[Mesa-dev] [PATCH 01/10] nir: Convert ineg(b2i(a)) to a if it's a boolean.

[Matt Turner]

On Sat, Jan 7, 2017 at 3:58 AM, Timothy Arceri
<timothy.arceri at collabora.com> wrote:
> From: Kenneth Graunke <kenneth at whitecape.org>
>
> On BDW:
>
> total instructions in shared programs: 13071119 -> 13070371 (-0.01%)
> instructions in affected programs: 83424 -> 82676 (-0.90%)
> helped: 505
> HURT: 45 (all TCS, all hurt by a single instruction)

I investigated these hurt programs when Ken originally sent the patch.
They're all because of the extra not.nz instruction.

I sent a patch "i965: Turn not.nz x into cmp.z x,0." that fixed that,
was Ken noticed it was subtly wrong. Maybe you can spot another way of
doing the same thing.

Regardless,

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