; LLVM IR from eyangch/competitive-programming :: CSES/Tree_Algorithms (tree_matching)

; 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.std::basic_istream" = type { ptr, i64, %"class.std::basic_ios" }
%"class.std::basic_ios" = type { %"class.std::ios_base", ptr, i8, i8, ptr, ptr, ptr, ptr }
%"class.std::ios_base" = type { ptr, i64, i64, i32, i32, i32, ptr, %"struct.std::ios_base::_Words", [8 x %"struct.std::ios_base::_Words"], i32, ptr, %"class.std::locale" }
%"struct.std::ios_base::_Words" = type { ptr, i64 }
%"class.std::locale" = type { ptr }
%"class.std::basic_ostream" = type { ptr, %"class.std::basic_ios" }

@N = external dso_local global i32, align 4
@graph = external dso_local global [200000 x %"class.std::vector"], align 16
@ans = external dso_local global i32, align 4
@_ZSt3cin = external global %"class.std::basic_istream", align 8
@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@.str = external hidden unnamed_addr constant [2 x i8], align 1

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z3dfsii(i32 noundef, i32 noundef) #0

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

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

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() #2 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  store i32 0, ptr %1, align 4
  %7 = call noundef zeroext i1 @_ZNSt8ios_base15sync_with_stdioEb(i1 noundef zeroext false)
  %8 = load ptr, ptr @_ZSt3cin, align 8, !tbaa !5
  %9 = getelementptr i8, ptr %8, i64 -24
  %10 = load i64, ptr %9, align 8
  %11 = getelementptr inbounds i8, ptr @_ZSt3cin, i64 %10
  %12 = call noundef ptr @_ZNSt9basic_iosIcSt11char_traitsIcEE3tieEPSo(ptr noundef nonnull align 8 dereferenceable(264) %11, ptr noundef null)
  %13 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) @N)
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #6
  store i32 0, ptr %2, align 4, !tbaa !8
  br label %14

14:                                               ; preds = %35, %0
  %15 = load i32, ptr %2, align 4, !tbaa !8
  %16 = load i32, ptr @N, align 4, !tbaa !8
  %17 = sub nsw i32 %16, 1
  %18 = icmp slt i32 %15, %17
  br i1 %18, label %20, label %19

19:                                               ; preds = %14
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #6
  br label %38

20:                                               ; preds = %14
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #6
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #6
  %21 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %3)
  %22 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) %21, ptr noundef nonnull align 4 dereferenceable(4) %4)
  %23 = load i32, ptr %3, align 4, !tbaa !8
  %24 = sub nsw i32 %23, 1
  %25 = sext i32 %24 to i64
  %26 = getelementptr inbounds [200000 x %"class.std::vector"], ptr @graph, i64 0, i64 %25
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #6
  %27 = load i32, ptr %4, align 4, !tbaa !8
  %28 = sub nsw i32 %27, 1
  store i32 %28, ptr %5, align 4, !tbaa !8
  call void @_ZNSt6vectorIiSaIiEE9push_backEOi(ptr noundef nonnull align 8 dereferenceable(24) %26, ptr noundef nonnull align 4 dereferenceable(4) %5)
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #6
  %29 = load i32, ptr %4, align 4, !tbaa !8
  %30 = sub nsw i32 %29, 1
  %31 = sext i32 %30 to i64
  %32 = getelementptr inbounds [200000 x %"class.std::vector"], ptr @graph, i64 0, i64 %31
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #6
  %33 = load i32, ptr %3, align 4, !tbaa !8
  %34 = sub nsw i32 %33, 1
  store i32 %34, ptr %6, align 4, !tbaa !8
  call void @_ZNSt6vectorIiSaIiEE9push_backEOi(ptr noundef nonnull align 8 dereferenceable(24) %32, ptr noundef nonnull align 4 dereferenceable(4) %6)
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #6
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #6
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #6
  br label %35

35:                                               ; preds = %20
  %36 = load i32, ptr %2, align 4, !tbaa !8
  %37 = add nsw i32 %36, 1
  store i32 %37, ptr %2, align 4, !tbaa !8
  br label %14, !llvm.loop !11

38:                                               ; preds = %19
  call void @_Z3dfsii(i32 noundef 0, i32 noundef -1)
  %39 = load i32, ptr @ans, align 4, !tbaa !8
  %40 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %39)
  %41 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) %40, ptr noundef @.str)
  %42 = load i32, ptr %1, align 4
  ret i32 %42
}

declare noundef zeroext i1 @_ZNSt8ios_base15sync_with_stdioEb(i1 noundef zeroext) #3

; Function Attrs: mustprogress nounwind uwtable
declare noundef ptr @_ZNSt9basic_iosIcSt11char_traitsIcEE3tieEPSo(ptr noundef nonnull align 8 dereferenceable(264), ptr noundef) #4 align 2

declare noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 4 dereferenceable(4)) #3

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZNSt6vectorIiSaIiEE9push_backEOi(ptr noundef nonnull align 8 dereferenceable(24), ptr noundef nonnull align 4 dereferenceable(4)) #0 align 2

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) #5

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) #3

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 norecurse 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 = { "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 = { 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 = { inlinehint 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 #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, !6, i64 0}
!6 = !{!"vtable pointer", !7, i64 0}
!7 = !{!"Simple C++ TBAA"}
!8 = !{!9, !9, i64 0}
!9 = !{!"int", !10, i64 0}
!10 = !{!"omnipotent char", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"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 }
%"class.std::basic_istream" = type { ptr, i64, %"class.std::basic_ios" }
%"class.std::basic_ios" = type { %"class.std::ios_base", ptr, i8, i8, ptr, ptr, ptr, ptr }
%"class.std::ios_base" = type { ptr, i64, i64, i32, i32, i32, ptr, %"struct.std::ios_base::_Words", [8 x %"struct.std::ios_base::_Words"], i32, ptr, %"class.std::locale" }
%"struct.std::ios_base::_Words" = type { ptr, i64 }
%"class.std::locale" = type { ptr }
%"class.std::basic_ostream" = type { ptr, %"class.std::basic_ios" }

@N = external dso_local global i32, align 4
@graph = external dso_local global [200000 x %"class.std::vector"], align 16
@ans = external dso_local local_unnamed_addr global i32, align 4
@_ZSt3cin = external global %"class.std::basic_istream", align 8
@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@.str = external hidden unnamed_addr constant [2 x i8], align 1

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z3dfsii(i32 noundef, i32 noundef) local_unnamed_addr #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 nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() local_unnamed_addr #2 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = tail call noundef zeroext i1 @_ZNSt8ios_base15sync_with_stdioEb(i1 noundef zeroext false)
  %6 = load ptr, ptr @_ZSt3cin, align 8, !tbaa !5
  %7 = getelementptr i8, ptr %6, i64 -24
  %8 = load i64, ptr %7, align 8
  %9 = getelementptr inbounds i8, ptr @_ZSt3cin, i64 %8
  %10 = tail call noundef ptr @_ZNSt9basic_iosIcSt11char_traitsIcEE3tieEPSo(ptr noundef nonnull align 8 dereferenceable(264) %9, ptr noundef null)
  %11 = tail call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) @N)
  %12 = load i32, ptr @N, align 4, !tbaa !8
  %13 = icmp sgt i32 %12, 1
  br i1 %13, label %.lr.ph, label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph, %0
  call void @_Z3dfsii(i32 noundef 0, i32 noundef -1)
  %14 = load i32, ptr @ans, align 4, !tbaa !8
  %15 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %14)
  %16 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) %15, ptr noundef nonnull @.str)
  ret i32 0

.lr.ph:                                           ; preds = %0, %.lr.ph
  %.03 = phi i32 [ %31, %.lr.ph ], [ 0, %0 ]
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %1) #6
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %2) #6
  %17 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %1)
  %18 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) %17, ptr noundef nonnull align 4 dereferenceable(4) %2)
  %19 = load i32, ptr %1, align 4, !tbaa !8
  %20 = add nsw i32 %19, -1
  %21 = sext i32 %20 to i64
  %22 = getelementptr inbounds [200000 x %"class.std::vector"], ptr @graph, i64 0, i64 %21
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %3) #6
  %23 = load i32, ptr %2, align 4, !tbaa !8
  %24 = add nsw i32 %23, -1
  store i32 %24, ptr %3, align 4, !tbaa !8
  call void @_ZNSt6vectorIiSaIiEE9push_backEOi(ptr noundef nonnull align 8 dereferenceable(24) %22, ptr noundef nonnull align 4 dereferenceable(4) %3)
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %3) #6
  %25 = load i32, ptr %2, align 4, !tbaa !8
  %26 = add nsw i32 %25, -1
  %27 = sext i32 %26 to i64
  %28 = getelementptr inbounds [200000 x %"class.std::vector"], ptr @graph, i64 0, i64 %27
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %4) #6
  %29 = load i32, ptr %1, align 4, !tbaa !8
  %30 = add nsw i32 %29, -1
  store i32 %30, ptr %4, align 4, !tbaa !8
  call void @_ZNSt6vectorIiSaIiEE9push_backEOi(ptr noundef nonnull align 8 dereferenceable(24) %28, ptr noundef nonnull align 4 dereferenceable(4) %4)
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %4) #6
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %2) #6
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %1) #6
  %31 = add nuw nsw i32 %.03, 1
  %32 = load i32, ptr @N, align 4, !tbaa !8
  %33 = add nsw i32 %32, -1
  %34 = icmp slt i32 %31, %33
  br i1 %34, label %.lr.ph, label %._crit_edge, !llvm.loop !11
}

declare noundef zeroext i1 @_ZNSt8ios_base15sync_with_stdioEb(i1 noundef zeroext) local_unnamed_addr #3

; Function Attrs: mustprogress nounwind uwtable
declare noundef ptr @_ZNSt9basic_iosIcSt11char_traitsIcEE3tieEPSo(ptr noundef nonnull align 8 dereferenceable(264), ptr noundef) local_unnamed_addr #4 align 2

declare noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 4 dereferenceable(4)) local_unnamed_addr #3

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZNSt6vectorIiSaIiEE9push_backEOi(ptr noundef nonnull align 8 dereferenceable(24), ptr noundef nonnull align 4 dereferenceable(4)) local_unnamed_addr #0 align 2

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) local_unnamed_addr #5

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) local_unnamed_addr #3

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 = { mustprogress norecurse 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 = { "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 = { 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 = { inlinehint 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 #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, !6, i64 0}
!6 = !{!"vtable pointer", !7, i64 0}
!7 = !{!"Simple C++ TBAA"}
!8 = !{!9, !9, i64 0}
!9 = !{!"int", !10, i64 0}
!10 = !{!"omnipotent char", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}


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