Decorating vptr load & stores with !invariant.group

Adding !invariant.group to vptr load/stores for devirtualization purposes.
For more goto:
http://lists.llvm.org/pipermail/cfe-dev/2015-July/044227.html

http://reviews.llvm.org/D12026

llvm-svn: 247725

1 files changed, 75 insertions, 0 deletions

diff --git a/clang/test/CodeGenCXX/invariant.group-for-vptrs.cpp b/clang/test/CodeGenCXX/invariant.group-for-vptrs.cpp
new file mode 100644
index 00000000000..8458aeb5b06
--- /dev/null
+++ b/clang/test/CodeGenCXX/invariant.group-for-vptrs.cpp
@@ -0,0 +1,75 @@
+// RUN: %clang_cc1 -triple %itanium_abi_triple -emit-llvm %s -fstrict-vtable-pointers -O1 -o - -disable-llvm-optzns | FileCheck %s
+
+struct A {
+  virtual void foo();
+};
+
+struct D : A {
+  void foo();
+};
+
+// CHECK-LABEL: define void @_Z21testExternallyVisiblev()
+void testExternallyVisible() {
+  A *a = new A;
+
+  // CHECK: load {{.*}} !invariant.group ![[A_MD:[0-9]+]]
+  a->foo();
+
+  D *d = new D;
+  // CHECK: call void @_ZN1DC1Ev(
+  // CHECK: load {{.*}} !invariant.group ![[D_MD:[0-9]+]]
+  d->foo();
+  A *a2 = d;
+  // CHECK: load {{.*}} !invariant.group ![[A_MD]]
+  a2->foo();
+}
+// CHECK-LABEL: }
+
+namespace {
+
+struct B {
+  virtual void bar();
+};
+
+struct C : B {
+  void bar();
+};
+
+}
+
+// CHECK-LABEL: define void @_Z21testInternallyVisibleb(
+void testInternallyVisible(bool p) {
+  B *b = new B;
+  // CHECK: = load {{.*}}, !invariant.group ![[B_MD:[0-9]+]]
+  b->bar();
+
+  // CHECK: call void @_ZN12_GLOBAL__N_11CC1Ev(
+  C *c = new C;
+  // CHECK: = load {{.*}}, !invariant.group ![[C_MD:[0-9]+]]
+  c->bar();
+}
+
+// Checking A::A()
+// CHECK-LABEL: define linkonce_odr void @_ZN1AC2Ev(
+// CHECK: store {{.*}}, !invariant.group ![[A_MD]]
+// CHECK-LABEL: }
+
+// Checking D::D()
+// CHECK-LABEL: define linkonce_odr void @_ZN1DC2Ev(
+
+// CHECK:  call void @_ZN1AC2Ev(%struct.A*
+// CHECK:  = call i8* @llvm.invariant.group.barrier(i8*
+// CHECK: store {{.*}} !invariant.group ![[D_MD]]
+
+// Checking B::B()
+// CHECK-LABEL: define internal void @_ZN12_GLOBAL__N_11BC2Ev(
+// CHECK:  store {{.*}}, !invariant.group ![[B_MD]]
+
+// Checking C::C()
+// CHECK-LABEL: define internal void @_ZN12_GLOBAL__N_11CC2Ev(
+// CHECK:  store {{.*}}, !invariant.group ![[C_MD]]
+
+// CHECK: ![[A_MD]] = !{!"_ZTS1A"}
+// CHECK: ![[D_MD]] = !{!"_ZTS1D"}
+// CHECK: ![[B_MD]] = distinct !{}
+// CHECK: ![[C_MD]] = distinct !{}