[llvm] r179213 - Use a real union for IdentifyingPassPtr.

[Benjamin Kramer]

Author: d0k
Date: Wed Apr 10 15:50:44 2013
New Revision: 179213

URL: http://llvm.org/viewvc/llvm-project?rev=179213&view=rev
Log:
Use a real union for IdentifyingPassPtr.

This avoids a nasty const correctness issue (AnalysisIDs are const, Pass* isn't).

Modified:
    llvm/trunk/include/llvm/CodeGen/Passes.h

Modified: llvm/trunk/include/llvm/CodeGen/Passes.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/Passes.h?rev=179213&r1=179212&r2=179213&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/Passes.h (original)
+++ llvm/trunk/include/llvm/CodeGen/Passes.h Wed Apr 10 15:50:44 2013
@@ -50,24 +50,26 @@ class PassConfigImpl;
 ///
 /// AnalysisID is sadly char*, so PointerIntPair won't work.
 class IdentifyingPassPtr {
-  void *P;
+  union {
+    AnalysisID ID;
+    Pass *P;
+  };
   bool IsInstance;
 public:
-  IdentifyingPassPtr(): P(0), IsInstance(false) {}
-  IdentifyingPassPtr(AnalysisID IDPtr): P((void*)IDPtr), IsInstance(false) {}
-  IdentifyingPassPtr(Pass *InstancePtr)
-    : P((void*)InstancePtr), IsInstance(true) {}
+  IdentifyingPassPtr() : P(0), IsInstance(false) {}
+  IdentifyingPassPtr(AnalysisID IDPtr) : ID(IDPtr), IsInstance(false) {}
+  IdentifyingPassPtr(Pass *InstancePtr) : P(InstancePtr), IsInstance(true) {}
 
   bool isValid() const { return P; }
   bool isInstance() const { return IsInstance; }
 
   AnalysisID getID() const {
     assert(!IsInstance && "Not a Pass ID");
-    return (AnalysisID)P;
+    return ID;
   }
   Pass *getInstance() const {
     assert(IsInstance && "Not a Pass Instance");
-    return (Pass *)P;
+    return P;
   }
 };