; LLVM IR from Py-Contributors/AlgorithmsAndDataStructure :: C++/Data Structure/Graphs (Tarjan's Algorithm)

; 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<long long, std::allocator<long long>>::_Vector_impl" }
%"struct.std::_Vector_base<long long, std::allocator<long long>>::_Vector_impl" = type { %"struct.std::_Vector_base<long long, std::allocator<long long>>::_Vector_impl_data" }
%"struct.std::_Vector_base<long long, std::allocator<long long>>::_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 }

@gr = external dso_local global [100005 x %"class.std::vector"], align 16
@_ZSt3cin = external global %"class.std::basic_istream", align 8

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z3dfsxx(i64 noundef, i64 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: mustprogress uwtable
declare dso_local void @_ZNSt6vectorIxSaIxEE9push_backERKx(ptr noundef nonnull align 8 dereferenceable(24), ptr noundef nonnull align 8 dereferenceable(8)) #0 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 norecurse uwtable
define dso_local noundef i32 @main() #2 {
  %1 = alloca i32, align 4
  %2 = alloca i64, align 8
  %3 = alloca i64, align 8
  %4 = alloca i64, align 8
  %5 = alloca i64, align 8
  %6 = alloca i64, align 8
  %7 = alloca i64, align 8
  %8 = alloca i64, align 8
  %9 = alloca i64, align 8
  %10 = alloca i64, align 8
  %11 = alloca i64, align 8
  store i32 0, ptr %1, align 4
  call void @llvm.lifetime.start.p0(i64 8, ptr %2) #3
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #3
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #3
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #3
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #3
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #3
  store i64 0, ptr %7, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %8) #3
  store i64 0, ptr %8, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %9) #3
  store i64 0, ptr %9, align 8, !tbaa !5
  %12 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERx(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 8 dereferenceable(8) %5)
  %13 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERx(ptr noundef nonnull align 8 dereferenceable(16) %12, ptr noundef nonnull align 8 dereferenceable(8) %6)
  store i64 0, ptr %2, align 8, !tbaa !5
  br label %14

14:                                               ; preds = %23, %0
  %15 = load i64, ptr %2, align 8, !tbaa !5
  %16 = load i64, ptr %6, align 8, !tbaa !5
  %17 = icmp slt i64 %15, %16
  br i1 %17, label %18, label %26

18:                                               ; preds = %14
  call void @llvm.lifetime.start.p0(i64 8, ptr %10) #3
  call void @llvm.lifetime.start.p0(i64 8, ptr %11) #3
  %19 = load i64, ptr %10, align 8, !tbaa !5
  %20 = getelementptr inbounds [100005 x %"class.std::vector"], ptr @gr, i64 0, i64 %19
  call void @_ZNSt6vectorIxSaIxEE9push_backERKx(ptr noundef nonnull align 8 dereferenceable(24) %20, ptr noundef nonnull align 8 dereferenceable(8) %11)
  %21 = load i64, ptr %11, align 8, !tbaa !5
  %22 = getelementptr inbounds [100005 x %"class.std::vector"], ptr @gr, i64 0, i64 %21
  call void @_ZNSt6vectorIxSaIxEE9push_backERKx(ptr noundef nonnull align 8 dereferenceable(24) %22, ptr noundef nonnull align 8 dereferenceable(8) %10)
  call void @llvm.lifetime.end.p0(i64 8, ptr %11) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %10) #3
  br label %23

23:                                               ; preds = %18
  %24 = load i64, ptr %2, align 8, !tbaa !5
  %25 = add nsw i64 %24, 1
  store i64 %25, ptr %2, align 8, !tbaa !5
  br label %14, !llvm.loop !9

26:                                               ; preds = %14
  call void @_Z3dfsxx(i64 noundef 1, i64 noundef 0)
  call void @llvm.lifetime.end.p0(i64 8, ptr %9) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %8) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %2) #3
  %27 = load i32, ptr %1, align 4
  ret i32 %27
}

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERx(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 8 dereferenceable(8)) #0 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 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 = { 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 = !{!"long long", !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<long long, std::allocator<long long>>::_Vector_impl" }
%"struct.std::_Vector_base<long long, std::allocator<long long>>::_Vector_impl" = type { %"struct.std::_Vector_base<long long, std::allocator<long long>>::_Vector_impl_data" }
%"struct.std::_Vector_base<long long, std::allocator<long long>>::_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 }

@gr = external dso_local global [100005 x %"class.std::vector"], align 16
@_ZSt3cin = external global %"class.std::basic_istream", align 8

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z3dfsxx(i64 noundef, i64 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 uwtable
declare dso_local void @_ZNSt6vectorIxSaIxEE9push_backERKx(ptr noundef nonnull align 8 dereferenceable(24), 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 norecurse uwtable
define dso_local noundef i32 @main() local_unnamed_addr #2 {
  %1 = alloca i64, align 8
  %2 = alloca i64, align 8
  %3 = alloca i64, align 8
  %4 = alloca i64, align 8
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %1) #3
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %2) #3
  %5 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERx(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 8 dereferenceable(8) %1)
  %6 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERx(ptr noundef nonnull align 8 dereferenceable(16) %5, ptr noundef nonnull align 8 dereferenceable(8) %2)
  %7 = load i64, ptr %2, align 8, !tbaa !5
  %8 = icmp sgt i64 %7, 0
  br i1 %8, label %.lr.ph, label %._crit_edge

.lr.ph:                                           ; preds = %0, %.lr.ph
  %.03 = phi i64 [ %11, %.lr.ph ], [ 0, %0 ]
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %3) #3
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %4) #3
  call void @_ZNSt6vectorIxSaIxEE9push_backERKx(ptr noundef nonnull align 8 dereferenceable(24) @gr, ptr noundef nonnull align 8 dereferenceable(8) %4)
  %9 = load i64, ptr %4, align 8, !tbaa !5
  %10 = getelementptr inbounds [100005 x %"class.std::vector"], ptr @gr, i64 0, i64 %9
  call void @_ZNSt6vectorIxSaIxEE9push_backERKx(ptr noundef nonnull align 8 dereferenceable(24) %10, ptr noundef nonnull align 8 dereferenceable(8) %3)
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %4) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %3) #3
  %11 = add nuw nsw i64 %.03, 1
  %12 = load i64, ptr %2, align 8, !tbaa !5
  %13 = icmp slt i64 %11, %12
  br i1 %13, label %.lr.ph, label %._crit_edge, !llvm.loop !9

._crit_edge:                                      ; preds = %.lr.ph, %0
  call void @_Z3dfsxx(i64 noundef 1, i64 noundef 0)
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %2) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %1) #3
  ret i32 0
}

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERx(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 8 dereferenceable(8)) local_unnamed_addr #0 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 = { 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 = { 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 = !{!"long long", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


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