; LLVM IR from yanglr/leetcode-ac :: cpp-leetcode (leetcode430-flatten-a-multilevel-doubly-linked-list_dfs1)

; 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.__gnu_cxx::__normal_iterator" = type { ptr }
%class.Node = type { i32, ptr, ptr, ptr }

; Function Attrs: mustprogress uwtable
define dso_local noundef ptr @_Z14gengerateNodesSt6vectorIiSaIiEE(ptr noundef %0) #0 personality ptr @__gxx_personality_v0 {
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca ptr, align 8
  %7 = alloca ptr, align 8
  %8 = alloca %"class.__gnu_cxx::__normal_iterator", align 8
  %9 = alloca %"class.__gnu_cxx::__normal_iterator", align 8
  %10 = alloca i32, align 4
  store ptr %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #6
  %11 = call noalias noundef nonnull ptr @_Znwm(i64 noundef 32) #7
  invoke void @_ZN4NodeC2Ei(ptr noundef nonnull align 8 dereferenceable(32) %11, i32 noundef 0)
          to label %12 unwind label %23

12:                                               ; preds = %1
  store ptr %11, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #6
  %13 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %13, ptr %6, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #6
  store ptr %0, ptr %7, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %8) #6
  %14 = load ptr, ptr %7, align 8, !tbaa !5
  %15 = call ptr @_ZNSt6vectorIiSaIiEE5beginEv(ptr noundef nonnull align 8 dereferenceable(24) %14) #6
  %16 = getelementptr inbounds %"class.__gnu_cxx::__normal_iterator", ptr %8, i32 0, i32 0
  store ptr %15, ptr %16, align 8
  call void @llvm.lifetime.start.p0(i64 8, ptr %9) #6
  %17 = load ptr, ptr %7, align 8, !tbaa !5
  %18 = call ptr @_ZNSt6vectorIiSaIiEE3endEv(ptr noundef nonnull align 8 dereferenceable(24) %17) #6
  %19 = getelementptr inbounds %"class.__gnu_cxx::__normal_iterator", ptr %9, i32 0, i32 0
  store ptr %18, ptr %19, align 8
  br label %20

20:                                               ; preds = %34, %12
  %21 = call noundef zeroext i1 @_ZN9__gnu_cxxneIPiSt6vectorIiSaIiEEEEbRKNS_17__normal_iteratorIT_T0_EESA_(ptr noundef nonnull align 8 dereferenceable(8) %8, ptr noundef nonnull align 8 dereferenceable(8) %9) #6
  br i1 %21, label %27, label %22

22:                                               ; preds = %20
  call void @llvm.lifetime.end.p0(i64 8, ptr %9) #6
  call void @llvm.lifetime.end.p0(i64 8, ptr %8) #6
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #6
  br label %40

23:                                               ; preds = %1
  %24 = landingpad { ptr, i32 }
          cleanup
  %25 = extractvalue { ptr, i32 } %24, 0
  store ptr %25, ptr %4, align 8
  %26 = extractvalue { ptr, i32 } %24, 1
  store i32 %26, ptr %5, align 4
  call void @_ZdlPvm(ptr noundef %11, i64 noundef 32) #8
  br label %48

27:                                               ; preds = %20
  call void @llvm.lifetime.start.p0(i64 4, ptr %10) #6
  %28 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNK9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEdeEv(ptr noundef nonnull align 8 dereferenceable(8) %8) #6
  %29 = load i32, ptr %28, align 4, !tbaa !9
  store i32 %29, ptr %10, align 4, !tbaa !9
  %30 = call noalias noundef nonnull ptr @_Znwm(i64 noundef 32) #7
  %31 = load i32, ptr %10, align 4, !tbaa !9
  %32 = load ptr, ptr %6, align 8, !tbaa !5
  invoke void @_ZN4NodeC2EiPS_S0_(ptr noundef nonnull align 8 dereferenceable(32) %30, i32 noundef %31, ptr noundef null, ptr noundef %32)
          to label %33 unwind label %36

33:                                               ; preds = %27
  store ptr %30, ptr %6, align 8, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr %10) #6
  br label %34

34:                                               ; preds = %33
  %35 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZN9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEppEv(ptr noundef nonnull align 8 dereferenceable(8) %8) #6
  br label %20

36:                                               ; preds = %27
  %37 = landingpad { ptr, i32 }
          cleanup
  %38 = extractvalue { ptr, i32 } %37, 0
  store ptr %38, ptr %4, align 8
  %39 = extractvalue { ptr, i32 } %37, 1
  store i32 %39, ptr %5, align 4
  call void @_ZdlPvm(ptr noundef %30, i64 noundef 32) #8
  call void @llvm.lifetime.end.p0(i64 4, ptr %10) #6
  call void @llvm.lifetime.end.p0(i64 8, ptr %9) #6
  call void @llvm.lifetime.end.p0(i64 8, ptr %8) #6
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #6
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #6
  br label %48

40:                                               ; preds = %22
  %41 = load ptr, ptr %3, align 8, !tbaa !5
  %42 = getelementptr inbounds %class.Node, ptr %41, i32 0, i32 2
  %43 = load ptr, ptr %42, align 8, !tbaa !11
  %44 = getelementptr inbounds %class.Node, ptr %43, i32 0, i32 1
  store ptr null, ptr %44, align 8, !tbaa !13
  %45 = load ptr, ptr %3, align 8, !tbaa !5
  %46 = getelementptr inbounds %class.Node, ptr %45, i32 0, i32 2
  %47 = load ptr, ptr %46, align 8, !tbaa !11
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #6
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #6
  ret ptr %47

48:                                               ; preds = %36, %23
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #6
  br label %49

49:                                               ; preds = %48
  %50 = load ptr, ptr %4, align 8
  %51 = load i32, ptr %5, align 4
  %52 = insertvalue { ptr, i32 } poison, ptr %50, 0
  %53 = insertvalue { ptr, i32 } %52, i32 %51, 1
  resume { ptr, i32 } %53
}

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

; Function Attrs: nobuiltin allocsize(0)
declare noundef nonnull ptr @_Znwm(i64 noundef) #2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_ZN4NodeC2Ei(ptr noundef nonnull align 8 dereferenceable(32), i32 noundef) unnamed_addr #3 align 2

declare i32 @__gxx_personality_v0(...)

; Function Attrs: nobuiltin nounwind
declare void @_ZdlPvm(ptr noundef, i64 noundef) #4

; Function Attrs: mustprogress nounwind uwtable
declare dso_local ptr @_ZNSt6vectorIiSaIiEE5beginEv(ptr noundef nonnull align 8 dereferenceable(24)) #3 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local ptr @_ZNSt6vectorIiSaIiEE3endEv(ptr noundef nonnull align 8 dereferenceable(24)) #3 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)) #5

; 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)) #3 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_ZN4NodeC2EiPS_S0_(ptr noundef nonnull align 8 dereferenceable(32), i32 noundef, ptr noundef, ptr noundef) unnamed_addr #3 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)) #3 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 = { nobuiltin allocsize(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 = { 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 = { nobuiltin nounwind "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 #5 = { 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 #6 = { nounwind }
attributes #7 = { builtin allocsize(0) }
attributes #8 = { builtin 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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = !{!12, !6, i64 16}
!12 = !{!"_ZTS4Node", !10, i64 0, !6, i64 8, !6, i64 16, !6, i64 24}
!13 = !{!12, !6, i64 8}


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

; Function Attrs: mustprogress uwtable
define dso_local noundef ptr @_Z14gengerateNodesSt6vectorIiSaIiEE(ptr noundef %0) local_unnamed_addr #0 personality ptr @__gxx_personality_v0 {
  %2 = alloca %"class.__gnu_cxx::__normal_iterator", align 8
  %3 = alloca %"class.__gnu_cxx::__normal_iterator", align 8
  %4 = tail call noalias noundef nonnull dereferenceable(32) ptr @_Znwm(i64 noundef 32) #5
  tail call void @_ZN4NodeC2Ei(ptr noundef nonnull align 8 dereferenceable(32) %4, i32 noundef 0)
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %2) #6
  %5 = tail call ptr @_ZNSt6vectorIiSaIiEE5beginEv(ptr noundef nonnull align 8 dereferenceable(24) %0) #6
  store ptr %5, ptr %2, align 8
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %3) #6
  %6 = tail call ptr @_ZNSt6vectorIiSaIiEE3endEv(ptr noundef nonnull align 8 dereferenceable(24) %0) #6
  store ptr %6, ptr %3, align 8
  %7 = 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) #6
  br i1 %7, label %.lr.ph, label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph, %1
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %3) #6
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %2) #6
  %8 = getelementptr inbounds i8, ptr %4, i64 16
  %9 = load ptr, ptr %8, align 8, !tbaa !5
  %10 = getelementptr inbounds i8, ptr %9, i64 8
  store ptr null, ptr %10, align 8, !tbaa !11
  ret ptr %9

.lr.ph:                                           ; preds = %1, %.lr.ph
  %.06 = phi ptr [ %13, %.lr.ph ], [ %4, %1 ]
  %11 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNK9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEdeEv(ptr noundef nonnull align 8 dereferenceable(8) %2) #6
  %12 = load i32, ptr %11, align 4, !tbaa !12
  %13 = call noalias noundef nonnull dereferenceable(32) ptr @_Znwm(i64 noundef 32) #5
  call void @_ZN4NodeC2EiPS_S0_(ptr noundef nonnull align 8 dereferenceable(32) %13, i32 noundef %12, ptr noundef null, ptr noundef nonnull %.06)
  %14 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZN9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEppEv(ptr noundef nonnull align 8 dereferenceable(8) %2) #6
  %15 = 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) #6
  br i1 %15, label %.lr.ph, label %._crit_edge
}

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

; Function Attrs: nobuiltin allocsize(0)
declare noundef nonnull ptr @_Znwm(i64 noundef) local_unnamed_addr #2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_ZN4NodeC2Ei(ptr noundef nonnull align 8 dereferenceable(32), i32 noundef) unnamed_addr #3 align 2

declare i32 @__gxx_personality_v0(...)

; Function Attrs: mustprogress nounwind uwtable
declare dso_local ptr @_ZNSt6vectorIiSaIiEE5beginEv(ptr noundef nonnull align 8 dereferenceable(24)) local_unnamed_addr #3 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local ptr @_ZNSt6vectorIiSaIiEE3endEv(ptr noundef nonnull align 8 dereferenceable(24)) local_unnamed_addr #3 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 #4

; 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 #3 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_ZN4NodeC2EiPS_S0_(ptr noundef nonnull align 8 dereferenceable(32), i32 noundef, ptr noundef, ptr noundef) unnamed_addr #3 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 #3 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 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { nobuiltin allocsize(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 = { 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 = { 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 #5 = { builtin allocsize(0) }
attributes #6 = { 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, !10, i64 16}
!6 = !{!"_ZTS4Node", !7, i64 0, !10, i64 8, !10, i64 16, !10, i64 24}
!7 = !{!"int", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C++ TBAA"}
!10 = !{!"any pointer", !8, i64 0}
!11 = !{!6, !10, i64 8}
!12 = !{!7, !7, i64 0}


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