Re: [Qemu-arm] [PATCH v3 4/6] target/arm/translate: ensure gen_goto_tb sets exit flags

[Alex Bennée]

Richard Henderson <address@hidden> writes:

> On 07/11/2017 07:59 AM, Alex Bennée wrote:
>>       if (use_goto_tb(s, dest)) {
>>           tcg_gen_goto_tb(n);
>>           gen_set_pc_im(s, dest);
>>           tcg_gen_exit_tb((uintptr_t)s->tb + n);
>> +        s->is_jmp = DISAS_TB_JUMP;
>>       } else {
>>           gen_set_pc_im(s, dest);
>>           gen_goto_ptr();
>> +        s->is_jmp = DISAS_JUMP;
>>       }
>
> I think DISAS_TB_JUMP is appropriate for both cases.  When not using
> goto_tb, the jump is still static and we still chain to the next TB
> via goto_ptr.

OK - I guess we need to nail down what the essential difference is
between the two. I understood DISAS_TB_JUMP as a static known PC which
can be patched in the generated code because we know the two addresses
are in the same page - whereas DISAS_JUMP is a "computed" jump although
in this case the PC is already known.

Does making a distinction between computed and non-computer inter-page
jumps make any sense anyway?

>
> Otherwise,
>
> Reviewed-by: Richard Henderson <address@hidden>
>
>
> r~


--
Alex Bennée