spirv: handle UniformConstant for OpenCL kernels

The caller is responsible for setting up the ubo_addr_format value as
contrary to shared and global, it's not controlled by the spirv.

Right now clovers implementation of CL constant memory uses a 24/8 bit format
to encode the buffer index and offset, but that code is dead as all backends
treat constants as global memory to workaround annoying issues within OpenCL.

Maybe that will change, maybe not. But just in case somebody wants to look at
it, add a toggle for this inside vtn.

Signed-off-by: Karol Herbst <[email protected]>
Reviewed-by: Dave Airlie <[email protected]>

3 files changed, 19 insertions, 2 deletions

diff --git a/src/compiler/spirv/nir_spirv.h b/src/compiler/spirv/nir_spirv.h
index d5978a81bb4..81175ebf022 100644
--- a/src/compiler/spirv/nir_spirv.h
+++ b/src/compiler/spirv/nir_spirv.h
@@ -83,6 +83,12 @@ struct spirv_to_nir_options {
    nir_address_format global_addr_format;
    nir_address_format temp_addr_format;
 
+   /* Whether UniformConstant memory should be treated as normal global memory.
+    * This is usefull for CL 2.0 implementations with fine grain system SVM
+    * support.
+    */
+   bool constant_as_global;
+
    struct {
       void (*func)(void *private_data,
                    enum nir_spirv_debug_level level,
diff --git a/src/compiler/spirv/spirv_to_nir.c b/src/compiler/spirv/spirv_to_nir.c
index 0c1813b139d..aff11a2d579 100644
--- a/src/compiler/spirv/spirv_to_nir.c
+++ b/src/compiler/spirv/spirv_to_nir.c
@@ -1351,6 +1351,7 @@ vtn_handle_type(struct vtn_builder *b, SpvOp opcode,
             case SpvStorageClassFunction:
             case SpvStorageClassWorkgroup:
             case SpvStorageClassCrossWorkgroup:
+            case SpvStorageClassUniformConstant:
                val->type->stride = align(glsl_get_cl_size(val->type->deref->type),
                                          glsl_get_cl_alignment(val->type->deref->type));
                break;
diff --git a/src/compiler/spirv/vtn_variables.c b/src/compiler/spirv/vtn_variables.c
index 755d85642a0..d7edabb5656 100644
--- a/src/compiler/spirv/vtn_variables.c
+++ b/src/compiler/spirv/vtn_variables.c
@@ -1816,8 +1816,18 @@ vtn_storage_class_to_mode(struct vtn_builder *b,
       nir_mode = nir_var_mem_global;
       break;
    case SpvStorageClassUniformConstant:
-      mode = vtn_variable_mode_uniform;
-      nir_mode = nir_var_uniform;
+      if (b->shader->info.stage == MESA_SHADER_KERNEL) {
+         if (b->options->constant_as_global) {
+            mode = vtn_variable_mode_cross_workgroup;
+            nir_mode = nir_var_mem_global;
+         } else {
+            mode = vtn_variable_mode_ubo;
+            nir_mode = nir_var_mem_ubo;
+         }
+      } else {
+         mode = vtn_variable_mode_uniform;
+         nir_mode = nir_var_uniform;
+      }
       break;
    case SpvStorageClassPushConstant:
       mode = vtn_variable_mode_push_constant;