[Mesa-dev] [PATCH 1/4] anv: Canonicalize known offsets

[Chris Wilson]

On Thu, May 11, 2017 at 09:32:01AM -0700, Jason Ekstrand wrote:
>    This is probably a good idea thought it doesn't solve any actual bugs ATM
>    since the kernel always provides us canonical offsets.  I considered doing
>    it earlier when I was bringing up 48bit but didn't for that reason.  I dug
>    up the patch I had for doing it directly in genxml and sent it out.  I'm
>    not sure if it's better to do it there or here though if we're going to do
>    it here, then blorp and i965 need to be updated as well.

There's always a chance we get (1<<47)-4096 as the target's offset then
apply a delta past the 1<<47 boundary. Not all deltas are zero here
iirc. Might as well do a belt and braces approach, just in case we ever
do meet that mythical instruction that expects those high bits set.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre