Re: [PATCH v5 3/9] target/arm: Change gen_*set_pc_im to gen_*update_pc

[Philippe Mathieu-Daudé]

On 1/10/22 00:03, Richard Henderson wrote:
> In preparation for TARGET_TB_PCREL, reduce reliance on
> absolute values by passing in pc difference.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   target/arm/translate-a32.h |  2 +-
>   target/arm/translate.h     |  6 ++--
>   target/arm/translate-a64.c | 32 +++++++++---------
>   target/arm/translate-vfp.c |  2 +-
>   target/arm/translate.c     | 68 ++++++++++++++++++++------------------
>   5 files changed, 56 insertions(+), 54 deletions(-)

> -void gen_a64_set_pc_im(uint64_t val)
> +void gen_a64_update_pc(DisasContext *s, target_long diff)
>   {
> -    tcg_gen_movi_i64(cpu_pc, val);
> +    tcg_gen_movi_i64(cpu_pc, s->pc_curr + diff);
>   }

> @@ -384,11 +384,11 @@ static void gen_goto_tb(DisasContext *s, int n, int64_t 
> diff)
>   

Adding more context from previous patch to ease review:

>       uint64_t dest = s->pc_curr + diff;

>       if (use_goto_tb(s, dest)) {
>           tcg_gen_goto_tb(n);
> -        gen_a64_set_pc_im(dest);
> +        gen_a64_update_pc(s, diff);
>           tcg_gen_exit_tb(s->base.tb, n);
>           s->base.is_jmp = DISAS_NORETURN;
>       } else {
> -        gen_a64_set_pc_im(dest);
> +        gen_a64_update_pc(s, diff);
>           if (s->ss_active) {
>               gen_step_complete_exception(s);
>           } else {

> diff --git a/target/arm/translate.c b/target/arm/translate.c
> index 6855128fb1..01b7536c7e 100644
> --- a/target/arm/translate.c
> +++ b/target/arm/translate.c
> @@ -772,9 +772,9 @@ void gen_set_condexec(DisasContext *s)
>       }
>   }
>   
> -void gen_set_pc_im(DisasContext *s, target_ulong val)
> +void gen_update_pc(DisasContext *s, target_long diff)
>   {
> -    tcg_gen_movi_i32(cpu_R[15], val);
> +    tcg_gen_movi_i32(cpu_R[15], s->pc_curr + diff);
>   }

> @@ -2600,10 +2600,10 @@ static void gen_goto_tb(DisasContext *s, int n, int 
> diff)
>   

Ditto:

>       target_ulong dest = s->pc_curr + diff;

>       if (translator_use_goto_tb(&s->base, dest)) {
>           tcg_gen_goto_tb(n);
> -        gen_set_pc_im(s, dest);
> +        gen_update_pc(s, diff);
>           tcg_gen_exit_tb(s->base.tb, n);
>       } else {
> -        gen_set_pc_im(s, dest);
> +        gen_update_pc(s, diff);
>           gen_goto_ptr();
>       }

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>