[TBAA] Add extra tests to copy structs with union members.

Adds extra test coverage for TBAA generation for copies of structs with
union members.

Author: fhahn

clang/test/CodeGen/tbaa-struct.cpp

@@ -151,6 +151,38 @@ void copy10(NamedBitfields3 *a1, NamedBitfields3 *a2) {
   *a1 = *a2;
 }
 
+union U2 {
+  double d;
+  float f;
+};
+
+struct UnionMember1 {
+  U2 u;
+  int p;
+};
+
+void copy11(UnionMember1 *a1, UnionMember1 *a2) {
+// CHECK-LABEL: _Z6copy11P12UnionMember1S0_
+// CHECK:   tail call void @llvm.memcpy.p0.p0.i64(ptr noundef nonnull align 8 dereferenceable(16) %a1, ptr noundef nonnull align 8 dereferenceable(16) %a2, i64 16, i1 false),
+// CHECK-OLD-SAME: !tbaa.struct [[TS9:!.*]]
+// CHECK-NEW-SAME: !tbaa [[TAG_UnionMember1:!.+]], !tbaa.struct
+  *a1 = *a2;
+}
+
+struct UnionMember2 {
+  int p;
+  U2 u;
+};
+
+void copy12(UnionMember2 *a1, UnionMember2 *a2) {
+// CHECK-LABEL: _Z6copy12P12UnionMember2S0_
+// CHECK:   tail call void @llvm.memcpy.p0.p0.i64(ptr noundef nonnull align 8 dereferenceable(16) %a1, ptr noundef nonnull align 8 dereferenceable(16) %a2, i64 16, i1 false),
+// CHECK-OLD-SAME: !tbaa.struct [[TS10:!.*]]
+// CHECK-NEW-SAME: !tbaa [[TAG_UnionMember2:!.+]], !tbaa.struct
+
+  *a1 = *a2;
+}
+
 // CHECK-OLD: [[TS]] = !{i64 0, i64 2, !{{.*}}, i64 4, i64 4, !{{.*}}, i64 8, i64 1, !{{.*}}, i64 12, i64 4, !{{.*}}}
 // CHECK-OLD: [[CHAR:!.*]] = !{!"omnipotent char", !{{.*}}}
 // CHECK-OLD: [[TAG_INT:!.*]] = !{[[INT:!.*]], [[INT]], i64 0}
@@ -167,6 +199,10 @@ void copy10(NamedBitfields3 *a1, NamedBitfields3 *a2) {
 // CHECK-OLD  [[DOUBLE]] = !{!"double", [[CHAR]], i64 0}
 // CHECK-OLD: [[TS7]] = !{i64 0, i64 1, [[TAG_CHAR]], i64 1, i64 1, [[TAG_CHAR]], i64 2, i64 1, [[TAG_CHAR]], i64 3, i64 1, [[TAG_CHAR]], i64 4, i64 1, [[TAG_CHAR]], i64 8, i64 8, [[TAG_DOUBLE]], i64 16, i64 1, [[TAG_CHAR]]}
 // CHECK-OLD: [[TS8]] = !{i64 0, i64 4, [[TAG_CHAR]], i64 8, i64 8, [[TAG_DOUBLE]]}
+// CHECK-OLD: [[TS9]] = !{i64 0, i64 8, [[TAG_DOUBLE]], i64 0, i64 4, [[TAG_FLOAT:!.+]], i64 8, i64 4, [[TAG_INT]]}
+// CHECK-OLD: [[TAG_FLOAT]]  = !{[[FLOAT:!.+]], [[FLOAT]], i64 0}
+// CHECK-OLD: [[FLOAT]] = !{!"float", [[CHAR]], i64 0}
+// CHECK-OLD: [[TS10]] = !{i64 0, i64 4, [[TAG_INT]], i64 8, i64 8, [[TAG_DOUBLE]], i64 8, i64 4, [[TAG_FLOAT:!.+]]}
 
 // CHECK-NEW-DAG: [[TYPE_char:!.*]] = !{{{.*}}, i64 1, !"omnipotent char"}
 // CHECK-NEW-DAG: [[TAG_char]] = !{[[TYPE_char]], [[TYPE_char]], i64 0, i64 0}
@@ -188,3 +224,7 @@ void copy10(NamedBitfields3 *a1, NamedBitfields3 *a2) {
 // CHECK-NEW-DAG: [[TYPE_NamedBitfields2]] = !{[[TYPE_char]], i64 24, !"_ZTS15NamedBitfields2", [[TYPE_char]], i64 0, i64 1, [[TYPE_char]], i64 1, i64 1, [[TYPE_char]], i64 2, i64 1, [[TYPE_int]], i64 3, i64 4, [[TYPE_int]], i64 3, i64 4, [[TYPE_char]], i64 4, i64 1, [[TYPE_double]], i64 8, i64 8, [[TYPE_int]], i64 16, i64 4}
 // CHECK-NEW-DAG: [[TAG_NamedBitfields3]] = !{[[TYPE_NamedBitfields3:!.+]], [[TYPE_NamedBitfields3]], i64 0, i64 16}
 // CHECK-NEW-DAG: [[TYPE_NamedBitfields3]] = !{[[TYPE_char]], i64 16, !"_ZTS15NamedBitfields3", [[TYPE_int]], i64 1, i64 4, [[TYPE_int]], i64 2, i64 4, [[TYPE_double]], i64 8, i64 8}
+// CHECK-NEW-DAG: [[TAG_UnionMember1]] = !{[[TYPE_UnionMember1:!.+]], [[TYPE_UnionMember1]], i64 0, i64 16}
+// CHECK-NEW-DAG: [[TYPE_UnionMember1]] = !{[[TYPE_char]], i64 16, !"_ZTS12UnionMember1", [[TYPE_char]], i64 0, i64 8, [[TYPE_int]], i64 8, i64 4}
+// CHECK-NEW-DAG: [[TAG_UnionMember2]] = !{[[TYPE_UnionMember2:!.+]], [[TYPE_UnionMember2]], i64 0, i64 16}
+// CHECK-NEW-DAG: [[TYPE_UnionMember2]] = !{[[TYPE_char]], i64 16, !"_ZTS12UnionMember2", [[TYPE_int]], i64 0, i64 4, [[TYPE_char]], i64 8, i64 8}