clang/test/CodeGenCXX/init-invariant.cpp

   1 // RUN: %clang_cc1 -triple i686-linux-gnu -emit-llvm %s -disable-llvm-passes -o - | FileCheck %s --check-prefix=CHECK-O0
   2 // RUN: %clang_cc1 -triple i686-linux-gnu -emit-llvm %s -O1 -disable-llvm-passes -o - | FileCheck %s
   3
   4 // Check that we add an llvm.invariant.start.p0i8 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.p0i8
  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
  40 void e() {
  41   static const A a = A();
  42 }
  43
  44 // CHECK: call void @_ZN1AC1Ev(ptr noundef {{[^,]*}} @a)
  45 // CHECK: call {{.*}}@llvm.invariant.start.p0(i64 4, ptr @a)
  46
  47 // CHECK: call void @_ZN1BC1Ev(ptr noundef {{[^,]*}} @b)
  48 // CHECK-NOT: call {{.*}}@llvm.invariant.start.p0(i64 noundef 4, ptr @b)
  49
  50 // CHECK: call void @_ZN1CC1Ev(ptr noundef {{[^,]*}} @c)
  51 // CHECK-NOT: call {{.*}}@llvm.invariant.start.p0(i64 noundef 4, ptr @c)
  52
  53 // CHECK: call noundef i32 @_Z1fv(
  54 // CHECK: store {{.*}}, ptr @d
  55 // CHECK: call {{.*}}@llvm.invariant.start.p0(i64 4, ptr @d)
  56
  57 // CHECK-LABEL: define{{.*}} void @_Z1ev(
  58 // CHECK: call void @_ZN1AC1Ev(ptr noundef {{[^,]*}} @_ZZ1evE1a)
  59 // CHECK: call {{.*}}@llvm.invariant.start.p0(i64 4, ptr {{.*}}@_ZZ1evE1a)
  60 // CHECK-NOT: llvm.invariant.end