[SYCL] Fix address space in casts from derived to base class (#512)

In case of multiple inheritance of non-empty classes clang emits two
bitcasts and a GEP for conversion from derived to a base class. First
bitcast converts pointer to derived class to int8 pointer, then GEP
takes this int8 pointer and applies base class offset, next second
bitcast converts int8 pointer with offset to base class pointer. With
new SYCL address space rules pointer to derived class may have generic
address space. In this case two bitcasts to int8 pointer with generic
address space should be emitted.
This problem caused assertion fail inside the CodeGen and invalid module
generation.

Signed-off-by: Mariya Podchishchaeva <mariya.podchishchaeva@intel.com>

Author: Fznamznon

clang/lib/CodeGen/CGClass.cpp

@@ -246,7 +246,9 @@ ApplyNonVirtualAndVirtualOffset(CodeGenFunction &CGF, Address addr,
 
   // Apply the base offset.
   llvm::Value *ptr = addr.getPointer();
-  ptr = CGF.Builder.CreateBitCast(ptr, CGF.Int8PtrTy);
+  llvm::Type *resTy = llvm::PointerType::getInt8PtrTy(
+      CGF.getLLVMContext(), ptr->getType()->getPointerAddressSpace());
+  ptr = CGF.Builder.CreateBitCast(ptr, resTy);
   ptr = CGF.Builder.CreateInBoundsGEP(ptr, baseOffset, "add.ptr");
 
   // If we have a virtual component, the alignment of the result will

clang/test/CodeGenSYCL/address-space-new.cpp

@@ -1,6 +1,22 @@
 // RUN: DISABLE_INFER_AS=1 %clang_cc1 -triple spir64-unknown-linux-sycldevice  -std=c++11 -fsycl-is-device -disable-llvm-passes -emit-llvm -x c++ %s -o - | FileCheck %s --check-prefixes=CHECK,CHECK-LEGACY
 // RUN: %clang_cc1 -triple spir64-unknown-linux-sycldevice  -std=c++11 -fsycl-is-device -disable-llvm-passes -emit-llvm -x c++ %s -o - | FileCheck %s --check-prefixes=CHECK,CHECK-NEW
 
+struct SpaceWaster {
+  int i, j;
+};
+
+struct HasX {
+  int x;
+};
+
+struct Y : SpaceWaster, HasX {};
+
+void bar(HasX &hx);
+
+void baz(Y &y) {
+  bar(y);
+}
+
 void test() {
   static const int foo = 0x42;
   // CHECK-LEGACY: @_ZZ4testvE3foo = internal constant i32 66, align 4
@@ -88,6 +104,19 @@ void test() {
   (void)select_str_trivial2;
   // CHECK-LEGACY: store i8* getelementptr inbounds ([21 x i8], [21 x i8]* @{{.*}}, i64 0, i64 0), i8** %{{.*}}
   // CHECK-NEW: store i8 addrspace(4)* addrspacecast (i8* getelementptr inbounds ([21 x i8], [21 x i8]* @{{.*}}, i64 0, i64 0) to i8 addrspace(4)*), i8 addrspace(4)** %{{.*}}
+  //
+  //
+  Y yy;
+  baz(yy);
+  // CHECK: define spir_func void @{{.*}}baz{{.*}}
+  // CHECK-LEGACY: %[[FIRST:[a-zA-Z0-9]+]] = bitcast %struct.{{.*}}.Y* %{{.*}} to i8*
+  // CHECK-LEGACY: %[[OFFSET:[a-zA-Z0-9]+]].ptr = getelementptr inbounds i8, i8* %[[FIRST]], i64 8
+  // CHECK-LEGACY: %[[SECOND:[a-zA-Z0-9]+]] = bitcast i8* %[[OFFSET]].ptr to %struct.{{.*}}.HasX*
+  // CHECK-LEGACY: call spir_func void @{{.*}}bar{{.*}}(%struct.{{.*}}.HasX* dereferenceable(4) %[[SECOND]])
+  // CHECK-NEW: %[[FIRST:[a-zA-Z0-9]+]] = bitcast %struct.{{.*}}.Y addrspace(4)* %{{.*}} to i8 addrspace(4)*
+  // CHECK-NEW: %[[OFFSET:[a-zA-Z0-9]+]].ptr = getelementptr inbounds i8, i8 addrspace(4)* %[[FIRST]], i64 8
+  // CHECK-NEW: %[[SECOND:[a-zA-Z0-9]+]] = bitcast i8 addrspace(4)* %[[OFFSET]].ptr to %struct.{{.*}}.HasX addrspace(4)*
+  // CHECK-NEW: call spir_func void @{{.*}}bar{{.*}}(%struct.{{.*}}.HasX addrspace(4)* dereferenceable(4) %[[SECOND]])
 }