gallium/tgsi: Split sampler views from shader resources.

This commit splits the current concept of resource into "sampler
views" and "shader resources":

"Sampler views" are textures or buffers that are bound to a given
shader stage and can be read from in conjunction with a sampler
object.  They are analogous to OpenGL texture objects or Direct3D
SRVs.

"Shader resources" are textures or buffers that can be read and
written from a shader.  There's no support for floating point
coordinates, address wrap modes or filtering, and, unlike sampler
views, shader resources are global for the whole graphics pipeline.
They are analogous to OpenGL image objects (as in
ARB_shader_image_load_store) or Direct3D UAVs.

Most hardware is likely to implement shader resources and sampler
views as separate objects, so, having the distinction at the API level
simplifies things slightly for the driver.

This patch introduces the SVIEW register file with a declaration token
and syntax analogous to the already existing RES register file.  After
this change, the SAMPLE_* opcodes no longer accept a resource as
input, but rather a SVIEW object.  To preserve the functionality of
reading from a sampler view with integer coordinates, the
SAMPLE_I(_MS) opcodes are introduced which are similar to LOAD(_MS)
but take a SVIEW register instead of a RES register as argument.

1 files changed, 64 insertions, 24 deletions

diff --git a/src/gallium/auxiliary/tgsi/tgsi_build.c b/src/gallium/auxiliary/tgsi/tgsi_build.c
index 6ec2b0d8f21..6c3f77581f0 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_build.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_build.c
@@ -227,42 +227,66 @@ tgsi_build_declaration_semantic(
    return ds;
 }
 
-
 static struct tgsi_declaration_resource
 tgsi_default_declaration_resource(void)
 {
-   struct tgsi_declaration_resource declaration_resource;
+   struct tgsi_declaration_resource dr;
 
-   declaration_resource.Resource = TGSI_TEXTURE_UNKNOWN;
-   declaration_resource.ReturnTypeX = PIPE_TYPE_UNORM;
-   declaration_resource.ReturnTypeY = PIPE_TYPE_UNORM;
-   declaration_resource.ReturnTypeZ = PIPE_TYPE_UNORM;
-   declaration_resource.ReturnTypeW = PIPE_TYPE_UNORM;
+   dr.Resource = TGSI_BUFFER;
 
-   return declaration_resource;
+   return dr;
 }
 
 static struct tgsi_declaration_resource
 tgsi_build_declaration_resource(unsigned texture,
-                                unsigned return_type_x,
-                                unsigned return_type_y,
-                                unsigned return_type_z,
-                                unsigned return_type_w,
                                 struct tgsi_declaration *declaration,
                                 struct tgsi_header *header)
 {
-   struct tgsi_declaration_resource declaration_resource;
+   struct tgsi_declaration_resource dr;
+
+   dr = tgsi_default_declaration_resource();
+   dr.Resource = texture;
+
+   declaration_grow(declaration, header);
+
+   return dr;
+}
+
+static struct tgsi_declaration_sampler_view
+tgsi_default_declaration_sampler_view(void)
+{
+   struct tgsi_declaration_sampler_view dsv;
+
+   dsv.Resource = TGSI_BUFFER;
+   dsv.ReturnTypeX = PIPE_TYPE_UNORM;
+   dsv.ReturnTypeY = PIPE_TYPE_UNORM;
+   dsv.ReturnTypeZ = PIPE_TYPE_UNORM;
+   dsv.ReturnTypeW = PIPE_TYPE_UNORM;
+
+   return dsv;
+}
+
+static struct tgsi_declaration_sampler_view
+tgsi_build_declaration_sampler_view(unsigned texture,
+                                    unsigned return_type_x,
+                                    unsigned return_type_y,
+                                    unsigned return_type_z,
+                                    unsigned return_type_w,
+                                    struct tgsi_declaration *declaration,
+                                    struct tgsi_header *header)
+{
+   struct tgsi_declaration_sampler_view dsv;
 
-   declaration_resource = tgsi_default_declaration_resource();
-   declaration_resource.Resource = texture;
-   declaration_resource.ReturnTypeX = return_type_x;
-   declaration_resource.ReturnTypeY = return_type_y;
-   declaration_resource.ReturnTypeZ = return_type_z;
-   declaration_resource.ReturnTypeW = return_type_w;
+   dsv = tgsi_default_declaration_sampler_view();
+   dsv.Resource = texture;
+   dsv.ReturnTypeX = return_type_x;
+   dsv.ReturnTypeY = return_type_y;
+   dsv.ReturnTypeZ = return_type_z;
+   dsv.ReturnTypeW = return_type_w;
 
    declaration_grow(declaration, header);
 
-   return declaration_resource;
+   return dsv;
 }
 
 
@@ -276,6 +300,7 @@ tgsi_default_full_declaration( void )
    full_declaration.Semantic = tgsi_default_declaration_semantic();
    full_declaration.ImmediateData.u = NULL;
    full_declaration.Resource = tgsi_default_declaration_resource();
+   full_declaration.SamplerView = tgsi_default_declaration_sampler_view();
 
    return full_declaration;
 }
@@ -375,14 +400,29 @@ tgsi_build_full_declaration(
       size++;
 
       *dr = tgsi_build_declaration_resource(full_decl->Resource.Resource,
-                                            full_decl->Resource.ReturnTypeX,
-                                            full_decl->Resource.ReturnTypeY,
-                                            full_decl->Resource.ReturnTypeZ,
-                                            full_decl->Resource.ReturnTypeW,
                                             declaration,
                                             header);
    }
 
+   if (full_decl->Declaration.File == TGSI_FILE_SAMPLER_VIEW) {
+      struct tgsi_declaration_sampler_view *dsv;
+
+      if (maxsize <= size) {
+         return  0;
+      }
+      dsv = (struct tgsi_declaration_sampler_view *)&tokens[size];
+      size++;
+
+      *dsv = tgsi_build_declaration_sampler_view(
+         full_decl->SamplerView.Resource,
+         full_decl->SamplerView.ReturnTypeX,
+         full_decl->SamplerView.ReturnTypeY,
+         full_decl->SamplerView.ReturnTypeZ,
+         full_decl->SamplerView.ReturnTypeW,
+         declaration,
+         header);
+   }
+
    return size;
 }