Re: [Qemu-devel] [PATCH v3 2/5] target-ppc: improve lxvw4x implementation

[Nikunj A Dadhania]

David Gibson <address@hidden> writes:

> [ Unknown signature status ]
> On Fri, Sep 16, 2016 at 04:21:48PM +0530, Nikunj A Dadhania wrote:
>> Load 8byte at a time and manipulate.
>> 
>> Signed-off-by: Nikunj A Dadhania <address@hidden>
>> ---
>>  target-ppc/helper.h                 |  1 +
>>  target-ppc/mem_helper.c             |  5 +++++
>>  target-ppc/translate/vsx-impl.inc.c | 19 +++++--------------
>>  3 files changed, 11 insertions(+), 14 deletions(-)
>> 
>> diff --git a/target-ppc/helper.h b/target-ppc/helper.h
>> index 966f2ce..9f6705d 100644
>> --- a/target-ppc/helper.h
>> +++ b/target-ppc/helper.h
>> @@ -297,6 +297,7 @@ DEF_HELPER_2(mtvscr, void, env, avr)
>>  DEF_HELPER_3(lvebx, void, env, avr, tl)
>>  DEF_HELPER_3(lvehx, void, env, avr, tl)
>>  DEF_HELPER_3(lvewx, void, env, avr, tl)
>> +DEF_HELPER_1(deposit32x2, i64, i64)
>>  DEF_HELPER_3(stvebx, void, env, avr, tl)
>>  DEF_HELPER_3(stvehx, void, env, avr, tl)
>>  DEF_HELPER_3(stvewx, void, env, avr, tl)
>> diff --git a/target-ppc/mem_helper.c b/target-ppc/mem_helper.c
>> index 6548715..86e493e 100644
>> --- a/target-ppc/mem_helper.c
>> +++ b/target-ppc/mem_helper.c
>> @@ -285,6 +285,11 @@ STVE(stvewx, cpu_stl_data_ra, bswap32, u32)
>>  #undef I
>>  #undef LVE
>>  
>> +uint64_t helper_deposit32x2(uint64_t x)
>> +{
>> +    return deposit64((x >> 32), 32, 32, (x));
>> +}
>
> It seems a shame to drop out to a helper for something this simple.
> How hard would it be to implement this.. wordswap, I guess you'd call
> it.. in tcg ops?

There is a tcg_ops for deposit64, I need to do the shifting and call it.
I will change that.

> I'm also not particularly fond of the deposit32x2 name, though a
> better one doesn't quickly come to mind.

Regards
Nikunj