Index: clang/lib/CodeGen/CGCall.cpp
===================================================================
--- clang/lib/CodeGen/CGCall.cpp
+++ clang/lib/CodeGen/CGCall.cpp
@@ -5114,12 +5114,15 @@
           auto LV = I->getKnownLValue();
           auto AS = LV.getAddressSpace();
 
-          if (!ArgInfo.getIndirectByVal() ||
+          bool isByValOrRef =
+              ArgInfo.isIndirectAliased() || ArgInfo.getIndirectByVal();
+
+          if (!isByValOrRef ||
               (LV.getAlignment() < getContext().getTypeAlignInChars(I->Ty))) {
             NeedCopy = true;
           }
           if (!getLangOpts().OpenCL) {
-            if ((ArgInfo.getIndirectByVal() &&
+            if ((isByValOrRef &&
                 (AS != LangAS::Default &&
                  AS != CGM.getASTAllocaAddressSpace()))) {
               NeedCopy = true;
@@ -5127,7 +5130,7 @@
           }
           // For OpenCL even if RV is located in default or alloca address space
           // we don't want to perform address space cast for it.
-          else if ((ArgInfo.getIndirectByVal() &&
+          else if ((isByValOrRef &&
                     Addr.getType()->getAddressSpace() != IRFuncTy->
                       getParamType(FirstIRArg)->getPointerAddressSpace())) {
             NeedCopy = true;
Index: clang/lib/CodeGen/Targets/AMDGPU.cpp
===================================================================
--- clang/lib/CodeGen/Targets/AMDGPU.cpp
+++ clang/lib/CodeGen/Targets/AMDGPU.cpp
@@ -250,6 +250,12 @@
     }
   }
 
+  if (Ty->isStructureOrClassType() || Ty->isUnionType()) {
+    return ABIArgInfo::getIndirectAliased(
+        getContext().getTypeAlignInChars(Ty),
+        getContext().getTargetAddressSpace(LangAS::opencl_private));
+  }
+
   // Otherwise just do the default thing.
   ABIArgInfo ArgInfo = DefaultABIInfo::classifyArgumentType(Ty);
   if (!ArgInfo.isIndirect()) {
Index: clang/test/CodeGenCXX/amdgcn-func-arg.cpp
===================================================================
--- clang/test/CodeGenCXX/amdgcn-func-arg.cpp
+++ clang/test/CodeGenCXX/amdgcn-func-arg.cpp
@@ -73,10 +73,12 @@
 
 // CHECK-LABEL: @_Z19func_with_byval_arg1B(
 // CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[COERCE:%.*]] = alloca %class.B, align 4, addrspace(5)
 // CHECK-NEXT:    [[P:%.*]] = alloca ptr, align 8, addrspace(5)
+// CHECK-NEXT:    [[B:%.*]] = addrspacecast ptr addrspace(5) [[COERCE]] to ptr
 // CHECK-NEXT:    [[P_ASCAST:%.*]] = addrspacecast ptr addrspace(5) [[P]] to ptr
-// CHECK-NEXT:    [[B_ASCAST:%.*]] = addrspacecast ptr addrspace(5) [[B:%.*]] to ptr
-// CHECK-NEXT:    store ptr [[B_ASCAST]], ptr [[P_ASCAST]], align 8
+// CHECK-NEXT:    call void @llvm.memcpy.p0.p5.i64(ptr align 4 [[B]], ptr addrspace(5) align 4 %0, i64 400, i1 false)
+// CHECK-NEXT:    store ptr [[B]], ptr [[P_ASCAST]], align 8
 // CHECK-NEXT:    ret void
 //
 void func_with_byval_arg(B b) {
@@ -91,7 +93,7 @@
 // CHECK-NEXT:    [[AGG_TMP_ASCAST:%.*]] = addrspacecast ptr addrspace(5) [[AGG_TMP]] to ptr
 // CHECK-NEXT:    call void @llvm.memcpy.p0.p0.i64(ptr align 4 [[AGG_TMP_ASCAST]], ptr align 4 [[B_ASCAST]], i64 400, i1 false)
 // CHECK-NEXT:    [[AGG_TMP_ASCAST_ASCAST:%.*]] = addrspacecast ptr [[AGG_TMP_ASCAST]] to ptr addrspace(5)
-// CHECK-NEXT:    call void @_Z19func_with_byval_arg1B(ptr addrspace(5) noundef byval([[CLASS_B]]) align 4 [[AGG_TMP_ASCAST_ASCAST]])
+// CHECK-NEXT:    call void @_Z19func_with_byval_arg1B(ptr addrspace(5) byref([[CLASS_B]]) align 4 [[AGG_TMP_ASCAST_ASCAST]])
 // CHECK-NEXT:    call void @_Z17func_with_ref_argR1B(ptr noundef nonnull align 4 dereferenceable(400) [[B_ASCAST]])
 // CHECK-NEXT:    ret void
 //
@@ -107,7 +109,7 @@
 // CHECK-NEXT:    [[AGG_TMP_ASCAST:%.*]] = addrspacecast ptr addrspace(5) [[AGG_TMP]] to ptr
 // CHECK-NEXT:    call void @llvm.memcpy.p0.p0.i64(ptr align 4 [[AGG_TMP_ASCAST]], ptr align 4 addrspacecast (ptr addrspace(1) @g_b to ptr), i64 400, i1 false)
 // CHECK-NEXT:    [[AGG_TMP_ASCAST_ASCAST:%.*]] = addrspacecast ptr [[AGG_TMP_ASCAST]] to ptr addrspace(5)
-// CHECK-NEXT:    call void @_Z19func_with_byval_arg1B(ptr addrspace(5) noundef byval([[CLASS_B]]) align 4 [[AGG_TMP_ASCAST_ASCAST]])
+// CHECK-NEXT:    call void @_Z19func_with_byval_arg1B(ptr addrspace(5) byref([[CLASS_B]]) align 4 [[AGG_TMP_ASCAST_ASCAST]])
 // CHECK-NEXT:    call void @_Z17func_with_ref_argR1B(ptr noundef nonnull align 4 dereferenceable(400) addrspacecast (ptr addrspace(1) @g_b to ptr))
 // CHECK-NEXT:    ret void
 //
Index: clang/test/CodeGenOpenCL/addr-space-struct-arg.cl
===================================================================
--- clang/test/CodeGenOpenCL/addr-space-struct-arg.cl
+++ clang/test/CodeGenOpenCL/addr-space-struct-arg.cl
@@ -66,7 +66,7 @@
 }
 
 // X86-LABEL: define{{.*}} void @foo_large(ptr noalias sret(%struct.Mat64X64) align 4 %agg.result, ptr noundef byval(%struct.Mat32X32) align 4 %in)
-// AMDGCN-LABEL: define{{.*}} void @foo_large(ptr addrspace(5) noalias sret(%struct.Mat64X64) align 4 %agg.result, ptr addrspace(5) noundef byval(%struct.Mat32X32) align 4 %in)
+// AMDGCN-LABEL: define{{.*}} void @foo_large(ptr addrspace(5) noalias sret(%struct.Mat64X64) align 4 %agg.result, ptr addrspace(5) byref(%struct.Mat32X32) align 4
 Mat64X64 __attribute__((noinline)) foo_large(Mat32X32 in) {
   Mat64X64 out;
   return out;
@@ -88,7 +88,7 @@
   u.x = (int2)(0, 0);
 }
 
-// AMDGCN-LABEL: define{{.*}} void @FuncOneLargeMember(ptr addrspace(5) noundef byval(%struct.LargeStructOneMember) align 8 %u)
+// AMDGCN-LABEL: define{{.*}} void @FuncOneLargeMember(ptr addrspace(5) byref(%struct.LargeStructOneMember) align 8
 // AMDGCN-NOT: addrspacecast
 // AMDGCN:   store <2 x i32> %{{.*}}, ptr addrspace(5)
 void FuncOneLargeMember(struct LargeStructOneMember u) {
@@ -96,9 +96,9 @@
 }
 
 // AMDGCN20-LABEL: define{{.*}} void @test_indirect_arg_globl()
-// AMDGCN20:  %[[byval_temp:.*]] = alloca %struct.LargeStructOneMember, align 8, addrspace(5)
-// AMDGCN20:  call void @llvm.memcpy.p5.p1.i64(ptr addrspace(5) align 8 %[[byval_temp]], ptr addrspace(1) align 8 @g_s, i64 800, i1 false)
-// AMDGCN20:  call void @FuncOneLargeMember(ptr addrspace(5) noundef byval(%struct.LargeStructOneMember) align 8 %[[byval_temp]])
+// AMDGCN20:  %[[byref_temp:.*]] = alloca %struct.LargeStructOneMember, align 8, addrspace(5)
+// AMDGCN20:  call void @llvm.memcpy.p5.p1.i64(ptr addrspace(5) align 8 %[[byref_temp]], ptr addrspace(1) align 8 @g_s, i64 800, i1 false)
+// AMDGCN20:  call void @FuncOneLargeMember(ptr addrspace(5) byref(%struct.LargeStructOneMember) align 8 %[[byref_temp]])
 #if (__OPENCL_C_VERSION__ == 200) || (__OPENCL_C_VERSION__ >= 300 && defined(__opencl_c_program_scope_global_variables))
 void test_indirect_arg_globl(void) {
   FuncOneLargeMember(g_s);
@@ -106,9 +106,9 @@
 #endif
 
 // AMDGCN-LABEL: define{{.*}} amdgpu_kernel void @test_indirect_arg_local()
-// AMDGCN: %[[byval_temp:.*]] = alloca %struct.LargeStructOneMember, align 8, addrspace(5)
-// AMDGCN: call void @llvm.memcpy.p5.p3.i64(ptr addrspace(5) align 8 %[[byval_temp]], ptr addrspace(3) align 8 @test_indirect_arg_local.l_s, i64 800, i1 false)
-// AMDGCN: call void @FuncOneLargeMember(ptr addrspace(5) noundef byval(%struct.LargeStructOneMember) align 8 %[[byval_temp]])
+// AMDGCN: %[[byref_temp:.*]] = alloca %struct.LargeStructOneMember, align 8, addrspace(5)
+// AMDGCN: call void @llvm.memcpy.p5.p3.i64(ptr addrspace(5) align 8 %[[byref_temp]], ptr addrspace(3) align 8 @test_indirect_arg_local.l_s, i64 800, i1 false)
+// AMDGCN: call void @FuncOneLargeMember(ptr addrspace(5) byref(%struct.LargeStructOneMember) align 8 %[[byref_temp]])
 kernel void test_indirect_arg_local(void) {
   local struct LargeStructOneMember l_s;
   FuncOneLargeMember(l_s);
@@ -117,7 +117,7 @@
 // AMDGCN-LABEL: define{{.*}} void @test_indirect_arg_private()
 // AMDGCN: %[[p_s:.*]] = alloca %struct.LargeStructOneMember, align 8, addrspace(5)
 // AMDGCN-NOT: @llvm.memcpy
-// AMDGCN-NEXT: call void @FuncOneLargeMember(ptr addrspace(5) noundef byval(%struct.LargeStructOneMember) align 8 %[[p_s]])
+// AMDGCN-NEXT: call void @FuncOneLargeMember(ptr addrspace(5) byref(%struct.LargeStructOneMember) align 8 %[[p_s]])
 void test_indirect_arg_private(void) {
   struct LargeStructOneMember p_s;
   FuncOneLargeMember(p_s);
@@ -142,7 +142,7 @@
 // AMDGCN-LABEL: define{{.*}} amdgpu_kernel void @KernelLargeOneMember(
 // AMDGCN:  %[[U:.*]] = alloca %struct.LargeStructOneMember, align 8, addrspace(5)
 // AMDGCN:  store %struct.LargeStructOneMember %u.coerce, ptr addrspace(5) %[[U]], align 8
-// AMDGCN:  call void @FuncOneLargeMember(ptr addrspace(5) noundef byval(%struct.LargeStructOneMember) align 8 %[[U]])
+// AMDGCN:  call void @FuncOneLargeMember(ptr addrspace(5) byref(%struct.LargeStructOneMember) align 8 %[[U]])
 kernel void KernelLargeOneMember(struct LargeStructOneMember u) {
   FuncOneLargeMember(u);
 }
@@ -152,7 +152,7 @@
   u.y = (int2)(0, 0);
 }
 
-// AMDGCN-LABEL: define{{.*}} void @FuncLargeTwoMember(ptr addrspace(5) noundef byval(%struct.LargeStructTwoMember) align 8 %u)
+// AMDGCN-LABEL: define{{.*}} void @FuncLargeTwoMember(ptr addrspace(5) byref(%struct.LargeStructTwoMember) align 8
 void FuncLargeTwoMember(struct LargeStructTwoMember u) {
   u.y[0] = (int2)(0, 0);
 }
@@ -171,7 +171,7 @@
 // AMDGCN-SAME:  (%struct.LargeStructTwoMember %[[u_coerce:.*]])
 // AMDGCN:  %[[u:.*]] = alloca %struct.LargeStructTwoMember, align 8, addrspace(5)
 // AMDGCN:  store %struct.LargeStructTwoMember %[[u_coerce]], ptr addrspace(5) %[[u]]
-// AMDGCN:  call void @FuncLargeTwoMember(ptr addrspace(5) noundef byval(%struct.LargeStructTwoMember) align 8 %[[u]])
+// AMDGCN:  call void @FuncLargeTwoMember(ptr addrspace(5) byref(%struct.LargeStructTwoMember) align 8 %[[u]])
 kernel void KernelLargeTwoMember(struct LargeStructTwoMember u) {
   FuncLargeTwoMember(u);
 }
Index: clang/test/CodeGenOpenCL/amdgpu-abi-struct-coerce.cl
===================================================================
--- clang/test/CodeGenOpenCL/amdgpu-abi-struct-coerce.cl
+++ clang/test/CodeGenOpenCL/amdgpu-abi-struct-coerce.cl
@@ -448,11 +448,11 @@
 // CHECK: define{{.*}} void @func_reg_state_lo(<4 x i32> noundef %arg0, <4 x i32> noundef %arg1, <4 x i32> noundef %arg2, i32 noundef %arg3, i32 %s.coerce0, float %s.coerce1, i32 %s.coerce2)
 void func_reg_state_lo(int4 arg0, int4 arg1, int4 arg2, int arg3, struct_arg_t s) { }
 
-// CHECK: define{{.*}} void @func_reg_state_hi(<4 x i32> noundef %arg0, <4 x i32> noundef %arg1, <4 x i32> noundef %arg2, i32 noundef %arg3, i32 noundef %arg4, ptr addrspace(5) nocapture noundef byval(%struct.struct_arg) align 4 %s)
+// CHECK: define{{.*}} void @func_reg_state_hi(<4 x i32> noundef %arg0, <4 x i32> noundef %arg1, <4 x i32> noundef %arg2, i32 noundef %arg3, i32 noundef %arg4, ptr addrspace(5) nocapture byref(%struct.struct_arg) align 4
 void func_reg_state_hi(int4 arg0, int4 arg1, int4 arg2, int arg3, int arg4, struct_arg_t s) { }
 
 // XXX - Why don't the inner structs flatten?
-// CHECK: define{{.*}} void @func_reg_state_num_regs_nested_struct(<4 x i32> noundef %arg0, i32 noundef %arg1, i32 %arg2.coerce0, %struct.nested %arg2.coerce1, i32 %arg3.coerce0, %struct.nested %arg3.coerce1, ptr addrspace(5) nocapture noundef byval(%struct.num_regs_nested_struct) align 8 %arg4)
+// CHECK: define{{.*}} void @func_reg_state_num_regs_nested_struct(<4 x i32> noundef %arg0, i32 noundef %arg1, i32 %arg2.coerce0, %struct.nested %arg2.coerce1, i32 %arg3.coerce0, %struct.nested %arg3.coerce1, ptr addrspace(5) nocapture byref(%struct.num_regs_nested_struct) align 8
 void func_reg_state_num_regs_nested_struct(int4 arg0, int arg1, num_regs_nested_struct arg2, num_regs_nested_struct arg3, num_regs_nested_struct arg4) { }
 
 // CHECK: define{{.*}} void @func_double_nested_struct_arg(<4 x i32> noundef %arg0, i32 noundef %arg1, i32 %arg2.coerce0, %struct.double_nested %arg2.coerce1, i16 %arg2.coerce2)
@@ -467,7 +467,7 @@
 // CHECK: define{{.*}} void @func_large_struct_padding_arg_direct(i8 %arg.coerce0, i32 %arg.coerce1, i8 %arg.coerce2, i32 %arg.coerce3, i8 %arg.coerce4, i8 %arg.coerce5, i16 %arg.coerce6, i16 %arg.coerce7, [3 x i8] %arg.coerce8, i64 %arg.coerce9, i32 %arg.coerce10, i8 %arg.coerce11, i32 %arg.coerce12, i16 %arg.coerce13, i8 %arg.coerce14)
 void func_large_struct_padding_arg_direct(large_struct_padding arg) { }
 
-// CHECK: define{{.*}} void @func_large_struct_padding_arg_store(ptr addrspace(1) nocapture noundef writeonly %out, ptr addrspace(5) nocapture noundef readonly byval(%struct.large_struct_padding) align 8 %arg)
+// CHECK: define{{.*}} void @func_large_struct_padding_arg_store(ptr addrspace(1) nocapture noundef writeonly %out, ptr addrspace(5) nocapture readonly byref(%struct.large_struct_padding) align 8
 void func_large_struct_padding_arg_store(global large_struct_padding* out, large_struct_padding arg) {
   *out = arg;
 }
@@ -485,7 +485,7 @@
 void v4i16_reg_count(short4 arg0, short4 arg1, short4 arg2, short4 arg3,
                      short4 arg4, short4 arg5, struct_4regs arg6) { }
 
-// CHECK: define{{.*}} void @v4i16_pair_reg_count_over(<4 x i16> noundef %arg0, <4 x i16> noundef %arg1, <4 x i16> noundef %arg2, <4 x i16> noundef %arg3, <4 x i16> noundef %arg4, <4 x i16> noundef %arg5, <4 x i16> noundef %arg6, ptr addrspace(5) nocapture noundef byval(%struct.struct_4regs) align 4 %arg7)
+// CHECK: define{{.*}} void @v4i16_pair_reg_count_over(<4 x i16> noundef %arg0, <4 x i16> noundef %arg1, <4 x i16> noundef %arg2, <4 x i16> noundef %arg3, <4 x i16> noundef %arg4, <4 x i16> noundef %arg5, <4 x i16> noundef %arg6, ptr addrspace(5) nocapture byref(%struct.struct_4regs) align 4
 void v4i16_pair_reg_count_over(short4 arg0, short4 arg1, short4 arg2, short4 arg3,
                                short4 arg4, short4 arg5, short4 arg6, struct_4regs arg7) { }
 
@@ -493,7 +493,7 @@
 void v3i16_reg_count(short3 arg0, short3 arg1, short3 arg2, short3 arg3,
                      short3 arg4, short3 arg5, struct_4regs arg6) { }
 
-// CHECK: define{{.*}} void @v3i16_reg_count_over(<3 x i16> noundef %arg0, <3 x i16> noundef %arg1, <3 x i16> noundef %arg2, <3 x i16> noundef %arg3, <3 x i16> noundef %arg4, <3 x i16> noundef %arg5, <3 x i16> noundef %arg6, ptr addrspace(5) nocapture noundef byval(%struct.struct_4regs) align 4 %arg7)
+// CHECK: define{{.*}} void @v3i16_reg_count_over(<3 x i16> noundef %arg0, <3 x i16> noundef %arg1, <3 x i16> noundef %arg2, <3 x i16> noundef %arg3, <3 x i16> noundef %arg4, <3 x i16> noundef %arg5, <3 x i16> noundef %arg6, ptr addrspace(5) nocapture byref(%struct.struct_4regs) align 4
 void v3i16_reg_count_over(short3 arg0, short3 arg1, short3 arg2, short3 arg3,
                           short3 arg4, short3 arg5, short3 arg6, struct_4regs arg7) { }
 
@@ -503,7 +503,7 @@
                      short2 arg8, short2 arg9, short2 arg10, short2 arg11,
                      struct_4regs arg13) { }
 
-// CHECK: define{{.*}} void @v2i16_reg_count_over(<2 x i16> noundef %arg0, <2 x i16> noundef %arg1, <2 x i16> noundef %arg2, <2 x i16> noundef %arg3, <2 x i16> noundef %arg4, <2 x i16> noundef %arg5, <2 x i16> noundef %arg6, <2 x i16> noundef %arg7, <2 x i16> noundef %arg8, <2 x i16> noundef %arg9, <2 x i16> noundef %arg10, <2 x i16> noundef %arg11, <2 x i16> noundef %arg12, ptr addrspace(5) nocapture noundef byval(%struct.struct_4regs) align 4 %arg13)
+// CHECK: define{{.*}} void @v2i16_reg_count_over(<2 x i16> noundef %arg0, <2 x i16> noundef %arg1, <2 x i16> noundef %arg2, <2 x i16> noundef %arg3, <2 x i16> noundef %arg4, <2 x i16> noundef %arg5, <2 x i16> noundef %arg6, <2 x i16> noundef %arg7, <2 x i16> noundef %arg8, <2 x i16> noundef %arg9, <2 x i16> noundef %arg10, <2 x i16> noundef %arg11, <2 x i16> noundef %arg12, ptr addrspace(5) nocapture byref(%struct.struct_4regs) align 4
 void v2i16_reg_count_over(short2 arg0, short2 arg1, short2 arg2, short2 arg3,
                           short2 arg4, short2 arg5, short2 arg6, short2 arg7,
                           short2 arg8, short2 arg9, short2 arg10, short2 arg11,
@@ -513,7 +513,7 @@
 void v2i8_reg_count(char2 arg0, char2 arg1, char2 arg2, char2 arg3,
                     char2 arg4, char2 arg5, struct_4regs arg6) { }
 
-// CHECK: define{{.*}} void @v2i8_reg_count_over(<2 x i8> noundef %arg0, <2 x i8> noundef %arg1, <2 x i8> noundef %arg2, <2 x i8> noundef %arg3, <2 x i8> noundef %arg4, <2 x i8> noundef %arg5, i32 noundef %arg6, ptr addrspace(5) nocapture noundef byval(%struct.struct_4regs) align 4 %arg7)
+// CHECK: define{{.*}} void @v2i8_reg_count_over(<2 x i8> noundef %arg0, <2 x i8> noundef %arg1, <2 x i8> noundef %arg2, <2 x i8> noundef %arg3, <2 x i8> noundef %arg4, <2 x i8> noundef %arg5, i32 noundef %arg6, ptr addrspace(5) nocapture byref(%struct.struct_4regs) align 4
 void v2i8_reg_count_over(char2 arg0, char2 arg1, char2 arg2, char2 arg3,
                          char2 arg4, char2 arg5, int arg6, struct_4regs arg7) { }
 
Index: clang/test/CodeGenOpenCL/byval.cl
===================================================================
--- clang/test/CodeGenOpenCL/byval.cl
+++ clang/test/CodeGenOpenCL/byval.cl
@@ -8,8 +8,8 @@
 
 int g() {
   struct A a;
-  // CHECK: call i32 @f(ptr addrspace(5) noundef byval{{.*}}%a)
+  // CHECK: call i32 @f(ptr addrspace(5) byref{{.*}})
   return f(a);
 }
 
-// CHECK: declare i32 @f(ptr addrspace(5) noundef byval{{.*}})
+// CHECK: declare i32 @f(ptr addrspace(5) byref{{.*}})