On Sat, 30 Aug 2025 at 18:18, Richard Henderson
<[email protected]> wrote:
>
> Use delay_exception_el to move the exception out of line.
> Use TCG_COND_TSTNE instead of separate AND+NE.
>
> Reviewed-by: Pierrick Bouvier <[email protected]>
> Signed-off-by: Richard Henderson <[email protected]>
> ---
>  target/arm/tcg/translate.c | 18 ++++--------------
>  1 file changed, 4 insertions(+), 14 deletions(-)
>
> diff --git a/target/arm/tcg/translate.c b/target/arm/tcg/translate.c
> index c4dd3a747c..f6fdfaa551 100644
> --- a/target/arm/tcg/translate.c
> +++ b/target/arm/tcg/translate.c
> @@ -3033,21 +3033,11 @@ static void do_coproc_insn(DisasContext *s, int 
> cpnum, int is64,
>
>          if (maskbit != 4 && maskbit != 14) {
>              /* T4 and T14 are RES0 so never cause traps */
> -            TCGv_i32 t;
> -            DisasLabel over = gen_disas_label(s);
> +            TCGLabel *fail = delay_exception_el(s, EXCP_UDEF, syndrome, 2);
> +            TCGv_i32 t =
> +                load_cpu_offset(offsetoflow32(CPUARMState, cp15.hstr_el2));
>
> -            t = load_cpu_offset(offsetoflow32(CPUARMState, cp15.hstr_el2));

I almost certainly originally wrote this line with the declaration
of t and its initialization split to avoid this awkward linebreak
that you get if you put them together...

> -            tcg_gen_andi_i32(t, t, 1u << maskbit);
> -            tcg_gen_brcondi_i32(TCG_COND_EQ, t, 0, over.label);
> -
> -            gen_exception_insn_el(s, 0, EXCP_UDEF, syndrome, 2);
> -            /*
> -             * gen_exception_insn() will set is_jmp to DISAS_NORETURN,
> -             * but since we're conditionally branching over it, we want
> -             * to assume continue-to-next-instruction.
> -             */
> -            s->base.is_jmp = DISAS_NEXT;
> -            set_disas_label(s, over);
> +            tcg_gen_brcondi_i32(TCG_COND_TSTNE, t, 1u << maskbit, fail);
>          }
>      }

-- PMM

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