[OpenCL] Implemented restrictions for pointer conversions specified in OpenCL v2.0.

OpenCL v2.0 s6.5.5 restricts conversion of pointers to different address spaces:
- the named address spaces (__global, __local, and __private) => __generic - implicitly converted;
- __generic => named - with an explicit cast;
- named <=> named - disallowed;
- __constant <=> any other - disallowed.

llvm-svn: 222834

1 files changed, 2 insertions, 2 deletions

diff --git a/clang/lib/CodeGen/CGExprScalar.cpp b/clang/lib/CodeGen/CGExprScalar.cpp
index 19d453d3caa..a9e63dc7f76 100644
--- a/clang/lib/CodeGen/CGExprScalar.cpp
+++ b/clang/lib/CodeGen/CGExprScalar.cpp
@@ -1351,8 +1351,8 @@ Value *ScalarExprEmitter::VisitCastExpr(CastExpr *CE) {
     llvm::Type *DstTy = ConvertType(DestTy);
     if (SrcTy->isPtrOrPtrVectorTy() && DstTy->isPtrOrPtrVectorTy() &&
         SrcTy->getPointerAddressSpace() != DstTy->getPointerAddressSpace()) {
-      llvm::Type *MidTy = CGF.CGM.getDataLayout().getIntPtrType(SrcTy);
-      return Builder.CreateIntToPtr(Builder.CreatePtrToInt(Src, MidTy), DstTy);
+      llvm_unreachable("wrong cast for pointers in different address spaces"
+                       "(must be an address space cast)!");
     }
     return Builder.CreateBitCast(Src, DstTy);
   }