; LLVM IR from eyangch/competitive-programming :: USACOcontests/silver/2020.12/3.ll (Z3dfsi)

; 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 }
%"class.__gnu_cxx::__normal_iterator" = type { ptr }

@graph = external dso_local global [1000 x %"class.std::vector"], align 16
@children = external dso_local global [1000 x i32], align 16

; Function Attrs: mustprogress uwtable
define dso_local noundef i32 @_Z3dfsi(i32 noundef %0) #0 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca ptr, align 8
  %5 = alloca %"class.__gnu_cxx::__normal_iterator", align 8
  %6 = alloca %"class.__gnu_cxx::__normal_iterator", align 8
  %7 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  %8 = load i32, ptr %3, align 4, !tbaa !5
  %9 = sext i32 %8 to i64
  %10 = getelementptr inbounds [1000 x i32], ptr @children, i64 0, i64 %9
  %11 = load i32, ptr %10, align 4, !tbaa !5
  %12 = icmp ne i32 %11, 0
  br i1 %12, label %13, label %18

13:                                               ; preds = %1
  %14 = load i32, ptr %3, align 4, !tbaa !5
  %15 = sext i32 %14 to i64
  %16 = getelementptr inbounds [1000 x i32], ptr @children, i64 0, i64 %15
  %17 = load i32, ptr %16, align 4, !tbaa !5
  store i32 %17, ptr %2, align 4
  br label %51

18:                                               ; preds = %1
  %19 = load i32, ptr %3, align 4, !tbaa !5
  %20 = sext i32 %19 to i64
  %21 = getelementptr inbounds [1000 x i32], ptr @children, i64 0, i64 %20
  store i32 1, ptr %21, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #4
  %22 = load i32, ptr %3, align 4, !tbaa !5
  %23 = sext i32 %22 to i64
  %24 = getelementptr inbounds [1000 x %"class.std::vector"], ptr @graph, i64 0, i64 %23
  store ptr %24, ptr %4, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #4
  %25 = load ptr, ptr %4, align 8, !tbaa !9
  %26 = call ptr @_ZNSt6vectorIiSaIiEE5beginEv(ptr noundef nonnull align 8 dereferenceable(24) %25) #4
  %27 = getelementptr inbounds %"class.__gnu_cxx::__normal_iterator", ptr %5, i32 0, i32 0
  store ptr %26, ptr %27, align 8
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #4
  %28 = load ptr, ptr %4, align 8, !tbaa !9
  %29 = call ptr @_ZNSt6vectorIiSaIiEE3endEv(ptr noundef nonnull align 8 dereferenceable(24) %28) #4
  %30 = getelementptr inbounds %"class.__gnu_cxx::__normal_iterator", ptr %6, i32 0, i32 0
  store ptr %29, ptr %30, align 8
  br label %31

31:                                               ; preds = %44, %18
  %32 = call noundef zeroext i1 @_ZN9__gnu_cxxneIPiSt6vectorIiSaIiEEEEbRKNS_17__normal_iteratorIT_T0_EESA_(ptr noundef nonnull align 8 dereferenceable(8) %5, ptr noundef nonnull align 8 dereferenceable(8) %6) #4
  br i1 %32, label %34, label %33

33:                                               ; preds = %31
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #4
  br label %46

34:                                               ; preds = %31
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #4
  %35 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNK9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEdeEv(ptr noundef nonnull align 8 dereferenceable(8) %5) #4
  %36 = load i32, ptr %35, align 4, !tbaa !5
  store i32 %36, ptr %7, align 4, !tbaa !5
  %37 = load i32, ptr %7, align 4, !tbaa !5
  %38 = call noundef i32 @_Z3dfsi(i32 noundef %37)
  %39 = load i32, ptr %3, align 4, !tbaa !5
  %40 = sext i32 %39 to i64
  %41 = getelementptr inbounds [1000 x i32], ptr @children, i64 0, i64 %40
  %42 = load i32, ptr %41, align 4, !tbaa !5
  %43 = add nsw i32 %42, %38
  store i32 %43, ptr %41, align 4, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #4
  br label %44

44:                                               ; preds = %34
  %45 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZN9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEppEv(ptr noundef nonnull align 8 dereferenceable(8) %5) #4
  br label %31

46:                                               ; preds = %33
  %47 = load i32, ptr %3, align 4, !tbaa !5
  %48 = sext i32 %47 to i64
  %49 = getelementptr inbounds [1000 x i32], ptr @children, i64 0, i64 %48
  %50 = load i32, ptr %49, align 4, !tbaa !5
  store i32 %50, ptr %2, align 4
  br label %51

51:                                               ; preds = %46, %13
  %52 = load i32, ptr %2, align 4
  ret i32 %52
}

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: mustprogress nounwind uwtable
declare dso_local ptr @_ZNSt6vectorIiSaIiEE5beginEv(ptr noundef nonnull align 8 dereferenceable(24)) #2 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local ptr @_ZNSt6vectorIiSaIiEE3endEv(ptr noundef nonnull align 8 dereferenceable(24)) #2 align 2

; Function Attrs: inlinehint mustprogress nounwind uwtable
declare dso_local noundef zeroext i1 @_ZN9__gnu_cxxneIPiSt6vectorIiSaIiEEEEbRKNS_17__normal_iteratorIT_T0_EESA_(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef nonnull align 8 dereferenceable(8)) #3

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZNK9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEdeEv(ptr noundef nonnull align 8 dereferenceable(8)) #2 align 2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 8 dereferenceable(8) ptr @_ZN9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEppEv(ptr noundef nonnull align 8 dereferenceable(8)) #2 align 2

attributes #0 = { 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 #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = { inlinehint 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 #4 = { 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 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !7, i64 0}


; 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 }
%"class.__gnu_cxx::__normal_iterator" = type { ptr }

@graph = external dso_local global [1000 x %"class.std::vector"], align 16
@children = external dso_local local_unnamed_addr global [1000 x i32], align 16

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z3dfsi(i32 noundef %0) local_unnamed_addr #0 {
  %2 = alloca %"class.__gnu_cxx::__normal_iterator", align 8
  %3 = alloca %"class.__gnu_cxx::__normal_iterator", align 8
  %4 = sext i32 %0 to i64
  %5 = getelementptr inbounds [1000 x i32], ptr @children, i64 0, i64 %4
  %6 = load i32, ptr %5, align 4, !tbaa !5
  %.not = icmp eq i32 %6, 0
  br i1 %.not, label %7, label %20

7:                                                ; preds = %1
  store i32 1, ptr %5, align 4, !tbaa !5
  %8 = getelementptr inbounds [1000 x %"class.std::vector"], ptr @graph, i64 0, i64 %4
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %2) #3
  %9 = tail call ptr @_ZNSt6vectorIiSaIiEE5beginEv(ptr noundef nonnull align 8 dereferenceable(24) %8) #3
  store ptr %9, ptr %2, align 8
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %3) #3
  %10 = tail call ptr @_ZNSt6vectorIiSaIiEE3endEv(ptr noundef nonnull align 8 dereferenceable(24) %8) #3
  store ptr %10, ptr %3, align 8
  %11 = call noundef zeroext i1 @_ZN9__gnu_cxxneIPiSt6vectorIiSaIiEEEEbRKNS_17__normal_iteratorIT_T0_EESA_(ptr noundef nonnull align 8 dereferenceable(8) %2, ptr noundef nonnull align 8 dereferenceable(8) %3) #3
  br i1 %11, label %.lr.ph, label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph, %7
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %3) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %2) #3
  %12 = load i32, ptr %5, align 4, !tbaa !5
  br label %20

.lr.ph:                                           ; preds = %7, %.lr.ph
  %13 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNK9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEdeEv(ptr noundef nonnull align 8 dereferenceable(8) %2) #3
  %14 = load i32, ptr %13, align 4, !tbaa !5
  %15 = call noundef i32 @_Z3dfsi(i32 noundef %14)
  %16 = load i32, ptr %5, align 4, !tbaa !5
  %17 = add nsw i32 %16, %15
  store i32 %17, ptr %5, align 4, !tbaa !5
  %18 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZN9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEppEv(ptr noundef nonnull align 8 dereferenceable(8) %2) #3
  %19 = call noundef zeroext i1 @_ZN9__gnu_cxxneIPiSt6vectorIiSaIiEEEEbRKNS_17__normal_iteratorIT_T0_EESA_(ptr noundef nonnull align 8 dereferenceable(8) %2, ptr noundef nonnull align 8 dereferenceable(8) %3) #3
  br i1 %19, label %.lr.ph, label %._crit_edge

20:                                               ; preds = %1, %._crit_edge
  %.0 = phi i32 [ %12, %._crit_edge ], [ %6, %1 ]
  ret i32 %.0
}

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: mustprogress nounwind uwtable
declare dso_local ptr @_ZNSt6vectorIiSaIiEE5beginEv(ptr noundef nonnull align 8 dereferenceable(24)) local_unnamed_addr #0 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local ptr @_ZNSt6vectorIiSaIiEE3endEv(ptr noundef nonnull align 8 dereferenceable(24)) local_unnamed_addr #0 align 2

; Function Attrs: inlinehint mustprogress nounwind uwtable
declare dso_local noundef zeroext i1 @_ZN9__gnu_cxxneIPiSt6vectorIiSaIiEEEEbRKNS_17__normal_iteratorIT_T0_EESA_(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef nonnull align 8 dereferenceable(8)) local_unnamed_addr #2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZNK9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEdeEv(ptr noundef nonnull align 8 dereferenceable(8)) local_unnamed_addr #0 align 2

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 8 dereferenceable(8) ptr @_ZN9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEppEv(ptr noundef nonnull align 8 dereferenceable(8)) 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 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { inlinehint 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"}


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