last = decl->Range.Last;
mask = decl->Declaration.UsageMask;
+ /* XXX we could remove this special-case code since
+ * mach->InterpCoefs[first].a0 should already have the
+ * front/back-face value. But we should first update the
+ * ureg code to emit the right UsageMask value (WRITEMASK_X).
+ * Then, we could remove the tgsi_exec_machine::Face field.
+ */
if (decl->Semantic.Name == TGSI_SEMANTIC_FACE) {
uint i;