[Mesa-dev] [PATCH] nir: Use a single bit for the dual-source blend index

[Timothy Arceri]

The only values allowed are 0 and 1, and the value is checked before
assigning.

This is a copy of 8eeca7a56c that seems to have been made to the glsl
ir type after it was copied for use in nir but before nir landed.
---
 src/glsl/nir/nir.h | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/glsl/nir/nir.h b/src/glsl/nir/nir.h
index 4551d09..d47f352 100644
--- a/src/glsl/nir/nir.h
+++ b/src/glsl/nir/nir.h
@@ -293,9 +293,13 @@ typedef struct {
       unsigned int driver_location;
 
       /**
-       * output index for dual source blending.
+       * Output index for dual source blending.
+       *
+       * \note
+       * The GLSL spec only allows the values 0 or 1 for the index in \b dual
+       * source blending.
        */
-      int index;
+      unsigned index:1;
 
       /**
        * Initial binding point for a sampler or UBO.
-- 
2.4.3