Re: [PATCH v2 10/15] RISC-V: Adding T-Head FMemIdx extension

[Alistair Francis]

On Sat, Dec 24, 2022 at 4:09 AM Christoph Muellner
<christoph.muellner@vrull.eu> wrote:
>
> From: Christoph Müllner <christoph.muellner@vrull.eu>
>
> This patch adds support for the T-Head FMemIdx instructions.
> The patch uses the T-Head specific decoder and translation.
>
> Changes in v2:
> - Add ISA_EXT_DATA_ENTRY()
> - Use single decoder for XThead extensions
> - Use get_th_address_indexed for address calculations
>
> Co-developed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
> Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>

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

Alistair

> ---
>  target/riscv/cpu.c                         |   2 +
>  target/riscv/cpu.h                         |   1 +
>  target/riscv/insn_trans/trans_xthead.c.inc | 108 +++++++++++++++++++++
>  target/riscv/translate.c                   |   3 +-
>  target/riscv/xthead.decode                 |  10 ++
>  5 files changed, 123 insertions(+), 1 deletion(-)
>
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index 1fbfb7ccc3..9c31a50e90 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -113,6 +113,7 @@ static const struct isa_ext_data isa_edata_arr[] = {
>      ISA_EXT_DATA_ENTRY(xtheadbs, true, PRIV_VERSION_1_11_0, ext_xtheadbs),
>      ISA_EXT_DATA_ENTRY(xtheadcmo, true, PRIV_VERSION_1_11_0, ext_xtheadcmo),
>      ISA_EXT_DATA_ENTRY(xtheadcondmov, true, PRIV_VERSION_1_11_0, 
> ext_xtheadcondmov),
> +    ISA_EXT_DATA_ENTRY(xtheadfmemidx, true, PRIV_VERSION_1_11_0, 
> ext_xtheadfmemidx),
>      ISA_EXT_DATA_ENTRY(xtheadmac, true, PRIV_VERSION_1_11_0, ext_xtheadmac),
>      ISA_EXT_DATA_ENTRY(xtheadmemidx, true, PRIV_VERSION_1_11_0, 
> ext_xtheadmemidx),
>      ISA_EXT_DATA_ENTRY(xtheadmempair, true, PRIV_VERSION_1_11_0, 
> ext_xtheadmempair),
> @@ -1074,6 +1075,7 @@ static Property riscv_cpu_extensions[] = {
>      DEFINE_PROP_BOOL("xtheadbs", RISCVCPU, cfg.ext_xtheadbs, false),
>      DEFINE_PROP_BOOL("xtheadcmo", RISCVCPU, cfg.ext_xtheadcmo, false),
>      DEFINE_PROP_BOOL("xtheadcondmov", RISCVCPU, cfg.ext_xtheadcondmov, 
> false),
> +    DEFINE_PROP_BOOL("xtheadfmemidx", RISCVCPU, cfg.ext_xtheadfmemidx, 
> false),
>      DEFINE_PROP_BOOL("xtheadmac", RISCVCPU, cfg.ext_xtheadmac, false),
>      DEFINE_PROP_BOOL("xtheadmemidx", RISCVCPU, cfg.ext_xtheadmemidx, false),
>      DEFINE_PROP_BOOL("xtheadmempair", RISCVCPU, cfg.ext_xtheadmempair, 
> false),
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index 965dc46591..c97c1c0af0 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -470,6 +470,7 @@ struct RISCVCPUConfig {
>      bool ext_xtheadbs;
>      bool ext_xtheadcmo;
>      bool ext_xtheadcondmov;
> +    bool ext_xtheadfmemidx;
>      bool ext_xtheadmac;
>      bool ext_xtheadmemidx;
>      bool ext_xtheadmempair;
> diff --git a/target/riscv/insn_trans/trans_xthead.c.inc 
> b/target/riscv/insn_trans/trans_xthead.c.inc
> index 02b82ac327..dc1a11070e 100644
> --- a/target/riscv/insn_trans/trans_xthead.c.inc
> +++ b/target/riscv/insn_trans/trans_xthead.c.inc
> @@ -46,6 +46,12 @@
>      }                                            \
>  } while (0)
>
> +#define REQUIRE_XTHEADFMEMIDX(ctx) do {          \
> +    if (!ctx->cfg_ptr->ext_xtheadfmemidx) {      \
> +        return false;                            \
> +    }                                            \
> +} while (0)
> +
>  #define REQUIRE_XTHEADMAC(ctx) do {              \
>      if (!ctx->cfg_ptr->ext_xtheadmac) {          \
>          return false;                            \
> @@ -349,6 +355,108 @@ static bool trans_th_mvnez(DisasContext *ctx, 
> arg_th_mveqz *a)
>      return gen_th_condmove(ctx, a, TCG_COND_NE);
>  }
>
> +/* XTheadFMem */
> +
> +/*
> + * Load 64-bit float from indexed address.
> + * If !zext_offs, then address is rs1 + (rs2 << imm2).
> + * If  zext_offs, then address is rs1 + (zext(rs2[31:0]) << imm2).
> + */
> +static bool gen_fload_idx(DisasContext *ctx, arg_th_memidx *a, MemOp memop,
> +                          bool zext_offs)
> +{
> +    TCGv_i64 rd = cpu_fpr[a->rd];
> +    TCGv addr = get_th_address_indexed(ctx, a->rs1, a->rs2, a->imm2, 
> zext_offs);
> +
> +    tcg_gen_qemu_ld_i64(rd, addr, ctx->mem_idx, memop);
> +    if ((memop & MO_SIZE) == MO_32) {
> +        gen_nanbox_s(rd, rd);
> +    }
> +
> +    mark_fs_dirty(ctx);
> +    return true;
> +}
> +
> +/*
> + * Store 64-bit float to indexed address.
> + * If !zext_offs, then address is rs1 + (rs2 << imm2).
> + * If  zext_offs, then address is rs1 + (zext(rs2[31:0]) << imm2).
> + */
> +static bool gen_fstore_idx(DisasContext *ctx, arg_th_memidx *a, MemOp memop,
> +                           bool zext_offs)
> +{
> +    TCGv_i64 rd = cpu_fpr[a->rd];
> +    TCGv addr = get_th_address_indexed(ctx, a->rs1, a->rs2, a->imm2, 
> zext_offs);
> +
> +    tcg_gen_qemu_st_i64(rd, addr, ctx->mem_idx, memop);
> +
> +    return true;
> +}
> +
> +static bool trans_th_flrd(DisasContext *ctx, arg_th_memidx *a)
> +{
> +    REQUIRE_XTHEADFMEMIDX(ctx);
> +    REQUIRE_FPU;
> +    REQUIRE_EXT(ctx, RVD);
> +    return gen_fload_idx(ctx, a, MO_TEUQ, false);
> +}
> +
> +static bool trans_th_flrw(DisasContext *ctx, arg_th_memidx *a)
> +{
> +    REQUIRE_XTHEADFMEMIDX(ctx);
> +    REQUIRE_FPU;
> +    REQUIRE_EXT(ctx, RVF);
> +    return gen_fload_idx(ctx, a, MO_TEUL, false);
> +}
> +
> +static bool trans_th_flurd(DisasContext *ctx, arg_th_memidx *a)
> +{
> +    REQUIRE_XTHEADFMEMIDX(ctx);
> +    REQUIRE_FPU;
> +    REQUIRE_EXT(ctx, RVD);
> +    return gen_fload_idx(ctx, a, MO_TEUQ, true);
> +}
> +
> +static bool trans_th_flurw(DisasContext *ctx, arg_th_memidx *a)
> +{
> +    REQUIRE_XTHEADFMEMIDX(ctx);
> +    REQUIRE_FPU;
> +    REQUIRE_EXT(ctx, RVF);
> +    return gen_fload_idx(ctx, a, MO_TEUL, true);
> +}
> +
> +static bool trans_th_fsrd(DisasContext *ctx, arg_th_memidx *a)
> +{
> +    REQUIRE_XTHEADFMEMIDX(ctx);
> +    REQUIRE_FPU;
> +    REQUIRE_EXT(ctx, RVD);
> +    return gen_fstore_idx(ctx, a, MO_TEUQ, false);
> +}
> +
> +static bool trans_th_fsrw(DisasContext *ctx, arg_th_memidx *a)
> +{
> +    REQUIRE_XTHEADFMEMIDX(ctx);
> +    REQUIRE_FPU;
> +    REQUIRE_EXT(ctx, RVF);
> +    return gen_fstore_idx(ctx, a, MO_TEUL, false);
> +}
> +
> +static bool trans_th_fsurd(DisasContext *ctx, arg_th_memidx *a)
> +{
> +    REQUIRE_XTHEADFMEMIDX(ctx);
> +    REQUIRE_FPU;
> +    REQUIRE_EXT(ctx, RVD);
> +    return gen_fstore_idx(ctx, a, MO_TEUQ, true);
> +}
> +
> +static bool trans_th_fsurw(DisasContext *ctx, arg_th_memidx *a)
> +{
> +    REQUIRE_XTHEADFMEMIDX(ctx);
> +    REQUIRE_FPU;
> +    REQUIRE_EXT(ctx, RVF);
> +    return gen_fstore_idx(ctx, a, MO_TEUL, true);
> +}
> +
>  /* XTheadMac */
>
>  static bool gen_th_mac(DisasContext *ctx, arg_r *a,
> diff --git a/target/riscv/translate.c b/target/riscv/translate.c
> index f5a870a2ac..fb77df721e 100644
> --- a/target/riscv/translate.c
> +++ b/target/riscv/translate.c
> @@ -129,7 +129,8 @@ static bool has_xthead_p(DisasContext *ctx  
> __attribute__((__unused__)))
>  {
>      return ctx->cfg_ptr->ext_xtheadba || ctx->cfg_ptr->ext_xtheadbb ||
>             ctx->cfg_ptr->ext_xtheadbs || ctx->cfg_ptr->ext_xtheadcmo ||
> -           ctx->cfg_ptr->ext_xtheadcondmov || ctx->cfg_ptr->ext_xtheadmac ||
> +           ctx->cfg_ptr->ext_xtheadcondmov ||
> +           ctx->cfg_ptr->ext_xtheadfmemidx || ctx->cfg_ptr->ext_xtheadmac ||
>             ctx->cfg_ptr->ext_xtheadmemidx || ctx->cfg_ptr->ext_xtheadmempair 
> ||
>             ctx->cfg_ptr->ext_xtheadsync;
>  }
> diff --git a/target/riscv/xthead.decode b/target/riscv/xthead.decode
> index 69e40f22dc..81daf1d694 100644
> --- a/target/riscv/xthead.decode
> +++ b/target/riscv/xthead.decode
> @@ -100,6 +100,16 @@ th_l2cache_iall  0000000 10110 00000 000 00000 0001011
>  th_mveqz         0100000 ..... .....  001 ..... 0001011 @r
>  th_mvnez         0100001 ..... .....  001 ..... 0001011 @r
>
> +# XTheadFMemIdx
> +th_flrd          01100 .. ..... ..... 110 ..... 0001011 @th_memidx
> +th_flrw          01000 .. ..... ..... 110 ..... 0001011 @th_memidx
> +th_flurd         01110 .. ..... ..... 110 ..... 0001011 @th_memidx
> +th_flurw         01010 .. ..... ..... 110 ..... 0001011 @th_memidx
> +th_fsrd          01100 .. ..... ..... 111 ..... 0001011 @th_memidx
> +th_fsrw          01000 .. ..... ..... 111 ..... 0001011 @th_memidx
> +th_fsurd         01110 .. ..... ..... 111 ..... 0001011 @th_memidx
> +th_fsurw         01010 .. ..... ..... 111 ..... 0001011 @th_memidx
> +
>  # XTheadMac
>  th_mula          00100 00 ..... ..... 001 ..... 0001011 @r
>  th_mulah         00101 00 ..... ..... 001 ..... 0001011 @r
> --
> 2.38.1
>
>