[Nouveau] [PATCH v2 4/4] nvc0/ir: Handle OP_POPCNT when folding constant expressions

[Ilia Mirkin]

On Tue, Jun 3, 2014 at 4:58 PM, Tobias Klausmann
<tobias.johannes.klausmann at mni.thm.de> wrote:
> V2: Add support for a single-argument version of POPCNT for Maxwell (SM5)
>
> Signed-off-by: Tobias Klausmann <tobias.johannes.klausmann at mni.thm.de>
> ---
>  src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
>
> diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
> index c497335..19767b4 100644
> --- a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
> +++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
> @@ -548,6 +548,10 @@ ConstantFolding::expr(Instruction *i,
>        }
>        break;
>     }
> +   case OP_POPCNT: {
> +         res.data.u32 = util_bitcount(a->data.u32 & b->data.u32); break;
> +      break;

Do you really need 2 breaks here? Also, funy indentation.

> +   }
>     default:
>        return;
>     }
> @@ -966,6 +970,17 @@ ConstantFolding::opnd(Instruction *i, ImmediateValue &imm0, int s)
>        i->subOp = 0;
>        break;
>     }
> +   case OP_POPCNT: {
> +      uint32_t res;
> +      if (!i->srcExists(1)) {
> +         res = util_bitcount(imm0.reg.data.u32);
> +         i->setSrc(0, new_ImmediateValue(i->bb->getProgram(), res));
> +         i->setSrc(1, NULL);

A little overkill -- src(1) already doesn't exist... can get rid of
that, I think.

> +         i->op = OP_MOV;
> +         i->subOp = 0;
> +      }
> +      break;
> +   }
>     default:
>        return;
>     }
> --
> 1.8.4.5
>