1 // RUN: %clang_cc1 -triple x86_64-unknown-linux -flto -flto-unit -fvirtual-function-elimination -fwhole-program-vtables -emit-llvm -o - %s | FileCheck %s 2 3 4 struct __attribute__((visibility("default"))) A { 5 virtual void foo(); 6 }; 7 8 void test_1(A *p) { 9 // A has default visibility, so no need for type.checked.load. 10 // CHECK-LABEL: define void @_Z6test_1P1A 11 // CHECK: [[FN_PTR_ADDR:%.+]] = getelementptr inbounds void (%struct.A*)*, void (%struct.A*)** {{%.+}}, i64 0 12 // CHECK: [[FN_PTR:%.+]] = load void (%struct.A*)*, void (%struct.A*)** [[FN_PTR_ADDR]] 13 // CHECK: call void [[FN_PTR]]( 14 p->foo(); 15 } 16 17 18 struct __attribute__((visibility("hidden"))) [[clang::lto_visibility_public]] B { 19 virtual void foo(); 20 }; 21 22 void test_2(B *p) { 23 // B has public LTO visibility, so no need for type.checked.load. 24 // CHECK-LABEL: define void @_Z6test_2P1B 25 // CHECK: [[FN_PTR_ADDR:%.+]] = getelementptr inbounds void (%struct.B*)*, void (%struct.B*)** {{%.+}}, i64 0 26 // CHECK: [[FN_PTR:%.+]] = load void (%struct.B*)*, void (%struct.B*)** [[FN_PTR_ADDR]] 27 // CHECK: call void [[FN_PTR]]( 28 p->foo(); 29 } 30 31 32 struct __attribute__((visibility("hidden"))) C { 33 virtual void foo(); 34 virtual void bar(); 35 }; 36 37 void test_3(C *p) { 38 // C has hidden visibility, so we generate type.checked.load to allow VFE. 39 // CHECK-LABEL: define void @_Z6test_3P1C 40 // CHECK: [[LOAD:%.+]] = call { i8*, i1 } @llvm.type.checked.load(i8* {{%.+}}, i32 0, metadata !"_ZTS1C") 41 // CHECK: [[FN_PTR_I8:%.+]] = extractvalue { i8*, i1 } [[LOAD]], 0 42 // CHECK: [[FN_PTR:%.+]] = bitcast i8* [[FN_PTR_I8]] to void (%struct.C*)* 43 // CHECK: call void [[FN_PTR]]( 44 p->foo(); 45 } 46 47 void test_4(C *p) { 48 // When using type.checked.load, we pass the vtable offset to the intrinsic, 49 // rather than adding it to the pointer with a GEP. 50 // CHECK-LABEL: define void @_Z6test_4P1C 51 // CHECK: [[LOAD:%.+]] = call { i8*, i1 } @llvm.type.checked.load(i8* {{%.+}}, i32 8, metadata !"_ZTS1C") 52 // CHECK: [[FN_PTR_I8:%.+]] = extractvalue { i8*, i1 } [[LOAD]], 0 53 // CHECK: [[FN_PTR:%.+]] = bitcast i8* [[FN_PTR_I8]] to void (%struct.C*)* 54 // CHECK: call void [[FN_PTR]]( 55 p->bar(); 56 } 57 58 void test_5(C *p, void (C::*q)(void)) { 59 // We also use type.checked.load for the virtual side of member function 60 // pointer calls. We use a GEP to calculate the address to load from and pass 61 // 0 as the offset to the intrinsic, because we know that the load must be 62 // from exactly the point marked by one of the function-type metadatas (in 63 // this case "_ZTSM1CFvvE.virtual"). If we passed the offset from the member 64 // function pointer to the intrinsic, this information would be lost. No 65 // codegen changes on the non-virtual side. 66 // CHECK-LABEL: define void @_Z6test_5P1CMS_FvvE( 67 // CHECK: [[FN_PTR_ADDR:%.+]] = getelementptr i8, i8* %vtable, i64 {{%.+}} 68 // CHECK: [[LOAD:%.+]] = call { i8*, i1 } @llvm.type.checked.load(i8* [[FN_PTR_ADDR]], i32 0, metadata !"_ZTSM1CFvvE.virtual") 69 // CHECK: [[FN_PTR_I8:%.+]] = extractvalue { i8*, i1 } [[LOAD]], 0 70 // CHECK: [[FN_PTR:%.+]] = bitcast i8* [[FN_PTR_I8]] to void (%struct.C*)* 71 72 // CHECK: [[PHI:%.+]] = phi void (%struct.C*)* {{.*}}[ [[FN_PTR]], {{.*}} ] 73 // CHECK: call void [[PHI]]( 74 (p->*q)(); 75 } 76