[Nouveau] [PATCH] nv50/ir: Handle OP_CVT when folding constant expressions

[Ilia Mirkin]

On Sun, Jan 11, 2015 at 4:40 PM, Tobias Klausmann
<tobias.johannes.klausmann at mni.thm.de> wrote:
> Folding for conversions: F32->(U{16/32}, S{16/32}) and (U{16/32}, {S16/32})->F32
>
> Signed-off-by: Tobias Klausmann <tobias.johannes.klausmann at mni.thm.de>
> ---
> V2: Split out F64 parts
> V3: remove handling of saturate for (U/S)32,
>
>  .../drivers/nouveau/codegen/nv50_ir_peephole.cpp   | 73 ++++++++++++++++++++++
>  1 file changed, 73 insertions(+)
>
> diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
> index 21d20ca..aaf0d0d 100644
> --- a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
> +++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
> @@ -997,6 +997,79 @@ ConstantFolding::opnd(Instruction *i, ImmediateValue &imm0, int s)
>        i->op = OP_MOV;
>        break;
>     }
> +   case OP_CVT: {
> +      Storage res;
> +      bld.setPosition(i, true); /* make sure bld is init'ed */
> +      switch(i->dType) {
> +      case TYPE_U16:
> +         switch (i->sType) {
> +         case TYPE_F32:
> +            if (i->saturate)
> +               res.data.u16 = util_iround(CLAMP(imm0.reg.data.f32, 0,
> +                                                UINT16_MAX));
> +            else
> +              res.data.u16 = util_iround(imm0.reg.data.f32);
> +            break;
> +         default:
> +            return;
> +         }

This won't get hit for the U32 -> U16 conversion though right? Did you
test that case? Am I misreading/misunderstanding perhaps?

  -ilia