[Mesa-dev] [PATCH 2/4] nvc0/ir: Handle reverse subop for OP_EXTBF when folding constant expressions

[Ilia Mirkin]

Can you verify that you tested how the HW handles this, as well as
exactly how you did it (i.e. how did you modify the code + piglit
test, what the results were, etc)

On Thu, May 29, 2014 at 3:43 PM, Tobias Klausmann
<tobias.johannes.klausmann at mni.thm.de> wrote:
> Signed-off-by: Tobias Klausmann <tobias.johannes.klausmann at mni.thm.de>
> ---
>  src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp | 14 ++++++++++++--
>  1 file changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
> index 58092f4..93f7c2a 100644
> --- a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
> +++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
> @@ -529,8 +529,18 @@ ConstantFolding::expr(Instruction *i,
>           lshift = 32 - width - offset;
>        }
>        switch (i->dType) {
> -      case TYPE_S32: res.data.s32 = (a->data.s32 << lshift) >> rshift; break;
> -      case TYPE_U32: res.data.u32 = (a->data.u32 << lshift) >> rshift; break;
> +      case TYPE_S32: {
> +         res.data.s32 = (res.data.s32 << lshift) >> rshift;
> +         if (i->subOp == NV50_IR_SUBOP_EXTBF_REV)
> +            res.data.s32 = util_bitreverse(res.data.s32);
> +         break;
> +      }
> +      case TYPE_U32: {
> +         res.data.u32 = (res.data.u32 << lshift) >> rshift;
> +         if (i->subOp == NV50_IR_SUBOP_EXTBF_REV)
> +            res.data.u32 = util_bitreverse(res.data.u32);
> +         break;
> +      }
>        default:
>           return;
>        }
> --
> 1.8.4.5
>