From 7fce39484e68c0022b64357f844c9cc7e5853ea1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Iv=C3=A1n=20Briano?= <ivan.briano@intel.com>
Date: Tue, 23 Jul 2024 10:30:06 -0700
Subject: [PATCH] nir: add pass to convert ViewIndex to DeviceIndex

Used to implement VK_PIPELINE_CREATE_VIEW_INDEX_FROM_DEVICE_INDEX_BIT_KHR.

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30329>
---
 src/compiler/nir/meson.build                  |  1 +
 src/compiler/nir/nir.h                        |  2 ++
 .../nir_lower_view_index_to_device_index.c    | 24 +++++++++++++++++++
 3 files changed, 27 insertions(+)
 create mode 100644 src/compiler/nir/nir_lower_view_index_to_device_index.c

diff --git a/src/compiler/nir/meson.build b/src/compiler/nir/meson.build
index edb831fc528..000bdaf026a 100644
--- a/src/compiler/nir/meson.build
+++ b/src/compiler/nir/meson.build
@@ -203,6 +203,7 @@ files_libnir = files(
   'nir_lower_var_copies.c',
   'nir_lower_vec_to_regs.c',
   'nir_lower_vec3_to_vec4.c',
+  'nir_lower_view_index_to_device_index.c',
   'nir_lower_viewport_transform.c',
   'nir_lower_wpos_center.c',
   'nir_lower_wpos_ytransform.c',
diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
index c423398c167..65b9b9acb29 100644
--- a/src/compiler/nir/nir.h
+++ b/src/compiler/nir/nir.h
@@ -6512,6 +6512,8 @@ bool nir_shader_uses_view_index(nir_shader *shader);
 bool nir_can_lower_multiview(nir_shader *shader);
 bool nir_lower_multiview(nir_shader *shader, uint32_t view_mask);
 
+bool nir_lower_view_index_to_device_index(nir_shader *shader);
+
 typedef enum {
    nir_lower_fp16_rtz = (1 << 0),
    nir_lower_fp16_rtne = (1 << 1),
diff --git a/src/compiler/nir/nir_lower_view_index_to_device_index.c b/src/compiler/nir/nir_lower_view_index_to_device_index.c
new file mode 100644
index 00000000000..7010bd27cea
--- /dev/null
+++ b/src/compiler/nir/nir_lower_view_index_to_device_index.c
@@ -0,0 +1,24 @@
+/*
+ * Copyright 2024 Intel Corporation
+ * SPDX-License-Identifier: MIT
+ */
+
+#include "nir.h"
+
+bool
+nir_lower_view_index_to_device_index(nir_shader *shader)
+{
+   bool progress = false;
+
+   nir_foreach_variable_with_modes(var, shader, nir_var_system_value) {
+      if (var->data.location == SYSTEM_VALUE_VIEW_INDEX) {
+         var->data.location = SYSTEM_VALUE_DEVICE_INDEX;
+         progress = true;
+         /* Can there be more than one of these or should we break here? */
+      }
+   }
+
+   nir_shader_preserve_all_metadata(shader);
+
+   return progress;
+}