Re: [PATCH 3/7] [RFC] add support for BlueGene/P FPU
From: Eric Van Hensbergen
Date: Thu May 19 2011 - 20:30:30 EST
On Thu, May 19, 2011 at 6:16 PM, Michael Neuling <mikey@xxxxxxxxxxx> wrote:
> In message <BANLkTi=rc5vZm3xAXHpHSxSH1wBWKhv92A@xxxxxxxxxxxxxx> you wrote:
>> On Thu, May 19, 2011 at 4:36 PM, Michael Neuling <mikey@xxxxxxxxxxx> wrote:
>> > In message <BANLkTimKhApFW8G1-pG0u_9Kv2YB0R1O0w@xxxxxxxxxxxxxx> you wrote=
>> >> On Thu, May 19, 2011 at 12:58 AM, Michael Neuling <mikey@xxxxxxxxxxx> wr=
>> >> :
>> >> > Eric,
>> >> >
>> >> >> This patch adds save/restore register support for the BlueGene/P
>> >> >> double hummer FPU.
>> >> >
>> >> > What does this mean? =3DA0Needs more details here.
>> >> >
>> okay, I've changed it a bit in [V2], if you want more I can do my best.
> If you can describe the whole primary and secondary registers that'd be
> cool. ASCII art would be awesome! :-)
You sure you don't just want a bitfield.conf? :) I'll do my best, but my
ASCII art isn't what it used to be. I'll also include a reference to the PDF.
>> > Ok, sounds like there is 32*8*2 bytes of data, rather than the normal
>> > 32*8 bytes for FP only (ignoring VSX). =A0If this is the case, then you'l=
>> > need make 'fpr' in the thread struct bigger which you can do by setting
>> > TS_FPRWIDTH =3D 2 like we do for VSX.
Okay - so basically what I have now and TS_FPRWIDTH=2 ?
>> Since it isn't available on other chips, shoudl it just be PPC_BGP_FPU
>> or PPC_BGP_DOUBLE_FPU?
> I'd probably still prefer it disassociated with the CPU name, but we are
> really bike shedding here. I'm not too fussed.
I'll leave it separate and switch it to PPC_FP2 (or would you prefer
PPC_FP2_FPU to make it clear) since the public PDF refers to it this way.
If that all sounds good, I'll spin [V3] tomorrow.
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