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).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67407 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/SCCP.cpp b/lib/Transforms/Scalar/SCCP.cpp
index 7adc80f..a49bcc8 100644
--- a/lib/Transforms/Scalar/SCCP.cpp
+++ b/lib/Transforms/Scalar/SCCP.cpp
@@ -1131,7 +1131,7 @@
     // Transform load (constant global) into the value loaded.
     if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Ptr)) {
       if (GV->isConstant()) {
-        if (!GV->isDeclaration()) {
+        if (!GV->isDeclaration() && !GV->mayBeOverridden()) {
           markConstant(IV, &I, GV->getInitializer());
           return;
         }
@@ -1150,7 +1150,7 @@
     if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr))
       if (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())
         if (Constant *V =
              ConstantFoldLoadThroughGEPConstantExpr(GV->getInitializer(), CE)) {
           markConstant(IV, &I, V);