[Mesa-dev] [PATCH v2] nir: add a comparison simplification

[Timothy Arceri]

On 16/03/18 17:24, Jason Ekstrand wrote:
> Assuming the thing I typed in my phone actually works, r-b. :-). I'm a 
> bit surprised we didn't already have that one. It seems so obvious in 
> hindsight.

Yeah it worked :) and picked up one more combo I missed. The previous 
patch only impacted Tomb Raider and nothing else in shader-db so I guess 
that's why nobody has noticed before.

> 
> 
> On March 15, 2018 22:48:24 Timothy Arceri <tarceri at itsqueeze.com> wrote:
> 
>> These can be found in the Tomb Raider shaders, eliminating them
>> helps unroll more loops.
>> ---
>>  src/compiler/nir/nir_opt_algebraic.py | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/src/compiler/nir/nir_opt_algebraic.py 
>> b/src/compiler/nir/nir_opt_algebraic.py
>> index c9575e6be4..2148bc121b 100644
>> --- a/src/compiler/nir/nir_opt_algebraic.py
>> +++ b/src/compiler/nir/nir_opt_algebraic.py
>> @@ -152,6 +152,7 @@ optimizations = [
>>     (('inot', ('ige', a, b)), ('ilt', a, b)),
>>     (('inot', ('ieq', a, b)), ('ine', a, b)),
>>     (('inot', ('ine', a, b)), ('ieq', a, b)),
>> +   (('ine', ('b2i', 'a at bool'), 0), 'a'),
>>
>>     # 0.0 >= b2f(a)
>>     # b2f(a) <= 0.0
>> -- 
>> 2.14.3
>>
> 
>