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