Add a FIXME about preferred alignment to DataLayout.

Essentially DataLayout is global and affects the layout of ABI
level objects. Preferred alignment could change on a per function
basis as we change CPU features.

llvm-svn: 227118

diff --git a/llvm/include/llvm/IR/DataLayout.h b/llvm/include/llvm/IR/DataLayout.h
index a9e7595..9479ba4 100644 (file)
--- a/llvm/include/llvm/IR/DataLayout.h
+++ b/llvm/include/llvm/IR/DataLayout.h
@@ -53,6 +53,11 @@ enum AlignTypeEnum {
   AGGREGATE_ALIGN = 'a'
 };
 
+// FIXME: Currently the DataLayout string carries a "preferred alignment"
+// for types. As the DataLayout is module/global, this should likely be
+// sunk down to an FTTI element that is queried rather than a global
+// preference.
+
 /// \brief Layout alignment element.
 ///
 /// Stores the alignment data associated with a given alignment type (integer,