Re: [PATCH v6 03/25] target/riscv: Encode the FS and VS on a normal way for tb flags

[Alistair Francis]

On Sat, Mar 25, 2023 at 10:01 PM Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> From: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
>
> Reuse the MSTATUS_FS and MSTATUS_VS for the tb flags positions is not a
> normal way.
>
> It will make it hard to change the tb flags layout. And even worse, if we
> want to keep tb flags for a same extension togather without a hole.
>
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
> Signed-off-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
> Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
> Message-Id: <20230324143031.1093-4-zhiwei_liu@linux.alibaba.com>
> [rth: Adjust trans_rvf.c.inc as well; use the typedef]
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

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

Alistair

> ---
>  target/riscv/cpu.h                      | 15 +++++------
>  target/riscv/cpu_helper.c               | 11 ++++----
>  target/riscv/translate.c                | 34 ++++++++++++-------------
>  target/riscv/insn_trans/trans_rvf.c.inc |  2 +-
>  target/riscv/insn_trans/trans_rvv.c.inc |  8 +++---
>  5 files changed, 34 insertions(+), 36 deletions(-)
>
> diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> index 30d9828d59..f787145a21 100644
> --- a/target/riscv/cpu.h
> +++ b/target/riscv/cpu.h
> @@ -633,18 +633,17 @@ void riscv_cpu_set_fflags(CPURISCVState *env, 
> target_ulong);
>
>  #define TB_FLAGS_PRIV_MMU_MASK                3
>  #define TB_FLAGS_PRIV_HYP_ACCESS_MASK   (1 << 2)
> -#define TB_FLAGS_MSTATUS_FS MSTATUS_FS
> -#define TB_FLAGS_MSTATUS_VS MSTATUS_VS
>
>  #include "exec/cpu-all.h"
>
>  FIELD(TB_FLAGS, MEM_IDX, 0, 3)
> -FIELD(TB_FLAGS, LMUL, 3, 3)
> -FIELD(TB_FLAGS, SEW, 6, 3)
> -/* Skip MSTATUS_VS (0x600) bits */
> -FIELD(TB_FLAGS, VL_EQ_VLMAX, 11, 1)
> -FIELD(TB_FLAGS, VILL, 12, 1)
> -/* Skip MSTATUS_FS (0x6000) bits */
> +FIELD(TB_FLAGS, FS, 3, 2)
> +/* Vector flags */
> +FIELD(TB_FLAGS, VS, 5, 2)
> +FIELD(TB_FLAGS, LMUL, 7, 3)
> +FIELD(TB_FLAGS, SEW, 10, 3)
> +FIELD(TB_FLAGS, VL_EQ_VLMAX, 13, 1)
> +FIELD(TB_FLAGS, VILL, 14, 1)
>  /* Is a Hypervisor instruction load/store allowed? */
>  FIELD(TB_FLAGS, HLSX, 15, 1)
>  FIELD(TB_FLAGS, MSTATUS_HS_FS, 16, 2)
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index 9d50e7bbb6..1e7ee9aa30 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -79,16 +79,17 @@ void cpu_get_tb_cpu_state(CPURISCVState *env, 
> target_ulong *pc,
>      }
>
>  #ifdef CONFIG_USER_ONLY
> -    flags |= TB_FLAGS_MSTATUS_FS;
> -    flags |= TB_FLAGS_MSTATUS_VS;
> +    flags = FIELD_DP32(flags, TB_FLAGS, FS, EXT_STATUS_DIRTY);
> +    flags = FIELD_DP32(flags, TB_FLAGS, VS, EXT_STATUS_DIRTY);
>  #else
>      flags |= cpu_mmu_index(env, 0);
>      if (riscv_cpu_fp_enabled(env)) {
> -        flags |= env->mstatus & MSTATUS_FS;
> +        flags =  FIELD_DP32(flags, TB_FLAGS, FS,
> +                            get_field(env->mstatus,  MSTATUS_FS));
>      }
> -
>      if (riscv_cpu_vector_enabled(env)) {
> -        flags |= env->mstatus & MSTATUS_VS;
> +        flags =  FIELD_DP32(flags, TB_FLAGS, VS,
> +                            get_field(env->mstatus, MSTATUS_VS));
>      }
>
>      if (riscv_has_ext(env, RVH)) {
> diff --git a/target/riscv/translate.c b/target/riscv/translate.c
> index 880f6318aa..b897bf6006 100644
> --- a/target/riscv/translate.c
> +++ b/target/riscv/translate.c
> @@ -64,10 +64,10 @@ typedef struct DisasContext {
>      RISCVMXL xl;
>      uint32_t misa_ext;
>      uint32_t opcode;
> -    uint32_t mstatus_fs;
> -    uint32_t mstatus_vs;
> -    uint32_t mstatus_hs_fs;
> -    uint32_t mstatus_hs_vs;
> +    RISCVExtStatus mstatus_fs;
> +    RISCVExtStatus mstatus_vs;
> +    RISCVExtStatus mstatus_hs_fs;
> +    RISCVExtStatus mstatus_hs_vs;
>      uint32_t mem_idx;
>      /* Remember the rounding mode encoded in the previous fp instruction,
>         which we have already installed into env->fp_status.  Or -1 for
> @@ -598,8 +598,7 @@ static TCGv get_address_indexed(DisasContext *ctx, int 
> rs1, TCGv offs)
>  }
>
>  #ifndef CONFIG_USER_ONLY
> -/* The states of mstatus_fs are:
> - * 0 = disabled, 1 = initial, 2 = clean, 3 = dirty
> +/*
>   * We will have already diagnosed disabled state,
>   * and need to turn initial/clean into dirty.
>   */
> @@ -611,9 +610,9 @@ static void mark_fs_dirty(DisasContext *ctx)
>          return;
>      }
>
> -    if (ctx->mstatus_fs != MSTATUS_FS) {
> +    if (ctx->mstatus_fs != EXT_STATUS_DIRTY) {
>          /* Remember the state change for the rest of the TB. */
> -        ctx->mstatus_fs = MSTATUS_FS;
> +        ctx->mstatus_fs = EXT_STATUS_DIRTY;
>
>          tmp = tcg_temp_new();
>          tcg_gen_ld_tl(tmp, cpu_env, offsetof(CPURISCVState, mstatus));
> @@ -621,9 +620,9 @@ static void mark_fs_dirty(DisasContext *ctx)
>          tcg_gen_st_tl(tmp, cpu_env, offsetof(CPURISCVState, mstatus));
>      }
>
> -    if (ctx->virt_enabled && ctx->mstatus_hs_fs != MSTATUS_FS) {
> +    if (ctx->virt_enabled && ctx->mstatus_hs_fs != EXT_STATUS_DIRTY) {
>          /* Remember the stage change for the rest of the TB. */
> -        ctx->mstatus_hs_fs = MSTATUS_FS;
> +        ctx->mstatus_hs_fs = EXT_STATUS_DIRTY;
>
>          tmp = tcg_temp_new();
>          tcg_gen_ld_tl(tmp, cpu_env, offsetof(CPURISCVState, mstatus_hs));
> @@ -636,8 +635,7 @@ static inline void mark_fs_dirty(DisasContext *ctx) { }
>  #endif
>
>  #ifndef CONFIG_USER_ONLY
> -/* The states of mstatus_vs are:
> - * 0 = disabled, 1 = initial, 2 = clean, 3 = dirty
> +/*
>   * We will have already diagnosed disabled state,
>   * and need to turn initial/clean into dirty.
>   */
> @@ -645,9 +643,9 @@ static void mark_vs_dirty(DisasContext *ctx)
>  {
>      TCGv tmp;
>
> -    if (ctx->mstatus_vs != MSTATUS_VS) {
> +    if (ctx->mstatus_vs != EXT_STATUS_DIRTY) {
>          /* Remember the state change for the rest of the TB.  */
> -        ctx->mstatus_vs = MSTATUS_VS;
> +        ctx->mstatus_vs = EXT_STATUS_DIRTY;
>
>          tmp = tcg_temp_new();
>          tcg_gen_ld_tl(tmp, cpu_env, offsetof(CPURISCVState, mstatus));
> @@ -655,9 +653,9 @@ static void mark_vs_dirty(DisasContext *ctx)
>          tcg_gen_st_tl(tmp, cpu_env, offsetof(CPURISCVState, mstatus));
>      }
>
> -    if (ctx->virt_enabled && ctx->mstatus_hs_vs != MSTATUS_VS) {
> +    if (ctx->virt_enabled && ctx->mstatus_hs_vs != EXT_STATUS_DIRTY) {
>          /* Remember the stage change for the rest of the TB. */
> -        ctx->mstatus_hs_vs = MSTATUS_VS;
> +        ctx->mstatus_hs_vs = EXT_STATUS_DIRTY;
>
>          tmp = tcg_temp_new();
>          tcg_gen_ld_tl(tmp, cpu_env, offsetof(CPURISCVState, mstatus_hs));
> @@ -1153,8 +1151,8 @@ static void 
> riscv_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
>
>      ctx->pc_succ_insn = ctx->base.pc_first;
>      ctx->mem_idx = FIELD_EX32(tb_flags, TB_FLAGS, MEM_IDX);
> -    ctx->mstatus_fs = tb_flags & TB_FLAGS_MSTATUS_FS;
> -    ctx->mstatus_vs = tb_flags & TB_FLAGS_MSTATUS_VS;
> +    ctx->mstatus_fs = FIELD_EX32(tb_flags, TB_FLAGS, FS);
> +    ctx->mstatus_vs = FIELD_EX32(tb_flags, TB_FLAGS, VS);
>      ctx->priv_ver = env->priv_ver;
>      ctx->virt_enabled = FIELD_EX32(tb_flags, TB_FLAGS, VIRT_ENABLED);
>      ctx->misa_ext = env->misa_ext;
> diff --git a/target/riscv/insn_trans/trans_rvf.c.inc 
> b/target/riscv/insn_trans/trans_rvf.c.inc
> index 052408f45c..31cd3d0e05 100644
> --- a/target/riscv/insn_trans/trans_rvf.c.inc
> +++ b/target/riscv/insn_trans/trans_rvf.c.inc
> @@ -19,7 +19,7 @@
>   */
>
>  #define REQUIRE_FPU do {\
> -    if (ctx->mstatus_fs == 0) \
> +    if (ctx->mstatus_fs == EXT_STATUS_DISABLED) \
>          if (!ctx->cfg_ptr->ext_zfinx) \
>              return false; \
>  } while (0)
> diff --git a/target/riscv/insn_trans/trans_rvv.c.inc 
> b/target/riscv/insn_trans/trans_rvv.c.inc
> index f2e3d38515..6297c3b50d 100644
> --- a/target/riscv/insn_trans/trans_rvv.c.inc
> +++ b/target/riscv/insn_trans/trans_rvv.c.inc
> @@ -29,12 +29,12 @@ static inline bool is_overlapped(const int8_t astart, 
> int8_t asize,
>
>  static bool require_rvv(DisasContext *s)
>  {
> -    return s->mstatus_vs != 0;
> +    return s->mstatus_vs != EXT_STATUS_DISABLED;
>  }
>
>  static bool require_rvf(DisasContext *s)
>  {
> -    if (s->mstatus_fs == 0) {
> +    if (s->mstatus_fs == EXT_STATUS_DISABLED) {
>          return false;
>      }
>
> @@ -52,7 +52,7 @@ static bool require_rvf(DisasContext *s)
>
>  static bool require_scale_rvf(DisasContext *s)
>  {
> -    if (s->mstatus_fs == 0) {
> +    if (s->mstatus_fs == EXT_STATUS_DISABLED) {
>          return false;
>      }
>
> @@ -70,7 +70,7 @@ static bool require_scale_rvf(DisasContext *s)
>
>  static bool require_scale_rvfmin(DisasContext *s)
>  {
> -    if (s->mstatus_fs == 0) {
> +    if (s->mstatus_fs == EXT_STATUS_DISABLED) {
>          return false;
>      }
>
> --
> 2.34.1
>
>