[Mesa-dev] [PATCH 2/6] i965/fs: copy propagate 'NOT' instruction when used with logical operation

Matt Turner mattst88 at gmail.com
Wed Jun 4 15:12:36 PDT 2014

On Tue, Jun 3, 2014 at 3:59 PM, Abdiel Janulgue
<abdiel.janulgue at linux.intel.com> wrote:
> On Broadwell, this reduces the instruction to 1 operation when NOT is used with
> a logical instruction

I expected patch #2 to fix the bug were we'd copy propagate

mov a, -b
and c, e, a

and yield

and c, e, -b

As it is, this patch is allowing copy propagation from a NOT
instruction on Broadwell into any instruction, not just logical

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