DEFINE_PROP_BOOL("x-zicond", RISCVCPU, cfg.ext_zicond, false),
>      DEFINE_PROP_BOOL("x-j", RISCVCPU, cfg.ext_j, false),
>      /* ePMP 0.9.3 */
>      DEFINE_PROP_BOOL("x-epmp", RISCVCPU, cfg.epmp, false),
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index 7128438d8e..81b7c92e7a 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -447,6 +447,7 @@ struct RISCVCPUConfig {
>      bool ext_zkt;
>      bool ext_ifencei;
>      bool ext_icsr;
> +    bool ext_zicond;
>      bool ext_zihintpause;
>      bool ext_smstateen;
>      bool ext_sstc;
> diff --git a/target/riscv/insn32.decode b/target/riscv/insn32.decode
> index b7e7613ea2..fb537e922e 100644
> --- a/target/riscv/insn32.decode
> +++ b/target/riscv/insn32.decode
> @@ -890,3 +890,7 @@ sm3p1       00 01000 01001 ..... 001 ..... 0010011 @r2
>  # *** RV32 Zksed Standard Extension ***
>  sm4ed       .. 11000 ..... ..... 000 ..... 0110011 @k_aes
>  sm4ks       .. 11010 ..... ..... 000 ..... 0110011 @k_aes
> +
> +# *** RV32 Zicond Standard Extension ***
> +czero_eqz   0000111  ..... ..... 101 ..... 0110011 @r
> +czero_nez   0000111  ..... ..... 111 ..... 0110011 @r
> diff --git a/target/riscv/insn_trans/trans_rvzicond.c.inc
> b/target/riscv/insn_trans/trans_rvzicond.c.inc
> new file mode 100644
> index 0000000000..645260164e
> --- /dev/null
> +++ b/target/riscv/insn_trans/trans_rvzicond.c.inc
> @@ -0,0 +1,49 @@
> +/*
> + * RISC-V translation routines for the Zicond Standard Extension.
> + *
> + * Copyright (c) 2020-2023 PLCT Lab
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2 or later, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
> for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License
> along with
> + * this program.  If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#define REQUIRE_ZICOND(ctx) do {          \
> +    if (!ctx->cfg_ptr->ext_zicond) {      \
> +        return false;                     \
> +    }                                     \
> +} while (0)
> +
> +static bool trans_czero_eqz(DisasContext *ctx, arg_czero_eqz *a)
> +{
> +    REQUIRE_ZICOND(ctx);
> +
> +    TCGv dest = dest_gpr(ctx, a->rd);
> +    TCGv src1 = get_gpr(ctx, a->rs1, EXT_NONE);
> +    TCGv src2 = get_gpr(ctx, a->rs2, EXT_NONE);
> +
> +    tcg_gen_movcond_tl(TCG_COND_EQ, dest, src2, ctx->zero, ctx->zero,
> src1);
> +    gen_set_gpr(ctx, a->rd, dest);
> +    return true;
> +}
> +
> +static bool trans_czero_nez(DisasContext *ctx, arg_czero_nez *a)
> +{
> +    REQUIRE_ZICOND(ctx);
> +
> +    TCGv dest = dest_gpr(ctx, a->rd);
> +    TCGv src1 = get_gpr(ctx, a->rs1, EXT_NONE);
> +    TCGv src2 = get_gpr(ctx, a->rs2, EXT_NONE);
> +
> +    tcg_gen_movcond_tl(TCG_COND_NE, dest, src2, ctx->zero, ctx->zero,
> src1);
> +    gen_set_gpr(ctx, a->rd, dest);
> +    return true;
> +}
> diff --git a/target/riscv/translate.c b/target/riscv/translate.c
> index 772f9d7973..6e65c6afca 100644
> --- a/target/riscv/translate.c
> +++ b/target/riscv/translate.c
> @@ -1103,6 +1103,7 @@ static uint32_t opcode_at(DisasContextBase *dcbase,
> target_ulong pc)
>  #include "insn_trans/trans_rvh.c.inc"
>  #include "insn_trans/trans_rvv.c.inc"
>  #include "insn_trans/trans_rvb.c.inc"
> +#include "insn_trans/trans_rvzicond.c.inc"
>  #include "insn_trans/trans_rvzawrs.c.inc"
>  #include "insn_trans/trans_rvzfh.c.inc"
>  #include "insn_trans/trans_rvk.c.inc"
> --
> 2.25.1
>
>
>

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