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1; RUN: opt < %s -passes=globaldce -S | FileCheck %s2 3target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"4 5declare { ptr, i1 } @llvm.type.checked.load(ptr, i32, metadata)6 7; A vtable with "relative pointers", slots don't contain pointers to implementations, but instead have an i32 offset from the vtable itself to the implementation.8@vtable = internal unnamed_addr constant { [2 x i32] } { [2 x i32] [9 i32 trunc (i64 sub (i64 ptrtoint (ptr @vfunc1_live to i64), i64 ptrtoint (ptr @vtable to i64)) to i32),10 i32 trunc (i64 sub (i64 ptrtoint (ptr @vfunc2_dead to i64), i64 ptrtoint (ptr @vtable to i64)) to i32)11]}, align 8, !type !0, !type !1, !vcall_visibility !{i64 2}12!0 = !{i64 0, !"vfunc1.type"}13!1 = !{i64 4, !"vfunc2.type"}14 15; CHECK: @vtable = internal unnamed_addr constant { [2 x i32] } { [2 x i32] [16; CHECK-SAME: i32 trunc (i64 sub (i64 ptrtoint (ptr @vfunc1_live to i64), i64 ptrtoint (ptr @vtable to i64)) to i32),17; CHECK-SAME: i32 018; CHECK-SAME: ] }, align 8, !type !0, !type !1, !vcall_visibility !219 20; Similar to above, but the vtable is more aligned to how C++ relative vtables look.21; That is, the functions may not be dso-local.22@vtable2 = internal unnamed_addr constant { [2 x i32] } { [2 x i32] [23 i32 trunc (i64 sub (i64 ptrtoint (ptr dso_local_equivalent @vfunc3_live_extern to i64), i64 ptrtoint (ptr @vtable2 to i64)) to i32),24 i32 trunc (i64 sub (i64 ptrtoint (ptr dso_local_equivalent @vfunc4_dead_extern to i64), i64 ptrtoint (ptr @vtable2 to i64)) to i32)25]}, align 4, !type !3, !type !4, !vcall_visibility !{i64 2}26!3 = !{i64 0, !"vfunc3.type"}27!4 = !{i64 4, !"vfunc4.type"}28 29; CHECK: @vtable2 = internal unnamed_addr constant { [2 x i32] } { [2 x i32] [30; CHECK-SAME: i32 trunc (i64 sub (i64 ptrtoint (ptr dso_local_equivalent @vfunc3_live_extern to i64), i64 ptrtoint (ptr @vtable2 to i64)) to i32),31; CHECK-SAME: i32 032; CHECK-SAME: ] }, align 4, !type !3, !type !4, !vcall_visibility !233 34; (1) vfunc1_live is referenced from @main, stays alive35define internal void @vfunc1_live() {36 ; CHECK: define internal void @vfunc1_live(37 ret void38}39 40; (2) vfunc2_dead is never referenced, gets removed and vtable slot is null'd41define internal void @vfunc2_dead() {42 ; CHECK-NOT: define internal void @vfunc2_dead(43 ret void44}45 46; (3) vfunc3_live_extern is referenced from @main, stays alive47; CHECK: declare void @vfunc3_live_extern48declare void @vfunc3_live_extern()49 50; (4) vfunc4_dead_extern is never referenced, gets removed and vtable slot is null'd51; CHECK-NOT: declare void @vfunc4_dead_extern52declare void @vfunc4_dead_extern()53 54define void @main() {55 %1 = ptrtoint ptr @vtable to i64 ; to keep @vtable alive56 %2 = tail call { ptr, i1 } @llvm.type.checked.load(ptr null, i32 0, metadata !"vfunc1.type")57 %3 = ptrtoint ptr @vtable2 to i64 ; to keep @vtable2 alive58 %4 = tail call { ptr, i1 } @llvm.type.checked.load(ptr null, i32 0, metadata !"vfunc3.type")59 ret void60}61 62!999 = !{i32 1, !"Virtual Function Elim", i32 1}63!llvm.module.flags = !{!999}64