[Mesa-dev] [PATCH] i965: Emit IF/ELSE/ENDIF/WHILE JIP with type W on Gen7

[Matt Turner]

On Fri, Mar 13, 2015 at 3:41 AM, Antia Puentes <apuentes at igalia.com> wrote:
> IvyBridge and Haswell PRM say that the JIP should be emitted
> with type W but we were using UD. The previous implementation
> did not show adverse effects, however changing the type to
> D caused a GPU hang, see bug 84557; IMHO it is safer to
> follow the specification thoroughly.
> ---

The change seems fine to me, though changing the type to D never
seemed like the thing that was actually causing the hang. It seemed
much more likely that allowing the ELSE and ENDIF instructions to be
compacted violated some assumption in our code and we misaligned some
jump target by 8-bytes.

I should investigate more.

I'd probably remove the "however changing the type to D caused a GPU
hang, see bug 84557" comment from the commit.

Reviewed-by: Matt Turner <mattst88 at gmail.com>