anv: Emulate texture swizzle in the shader when needed

Now that we have the descriptor buffer mechanism, emulated texture
swizzle can be implemented in a very non-invasive way.  Previous
attempts all tried to extend the push constant based image param
mechanism which was gross.  This could, in theory, be done much faster
with a magic back-end instruction which does indirect MOVs but Vulkan on
IVB is already so slow this isn't going to matter much.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104355
Cc: "19.1" <[email protected]>
Reviewed-by: Lionel Landwerlin <[email protected]>
(cherry picked from commit d2aa65eb1892f7b300ac24560f9dbda6b600b5a7)

1 files changed, 13 insertions, 0 deletions

diff --git a/src/intel/vulkan/anv_private.h b/src/intel/vulkan/anv_private.h
index 2d3abe3961b..7501188903c 100644
--- a/src/intel/vulkan/anv_private.h
+++ b/src/intel/vulkan/anv_private.h
@@ -1548,6 +1548,17 @@ struct anv_sampled_image_descriptor {
    uint32_t sampler;
 };
 
+struct anv_texture_swizzle_descriptor {
+   /** Texture swizzle
+    *
+    * See also nir_intrinsic_channel_select_intel
+    */
+   uint8_t swizzle[4];
+
+   /** Unused padding to ensure the struct is a multiple of 64 bits */
+   uint32_t _pad;
+};
+
 /** Struct representing a storage image descriptor */
 struct anv_storage_image_descriptor {
    /** Bindless image handles
@@ -1589,6 +1600,8 @@ enum anv_descriptor_data {
    ANV_DESCRIPTOR_SAMPLED_IMAGE  = (1 << 6),
    /** Storage image handles */
    ANV_DESCRIPTOR_STORAGE_IMAGE  = (1 << 7),
+   /** Storage image handles */
+   ANV_DESCRIPTOR_TEXTURE_SWIZZLE  = (1 << 8),
 };
 
 struct anv_descriptor_set_binding_layout {