Add test for disabling Dead Virtual Function Elimination

Differential Revision: https://reviews.llvm.org/D88349

Author: ddcc

clang/test/CodeGenCXX/virtual-function-elimination.cpp

@@ -1,5 +1,5 @@
 // RUN: %clang_cc1 -triple x86_64-unknown-linux -flto -flto-unit -fvirtual-function-elimination -fwhole-program-vtables -emit-llvm -o - %s | FileCheck %s
-
+// RUN: %clang -target x86_64-unknown-linux -flto -fvirtual-function-elimination -fno-virtual-function-elimination -fwhole-program-vtables -S -emit-llvm -o - %s | FileCheck %s -check-prefix=NOVFE
 
 struct __attribute__((visibility("default"))) A {
   virtual void foo();
@@ -8,9 +8,13 @@ struct __attribute__((visibility("default"))) A {
 void test_1(A *p) {
   // A has default visibility, so no need for type.checked.load.
 // CHECK-LABEL: define void @_Z6test_1P1A
+// NOVFE-LABEL: define dso_local void @_Z6test_1P1A
 // CHECK: [[FN_PTR_ADDR:%.+]] = getelementptr inbounds void (%struct.A*)*, void (%struct.A*)** {{%.+}}, i64 0
+// NOVFE: [[FN_PTR_ADDR:%.+]] = getelementptr inbounds void (%struct.A*)*, void (%struct.A*)** {{%.+}}, i64 0
 // CHECK: [[FN_PTR:%.+]] = load void (%struct.A*)*, void (%struct.A*)** [[FN_PTR_ADDR]]
+// NOVFE: [[FN_PTR:%.+]] = load void (%struct.A*)*, void (%struct.A*)** [[FN_PTR_ADDR]]
 // CHECK: call void [[FN_PTR]](
+// NOVFE: call void [[FN_PTR]](
   p->foo();
 }
 
@@ -22,9 +26,13 @@ struct __attribute__((visibility("hidden"))) [[clang::lto_visibility_public]] B
 void test_2(B *p) {
   // B has public LTO visibility, so no need for type.checked.load.
 // CHECK-LABEL: define void @_Z6test_2P1B
+// NOVFE-LABEL: define dso_local void @_Z6test_2P1B
 // CHECK: [[FN_PTR_ADDR:%.+]] = getelementptr inbounds void (%struct.B*)*, void (%struct.B*)** {{%.+}}, i64 0
+// NOVFE: [[FN_PTR_ADDR:%.+]] = getelementptr inbounds void (%struct.B*)*, void (%struct.B*)** {{%.+}}, i64 0
 // CHECK: [[FN_PTR:%.+]] = load void (%struct.B*)*, void (%struct.B*)** [[FN_PTR_ADDR]]
+// NOVFE: [[FN_PTR:%.+]] = load void (%struct.B*)*, void (%struct.B*)** [[FN_PTR_ADDR]]
 // CHECK: call void [[FN_PTR]](
+// NOVFE: call void [[FN_PTR]](
   p->foo();
 }
 
@@ -37,21 +45,29 @@ struct __attribute__((visibility("hidden"))) C {
 void test_3(C *p) {
   // C has hidden visibility, so we generate type.checked.load to allow VFE.
 // CHECK-LABEL: define void @_Z6test_3P1C
+// NOVFE-LABEL: define dso_local void @_Z6test_3P1C
 // CHECK: [[LOAD:%.+]] = call { i8*, i1 } @llvm.type.checked.load(i8* {{%.+}}, i32 0, metadata !"_ZTS1C")
+// NOVFE: call i1 @llvm.type.test(i8* {{%.+}}, metadata !"_ZTS1C")
 // CHECK: [[FN_PTR_I8:%.+]] = extractvalue { i8*, i1 } [[LOAD]], 0
+// NOVFE: [[FN_PTR:%.+]] = load void (%struct.C*)*, void (%struct.C*)** {{%.+}}, align 8
 // CHECK: [[FN_PTR:%.+]] = bitcast i8* [[FN_PTR_I8]] to void (%struct.C*)*
 // CHECK: call void [[FN_PTR]](
+// NOVFE: call void [[FN_PTR]](
   p->foo();
 }
 
 void test_4(C *p) {
   // When using type.checked.load, we pass the vtable offset to the intrinsic,
   // rather than adding it to the pointer with a GEP.
 // CHECK-LABEL: define void @_Z6test_4P1C
+// NOVFE-LABEL: define dso_local void @_Z6test_4P1C
 // CHECK: [[LOAD:%.+]] = call { i8*, i1 } @llvm.type.checked.load(i8* {{%.+}}, i32 8, metadata !"_ZTS1C")
+// NOVFE: call i1 @llvm.type.test(i8* {{%.+}}, metadata !"_ZTS1C")
 // CHECK: [[FN_PTR_I8:%.+]] = extractvalue { i8*, i1 } [[LOAD]], 0
+// NOVFE: [[FN_PTR:%.+]] = load void (%struct.C*)*, void (%struct.C*)** {{%.+}}, align 8
 // CHECK: [[FN_PTR:%.+]] = bitcast i8* [[FN_PTR_I8]] to void (%struct.C*)*
 // CHECK: call void [[FN_PTR]](
+// NOVFE: call void [[FN_PTR]](
   p->bar();
 }
 
@@ -64,12 +80,17 @@ void test_5(C *p, void (C::*q)(void)) {
   // function pointer to the intrinsic, this information would be lost. No
   // codegen changes on the non-virtual side.
 // CHECK-LABEL: define void @_Z6test_5P1CMS_FvvE(
+// NOVFE-LABEL: define dso_local void @_Z6test_5P1CMS_FvvE(
 // CHECK: [[FN_PTR_ADDR:%.+]] = getelementptr i8, i8* %vtable, i64 {{%.+}}
 // CHECK: [[LOAD:%.+]] = call { i8*, i1 } @llvm.type.checked.load(i8* [[FN_PTR_ADDR]], i32 0, metadata !"_ZTSM1CFvvE.virtual")
+// NOVFE-NOT: call { i8*, i1 } @llvm.type.checked.load(i8* {{%.+}}, i32 0, metadata !"_ZTSM1CFvvE.virtual")
 // CHECK: [[FN_PTR_I8:%.+]] = extractvalue { i8*, i1 } [[LOAD]], 0
 // CHECK: [[FN_PTR:%.+]] = bitcast i8* [[FN_PTR_I8]] to void (%struct.C*)*
+// NOVFE: [[FN_PTR:%.+]] = load void (%struct.C*)*, void (%struct.C*)** {{%.+}}, align 8
 
 // CHECK: [[PHI:%.+]] = phi void (%struct.C*)* {{.*}}[ [[FN_PTR]], {{.*}} ]
+// NOVFE: [[PHI:%.+]] = phi void (%struct.C*)* {{.*}}[ [[FN_PTR]], {{.*}} ]
 // CHECK: call void [[PHI]](
+// NOVFE: call void [[PHI]](
   (p->*q)();
 }