From 8e01c66da6c780601f941aa5b9939962c219fdbd Mon Sep 17 00:00:00 2001 From: Ian Romanick Date: Mon, 8 Sep 2014 12:23:39 -0700 Subject: [PATCH] glsl: Make sure fields after small structs have correct padding Previously the linker would correctly calculate the layout, but the lower_ubo_reference pass would not apply correct alignment to fields following small (less than 16-byte) nested structures. Signed-off-by: Ian Romanick Reviewed-by: Jordan Justen Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=83533 Cc: mesa-stable@lists.freedesktop.org --- src/glsl/lower_ubo_reference.cpp | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/src/glsl/lower_ubo_reference.cpp b/src/glsl/lower_ubo_reference.cpp index 3cdfc04ac5c..4ae1aac7765 100644 --- a/src/glsl/lower_ubo_reference.cpp +++ b/src/glsl/lower_ubo_reference.cpp @@ -327,6 +327,15 @@ lower_ubo_reference_visitor::handle_rvalue(ir_rvalue **rvalue) const glsl_type *struct_type = deref_record->record->type; unsigned intra_struct_offset = 0; + /* glsl_type::std140_base_alignment doesn't grok interfaces. Use + * 16-bytes for the alignment because that is the general minimum of + * std140. + */ + const unsigned struct_alignment = struct_type->is_interface() + ? 16 + : struct_type->std140_base_alignment(row_major); + + for (unsigned int i = 0; i < struct_type->length; i++) { const glsl_type *type = struct_type->fields.structure[i].type; @@ -346,6 +355,19 @@ lower_ubo_reference_visitor::handle_rvalue(ir_rvalue **rvalue) deref_record->field) == 0) break; intra_struct_offset += type->std140_size(field_row_major); + + /* If the field just examined was itself a structure, apply rule + * #9: + * + * "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." + */ + if (type->without_array()->is_record()) { + intra_struct_offset = glsl_align(intra_struct_offset, + struct_alignment); + + } } const_offset += intra_struct_offset; -- 2.30.2