1 // RUN: %clang_cc1 -std=c++2a %s -emit-llvm -o - -triple x86_64-linux-gnu | FileCheck %s 2 // RUN: %clang_cc1 -std=c++2a %s -emit-llvm -o - -triple x86_64-linux-gnu -O2 -disable-llvm-passes | FileCheck %s --check-prefix=CHECK-OPT 3 4 struct A { ~A(); int n; char c[3]; }; 5 struct B { [[no_unique_address]] A a; char k; }; 6 // CHECK-DAG: @b ={{.*}} global { i32, [3 x i8], i8 } { i32 1, [3 x i8] c"\02\03\04", i8 5 } 7 B b = {1, 2, 3, 4, 5}; 8 9 struct C : A {}; 10 struct D : C {}; 11 struct E { int e; [[no_unique_address]] D d; char k; }; 12 // CHECK-DAG: @e ={{.*}} global { i32, i32, [3 x i8], i8 } { i32 1, i32 2, [3 x i8] c"\03\04\05", i8 6 } 13 E e = {1, 2, 3, 4, 5, 6}; 14 15 struct Empty1 {}; 16 struct Empty2 {}; 17 struct Empty3 {}; 18 struct HasEmpty { 19 [[no_unique_address]] Empty1 e1; 20 int a; 21 [[no_unique_address]] Empty2 e2; 22 int b; 23 [[no_unique_address]] Empty3 e3; 24 }; 25 // CHECK-DAG: @he ={{.*}} global %{{[^ ]*}} { i32 1, i32 2 } 26 HasEmpty he = {{}, 1, {}, 2, {}}; 27 28 struct HasEmptyDuplicates { 29 [[no_unique_address]] Empty1 e1; // +0 30 int a; 31 [[no_unique_address]] Empty1 e2; // +4 32 int b; 33 [[no_unique_address]] Empty1 e3; // +8 34 }; 35 // CHECK-DAG: @off1 ={{.*}} global i64 0 36 Empty1 HasEmptyDuplicates::*off1 = &HasEmptyDuplicates::e1; 37 // CHECK-DAG: @off2 ={{.*}} global i64 4 38 Empty1 HasEmptyDuplicates::*off2 = &HasEmptyDuplicates::e2; 39 // CHECK-DAG: @off3 ={{.*}} global i64 8 40 Empty1 HasEmptyDuplicates::*off3 = &HasEmptyDuplicates::e3; 41 42 // CHECK-DAG: @hed ={{.*}} global %{{[^ ]*}} { i32 1, i32 2, [4 x i8] undef } 43 HasEmptyDuplicates hed = {{}, 1, {}, 2, {}}; 44 45 struct __attribute__((packed, aligned(2))) PackedAndPadded { 46 ~PackedAndPadded(); 47 char c; 48 int n; 49 }; 50 struct WithPackedAndPadded { 51 [[no_unique_address]] PackedAndPadded pap; 52 char d; 53 }; 54 // CHECK-DAG: @wpap ={{.*}} global <{ i8, i32, i8 }> <{ i8 1, i32 2, i8 3 }> 55 WithPackedAndPadded wpap = {1, 2, 3}; 56 57 struct FieldOverlap { 58 [[no_unique_address]] Empty1 e1, e2, e3, e4; 59 int n; 60 }; 61 static_assert(sizeof(FieldOverlap) == 4); 62 // CHECK-DAG: @fo ={{.*}} global %{{[^ ]*}} { i32 1234 } 63 FieldOverlap fo = {{}, {}, {}, {}, 1234}; 64 65 // CHECK-DAG: @e1 ={{.*}} constant %[[E1:[^ ]*]]* bitcast (%[[FO:[^ ]*]]* @fo to %[[E1]]*) 66 Empty1 &e1 = fo.e1; 67 // CHECK-DAG: @e2 ={{.*}} constant %[[E1]]* bitcast (i8* getelementptr (i8, i8* bitcast (%[[FO]]* @fo to i8*), i64 1) to %[[E1]]*) 68 Empty1 &e2 = fo.e2; 69 70 // CHECK-LABEL: accessE1 71 // CHECK: %[[RET:.*]] = bitcast %[[FO]]* %{{.*}} to %[[E1]]* 72 // CHECK: ret %[[E1]]* %[[RET]] 73 Empty1 &accessE1(FieldOverlap &fo) { return fo.e1; } 74 75 // CHECK-LABEL: accessE2 76 // CHECK: %[[AS_I8:.*]] = bitcast %[[FO]]* %{{.*}} to i8* 77 // CHECK: %[[ADJUSTED:.*]] = getelementptr inbounds i8, i8* %[[AS_I8]], i64 1 78 // CHECK: %[[RET:.*]] = bitcast i8* %[[ADJUSTED]] to %[[E1]]* 79 // CHECK: ret %[[E1]]* %[[RET]] 80 Empty1 &accessE2(FieldOverlap &fo) { return fo.e2; } 81 82 struct LaterDeclaredFieldHasLowerOffset { 83 int a; 84 int b; 85 [[no_unique_address]] Empty1 e; 86 }; 87 // CHECK-OPT-LABEL: @_Z41loadWhereLaterDeclaredFieldHasLowerOffset 88 int loadWhereLaterDeclaredFieldHasLowerOffset(LaterDeclaredFieldHasLowerOffset &a) { 89 // CHECK-OPT: getelementptr 90 // CHECK-OPT: load {{.*}}, !tbaa ![[TBAA_AB:[0-9]*]] 91 return a.b; 92 } 93 // Note, never emit TBAA for zero-size fields. 94 // CHECK-OPT: ![[TBAA_AB]] = !{![[TBAA_A:[0-9]*]], ![[TBAA_INT:[0-9]*]], i64 4} 95 // CHECK-OPT: ![[TBAA_A]] = !{!"_ZTS32LaterDeclaredFieldHasLowerOffset", ![[TBAA_INT]], i64 0, ![[TBAA_INT]], i64 4} 96