; LLVM IR from Izaron/ACM-ICPC :: Timus Online Judge/Volume 1/1022. Genealogical Tree.ll (Z3dfsii)

; Unoptimized IR (clang -disable-llvm-passes):
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

%"class.std::vector" = type { %"struct.std::_Vector_base" }
%"struct.std::_Vector_base" = type { %"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl" }
%"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl" = type { %"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl_data" }
%"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl_data" = type { ptr, ptr, ptr }

@g = external dso_local global [100 x %"class.std::vector"], align 16
@m = external dso_local global [100 x i32], align 16

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: mustprogress uwtable
define dso_local void @_Z3dfsii(i32 noundef %0, i32 noundef %1) #1 {
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !5
  %7 = load i32, ptr %4, align 4, !tbaa !5
  %8 = load i32, ptr %3, align 4, !tbaa !5
  %9 = sext i32 %8 to i64
  %10 = getelementptr inbounds [100 x i32], ptr @m, i64 0, i64 %9
  store i32 %7, ptr %10, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #3
  store i32 0, ptr %5, align 4, !tbaa !5
  br label %11

11:                                               ; preds = %40, %2
  %12 = load i32, ptr %5, align 4, !tbaa !5
  %13 = sext i32 %12 to i64
  %14 = load i32, ptr %3, align 4, !tbaa !5
  %15 = sext i32 %14 to i64
  %16 = getelementptr inbounds [100 x %"class.std::vector"], ptr @g, i64 0, i64 %15
  %17 = call noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24) %16) #3
  %18 = icmp ult i64 %13, %17
  br i1 %18, label %20, label %19

19:                                               ; preds = %11
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #3
  br label %43

20:                                               ; preds = %11
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #3
  %21 = load i32, ptr %3, align 4, !tbaa !5
  %22 = sext i32 %21 to i64
  %23 = getelementptr inbounds [100 x %"class.std::vector"], ptr @g, i64 0, i64 %22
  %24 = load i32, ptr %5, align 4, !tbaa !5
  %25 = sext i32 %24 to i64
  %26 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24) %23, i64 noundef %25) #3
  %27 = load i32, ptr %26, align 4, !tbaa !5
  store i32 %27, ptr %6, align 4, !tbaa !5
  %28 = load i32, ptr %6, align 4, !tbaa !5
  %29 = sext i32 %28 to i64
  %30 = getelementptr inbounds [100 x i32], ptr @m, i64 0, i64 %29
  %31 = load i32, ptr %30, align 4, !tbaa !5
  %32 = load i32, ptr %4, align 4, !tbaa !5
  %33 = sub nsw i32 %32, 1
  %34 = icmp sgt i32 %31, %33
  br i1 %34, label %35, label %39

35:                                               ; preds = %20
  %36 = load i32, ptr %6, align 4, !tbaa !5
  %37 = load i32, ptr %4, align 4, !tbaa !5
  %38 = sub nsw i32 %37, 1
  call void @_Z3dfsii(i32 noundef %36, i32 noundef %38)
  br label %39

39:                                               ; preds = %35, %20
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #3
  br label %40

40:                                               ; preds = %39
  %41 = load i32, ptr %5, align 4, !tbaa !5
  %42 = add nsw i32 %41, 1
  store i32 %42, ptr %5, align 4, !tbaa !5
  br label %11, !llvm.loop !9

43:                                               ; preds = %19
  ret void
}

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24)) #2 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24), i64 noundef) #2 align 2

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { mustprogress uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #2 = { mustprogress nounwind uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #3 = { nounwind }

!llvm.module.flags = !{!0, !1, !2, !3}
!llvm.ident = !{!4}

!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{i32 8, !"PIC Level", i32 2}
!2 = !{i32 7, !"PIE Level", i32 2}
!3 = !{i32 7, !"uwtable", i32 2}
!4 = !{!"clang version 19.1.0 (git@github.com:llvm/llvm-project.git a4bf6cd7cfb1a1421ba92bca9d017b49936c55e4)"}
!5 = !{!6, !6, i64 0}
!6 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


; Optimized IR (opt -passes='default<O3>'):
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

%"class.std::vector" = type { %"struct.std::_Vector_base" }
%"struct.std::_Vector_base" = type { %"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl" }
%"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl" = type { %"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl_data" }
%"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl_data" = type { ptr, ptr, ptr }

@g = external dso_local global [100 x %"class.std::vector"], align 16
@m = external dso_local local_unnamed_addr global [100 x i32], align 16

; Function Attrs: mustprogress nounwind uwtable
define dso_local void @_Z3dfsii(i32 noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = sext i32 %0 to i64
  %4 = getelementptr inbounds [100 x i32], ptr @m, i64 0, i64 %3
  store i32 %1, ptr %4, align 4, !tbaa !5
  %5 = getelementptr inbounds [100 x %"class.std::vector"], ptr @g, i64 0, i64 %3
  %6 = tail call noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24) %5) #1
  %.not14 = icmp eq i64 %6, 0
  br i1 %.not14, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %2
  %7 = add nsw i32 %1, -1
  br label %8

._crit_edge:                                      ; preds = %15, %2
  ret void

8:                                                ; preds = %.lr.ph, %15
  %indvars.iv = phi i64 [ 0, %.lr.ph ], [ %indvars.iv.next, %15 ]
  %9 = tail call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24) %5, i64 noundef %indvars.iv) #1
  %10 = load i32, ptr %9, align 4, !tbaa !5
  %11 = sext i32 %10 to i64
  %12 = getelementptr inbounds [100 x i32], ptr @m, i64 0, i64 %11
  %13 = load i32, ptr %12, align 4, !tbaa !5
  %.not = icmp slt i32 %13, %1
  br i1 %.not, label %15, label %14

14:                                               ; preds = %8
  tail call void @_Z3dfsii(i32 noundef %10, i32 noundef %7)
  br label %15

15:                                               ; preds = %14, %8
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %16 = tail call noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24) %5) #1
  %17 = icmp ugt i64 %16, %indvars.iv.next
  br i1 %17, label %8, label %._crit_edge, !llvm.loop !9
}

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24)) local_unnamed_addr #0 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24), i64 noundef) local_unnamed_addr #0 align 2

attributes #0 = { mustprogress nounwind uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #1 = { nounwind }

!llvm.module.flags = !{!0, !1, !2, !3}
!llvm.ident = !{!4}

!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{i32 8, !"PIC Level", i32 2}
!2 = !{i32 7, !"PIE Level", i32 2}
!3 = !{i32 7, !"uwtable", i32 2}
!4 = !{!"clang version 19.1.0 (git@github.com:llvm/llvm-project.git a4bf6cd7cfb1a1421ba92bca9d017b49936c55e4)"}
!5 = !{!6, !6, i64 0}
!6 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LICMPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass