Re: [PATCH 4/7] target/nios2: Add DisasContextBase to DisasContext

[Peter Maydell]

On Sun, 20 Jun 2021 at 06:31, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> Migrate the is_jmp, tb and singlestep_enabled fields
> from DisasContext into the base.

The commit message says we're only moving is_jmp, tb and
singlestep_enabled, but...

>  static bool use_goto_tb(DisasContext *dc, uint32_t dest)
>  {
> -    if (unlikely(dc->singlestep_enabled)) {
> +    if (unlikely(dc->base.singlestep_enabled)) {
>          return false;
>      }
>
>  #ifndef CONFIG_USER_ONLY
> -    return (dc->tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK);
> +    return (dc->base.pc_first & TARGET_PAGE_MASK) == (dest & 
> TARGET_PAGE_MASK);

...here we change one, but only one, of the uses of a PC related
variable too...

> @@ -812,11 +810,16 @@ void gen_intermediate_code(CPUState *cs, 
> TranslationBlock *tb, int max_insns)
>      int num_insns;
>
>      /* Initialize DC */
> -    dc->is_jmp  = DISAS_NEXT;
> +
> +    dc->base.tb = tb;
> +    dc->base.singlestep_enabled = cs->singlestep_enabled;
> +    dc->base.is_jmp = DISAS_NEXT;
> +    dc->base.pc_first = tb->pc;
> +    dc->base.pc_next = tb->pc;

...which AFAICT is the only reason we needed to set pc_first/pc_next
here, which lines are then deleted again in the next patch.

I guess we get to where we're trying to get to in the end.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM