Re: [PATCH v2 01/15] target/m68k: Raise the TRAPn exception with the correct pc

[Laurent Vivier]

Le 02/12/2021 à 21:48, Richard Henderson a écrit :
> Rather than adjust the PC in all of the consumers, raise
> the exception with the correct PC in the first place.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   linux-user/m68k/cpu_loop.c | 1 -
>   target/m68k/op_helper.c    | 9 ---------
>   target/m68k/translate.c    | 2 +-
>   3 files changed, 1 insertion(+), 11 deletions(-)
>
> diff --git a/linux-user/m68k/cpu_loop.c b/linux-user/m68k/cpu_loop.c
> index 790bd558c3..287f24cc60 100644
> --- a/linux-user/m68k/cpu_loop.c
> +++ b/linux-user/m68k/cpu_loop.c
> @@ -70,7 +70,6 @@ void cpu_loop(CPUM68KState *env)
>               {
>                   abi_long ret;
>                   n = env->dregs[0];
> -                env->pc += 2;
>                   ret = do_syscall(env,
>                                    n,
>                                    env->dregs[1],
> diff --git a/target/m68k/op_helper.c b/target/m68k/op_helper.c
> index cfbc987ba6..36662de149 100644
> --- a/target/m68k/op_helper.c
> +++ b/target/m68k/op_helper.c
> @@ -216,11 +216,6 @@ static void cf_interrupt_all(CPUM68KState *env, int is_hw)
>               cpu_loop_exit(cs);
>               return;
>           }
> -        if (cs->exception_index >= EXCP_TRAP0
> -            && cs->exception_index <= EXCP_TRAP15) {
> -            /* Move the PC after the trap instruction.  */
> -            retaddr += 2;
> -        }
>       }
>   
>       vector = cs->exception_index << 2;
> @@ -303,10 +298,6 @@ static void m68k_interrupt_all(CPUM68KState *env, int 
> is_hw)
>               /* Return from an exception.  */
>               m68k_rte(env);
>               return;
> -        case EXCP_TRAP0 ...  EXCP_TRAP15:
> -            /* Move the PC after the trap instruction.  */
> -            retaddr += 2;
> -            break;
>           }
>       }
>   
> diff --git a/target/m68k/translate.c b/target/m68k/translate.c
> index af43c8eab8..af3febdd48 100644
> --- a/target/m68k/translate.c
> +++ b/target/m68k/translate.c
> @@ -4860,7 +4860,7 @@ DISAS_INSN(wdebug)
>   
>   DISAS_INSN(trap)
>   {
> -    gen_exception(s, s->base.pc_next, EXCP_TRAP0 + (insn & 0xf));
> +    gen_exception(s, s->pc, EXCP_TRAP0 + (insn & 0xf));
>   }
>   
>   static void gen_load_fcr(DisasContext *s, TCGv res, int reg)

Reviewed-by: Laurent Vivier <laurent@vivier.eu>