nir: pack nir_variable::data::xfb_*

Reviewed-by: Connor Abbott <cwabbott0@gmail.com>

src/compiler/glsl/glsl_to_nir.cpp

@@ -600,14 +600,17 @@ nir_visitor::visit(ir_variable *ir)
    var->data.bindless = ir->data.bindless;
    var->data.offset = ir->data.offset;
 
-   var->data.image.access = (gl_access_qualifier)image_access;
-   var->data.image.format = ir->data.image_format;
+   if (var->type->is_image()) {
+      var->data.image.access = (gl_access_qualifier)image_access;
+      var->data.image.format = ir->data.image_format;
+   } else {
+      var->data.xfb.buffer = ir->data.xfb_buffer;
+      var->data.xfb.stride = ir->data.xfb_stride;
+   }
 
    var->data.fb_fetch_output = ir->data.fb_fetch_output;
    var->data.explicit_xfb_buffer = ir->data.explicit_xfb_buffer;
    var->data.explicit_xfb_stride = ir->data.explicit_xfb_stride;
-   var->data.xfb_buffer = ir->data.xfb_buffer;
-   var->data.xfb_stride = ir->data.xfb_stride;
 
    var->num_state_slots = ir->get_num_state_slots();
    if (var->num_state_slots > 0) {

src/compiler/nir/nir.h

@@ -478,25 +478,29 @@ typedef struct nir_variable {
        */
       unsigned offset;
 
-      /**
-       * Transform feedback buffer.
-       */
-      unsigned xfb_buffer;
-
-      /**
-       * Transform feedback stride.
-       */
-      unsigned xfb_stride;
-
-      /**
-       * ARB_shader_image_load_store qualifiers.
-       */
-      struct {
-         enum gl_access_qualifier access;
-
-         /** Image internal format if specified explicitly, otherwise GL_NONE. */
-         GLenum format;
-      } image;
+      union {
+         /**
+          * ARB_shader_image_load_store qualifiers.
+          */
+         struct {
+            enum gl_access_qualifier access;
+
+            /** Image internal format if specified explicitly, otherwise GL_NONE. */
+            GLenum format;
+         } image;
+
+         struct {
+            /**
+             * Transform feedback buffer.
+             */
+            uint16_t buffer:2;
+
+            /**
+             * Transform feedback stride.
+             */
+            uint16_t stride;
+         } xfb;
+      };
    } data;
 
    /* Number of nir_variable_data members */

src/compiler/nir/nir_gather_xfb_info.c

@@ -38,9 +38,9 @@ add_var_xfb_varying(nir_xfb_info *xfb,
    nir_xfb_varying_info *varying = &varyings->varyings[varyings->varying_count++];
 
    varying->type = type;
-   varying->buffer = var->data.xfb_buffer;
+   varying->buffer = var->data.xfb.buffer;
    varying->offset = offset;
-   xfb->buffers[var->data.xfb_buffer].varying_count++;
+   xfb->buffers[var->data.xfb.buffer].varying_count++;
 }
 
 
@@ -100,11 +100,11 @@ add_var_xfb_outputs(nir_xfb_info *xfb,
    } else {
       assert(buffer < NIR_MAX_XFB_BUFFERS);
       if (xfb->buffers_written & (1 << buffer)) {
-         assert(xfb->buffers[buffer].stride == var->data.xfb_stride);
+         assert(xfb->buffers[buffer].stride == var->data.xfb.stride);
          assert(xfb->buffer_to_stream[buffer] == var->data.stream);
       } else {
          xfb->buffers_written |= (1 << buffer);
-         xfb->buffers[buffer].stride = var->data.xfb_stride;
+         xfb->buffers[buffer].stride = var->data.xfb.stride;
          xfb->buffer_to_stream[buffer] = var->data.stream;
       }
 
@@ -235,7 +235,7 @@ nir_gather_xfb_info_with_varyings(const nir_shader *shader,
 
       if (var->data.explicit_offset && !is_array_block) {
          unsigned offset = var->data.offset;
-         add_var_xfb_outputs(xfb, varyings_info, var, var->data.xfb_buffer,
+         add_var_xfb_outputs(xfb, varyings_info, var, var->data.xfb.buffer,
                              &location, &offset, var->type, false);
       } else if (is_array_block) {
          assert(glsl_type_is_struct_or_ifc(var->interface_type));
@@ -253,7 +253,7 @@ nir_gather_xfb_info_with_varyings(const nir_shader *shader,
                }
 
                unsigned offset = foffset;
-               add_var_xfb_outputs(xfb, varyings_info, var, var->data.xfb_buffer + b,
+               add_var_xfb_outputs(xfb, varyings_info, var, var->data.xfb.buffer + b,
                                    &location, &offset, ftype, false);
             }
          }

src/compiler/spirv/vtn_variables.c

@@ -1586,12 +1586,12 @@ apply_var_decoration(struct vtn_builder *b,
 
    case SpvDecorationXfbBuffer:
       var_data->explicit_xfb_buffer = true;
-      var_data->xfb_buffer = dec->operands[0];
+      var_data->xfb.buffer = dec->operands[0];
       var_data->always_active_io = true;
       break;
    case SpvDecorationXfbStride:
       var_data->explicit_xfb_stride = true;
-      var_data->xfb_stride = dec->operands[0];
+      var_data->xfb.stride = dec->operands[0];
       break;
    case SpvDecorationOffset:
       var_data->explicit_offset = true;