nir: Add blend_const_color_rgba sysval

This represents a float vec4 constant color, as passed to glBlendColor.
While the existing 4 shader sysvals are retained to minimize code churn,
a single vectorized intrinsic is required for efficient blending on
vector architectures. (This may also apply to archictectures like
Bifrost where ALU is scalar but load/store is vector; it largely depends
on how blending is implemented per-driver.)

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>

diff --git a/src/compiler/nir/nir_intrinsics.py b/src/compiler/nir/nir_intrinsics.py
index 3a0470c2ca1f60569e11495faf7b734a0321049b..df459a3cdec20f2ad7b3a7ba05390734d19535a9 100644 (file)
--- a/src/compiler/nir/nir_intrinsics.py
+++ b/src/compiler/nir/nir_intrinsics.py
@@ -568,11 +568,14 @@ system_value("viewport_z_offset", 1)
 system_value("viewport_scale", 3)
 system_value("viewport_offset", 3)
 
-# Blend constant color values.  Float values are clamped.#
+# Blend constant color values.  Float values are clamped. Vectored versions are
+# provided as well for driver convenience
+
 system_value("blend_const_color_r_float", 1)
 system_value("blend_const_color_g_float", 1)
 system_value("blend_const_color_b_float", 1)
 system_value("blend_const_color_a_float", 1)
+system_value("blend_const_color_rgba", 4)
 system_value("blend_const_color_rgba8888_unorm", 1)
 system_value("blend_const_color_aaaa8888_unorm", 1)