1 // RUN: %clang_cc1 -triple i686-linux-gnu -emit-llvm %s -o - | FileCheck %s --check-prefix=CHECK-O0
2 // RUN: %clang_cc1 -triple i686-linux-gnu -emit-llvm %s -O1 -o - | FileCheck %s
3 
4 // Check that we add an llvm.invariant.start to mark when a global becomes
5 // read-only. If globalopt can fold the initializer, it will then mark the
6 // variable as constant.
7 
8 // Do not produce markers at -O0.
9 // CHECK-O0-NOT: llvm.invariant.start
10 
11 struct A {
12   A();
13   int n;
14 };
15 
16 // CHECK: @a = global {{.*}} zeroinitializer
17 extern const A a = A();
18 
19 struct B {
20   B();
21   mutable int n;
22 };
23 
24 // CHECK: @b = global {{.*}} zeroinitializer
25 extern const B b = B();
26 
27 struct C {
28   C();
29   ~C();
30   int n;
31 };
32 
33 // CHECK: @c = global {{.*}} zeroinitializer
34 extern const C c = C();
35 
36 int f();
37 // CHECK: @d = global i32 0
38 extern const int d = f();
39 
e()40 void e() {
41   static const A a = A();
42 }
43 
44 // CHECK: call void @_ZN1AC1Ev({{.*}}* nonnull @a)
45 // CHECK: call {{.*}}@llvm.invariant.start(i64 4, i8* bitcast ({{.*}} @a to i8*))
46 
47 // CHECK: call void @_ZN1BC1Ev({{.*}}* nonnull @b)
48 // CHECK-NOT: call {{.*}}@llvm.invariant.start(i64 4, i8* bitcast ({{.*}} @b to i8*))
49 
50 // CHECK: call void @_ZN1CC1Ev({{.*}}* nonnull @c)
51 // CHECK-NOT: call {{.*}}@llvm.invariant.start(i64 4, i8* bitcast ({{.*}} @c to i8*))
52 
53 // CHECK: call i32 @_Z1fv(
54 // CHECK: store {{.*}}, i32* @d
55 // CHECK: call {{.*}}@llvm.invariant.start(i64 4, i8* bitcast ({{.*}} @d to i8*))
56 
57 // CHECK-LABEL: define void @_Z1ev(
58 // CHECK: call void @_ZN1AC1Ev(%struct.A* nonnull @_ZZ1evE1a)
59 // CHECK: call {{.*}}@llvm.invariant.start(i64 4, i8* {{.*}}bitcast ({{.*}} @_ZZ1evE1a to i8*))
60 // CHECK-NOT: llvm.invariant.end
61