[Mesa-dev] [PATCH 1/2] i965/vec4: Handle nir_instr_type_deref to silence run-time output

[Jason Ekstrand]

Do we do this in fs?  I'm very confused as to how any deref instructions 
can survive this late.  They can for fs but only for images (not textures). 
I would expect them to be killed off by DCE long before we get here.

On July 3, 2018 00:26:32 "Ian Romanick" <idr at freedesktop.org> wrote:

> From: Ian Romanick <ian.d.romanick at intel.com>
>
> Previously, shader-db runs on Gen5 through Haswell would spew tons of
> messages like:
>
>    VS instruction not yet implemented by NIR->vec4
>
> I checked several instance of this, and all of them were
> nir_instr_type_deref instructions in vertex shaders that had texture
> accesses (e.g., UnrealEngine4/EffectsCaveDemo/239.shader_test).
>
> Solution copied directly from fs_visitor::nir_emit_instr.
>
> Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
> Fixes: 5a02ffb733e nir: Rework lower_locals_to_regs to use deref instructions
> Cc: Jason Ekstrand <jason at jlekstrand.net>
> ---
> src/intel/compiler/brw_vec4_nir.cpp | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/src/intel/compiler/brw_vec4_nir.cpp 
> b/src/intel/compiler/brw_vec4_nir.cpp
> index 7131fa06b4a..5f45d5b0c98 100644
> --- a/src/intel/compiler/brw_vec4_nir.cpp
> +++ b/src/intel/compiler/brw_vec4_nir.cpp
> @@ -168,6 +168,10 @@ vec4_visitor::nir_emit_instr(nir_instr *instr)
>       nir_emit_undef(nir_instr_as_ssa_undef(instr));
>       break;
>
> +   case nir_instr_type_deref:
> +      /* Derefs can exist for images but they do nothing */
> +      break;
> +
>    default:
>       fprintf(stderr, "VS instruction not yet implemented by NIR->vec4\n");
>       break;
> --
> 2.14.4