mesa,glsl,ttn: Set subgroup_size to UNIFORM

Reviewed-by: Caio Oliveira <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/17337>

src/compiler/glsl/glsl_to_nir.cpp

@@ -253,6 +253,8 @@ glsl_to_nir(const struct gl_constants *consts,
    if (shader_prog->Label)
       shader->info.label = ralloc_strdup(shader, shader_prog->Label);
 
+   shader->info.subgroup_size = SUBGROUP_SIZE_UNIFORM;
+
    if (shader->info.stage == MESA_SHADER_FRAGMENT) {
       shader->info.fs.pixel_center_integer = sh->Program->info.fs.pixel_center_integer;
       shader->info.fs.origin_upper_left = sh->Program->info.fs.origin_upper_left;

src/compiler/shader_enums.h

@@ -1223,6 +1223,12 @@ enum PACKED gl_subgroup_size
    /** Actual subgroup size, whatever that happens to be */
    SUBGROUP_SIZE_VARYING = 0,
 
+   /** Subgroup size must appear to be draw or dispatch-uniform
+    *
+    * This is the OpenGL behavior
+    */
+   SUBGROUP_SIZE_UNIFORM,
+
    /** Subgroup size must appear to be the API advertised constant
     *
     * This is the default Vulkan 1.1 behavior

src/gallium/auxiliary/nir/tgsi_to_nir.c

@@ -2323,6 +2323,8 @@ ttn_compile_init(const void *tgsi_tokens,
       c->cap_face_is_sysval = true;
    }
 
+   s->info.subgroup_size = SUBGROUP_SIZE_UNIFORM;
+
    if (s->info.stage == MESA_SHADER_FRAGMENT)
       s->info.fs.untyped_color_outputs = true;
 

src/mesa/main/glspirv.c

@@ -244,6 +244,7 @@ _mesa_spirv_to_nir(struct gl_context *ctx,
    const struct spirv_to_nir_options spirv_options = {
       .environment = NIR_SPIRV_OPENGL,
       .use_deref_buffer_array_length = true,
+      .subgroup_size = SUBGROUP_SIZE_UNIFORM,
       .caps = ctx->Const.SpirVCapabilities,
       .ubo_addr_format = nir_address_format_32bit_index_offset,
       .ssbo_addr_format = nir_address_format_32bit_index_offset,