FW: altivec: switch to disable VRSAVE generation

[Alex Rosenberg <alexr at spies dot com>]

Aldy asked me to forward his response to me to the list.

I believe that there are other OSes that use VRSAVE besides Apple. For
example, I think Mercury Computer uses it.

+------------------------------------------------------------+
| Alexander M. Rosenberg           <mailto:alexr@_spies.com> |
| Nobody cares what I say. Remove the underscore to mail me. |


------ Forwarded Message
From: Aldy Hernandez <aldyh@redhat.com>
Reply-To: aldyh@redhat.com
Date: Tue, 30 Apr 2002 17:27:58 -0700
To: Alex Rosenberg <alexr@spies.com>
Subject: Re: altivec: switch to disable VRSAVE generation

> For OSes that require VRSAVE use, disabling it will lead to difficult to
> track down bugs (since context switching will go wrong). It may be worth
> some words in the docs to discourage fiddling with this setting if you're
> not sure if your OS requires VRSAVE or not.
> 
> This comes up all the time due to the attractive checkbox Metrowerks has to
> disable VRSAVE.

either way is fine with me, but according to motorola, only apple uses
vrsave.  i suppose i wasn't taking into consideration other small OSes
being written.

we *could* get really smart and turn it off for linux since we know it's
never used there, but i suppose the safest thing is to leave it on and
provide an option to disable it.

speak up anyone who has any comments.

aldy


------ End of Forwarded Message