Instrcombine should not change load(cast p) to cast(load p) if the cast
changes the address space of the pointer.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64035 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 97af83f..b426274 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -11007,8 +11007,14 @@
     }
   }
 
-  const Type *DestPTy = cast<PointerType>(CI->getType())->getElementType();
+  const PointerType *DestTy = cast<PointerType>(CI->getType());
+  const Type *DestPTy = DestTy->getElementType();
   if (const PointerType *SrcTy = dyn_cast<PointerType>(CastOp->getType())) {
+
+    // If the address spaces don't match, don't eliminate the cast.
+    if (DestTy->getAddressSpace() != SrcTy->getAddressSpace())
+      return 0;
+
     const Type *SrcPTy = SrcTy->getElementType();
 
     if (DestPTy->isInteger() || isa<PointerType>(DestPTy) ||