Don't load values out of global constants with weak
linkage: the value may be replaced with something
different at link time.  (Frontends that want to
allow values to be loaded out of weak constants can
give their constants weak_odr linkage).

llvm-svn: 67407
diff --git a/llvm/lib/Transforms/Utils/CloneFunction.cpp b/llvm/lib/Transforms/Utils/CloneFunction.cpp
index 5921102..5dc2d1c 100644
--- a/llvm/lib/Transforms/Utils/CloneFunction.cpp
+++ b/llvm/lib/Transforms/Utils/CloneFunction.cpp
@@ -335,7 +335,8 @@
     if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ops[0]))
       if (!LI->isVolatile() && CE->getOpcode() == Instruction::GetElementPtr)
         if (GlobalVariable *GV = dyn_cast<GlobalVariable>(CE->getOperand(0)))
-          if (GV->isConstant() && !GV->isDeclaration())
+          if (GV->isConstant() && !GV->isDeclaration() &&
+              !GV->mayBeOverridden())
             return ConstantFoldLoadThroughGEPConstantExpr(GV->getInitializer(),
                                                           CE);