Constant *TopLevelGlobal = nullptr);
/// Finds the same "relative pointer" pattern as described above, where the
-/// target is `C`, and replaces the entire pattern with a constant zero.
-void replaceRelativePointerUsersWithZero(Constant *C);
+/// target is `F`, and replaces the entire pattern with a constant zero.
+void replaceRelativePointerUsersWithZero(Function *F);
} // namespace llvm
return nullptr;
}
-static void replaceRelativePointerUserWithZero(User *U) {
- auto *PtrExpr = dyn_cast<ConstantExpr>(U);
- if (!PtrExpr || PtrExpr->getOpcode() != Instruction::PtrToInt)
- return;
-
- for (auto *PtrToIntUser : PtrExpr->users()) {
- auto *SubExpr = dyn_cast<ConstantExpr>(PtrToIntUser);
- if (!SubExpr || SubExpr->getOpcode() != Instruction::Sub)
- return;
+void llvm::replaceRelativePointerUsersWithZero(Function *F) {
+ for (auto *U : F->users()) {
+ auto *PtrExpr = dyn_cast<ConstantExpr>(U);
+ if (!PtrExpr || PtrExpr->getOpcode() != Instruction::PtrToInt)
+ continue;
- SubExpr->replaceNonMetadataUsesWith(
- ConstantInt::get(SubExpr->getType(), 0));
- }
-}
+ for (auto *PtrToIntUser : PtrExpr->users()) {
+ auto *SubExpr = dyn_cast<ConstantExpr>(PtrToIntUser);
+ if (!SubExpr || SubExpr->getOpcode() != Instruction::Sub)
+ continue;
-void llvm::replaceRelativePointerUsersWithZero(Constant *C) {
- for (auto *U : C->users()) {
- if (auto *Equiv = dyn_cast<DSOLocalEquivalent>(U))
- replaceRelativePointerUsersWithZero(Equiv);
- else
- replaceRelativePointerUserWithZero(U);
+ SubExpr->replaceNonMetadataUsesWith(
+ ConstantInt::get(SubExpr->getType(), 0));
+ }
}
}
; CHECK: @vtable = internal unnamed_addr constant { [3 x i32] } zeroinitializer, align 8, !type !0, !type !1, !vcall_visibility !2
-@vtable2 = internal unnamed_addr constant { [3 x i32] } { [3 x i32] [
- i32 trunc (i64 sub (i64 ptrtoint (ptr dso_local_equivalent @vfunc3 to i64), i64 ptrtoint (ptr @vtable2 to i64)) to i32),
- i32 trunc (i64 sub (i64 ptrtoint (ptr dso_local_equivalent @vfunc4 to i64), i64 ptrtoint (ptr @vtable2 to i64)) to i32),
-
- ; a "bad" relative pointer because it's base is not the @vtable symbol
- i32 trunc (i64 sub (i64 ptrtoint (ptr @weird_ref_3 to i64), i64 ptrtoint (ptr @weird_ref_4 to i64)) to i32)
-]}, align 4, !type !3, !type !4, !vcall_visibility !{i64 2}
-!3 = !{i64 0, !"vfunc3.type"}
-!4 = !{i64 4, !"vfunc4.type"}
-
-; CHECK: @vtable2 = internal unnamed_addr constant { [3 x i32] } zeroinitializer, align 4, !type !3, !type !4, !vcall_visibility !2
-
define internal void @vfunc1() { ret void }
define internal void @vfunc2() { ret void }
define internal void @weird_ref_1() { ret void }
define internal void @weird_ref_2() { ret void }
-declare void @vfunc3()
-declare void @vfunc4()
-declare void @weird_ref_3()
-declare void @weird_ref_4()
define void @main() {
%1 = ptrtoint ptr @vtable to i64 ; to keep @vtable alive
call void @weird_ref_2()
- %2 = ptrtoint ptr @vtable2 to i64 ; to keep @vtable2 alive
- call void @weird_ref_4()
ret void
}
; CHECK-SAME: i32 0
; CHECK-SAME: ] }, align 8, !type !0, !type !1, !vcall_visibility !2
-@vtable2 = internal unnamed_addr constant { [4 x i32] } { [4 x i32] [
- i32 42,
- i32 1337,
- i32 trunc (i64 sub (i64 ptrtoint (ptr dso_local_equivalent @vfunc3_live_extern to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [4 x i32] }, ptr @vtable2, i32 0, i32 0, i32 2) to i64)) to i32),
- i32 trunc (i64 sub (i64 ptrtoint (ptr dso_local_equivalent @vfunc4_dead_extern to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [4 x i32] }, ptr @vtable2, i32 0, i32 0, i32 2) to i64)) to i32)
-]}, align 4, !type !3, !type !4, !vcall_visibility !{i64 2}
-!3 = !{i64 8, !"vfunc3.type"}
-!4 = !{i64 12, !"vfunc4.type"}
-
-; CHECK: @vtable2 = internal unnamed_addr constant { [4 x i32] } { [4 x i32] [
-; CHECK-SAME: i32 trunc (i64 sub (i64 ptrtoint (ptr dso_local_equivalent @vfunc3_live_extern to i64), i64 ptrtoint (ptr getelementptr inbounds ({ [4 x i32] }, ptr @vtable2, i32 0, i32 0, i32 2) to i64)) to i32),
-; CHECK-SAME: i32 0
-; CHECK-SAME: ] }, align 4, !type !3, !type !4, !vcall_visibility !2
-
; (1) vfunc1_live is referenced from @main, stays alive
define internal void @vfunc1_live() {
; CHECK: define internal void @vfunc1_live(
ret void
}
-; (3) vfunc3_live_extern is referenced from @main, stays alive
-; CHECK: declare void @vfunc3_live_extern
-declare void @vfunc3_live_extern()
-
-; (4) vfunc4_dead_extern is never referenced, gets removed and vtable slot is null'd
-; CHECK-NOT: declare void @vfunc4_dead_extern
-declare void @vfunc4_dead_extern()
-
define void @main() {
%1 = ptrtoint ptr @vtable to i64 ; to keep @vtable alive
%2 = tail call { ptr, i1 } @llvm.type.checked.load(ptr null, i32 0, metadata !"vfunc1.type")
- %3 = ptrtoint ptr @vtable2 to i64 ; to keep @vtable2 alive
- %4 = tail call { ptr, i1 } @llvm.type.checked.load(ptr null, i32 0, metadata !"vfunc3.type")
ret void
}
; CHECK-SAME: i32 0
; CHECK-SAME: ] }, align 8, !type !0, !type !1, !vcall_visibility !2
-; Similar to above, but the vtable is more aligned to how C++ relative vtables look.
-; That is, the functions may not be dso-local.
-@vtable2 = internal unnamed_addr constant { [2 x i32] } { [2 x i32] [
- i32 trunc (i64 sub (i64 ptrtoint (ptr dso_local_equivalent @vfunc3_live_extern to i64), i64 ptrtoint (ptr @vtable2 to i64)) to i32),
- i32 trunc (i64 sub (i64 ptrtoint (ptr dso_local_equivalent @vfunc4_dead_extern to i64), i64 ptrtoint (ptr @vtable2 to i64)) to i32)
-]}, align 4, !type !3, !type !4, !vcall_visibility !{i64 2}
-!3 = !{i64 0, !"vfunc3.type"}
-!4 = !{i64 4, !"vfunc4.type"}
-
-; CHECK: @vtable2 = internal unnamed_addr constant { [2 x i32] } { [2 x i32] [
-; 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),
-; CHECK-SAME: i32 0
-; CHECK-SAME: ] }, align 4, !type !3, !type !4, !vcall_visibility !2
-
; (1) vfunc1_live is referenced from @main, stays alive
define internal void @vfunc1_live() {
; CHECK: define internal void @vfunc1_live(
ret void
}
-; (3) vfunc3_live_extern is referenced from @main, stays alive
-; CHECK: declare void @vfunc3_live_extern
-declare void @vfunc3_live_extern()
-
-; (4) vfunc4_dead_extern is never referenced, gets removed and vtable slot is null'd
-; CHECK-NOT: declare void @vfunc4_dead_extern
-declare void @vfunc4_dead_extern()
-
define void @main() {
%1 = ptrtoint ptr @vtable to i64 ; to keep @vtable alive
%2 = tail call { ptr, i1 } @llvm.type.checked.load(ptr null, i32 0, metadata !"vfunc1.type")
- %3 = ptrtoint ptr @vtable2 to i64 ; to keep @vtable2 alive
- %4 = tail call { ptr, i1 } @llvm.type.checked.load(ptr null, i32 0, metadata !"vfunc3.type")
ret void
}