From 8a61e3a0c0704dcc81fcccb17b815f5f5475b7e0 Mon Sep 17 00:00:00 2001
From: Jason Ekstrand <jason.ekstrand@intel.com>
Date: Fri, 15 Jan 2021 17:20:22 -0600
Subject: [PATCH] anv: Zero out the last dword of UBO/SSBO descriptors in the
 shader

This way, NIR can constant fold it.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8635>
---
 src/intel/vulkan/anv_nir_apply_pipeline_layout.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/intel/vulkan/anv_nir_apply_pipeline_layout.c b/src/intel/vulkan/anv_nir_apply_pipeline_layout.c
index b20733fcb29..02a44a27736 100644
--- a/src/intel/vulkan/anv_nir_apply_pipeline_layout.c
+++ b/src/intel/vulkan/anv_nir_apply_pipeline_layout.c
@@ -549,7 +549,14 @@ build_ssbo_descriptor_load(nir_builder *b, const VkDescriptorType desc_type,
                    .range_base = 0,
                    .range = ~0);
 
-   return desc_load;
+   /* The last element of the vec4 is always zero.
+    *
+    * See also struct anv_address_range_descriptor
+    */
+   return nir_vec4(b, nir_channel(b, desc_load, 0),
+                      nir_channel(b, desc_load, 1),
+                      nir_channel(b, desc_load, 2),
+                      nir_imm_int(b, 0));
 }
 
 static bool