1 2; RUN: opt < %s -passes=globaldce -S | FileCheck %s 3 4target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" 5 6; struct A { 7; A(); 8; virtual int foo(int); 9; virtual int bar(float); 10; }; 11; 12; struct B : A { 13; B(); 14; virtual int foo(int); 15; virtual int bar(float); 16; }; 17; 18; A::A() {} 19; B::B() {} 20; int A::foo(int) { return 1; } 21; int A::bar(float) { return 2; } 22; int B::foo(int) { return 3; } 23; int B::bar(float) { return 4; } 24; 25; extern "C" int test(B *p, int (B::*q)(int)) { return (p->*q)(42); } 26 27; Member function pointers are tracked by the combination of their object type 28; and function type, which must both be compatible. Here, the call is through a 29; pointer of type "int (B::*q)(int)", so the call could only be dispatched to 30; B::foo. It can't be dispatched to A::bar or B::bar as the function pointer 31; does not match, and it can't be dispatched to A::foo as the object type 32; doesn't match, so those can be removed. 33 34%struct.A = type { ptr } 35%struct.B = type { %struct.A } 36 37; CHECK: @_ZTV1A = internal unnamed_addr constant { [4 x ptr] } zeroinitializer 38@_ZTV1A = internal unnamed_addr constant { [4 x ptr] } { [4 x ptr] [ptr null, ptr null, ptr @_ZN1A3fooEi, ptr @_ZN1A3barEf] }, align 8, !type !0, !type !1, !type !2, !vcall_visibility !3 39; CHECK: @_ZTV1B = internal unnamed_addr constant { [4 x ptr] } { [4 x ptr] [ptr null, ptr null, ptr @_ZN1B3fooEi, ptr null] } 40@_ZTV1B = internal unnamed_addr constant { [4 x ptr] } { [4 x ptr] [ptr null, ptr null, ptr @_ZN1B3fooEi, ptr @_ZN1B3barEf] }, align 8, !type !0, !type !1, !type !2, !type !4, !type !5, !type !6, !vcall_visibility !3 41 42 43; CHECK-NOT: define internal i32 @_ZN1A3fooEi( 44define internal i32 @_ZN1A3fooEi(ptr nocapture readnone %this, i32) unnamed_addr #1 align 2 { 45entry: 46 ret i32 1 47} 48 49; CHECK-NOT: define internal i32 @_ZN1A3barEf( 50define internal i32 @_ZN1A3barEf(ptr nocapture readnone %this, float) unnamed_addr #1 align 2 { 51entry: 52 ret i32 2 53} 54 55; CHECK: define internal i32 @_ZN1B3fooEi( 56define internal i32 @_ZN1B3fooEi(ptr nocapture readnone %this, i32) unnamed_addr #1 align 2 { 57entry: 58 ret i32 3 59} 60 61; CHECK-NOT: define internal i32 @_ZN1B3barEf( 62define internal i32 @_ZN1B3barEf(ptr nocapture readnone %this, float) unnamed_addr #1 align 2 { 63entry: 64 ret i32 4 65} 66 67 68define hidden void @_ZN1AC2Ev(ptr nocapture %this) { 69entry: 70 store ptr getelementptr inbounds inrange(-16, 16) ({ [4 x ptr] }, ptr @_ZTV1A, i64 0, i32 0, i64 2), ptr %this, align 8 71 ret void 72} 73 74define hidden void @_ZN1BC2Ev(ptr nocapture %this) { 75entry: 76 store ptr getelementptr inbounds inrange(-16, 16) ({ [4 x ptr] }, ptr @_ZTV1B, i64 0, i32 0, i64 2), ptr %this, align 8 77 ret void 78} 79 80define hidden i32 @test(ptr %p, i64 %q.coerce0, i64 %q.coerce1) { 81entry: 82 %0 = getelementptr inbounds i8, ptr %p, i64 %q.coerce1 83 %1 = and i64 %q.coerce0, 1 84 %memptr.isvirtual = icmp eq i64 %1, 0 85 br i1 %memptr.isvirtual, label %memptr.nonvirtual, label %memptr.virtual 86 87memptr.virtual: ; preds = %entry 88 %vtable = load ptr, ptr %0, align 8 89 %2 = add i64 %q.coerce0, -1 90 %3 = getelementptr i8, ptr %vtable, i64 %2, !nosanitize !12 91 %4 = tail call { ptr, i1 } @llvm.type.checked.load(ptr %3, i32 0, metadata !"_ZTSM1BFiiE.virtual"), !nosanitize !12 92 %5 = extractvalue { ptr, i1 } %4, 0, !nosanitize !12 93 br label %memptr.end 94 95memptr.nonvirtual: ; preds = %entry 96 %memptr.nonvirtualfn = inttoptr i64 %q.coerce0 to ptr 97 br label %memptr.end 98 99memptr.end: ; preds = %memptr.nonvirtual, %memptr.virtual 100 %6 = phi ptr [ %5, %memptr.virtual ], [ %memptr.nonvirtualfn, %memptr.nonvirtual ] 101 %call = tail call i32 %6(ptr %0, i32 42) 102 ret i32 %call 103} 104 105declare { ptr, i1 } @llvm.type.checked.load(ptr, i32, metadata) 106 107!llvm.module.flags = !{!7} 108 109!0 = !{i64 16, !"_ZTS1A"} 110!1 = !{i64 16, !"_ZTSM1AFiiE.virtual"} 111!2 = !{i64 24, !"_ZTSM1AFifE.virtual"} 112!3 = !{i64 2} 113!4 = !{i64 16, !"_ZTS1B"} 114!5 = !{i64 16, !"_ZTSM1BFiiE.virtual"} 115!6 = !{i64 24, !"_ZTSM1BFifE.virtual"} 116!7 = !{i32 1, !"Virtual Function Elim", i32 1} 117!12 = !{} 118