Re: [Qemu-arm] [PATCH v1 10/17] target-arm: implement setend

[Peter Crosthwaite]

On Tue, Jan 19, 2016 at 8:29 AM, Peter Maydell <address@hidden> wrote:
> On 18 January 2016 at 07:12, Peter Crosthwaite
> <address@hidden> wrote:
>> From: Paolo Bonzini <address@hidden>
>>
>> Since this is not a high-performance path, just use a helper to
>> flip the E bit and force a lookup in the hash table since the
>> flags have changed.
>>
>> Signed-off-by: Paolo Bonzini <address@hidden>
>> Signed-off-by: Peter Crosthwaite <address@hidden>
>> ---
>>
>>  target-arm/helper.h    |  1 +
>>  target-arm/op_helper.c |  5 +++++
>>  target-arm/translate.c | 16 ++++++++--------
>>  3 files changed, 14 insertions(+), 8 deletions(-)
>>
>> diff --git a/target-arm/helper.h b/target-arm/helper.h
>> index c2a85c7..2315a9c 100644
>> --- a/target-arm/helper.h
>> +++ b/target-arm/helper.h
>> @@ -48,6 +48,7 @@ DEF_HELPER_FLAGS_3(sel_flags, TCG_CALL_NO_RWG_SE,
>>                     i32, i32, i32, i32)
>>  DEF_HELPER_2(exception_internal, void, env, i32)
>>  DEF_HELPER_4(exception_with_syndrome, void, env, i32, i32, i32)
>> +DEF_HELPER_1(setend, void, env)
>>  DEF_HELPER_1(wfi, void, env)
>>  DEF_HELPER_1(wfe, void, env)
>>  DEF_HELPER_1(yield, void, env)
>> diff --git a/target-arm/op_helper.c b/target-arm/op_helper.c
>> index e42d287..2a4bc67 100644
>> --- a/target-arm/op_helper.c
>> +++ b/target-arm/op_helper.c
>> @@ -295,6 +295,11 @@ uint32_t HELPER(usat16)(CPUARMState *env, uint32_t x, 
>> uint32_t shift)
>>      return res;
>>  }
>>
>> +void HELPER(setend)(CPUARMState *env)
>> +{
>> +    env->uncached_cpsr ^= CPSR_E;
>> +}
>> +
>>  /* Function checks whether WFx (WFI/WFE) instructions are set up to be 
>> trapped.
>>   * The function returns the target EL (1-3) if the instruction is to be 
>> trapped;
>>   * otherwise it returns 0 indicating it is not trapped.
>> diff --git a/target-arm/translate.c b/target-arm/translate.c
>> index cb925ef..192a5d6 100644
>> --- a/target-arm/translate.c
>> +++ b/target-arm/translate.c
>> @@ -7726,10 +7726,10 @@ static void disas_arm_insn(DisasContext *s, unsigned 
>> int insn)
>>          if ((insn & 0x0ffffdff) == 0x01010000) {
>>              ARCH(6);
>>              /* setend */
>> -            if (((insn >> 9) & 1) != s->bswap_code) {
>> -                /* Dynamic endianness switching not implemented. */
>> -                qemu_log_mask(LOG_UNIMP, "arm: unimplemented setend\n");
>> -                goto illegal_op;
>> +            if (((insn >> 9) & 1) != !!(s->mo_endianness == MO_BE)) {
>> +                gen_helper_setend(cpu_env);
>> +                gen_set_pc_im(s, s->pc);
>> +                s->is_jmp = DISAS_JUMP;
>
> Rather than manually calling set_pc_im and using DISAS_JUMP, better
> to use DISAS_UPDATE, which will do the gen_set_pc_im() call for you.
>
> (Ditto in the other hunk.)
>

Fixed.

Regards,
Peter

> thanks
> -- PMM