[PATCH 5/9] powerpc: Introduce VSX thread_struct and CONFIG_VSX

[Kumar Gala]

On Jun 19, 2008, at 4:33 AM, Benjamin Herrenschmidt wrote:

> On Thu, 2008-06-19 at 01:10 -0500, Kumar Gala wrote:
>>> I still think using the union makes it is easier to read than what  
>>> you
>>> have here.  Also, it better reflects the structure of what's being
>>> stored there.
>>
>> I don't think that holds much weight with me.  We don't union the
>> vector128 type to show it also supports float, u16, and u8 types.
>
> But this is different. The same registers are either basic FP regs or
> full VSX regs.
>
> I don't see what's wrong with union, it's a nice way to express  
> things.

We also don't do this for SPE (the freescale version).

>> I stick by the fact that the ONLY place it looks like you access the
>> union via the .vsr member is for memset or memcpy so you clearly know
>> if the size should be sizeof(double) or sizeof(vector).
>>
>> Also, I can see the case in the future that 'fpr's become
>
> What's wrong with the union ? there's nothing ugly about them..

I'll wait for the next version and see how many places .vsr is  
actually accessed.

- k