Index: include/clang/Basic/TargetInfo.h
===================================================================
--- include/clang/Basic/TargetInfo.h
+++ include/clang/Basic/TargetInfo.h
@@ -294,6 +294,11 @@
     return AddrSpace == 0 ? PointerAlign : getPointerAlignV(AddrSpace);
   }
 
+  /// \brief Return the maximum width of pointers for OpenCL on this target.
+  virtual uint64_t getOpenCLMaxPointerWidth() const {
+    return PointerWidth;
+  }
+
   /// \brief Return the size of '_Bool' and C++ 'bool' for this target, in bits.
   unsigned getBoolWidth() const { return BoolWidth; }
 
Index: lib/Basic/TargetInfo.cpp
===================================================================
--- lib/Basic/TargetInfo.cpp
+++ lib/Basic/TargetInfo.cpp
@@ -306,8 +306,9 @@
     }
     LongDoubleWidth = LongDoubleAlign = 128;
 
-    assert(PointerWidth == 32 || PointerWidth == 64);
-    bool Is32BitArch = PointerWidth == 32;
+    unsigned MaxPointerWidth = getOpenCLMaxPointerWidth();
+    assert(MaxPointerWidth == 32 || MaxPointerWidth == 64);
+    bool Is32BitArch = MaxPointerWidth == 32;
     SizeType = Is32BitArch ? UnsignedInt : UnsignedLong;
     PtrDiffType = Is32BitArch ? SignedInt : SignedLong;
     IntPtrType = Is32BitArch ? SignedInt : SignedLong;
Index: lib/Basic/Targets.cpp
===================================================================
--- lib/Basic/Targets.cpp
+++ lib/Basic/Targets.cpp
@@ -2004,6 +2004,10 @@
     }
   }
 
+  uint64_t getOpenCLMaxPointerWidth() const override {
+    return getTriple().getArch() == llvm::Triple::amdgcn ? 64 : 32;
+  }
+
   const char * getClobbers() const override {
     return "";
   }
Index: lib/CodeGen/CodeGenModule.cpp
===================================================================
--- lib/CodeGen/CodeGenModule.cpp
+++ lib/CodeGen/CodeGenModule.cpp
@@ -104,7 +104,8 @@
   IntAlignInBytes =
     C.toCharUnitsFromBits(C.getTargetInfo().getIntAlign()).getQuantity();
   IntTy = llvm::IntegerType::get(LLVMContext, C.getTargetInfo().getIntWidth());
-  IntPtrTy = llvm::IntegerType::get(LLVMContext, PointerWidthInBits);
+  IntPtrTy = llvm::IntegerType::get(LLVMContext, LangOpts.OpenCL ?
+      C.getTargetInfo().getOpenCLMaxPointerWidth() : PointerWidthInBits);
   Int8PtrTy = Int8Ty->getPointerTo(0);
   Int8PtrPtrTy = Int8PtrTy->getPointerTo(0);
 
Index: test/CodeGenOpenCL/size_t.cl
===================================================================
--- /dev/null
+++ test/CodeGenOpenCL/size_t.cl
@@ -0,0 +1,45 @@
+// RUN: %clang_cc1 %s -cl-std=CL2.0 -finclude-default-header -emit-llvm -O0 -triple spir-unknown-unknown -o - | FileCheck --check-prefix=SZ32 %s
+// RUN: %clang_cc1 %s -cl-std=CL2.0 -finclude-default-header -emit-llvm -O0 -triple spir64-unknown-unknown -o - | FileCheck --check-prefix=SZ64 %s
+// RUN: %clang_cc1 %s -cl-std=CL2.0 -finclude-default-header -emit-llvm -O0 -triple amdgcn-- -o - | FileCheck --check-prefix=SZ64 %s
+
+//SZ32: define{{.*}} i32 @test_private(i8* %x)
+//SZ32: ptrtoint i8* %{{.*}} to i32
+//SZ64: define{{.*}} i64 @test_private(i8* %x)
+//SZ64: ptrtoint i8* %{{.*}} to i64
+size_t test_private(private char* x) {
+  return (size_t)x;
+}
+
+//SZ32: define{{.*}} i32 @test_global(i8 addrspace(1)* %x)
+//SZ32: ptrtoint i8 addrspace(1)* %{{.*}} to i32
+//SZ64: define{{.*}} i64 @test_global(i8 addrspace(1)* %x)
+//SZ64: ptrtoint i8 addrspace(1)* %{{.*}} to i64
+intptr_t test_global(global char* x) {
+  return (intptr_t)x;
+}
+
+//SZ32: define{{.*}} i32 @test_constant(i8 addrspace(2)* %x)
+//SZ32: ptrtoint i8 addrspace(2)* %{{.*}} to i32
+//SZ64: define{{.*}} i64 @test_constant(i8 addrspace(2)* %x)
+//SZ64: ptrtoint i8 addrspace(2)* %{{.*}} to i64
+uintptr_t test_constant(constant char* x) {
+  return (uintptr_t)x;
+}
+
+//SZ32: define{{.*}} i32 @test_local(i8 addrspace(3)* %x, i8 addrspace(3)* %y)
+//SZ32: ptrtoint i8 addrspace(3)* %{{.*}} to i32
+//SZ32: ptrtoint i8 addrspace(3)* %{{.*}} to i32
+//SZ64: define{{.*}} i64 @test_local(i8 addrspace(3)* %x, i8 addrspace(3)* %y)
+//SZ64: ptrtoint i8 addrspace(3)* %{{.*}} to i64
+//SZ64: ptrtoint i8 addrspace(3)* %{{.*}} to i64
+ptrdiff_t test_local(local char* x, local char *y) {
+  return x - y;
+}
+
+//SZ32: define{{.*}} i32 @test_generic(i8 addrspace(4)* %x)
+//SZ32: ptrtoint i8 addrspace(4)* %{{.*}} to i32
+//SZ64: define{{.*}} i64 @test_generic(i8 addrspace(4)* %x)
+//SZ64: ptrtoint i8 addrspace(4)* %{{.*}} to i64
+size_t test_generic(generic char* x) {
+  return (size_t)x;
+}