Add a new attribute, 'noduplicate'. If a function contains a noduplicate call, the call cannot be duplicated - Jump threading, loop unrolling, loop unswitching, and loop rotation are inhibited if they would duplicate the call.

Similarly inlining of the function is inhibited, if that would duplicate the call (in particular inlining is still allowed when there is only one callsite and the function has internal linkage).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170704 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 3 insertions, 0 deletions

diff --git a/lib/VMCore/Attributes.cpp b/lib/VMCore/Attributes.cpp
index 2782455..5bde563 100644
--- a/lib/VMCore/Attributes.cpp
+++ b/lib/VMCore/Attributes.cpp
@@ -213,6 +213,8 @@ std::string Attribute::getAsString() const {
     Result += utostr(getAlignment());
     Result += " ";
   }
+  if (hasAttribute(Attribute::NoDuplicate))
+    Result += "noduplicate ";
   // Trim the trailing space.
   assert(!Result.empty() && "Unknown attribute!");
   Result.erase(Result.end()-1);
@@ -327,6 +329,7 @@ uint64_t AttributeImpl::getAttrMask(uint64_t Val) {
   case Attribute::NonLazyBind:     return 1U << 31;
   case Attribute::AddressSafety:   return 1ULL << 32;
   case Attribute::MinSize:         return 1ULL << 33;
+  case Attribute::NoDuplicate:     return 1ULL << 34;
   }
   llvm_unreachable("Unsupported attribute type");
 }