diff --git a/include/llvm/IR/Function.h b/include/llvm/IR/Function.h
index cfb862d9b01..455469d1fa0 100644
--- a/include/llvm/IR/Function.h
+++ b/include/llvm/IR/Function.h
@@ -310,9 +310,16 @@ public:
     addAttribute(n, Attribute::NoCapture);
   }
 
+  bool doesNotAccessMemory(unsigned n) const {
+    return AttributeSets.hasAttribute(n, Attribute::ReadNone);
+  }
+  void setDoesNotAccessMemory(unsigned n) {
+    addAttribute(n, Attribute::ReadNone);
+  }
+
   bool onlyReadsMemory(unsigned n) const {
-    return AttributeSets.hasAttribute(n, Attribute::ReadOnly) ||
-           AttributeSets.hasAttribute(n, Attribute::ReadNone);
+    return doesNotAccessMemory(n) ||
+      AttributeSets.hasAttribute(n, Attribute::ReadOnly);
   }
   void setOnlyReadsMemory(unsigned n) {
     addAttribute(n, Attribute::ReadOnly);