[Mesa-dev] [PATCH v3 04/32] glsl: make component_slots() returns 2 for samplers/images

[Samuel Pitoiset]

Bindless samplers/images are 64-bit unsigned integers, which
means they consume two components as specified by
ARB_bindless_texture.

It looks like we are not wasting uniform storage by changing
this because default-block uniforms are not packed. So, if
we use N uint uniforms, they occupy N * 16 bytes in the
constant buffer. This is something that could be improved.

Though, count_uniform_size needs to be adjusted to not count
a sampler (or image) twice.

As a side effect, this will probably break the cache if you
have one because it will consider sampler/image types as
two components.

v3: - update the comments

Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
---
 src/compiler/glsl/link_uniforms.cpp | 8 ++++++--
 src/compiler/glsl_types.cpp         | 2 ++
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/compiler/glsl/link_uniforms.cpp b/src/compiler/glsl/link_uniforms.cpp
index f1e0885fbd..0a199dbbd6 100644
--- a/src/compiler/glsl/link_uniforms.cpp
+++ b/src/compiler/glsl/link_uniforms.cpp
@@ -340,9 +340,13 @@ private:
       if (type->contains_subroutine()) {
          this->num_shader_subroutines += values;
       } else if (type->contains_sampler()) {
-         this->num_shader_samplers += values;
+         /* Samplers (bound or bindless) are counted as two components as
+          * specified by ARB_bindless_texture. */
+         this->num_shader_samplers += values / 2;
       } else if (type->contains_image()) {
-         this->num_shader_images += values;
+         /* Images (bound or bindless) are counted as two components as
+          * specified by ARB_bindless_texture. */
+         this->num_shader_images += values / 2;
 
          /* As drivers are likely to represent image uniforms as
           * scalar indices, count them against the limit of uniform
diff --git a/src/compiler/glsl_types.cpp b/src/compiler/glsl_types.cpp
index bf078ad614..89f611d0cb 100644
--- a/src/compiler/glsl_types.cpp
+++ b/src/compiler/glsl_types.cpp
@@ -1293,6 +1293,8 @@ glsl_type::component_slots() const
 
    case GLSL_TYPE_SAMPLER:
    case GLSL_TYPE_IMAGE:
+      return 2;
+
    case GLSL_TYPE_SUBROUTINE:
       return 1;
 
-- 
2.12.2