nir: Add a cubemap normalizing pass

This commit adds a pass to L1-normalize cube-map coordinates.  Some hardware
such as i965 requires that largest cube-map coordinate is +-1.  We had a
pass to perform this normalization in GLSL IR but we need it in NIR for
cube maps on ARB programs to work correctly.

Reviewed-by: Jordan Justen <[email protected]>

v2 (Suggested by Eric):
 - Do a vector fabs and split into components later
 - Move to core NIR

Reviewed-by: Eric Anholt <[email protected]>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/glsl/nir/nir.h b/src/glsl/nir/nir.h
index 0509e64e1e2..199ecc0e3d3 100644
--- a/src/glsl/nir/nir.h
+++ b/src/glsl/nir/nir.h
@@ -1616,6 +1616,8 @@ void nir_lower_tex_projector(nir_shader *shader);
 void nir_lower_atomics(nir_shader *shader);
 void nir_lower_to_source_mods(nir_shader *shader);
 
+void nir_normalize_cubemap_coords(nir_shader *shader);
+
 void nir_live_variables_impl(nir_function_impl *impl);
 bool nir_ssa_defs_interfere(nir_ssa_def *a, nir_ssa_def *b);