Add a dereferenceable attribute

This attribute indicates that the parameter or return pointer is
dereferenceable. Practically speaking, loads from such a pointer within the
associated byte range are safe to speculatively execute. Such pointer
parameters are common in source languages (C++ references, for example).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213385 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 3 insertions, 1 deletions

diff --git a/lib/IR/AttributeImpl.h b/lib/IR/AttributeImpl.h
index 999a803c037..cc6d557ab4c 100644
--- a/lib/IR/AttributeImpl.h
+++ b/lib/IR/AttributeImpl.h
@@ -116,7 +116,8 @@ public:
   IntAttributeImpl(Attribute::AttrKind Kind, uint64_t Val)
       : EnumAttributeImpl(IntAttrEntry, Kind), Val(Val) {
     assert(
-        (Kind == Attribute::Alignment || Kind == Attribute::StackAlignment) &&
+        (Kind == Attribute::Alignment || Kind == Attribute::StackAlignment ||
+         Kind == Attribute::Dereferenceable) &&
         "Wrong kind for int attribute!");
   }
 
@@ -164,6 +165,7 @@ public:
 
   unsigned getAlignment() const;
   unsigned getStackAlignment() const;
+  uint64_t getDereferenceableBytes() const;
   std::string getAsString(bool InAttrGrp) const;
 
   typedef const Attribute *iterator;