linker: Add padding after the last field of a structure
authorIan Romanick <ian.d.romanick@intel.com>
Wed, 16 Jul 2014 22:40:32 +0000 (15:40 -0700)
committerIan Romanick <ian.d.romanick@intel.com>
Mon, 4 Aug 2014 21:40:07 +0000 (14:40 -0700)
This causes the thing following the structure to be vec4-aligned.

Fixes gles3conform failures in:

ES3-CTS.shaders.uniform_block.random.nested_structs.2
ES3-CTS.shaders.uniform_block.random.all_shared_buffer.5

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
src/glsl/glsl_types.cpp
src/glsl/link_uniform_blocks.cpp
src/glsl/link_uniforms.cpp

index 737e6dd04226b6c379fd61f9ae618dbf84d0c279..50e4fe558bcd649cc2f849d767ba628adfbbb334 100644 (file)
@@ -934,14 +934,20 @@ glsl_type::std140_size(bool row_major) const
     */
    if (this->is_record()) {
       unsigned size = 0;
+      unsigned max_align = 0;
+
       for (unsigned i = 0; i < this->length; i++) {
         const struct glsl_type *field_type = this->fields.structure[i].type;
         unsigned align = field_type->std140_base_alignment(row_major);
         size = glsl_align(size, align);
         size += field_type->std140_size(row_major);
+
+         max_align = MAX2(align, max_align);
+
+         if (field_type->is_record() && (i + 1 < this->length))
+            size = glsl_align(size, 16);
       }
-      size = glsl_align(size,
-                       this->fields.structure[0].type->std140_base_alignment(row_major));
+      size = glsl_align(size, max_align);
       return size;
    }
 
index ddd134a348aee091ee0cee38fbd371a3d851fb3d..3768205ee1f138c7c47f168cba1429092cc0e182 100644 (file)
@@ -104,7 +104,20 @@ private:
 
       this->offset = glsl_align(this->offset, alignment);
       v->Offset = this->offset;
+
+      /* If this is the last field of a structure, apply rule #9.  The
+       * GL_ARB_uniform_buffer_object spec says:
+       *
+       *     "The structure may have padding at the end; the base offset of
+       *     the member following the sub-structure is rounded up to the next
+       *     multiple of the base alignment of the structure."
+       *
+       * last_field won't be set if this is the last field of a UBO that is
+       * not a named instance.
+       */
       this->offset += size;
+      if (last_field)
+         this->offset = glsl_align(this->offset, 16);
 
       /* From the GL_ARB_uniform_buffer_object spec:
        *
index 8014a3d9a99ea533a4e9318a1851b1eb9a039908..cfb23effcf76f643891502dc59120dbd5ee2c1c6 100644 (file)
@@ -513,7 +513,7 @@ private:
 
    virtual void visit_field(const glsl_type *type, const char *name,
                             bool row_major, const glsl_type *record_type,
-                            bool /* last_field */)
+                            bool last_field)
    {
       assert(!type->without_array()->is_record());
       assert(!type->without_array()->is_interface());
@@ -582,6 +582,9 @@ private:
         this->uniforms[id].offset = this->ubo_byte_offset;
         this->ubo_byte_offset += type->std140_size(ubo_row_major);
 
+         if (last_field)
+            this->ubo_byte_offset = glsl_align(this->ubo_byte_offset, 16);
+
         if (type->is_array()) {
            this->uniforms[id].array_stride =
               glsl_align(type->fields.array->std140_size(ubo_row_major), 16);