MergeFunc: Make pointer and integer types generate the same hash.

The logic that actually compares the types considers pointers and integers the
same if they are of the same size. This created a strange mismatch between hash
and reality and made the test case for this fail on some platforms (yay,
test cases).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179905 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/IPO/MergeFunctions.cpp b/lib/Transforms/IPO/MergeFunctions.cpp
index 05f68db..4ce749c 100644
--- a/lib/Transforms/IPO/MergeFunctions.cpp
+++ b/lib/Transforms/IPO/MergeFunctions.cpp
@@ -72,6 +72,15 @@
 STATISTIC(NumAliasesWritten, "Number of aliases generated");
 STATISTIC(NumDoubleWeak, "Number of new functions created");
 
+/// Returns the type id for a type to be hashed. We turn pointer types into
+/// integers here because the actual compare logic below considers pointers and
+/// integers of the same size as equal.
+static Type::TypeID getTypeIDForHash(Type *Ty) {
+  if (Ty->isPointerTy())
+    return Type::IntegerTyID;
+  return Ty->getTypeID();
+}
+
 /// Creates a hash-code for the function which is the same for any two
 /// functions that will compare equal, without looking at the instructions
 /// inside the function.
@@ -83,9 +92,9 @@
   ID.AddInteger(F->getCallingConv());
   ID.AddBoolean(F->hasGC());
   ID.AddBoolean(FTy->isVarArg());
-  ID.AddInteger(FTy->getReturnType()->getTypeID());
+  ID.AddInteger(getTypeIDForHash(FTy->getReturnType()));
   for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
-    ID.AddInteger(FTy->getParamType(i)->getTypeID());
+    ID.AddInteger(getTypeIDForHash(FTy->getParamType(i)));
   return ID.ComputeHash();
 }