[Mesa-dev] [PATCH] nir: propagate known constant values into the if-then branch

[Caio Marcelo de Oliveira Filho]

Hi,

I like this patch, did it get dropped for a specific reason or just
forgotten?


shader-db results skl:

total instructions in shared programs: 15049273 -> 15049211 (<.01%)
instructions in affected programs: 75678 -> 75616 (-0.08%)
helped: 197
HURT: 8

total cycles in shared programs: 369994915 -> 370136090 (0.04%)
cycles in affected programs: 1750477 -> 1891652 (8.06%)
helped: 91
HURT: 91

total loops in shared programs: 4401 -> 4401 (0.00%)
loops in affected programs: 0 -> 0
helped: 0
HURT: 0

total spills in shared programs: 10159 -> 10159 (0.00%)
spills in affected programs: 0 -> 0
helped: 0
HURT: 0

total fills in shared programs: 22118 -> 22118 (0.00%)
fills in affected programs: 0 -> 0
helped: 0
HURT: 0

LOST:   0
GAINED: 0



> +static bool
> +opt_for_known_values(nir_builder *b, nir_if *nif)
> +{
> +   bool progress = false;

Remove because unused.


> +      nir_ssa_def *src0 = alu->src[0].src.ssa;
> +      nir_ssa_def *src1 = alu->src[1].src.ssa;
> +      if (src0a->parent_instr->type == nir_instr_type_load_const) {

You fixed this already.


> +
> +      break;
> +   }
> +
> +   default:
> +      return false;
> +   }
> +
> +   return false;

Optional: unless you plan to add more cases here, consider replacing
the switch with an if (alu->op == ... || alu->op == ...), so you don't
have this noise at the end.


With the 'progress' and the 'src0a' fixes, this patch is

Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira at intel.com>


	Caio