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
5declare { i8*, i1 } @llvm.type.checked.load(i8*, 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 (void ()* @vfunc1_live              to i64), i64 ptrtoint ({ [2 x i32] }* @vtable to i64)) to i32),
10  i32 trunc (i64 sub (i64 ptrtoint (void ()* @vfunc2_dead              to i64), i64 ptrtoint ({ [2 x i32] }* @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 (void ()* @vfunc1_live              to i64), i64 ptrtoint ({ [2 x i32] }* @vtable to i64)) to i32),
17; CHECK-SAME:   i32 0
18; CHECK-SAME: ] }, align 8, !type !0, !type !1, !vcall_visibility !2
19
20; (1) vfunc1_live is referenced from @main, stays alive
21define internal void @vfunc1_live() {
22  ; CHECK: define internal void @vfunc1_live(
23  ret void
24}
25
26; (2) vfunc2_dead is never referenced, gets removed and vtable slot is null'd
27define internal void @vfunc2_dead() {
28  ; CHECK-NOT: define internal void @vfunc2_dead(
29  ret void
30}
31
32define void @main() {
33  %1 = ptrtoint { [2 x i32] }* @vtable to i64 ; to keep @vtable alive
34  %2 = tail call { i8*, i1 } @llvm.type.checked.load(i8* null, i32 0, metadata !"vfunc1.type")
35  ret void
36}
37
38!999 = !{i32 1, !"Virtual Function Elim", i32 1}
39!llvm.module.flags = !{!999}
40