Re: [Qemu-devel] [PATCH v5 10/19] target/i386: introduce gen_jr helper to generate lookup_and_goto_ptr

["Alex Bennée" <alex.bennee@linaro.org>]

Richard Henderson <rth@twiddle.net> writes:

> From: "Emilio G. Cota" <cota@braap.org>
>
> This helper will be used by subsequent changes.
>
> Signed-off-by: Emilio G. Cota <cota@braap.org>
> Message-Id: <1493263764-18657-9-git-send-email-cota@braap.org>
> Signed-off-by: Richard Henderson <rth@twiddle.net>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

> ---
>  target/i386/translate.c | 25 ++++++++++++++++++++++++-
>  1 file changed, 24 insertions(+), 1 deletion(-)
>
> diff --git a/target/i386/translate.c b/target/i386/translate.c
> index 1d1372f..f0e48dc 100644
> --- a/target/i386/translate.c
> +++ b/target/i386/translate.c
> @@ -141,6 +141,7 @@ typedef struct DisasContext {
>  } DisasContext;
>
>  static void gen_eob(DisasContext *s);
> +static void gen_jr(DisasContext *s, TCGv dest);
>  static void gen_jmp(DisasContext *s, target_ulong eip);
>  static void gen_jmp_tb(DisasContext *s, target_ulong eip, int tb_num);
>  static void gen_op(DisasContext *s1, int op, TCGMemOp ot, int d);
> @@ -2509,7 +2510,8 @@ static void gen_bnd_jmp(DisasContext *s)
>     If INHIBIT, set HF_INHIBIT_IRQ_MASK if it isn't already set.
>     If RECHECK_TF, emit a rechecking helper for #DB, ignoring the state of
>     S->TF.  This is used by the syscall/sysret insns.  */
> -static void gen_eob_worker(DisasContext *s, bool inhibit, bool recheck_tf)
> +static void
> +do_gen_eob_worker(DisasContext *s, bool inhibit, bool recheck_tf, TCGv jr)
>  {
>      gen_update_cc_op(s);
>
> @@ -2530,12 +2532,27 @@ static void gen_eob_worker(DisasContext *s, bool inhibit, bool recheck_tf)
>          tcg_gen_exit_tb(0);
>      } else if (s->tf) {
>          gen_helper_single_step(cpu_env);
> +    } else if (!TCGV_IS_UNUSED(jr)) {
> +        TCGv vaddr = tcg_temp_new();
> +
> +        tcg_gen_add_tl(vaddr, jr, cpu_seg_base[R_CS]);
> +        tcg_gen_lookup_and_goto_ptr(vaddr);
> +        tcg_temp_free(vaddr);
>      } else {
>          tcg_gen_exit_tb(0);
>      }
>      s->is_jmp = DISAS_TB_JUMP;
>  }
>
> +static inline void
> +gen_eob_worker(DisasContext *s, bool inhibit, bool recheck_tf)
> +{
> +    TCGv unused;
> +
> +    TCGV_UNUSED(unused);
> +    do_gen_eob_worker(s, inhibit, recheck_tf, unused);
> +}
> +
>  /* End of block.
>     If INHIBIT, set HF_INHIBIT_IRQ_MASK if it isn't already set.  */
>  static void gen_eob_inhibit_irq(DisasContext *s, bool inhibit)
> @@ -2549,6 +2566,12 @@ static void gen_eob(DisasContext *s)
>      gen_eob_worker(s, false, false);
>  }
>
> +/* Jump to register */
> +static void gen_jr(DisasContext *s, TCGv dest)
> +{
> +    do_gen_eob_worker(s, false, false, dest);
> +}
> +
>  /* generate a jump to eip. No segment change must happen before as a
>     direct call to the next block may occur */
>  static void gen_jmp_tb(DisasContext *s, target_ulong eip, int tb_num)


--
Alex Bennée