Implement function prefix data as an IR feature.

Previous discussion:
http://lists.cs.uiuc.edu/pipermail/llvmdev/2013-July/063909.html

Differential Revision: http://llvm-reviews.chandlerc.com/D1191

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190773 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 10 insertions, 3 deletions

diff --git a/include/llvm/IR/Function.h b/include/llvm/IR/Function.h
index 0e51c6f..bba7ecd 100644
--- a/include/llvm/IR/Function.h
+++ b/include/llvm/IR/Function.h
@@ -159,11 +159,11 @@ public:
   /// calling convention of this function.  The enum values for the known
   /// calling conventions are defined in CallingConv.h.
   CallingConv::ID getCallingConv() const {
-    return static_cast<CallingConv::ID>(getSubclassDataFromValue() >> 1);
+    return static_cast<CallingConv::ID>(getSubclassDataFromValue() >> 2);
   }
   void setCallingConv(CallingConv::ID CC) {
-    setValueSubclassData((getSubclassDataFromValue() & 1) |
-                         (static_cast<unsigned>(CC) << 1));
+    setValueSubclassData((getSubclassDataFromValue() & 3) |
+                         (static_cast<unsigned>(CC) << 2));
   }
 
   /// @brief Return the attribute list for this Function.
@@ -427,6 +427,13 @@ public:
   size_t arg_size() const;
   bool arg_empty() const;
 
+  bool hasPrefixData() const {
+    return getSubclassDataFromValue() & 2;
+  }
+
+  Constant *getPrefixData() const;
+  void setPrefixData(Constant *PrefixData);
+
   /// viewCFG - This function is meant for use from the debugger.  You can just
   /// say 'call F->viewCFG()' and a ghostview window should pop up from the
   /// program, displaying the CFG of the current function with the code for each