1 files changed, 67 insertions, 0 deletions
diff --git a/src/vulkan/util/vk_util_compiler.c b/src/vulkan/util/vk_util_compiler.c
new file mode 100644
index 00000000000..619644ca830
--- /dev/null
+++ b/src/vulkan/util/vk_util_compiler.c
@@ -0,0 +1,67 @@
+/*
+ * Copyright 2024 Google LLC
+ * SPDX-License-Identifier: MIT
+ */
+
+#include "vk_util_compiler.h"
+#include "compiler/spirv/nir_spirv.h"
+
+struct nir_spirv_specialization*
+vk_spec_info_to_nir_spirv(const VkSpecializationInfo *spec_info,
+                          uint32_t *out_num_spec_entries)
+{
+   if (spec_info == NULL || spec_info->mapEntryCount == 0)
+      return NULL;
+
+   uint32_t num_spec_entries = spec_info->mapEntryCount;
+   struct nir_spirv_specialization *spec_entries =
+      calloc(num_spec_entries, sizeof(*spec_entries));
+
+   for (uint32_t i = 0; i < num_spec_entries; i++) {
+      VkSpecializationMapEntry entry = spec_info->pMapEntries[i];
+      const void *data = (uint8_t *)spec_info->pData + entry.offset;
+      assert((uint8_t *)data + entry.size <=
+             (uint8_t *)spec_info->pData + spec_info->dataSize);
+
+      spec_entries[i].id = spec_info->pMapEntries[i].constantID;
+      switch (entry.size) {
+      case 8:
+         spec_entries[i].value.u64 = *(const uint64_t *)data;
+         break;
+      case 4:
+         spec_entries[i].value.u32 = *(const uint32_t *)data;
+         break;
+      case 2:
+         spec_entries[i].value.u16 = *(const uint16_t *)data;
+         break;
+      case 1:
+         spec_entries[i].value.u8 = *(const uint8_t *)data;
+         break;
+      case 0:
+      default:
+         /* The Vulkan spec says:
+          *
+          *    "For a constantID specialization constant declared in a
+          *    shader, size must match the byte size of the constantID. If
+          *    the specialization constant is of type boolean, size must be
+          *    the byte size of VkBool32."
+          *
+          * Therefore, since only scalars can be decorated as
+          * specialization constants, we can assume that if it doesn't have
+          * a size of 1, 2, 4, or 8, any use in a shader would be invalid
+          * usage.  The spec further says:
+          *
+          *    "If a constantID value is not a specialization constant ID
+          *    used in the shader, that map entry does not affect the
+          *    behavior of the pipeline."
+          *
+          * so we should ignore any invalid specialization constants rather
+          * than crash or error out when we see one.
+          */
+         break;
+      }
+   }
+
+   *out_num_spec_entries = num_spec_entries;
+   return spec_entries;
+}