[Mesa-dev] [PATCH] i965/fs: Split VGRFs after lowering pull constants

[Jason Ekstrand]

The following shader test exercises the bug:

[require]
GLSL >= 1.10

[vertex shader]
void main()
{
   gl_Position = gl_Vertex;
}

[fragment shader]
uniform float f[4];
uniform ivec4 s;

void main()
{
   gl_FragColor = vec4(f[s.x], f[s.y], f[s.z], f[s.w]);
}

[test]
uniform float f[0] 0.0
uniform float f[1] 1.0
uniform ivec4 s 0 1 0 1
draw rect -1 -1 2 2

On Wed, Aug 19, 2015 at 2:32 PM, Jason Ekstrand <jason at jlekstrand.net> wrote:
> The split_virtual_grfs code doesn't properly rewrite reladdr so we need to
> make sure that any uniform indirects are lowered away first.
> ---
>  src/mesa/drivers/dri/i965/brw_fs.cpp | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
> index 2a4cbff..3d55dc8 100644
> --- a/src/mesa/drivers/dri/i965/brw_fs.cpp
> +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
> @@ -4784,11 +4784,11 @@ fs_visitor::optimize()
>      */
>     bld = fs_builder(this, 64);
>
> -   split_virtual_grfs();
> -
>     assign_constant_locations();
>     lower_constant_loads();
>
> +   split_virtual_grfs();
> +
>  #define OPT(pass, args...) ({                                           \
>        pass_num++;                                                       \
>        bool this_progress = pass(args);                                  \
> --
> 2.4.3
>