[Mesa-dev] [PATCH 3/7] i965: Assert that SYSTEM_VALUE_VERTEX_ID gets lowered

[Ian Romanick]

On 12/15/2015 12:28 AM, Kristian Høgsberg Kristensen wrote:
> fs_visitor::emit_vs_system_value() looks like it's trying to handle
> SYSTEM_VALUE_VERTEX_ID, but we should never see that value in the
> backend.
> ---
>  src/mesa/drivers/dri/i965/brw_fs_visitor.cpp | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
> index 68f2548..d5193a9 100644
> --- a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
> +++ b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
> @@ -46,6 +46,7 @@ fs_visitor::emit_vs_system_value(int location)
>        vs_prog_data->uses_vertexid = true;
>        break;
>     case SYSTEM_VALUE_VERTEX_ID:
> +      unreachable("should have been lowered");
>     case SYSTEM_VALUE_VERTEX_ID_ZERO_BASE:
>        reg->reg_offset = 2;
>        vs_prog_data->uses_vertexid = true;
> 

There was some reason that Ken and I decided to do this like this, but I
don't remember what it was.  I *think* this is probably a good change,
but I'd like Ken to weigh in.