Re: [Qemu-devel] [PATCH 14/14] target/ppc: improve VSX_FMADD with new GEN_VSX_HELPER_VSX_MADD macro

[Mark Cave-Ayland]

On 05/05/2019 16:17, Richard Henderson wrote:

> On 5/5/19 3:20 AM, Mark Cave-Ayland wrote:
>>> The afrm argument is no longer used.
>>> This also means that e.g.
>>>
>>> VSX_MADD(xsmaddadp, 1, float64, VsrD(0), MADD_FLGS, 1, 1, 0)
>>> VSX_MADD(xsmaddmdp, 1, float64, VsrD(0), MADD_FLGS, 0, 1, 0)
>>>
>>> are redundant.  Similarly with all of the other pairs.
>>
>> Agreed. What do you think is the best solution here - maybe a double macro 
>> that looks
>> something like this?
>>
>> #define VSX_MADD(op, prec, nels, tp, fld, maddflgs, sfprf, r2sp)
>> _VSX_MADD(op##aprec, nels, tp, fld, maddflgs, sfprf, r2sp)
>> _VSX_MADD(op##mprec, nels, tp, fld, maddflgs, sfprf, r2sp)
>>
>> VSX_MADD(xsmadd, dp, 1, float64, VsrD(0), MADD_FLGS, 1, 0)
> 
> I have no idea what you're suggesting.
> 
> I am suggesting one function, xsmadddp, replacing xsmaddadp + xsmaddmdp, that
> is used by both instructions.

Gotcha. I was thinking that the standard practice was to have a 1:1 
correspondence
between the gen function and helper function for instructions, but I'm happy to 
go
with your suggestion above.


ATB,

Mark.