anv: Add support for shaderStorageImageWriteWithoutFormat

This allows shaders to write to storage images declared with unknown
format if they are decorated with NonReadable ("writeonly" in GLSL).

Previously an image view would always use a lowered format for its
surface state, however when a shader declares a write-only image, we
should use the real format. Since we don't know at view creation time
whether it will be used with only write-only images in shaders, create
two surface states using both the original format and the lowered
format. When emitting the binding table, choose between the states
based on whether the image is declared write-only in the shader.

Tested on both Sascha Willems' computeshader sample (with the original
shaders and ones modified to declare images writeonly and omit their
format qualifiers) and on our own shaders for which we need support
for this.

Signed-off-by: Alex Smith <[email protected]>
Reviewed-by: Lionel Landwerlin <[email protected]>
Reviewed-by: Jason Ekstrand <[email protected]>

1 files changed, 10 insertions, 1 deletions

diff --git a/src/intel/vulkan/anv_private.h b/src/intel/vulkan/anv_private.h
index 51e85c74bd1..ec791a42871 100644
--- a/src/intel/vulkan/anv_private.h
+++ b/src/intel/vulkan/anv_private.h
@@ -953,6 +953,9 @@ struct anv_pipeline_binding {
 
    /* Input attachment index (relative to the subpass) */
    uint8_t input_attachment_index;
+
+   /* For a storage image, whether it is write-only */
+   bool write_only;
 };
 
 struct anv_pipeline_layout {
@@ -1683,8 +1686,13 @@ struct anv_image_view {
    /** RENDER_SURFACE_STATE when using image as a sampler surface. */
    struct anv_state sampler_surface_state;
 
-   /** RENDER_SURFACE_STATE when using image as a storage image. */
+   /**
+    * RENDER_SURFACE_STATE when using image as a storage image. Separate states
+    * for write-only and readable, using the real format for write-only and the
+    * lowered format for readable.
+    */
    struct anv_state storage_surface_state;
+   struct anv_state writeonly_storage_surface_state;
 
    struct brw_image_param storage_image_param;
 };
@@ -1715,6 +1723,7 @@ struct anv_buffer_view {
 
    struct anv_state surface_state;
    struct anv_state storage_surface_state;
+   struct anv_state writeonly_storage_surface_state;
 
    struct brw_image_param storage_image_param;
 };