Index: cfe/trunk/include/clang/Basic/TargetInfo.h
===================================================================
--- cfe/trunk/include/clang/Basic/TargetInfo.h
+++ cfe/trunk/include/clang/Basic/TargetInfo.h
@@ -294,6 +294,11 @@
     return AddrSpace == 0 ? PointerAlign : getPointerAlignV(AddrSpace);
   }
 
+  /// \brief Return the maximum width of pointers on this target.
+  virtual uint64_t getMaxPointerWidth() const {
+    return PointerWidth;
+  }
+
   /// \brief Return the size of '_Bool' and C++ 'bool' for this target, in bits.
   unsigned getBoolWidth() const { return BoolWidth; }
 
Index: cfe/trunk/lib/Basic/TargetInfo.cpp
===================================================================
--- cfe/trunk/lib/Basic/TargetInfo.cpp
+++ cfe/trunk/lib/Basic/TargetInfo.cpp
@@ -306,8 +306,9 @@
     }
     LongDoubleWidth = LongDoubleAlign = 128;
 
-    assert(PointerWidth == 32 || PointerWidth == 64);
-    bool Is32BitArch = PointerWidth == 32;
+    unsigned MaxPointerWidth = getMaxPointerWidth();
+    assert(MaxPointerWidth == 32 || MaxPointerWidth == 64);
+    bool Is32BitArch = MaxPointerWidth == 32;
     SizeType = Is32BitArch ? UnsignedInt : UnsignedLong;
     PtrDiffType = Is32BitArch ? SignedInt : SignedLong;
     IntPtrType = Is32BitArch ? SignedInt : SignedLong;
Index: cfe/trunk/lib/Basic/Targets.cpp
===================================================================
--- cfe/trunk/lib/Basic/Targets.cpp
+++ cfe/trunk/lib/Basic/Targets.cpp
@@ -2004,6 +2004,10 @@
     }
   }
 
+  uint64_t getMaxPointerWidth() const override {
+    return getTriple().getArch() == llvm::Triple::amdgcn ? 64 : 32;
+  }
+
   const char * getClobbers() const override {
     return "";
   }
Index: cfe/trunk/lib/CodeGen/CGExprScalar.cpp
===================================================================
--- cfe/trunk/lib/CodeGen/CGExprScalar.cpp
+++ cfe/trunk/lib/CodeGen/CGExprScalar.cpp
@@ -787,7 +787,7 @@
   // Handle pointer conversions next: pointers can only be converted to/from
   // other pointers and integers. Check for pointer types in terms of LLVM, as
   // some native types (like Obj-C id) may map to a pointer type.
-  if (isa<llvm::PointerType>(DstTy)) {
+  if (auto DstPT = dyn_cast<llvm::PointerType>(DstTy)) {
     // The source value may be an integer, or a pointer.
     if (isa<llvm::PointerType>(SrcTy))
       return Builder.CreateBitCast(Src, DstTy, "conv");
@@ -795,7 +795,7 @@
     assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?");
     // First, convert to the correct width so that we control the kind of
     // extension.
-    llvm::Type *MiddleTy = CGF.IntPtrTy;
+    llvm::Type *MiddleTy = CGF.CGM.getDataLayout().getIntPtrType(DstPT);
     bool InputSigned = SrcType->isSignedIntegerOrEnumerationType();
     llvm::Value* IntResult =
         Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv");
@@ -1510,12 +1510,13 @@
 
     // First, convert to the correct width so that we control the kind of
     // extension.
-    llvm::Type *MiddleTy = CGF.IntPtrTy;
+    auto DestLLVMTy = ConvertType(DestTy);
+    llvm::Type *MiddleTy = CGF.CGM.getDataLayout().getIntPtrType(DestLLVMTy);
     bool InputSigned = E->getType()->isSignedIntegerOrEnumerationType();
     llvm::Value* IntResult =
       Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv");
 
-    return Builder.CreateIntToPtr(IntResult, ConvertType(DestTy));
+    return Builder.CreateIntToPtr(IntResult, DestLLVMTy);
   }
   case CK_PointerToIntegral:
     assert(!DestTy->isBooleanType() && "bool should use PointerToBool");
@@ -2426,6 +2427,7 @@
 
   Value *pointer = op.LHS;
   Expr *pointerOperand = expr->getLHS();
+  auto PtrTy = cast<llvm::PointerType>(pointer->getType());
   Value *index = op.RHS;
   Expr *indexOperand = expr->getRHS();
 
@@ -2436,11 +2438,12 @@
   }
 
   unsigned width = cast<llvm::IntegerType>(index->getType())->getBitWidth();
-  if (width != CGF.PointerWidthInBits) {
+  auto &DL = CGF.CGM.getDataLayout();
+  if (width != DL.getTypeSizeInBits(PtrTy)) {
     // Zero-extend or sign-extend the pointer value according to
     // whether the index is signed or not.
     bool isSigned = indexOperand->getType()->isSignedIntegerOrEnumerationType();
-    index = CGF.Builder.CreateIntCast(index, CGF.PtrDiffTy, isSigned,
+    index = CGF.Builder.CreateIntCast(index, DL.getIntPtrType(PtrTy), isSigned,
                                       "idx.ext");
   }
 
Index: cfe/trunk/lib/CodeGen/CodeGenModule.cpp
===================================================================
--- cfe/trunk/lib/CodeGen/CodeGenModule.cpp
+++ cfe/trunk/lib/CodeGen/CodeGenModule.cpp
@@ -101,10 +101,13 @@
   PointerWidthInBits = C.getTargetInfo().getPointerWidth(0);
   PointerAlignInBytes =
     C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(0)).getQuantity();
+  SizeSizeInBytes =
+    C.toCharUnitsFromBits(C.getTargetInfo().getMaxPointerWidth()).getQuantity();
   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,
+    C.getTargetInfo().getMaxPointerWidth());
   Int8PtrTy = Int8Ty->getPointerTo(0);
   Int8PtrPtrTy = Int8PtrTy->getPointerTo(0);
 
Index: cfe/trunk/lib/CodeGen/CodeGenTypeCache.h
===================================================================
--- cfe/trunk/lib/CodeGen/CodeGenTypeCache.h
+++ cfe/trunk/lib/CodeGen/CodeGenTypeCache.h
@@ -80,9 +80,14 @@
   union {
     unsigned char PointerAlignInBytes;
     unsigned char PointerSizeInBytes;
+  };
+
+  /// The size and alignment of size_t.
+  union {
     unsigned char SizeSizeInBytes; // sizeof(size_t)
     unsigned char SizeAlignInBytes;
   };
+
   CharUnits getSizeSize() const {
     return CharUnits::fromQuantity(SizeSizeInBytes);
   }
Index: cfe/trunk/test/CodeGenOpenCL/size_t.cl
===================================================================
--- cfe/trunk/test/CodeGenOpenCL/size_t.cl
+++ cfe/trunk/test/CodeGenOpenCL/size_t.cl
@@ -0,0 +1,110 @@
+// 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 --check-prefix=SZ64ONLY %s
+// RUN: %clang_cc1 %s -cl-std=CL2.0 -finclude-default-header -emit-llvm -O0 -triple amdgcn-- -o - | FileCheck --check-prefix=SZ64 --check-prefix=AMDONLY %s
+
+//SZ32: define{{.*}} i32 @test_ptrtoint_private(i8* %x)
+//SZ32: ptrtoint i8* %{{.*}} to i32
+//SZ64: define{{.*}} i64 @test_ptrtoint_private(i8* %x)
+//SZ64: ptrtoint i8* %{{.*}} to i64
+size_t test_ptrtoint_private(private char* x) {
+  return (size_t)x;
+}
+
+//SZ32: define{{.*}} i32 @test_ptrtoint_global(i8 addrspace(1)* %x)
+//SZ32: ptrtoint i8 addrspace(1)* %{{.*}} to i32
+//SZ64: define{{.*}} i64 @test_ptrtoint_global(i8 addrspace(1)* %x)
+//SZ64: ptrtoint i8 addrspace(1)* %{{.*}} to i64
+intptr_t test_ptrtoint_global(global char* x) {
+  return (intptr_t)x;
+}
+
+//SZ32: define{{.*}} i32 @test_ptrtoint_constant(i8 addrspace(2)* %x)
+//SZ32: ptrtoint i8 addrspace(2)* %{{.*}} to i32
+//SZ64: define{{.*}} i64 @test_ptrtoint_constant(i8 addrspace(2)* %x)
+//SZ64: ptrtoint i8 addrspace(2)* %{{.*}} to i64
+uintptr_t test_ptrtoint_constant(constant char* x) {
+  return (uintptr_t)x;
+}
+
+//SZ32: define{{.*}} i32 @test_ptrtoint_local(i8 addrspace(3)* %x)
+//SZ32: ptrtoint i8 addrspace(3)* %{{.*}} to i32
+//SZ64: define{{.*}} i64 @test_ptrtoint_local(i8 addrspace(3)* %x)
+//SZ64: ptrtoint i8 addrspace(3)* %{{.*}} to i64
+size_t test_ptrtoint_local(local char* x) {
+  return (size_t)x;
+}
+
+//SZ32: define{{.*}} i32 @test_ptrtoint_generic(i8 addrspace(4)* %x)
+//SZ32: ptrtoint i8 addrspace(4)* %{{.*}} to i32
+//SZ64: define{{.*}} i64 @test_ptrtoint_generic(i8 addrspace(4)* %x)
+//SZ64: ptrtoint i8 addrspace(4)* %{{.*}} to i64
+size_t test_ptrtoint_generic(generic char* x) {
+  return (size_t)x;
+}
+
+//SZ32: define{{.*}} i8* @test_inttoptr_private(i32 %x)
+//SZ32: inttoptr i32 %{{.*}} to i8*
+//SZ64: define{{.*}} i8* @test_inttoptr_private(i64 %x)
+//AMDONLY: trunc i64 %{{.*}} to i32
+//AMDONLY: inttoptr i32 %{{.*}} to i8*
+//SZ64ONLY: inttoptr i64 %{{.*}} to i8*
+private char* test_inttoptr_private(size_t x) {
+  return (private char*)x;
+}
+
+//SZ32: define{{.*}} i8 addrspace(1)* @test_inttoptr_global(i32 %x)
+//SZ32: inttoptr i32 %{{.*}} to i8 addrspace(1)*
+//SZ64: define{{.*}} i8 addrspace(1)* @test_inttoptr_global(i64 %x)
+//SZ64: inttoptr i64 %{{.*}} to i8 addrspace(1)*
+global char* test_inttoptr_global(size_t x) {
+  return (global char*)x;
+}
+
+//SZ32: define{{.*}} i8 addrspace(3)* @test_add_local(i8 addrspace(3)* %x, i32 %y)
+//SZ32: getelementptr inbounds i8, i8 addrspace(3)* %{{.*}}, i32
+//SZ64: define{{.*}} i8 addrspace(3)* @test_add_local(i8 addrspace(3)* %x, i64 %y)
+//AMDONLY: trunc i64 %{{.*}} to i32
+//AMDONLY: getelementptr inbounds i8, i8 addrspace(3)* %{{.*}}, i32
+//SZ64ONLY: getelementptr inbounds i8, i8 addrspace(3)* %{{.*}}, i64
+local char* test_add_local(local char* x, ptrdiff_t y) {
+  return x + y;
+}
+
+//SZ32: define{{.*}} i8 addrspace(1)* @test_add_global(i8 addrspace(1)* %x, i32 %y)
+//SZ32: getelementptr inbounds i8, i8 addrspace(1)* %{{.*}}, i32
+//SZ64: define{{.*}} i8 addrspace(1)* @test_add_global(i8 addrspace(1)* %x, i64 %y)
+//SZ64: getelementptr inbounds i8, i8 addrspace(1)* %{{.*}}, i64
+global char* test_add_global(global char* x, ptrdiff_t y) {
+  return x + y;
+}
+
+//SZ32: define{{.*}} i32 @test_sub_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_sub_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_sub_local(local char* x, local char *y) {
+  return x - y;
+}
+
+//SZ32: define{{.*}} i32 @test_sub_private(i8* %x, i8* %y)
+//SZ32: ptrtoint i8* %{{.*}} to i32
+//SZ32: ptrtoint i8* %{{.*}} to i32
+//SZ64: define{{.*}} i64 @test_sub_private(i8* %x, i8* %y)
+//SZ64: ptrtoint i8* %{{.*}} to i64
+//SZ64: ptrtoint i8* %{{.*}} to i64
+ptrdiff_t test_sub_private(private char* x, private char *y) {
+  return x - y;
+}
+
+//SZ32: define{{.*}} i32 @test_sub_mix(i8* %x, i8 addrspace(4)* %y)
+//SZ32: ptrtoint i8* %{{.*}} to i32
+//SZ32: ptrtoint i8 addrspace(4)* %{{.*}} to i32
+//SZ64: define{{.*}} i64 @test_sub_mix(i8* %x, i8 addrspace(4)* %y)
+//SZ64: ptrtoint i8* %{{.*}} to i64
+//SZ64: ptrtoint i8 addrspace(4)* %{{.*}} to i64
+ptrdiff_t test_sub_mix(private char* x, generic char *y) {
+  return x - y;
+}
+