forked from OSchip/llvm-project
76 lines
3.1 KiB
C++
76 lines
3.1 KiB
C++
// RUN: %clang_cc1 -triple x86_64-unknown-linux -flto -flto-unit -fvirtual-function-elimination -fwhole-program-vtables -emit-llvm -o - %s | FileCheck %s
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struct __attribute__((visibility("default"))) A {
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virtual void foo();
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};
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void test_1(A *p) {
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// A has default visibility, so no need for type.checked.load.
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// CHECK-LABEL: define void @_Z6test_1P1A
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// CHECK: [[FN_PTR_ADDR:%.+]] = getelementptr inbounds void (%struct.A*)*, void (%struct.A*)** {{%.+}}, i64 0
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// CHECK: [[FN_PTR:%.+]] = load void (%struct.A*)*, void (%struct.A*)** [[FN_PTR_ADDR]]
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// CHECK: call void [[FN_PTR]](
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p->foo();
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}
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struct __attribute__((visibility("hidden"))) [[clang::lto_visibility_public]] B {
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virtual void foo();
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};
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void test_2(B *p) {
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// B has public LTO visibility, so no need for type.checked.load.
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// CHECK-LABEL: define void @_Z6test_2P1B
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// CHECK: [[FN_PTR_ADDR:%.+]] = getelementptr inbounds void (%struct.B*)*, void (%struct.B*)** {{%.+}}, i64 0
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// CHECK: [[FN_PTR:%.+]] = load void (%struct.B*)*, void (%struct.B*)** [[FN_PTR_ADDR]]
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// CHECK: call void [[FN_PTR]](
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p->foo();
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}
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struct __attribute__((visibility("hidden"))) C {
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virtual void foo();
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virtual void bar();
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};
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void test_3(C *p) {
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// C has hidden visibility, so we generate type.checked.load to allow VFE.
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// CHECK-LABEL: define void @_Z6test_3P1C
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// CHECK: [[LOAD:%.+]] = call { i8*, i1 } @llvm.type.checked.load(i8* {{%.+}}, i32 0, metadata !"_ZTS1C")
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// CHECK: [[FN_PTR_I8:%.+]] = extractvalue { i8*, i1 } [[LOAD]], 0
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// CHECK: [[FN_PTR:%.+]] = bitcast i8* [[FN_PTR_I8]] to void (%struct.C*)*
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// CHECK: call void [[FN_PTR]](
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p->foo();
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}
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void test_4(C *p) {
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// When using type.checked.load, we pass the vtable offset to the intrinsic,
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// rather than adding it to the pointer with a GEP.
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// CHECK-LABEL: define void @_Z6test_4P1C
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// CHECK: [[LOAD:%.+]] = call { i8*, i1 } @llvm.type.checked.load(i8* {{%.+}}, i32 8, metadata !"_ZTS1C")
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// CHECK: [[FN_PTR_I8:%.+]] = extractvalue { i8*, i1 } [[LOAD]], 0
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// CHECK: [[FN_PTR:%.+]] = bitcast i8* [[FN_PTR_I8]] to void (%struct.C*)*
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// CHECK: call void [[FN_PTR]](
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p->bar();
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}
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void test_5(C *p, void (C::*q)(void)) {
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// We also use type.checked.load for the virtual side of member function
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// pointer calls. We use a GEP to calculate the address to load from and pass
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// 0 as the offset to the intrinsic, because we know that the load must be
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// from exactly the point marked by one of the function-type metadatas (in
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// this case "_ZTSM1CFvvE.virtual"). If we passed the offset from the member
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// function pointer to the intrinsic, this information would be lost. No
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// codegen changes on the non-virtual side.
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// CHECK-LABEL: define void @_Z6test_5P1CMS_FvvE(
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// CHECK: [[FN_PTR_ADDR:%.+]] = getelementptr i8, i8* %vtable, i64 {{%.+}}
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// CHECK: [[LOAD:%.+]] = call { i8*, i1 } @llvm.type.checked.load(i8* [[FN_PTR_ADDR]], i32 0, metadata !"_ZTSM1CFvvE.virtual")
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// CHECK: [[FN_PTR_I8:%.+]] = extractvalue { i8*, i1 } [[LOAD]], 0
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// CHECK: [[FN_PTR:%.+]] = bitcast i8* [[FN_PTR_I8]] to void (%struct.C*)*
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// CHECK: [[PHI:%.+]] = phi void (%struct.C*)* {{.*}}[ [[FN_PTR]], {{.*}} ]
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// CHECK: call void [[PHI]](
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(p->*q)();
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}
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