; LLVM IR from HarshCasper/NeoAlgo :: C-Plus-Plus/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 }

@graph = external dso_local global [100001 x %"class.std::vector"], align 16
@vis = external dso_local global [100001 x i8], align 16
@onstack = external dso_local global [100001 x i8], align 16
@_ZSt3cin = external global %"class.std::basic_istream", align 8

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z3dfsx(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: 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
  store i32 0, ptr %1, align 4
  %9 = call noundef zeroext i1 @_ZNSt8ios_base15sync_with_stdioEb(i1 noundef zeroext false)
  %10 = load ptr, ptr @_ZSt3cin, align 8, !tbaa !5
  %11 = getelementptr i8, ptr %10, i64 -24
  %12 = load i64, ptr %11, align 8
  %13 = getelementptr inbounds i8, ptr @_ZSt3cin, i64 %12
  %14 = call noundef ptr @_ZNSt9basic_iosIcSt11char_traitsIcEE3tieEPSo(ptr noundef nonnull align 8 dereferenceable(264) %13, ptr noundef null)
  call void @llvm.lifetime.start.p0(i64 8, ptr %2) #5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #5
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #5
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #5
  %15 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERx(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 8 dereferenceable(8) %2)
  %16 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERx(ptr noundef nonnull align 8 dereferenceable(16) %15, ptr noundef nonnull align 8 dereferenceable(8) %3)
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #5
  store i64 1, ptr %6, align 8, !tbaa !8
  br label %17

17:                                               ; preds = %27, %0
  %18 = load i64, ptr %6, align 8, !tbaa !8
  %19 = load i64, ptr %3, align 8, !tbaa !8
  %20 = icmp sle i64 %18, %19
  br i1 %20, label %22, label %21

21:                                               ; preds = %17
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #5
  br label %30

22:                                               ; preds = %17
  %23 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERx(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 8 dereferenceable(8) %4)
  %24 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERx(ptr noundef nonnull align 8 dereferenceable(16) %23, ptr noundef nonnull align 8 dereferenceable(8) %5)
  %25 = load i64, ptr %4, align 8, !tbaa !8
  %26 = getelementptr inbounds [100001 x %"class.std::vector"], ptr @graph, i64 0, i64 %25
  call void @_ZNSt6vectorIxSaIxEE9push_backERKx(ptr noundef nonnull align 8 dereferenceable(24) %26, ptr noundef nonnull align 8 dereferenceable(8) %5)
  br label %27

27:                                               ; preds = %22
  %28 = load i64, ptr %6, align 8, !tbaa !8
  %29 = add nsw i64 %28, 1
  store i64 %29, ptr %6, align 8, !tbaa !8
  br label %17, !llvm.loop !11

30:                                               ; preds = %21
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #5
  store i64 1, ptr %7, align 8, !tbaa !8
  br label %31

31:                                               ; preds = %41, %30
  %32 = load i64, ptr %7, align 8, !tbaa !8
  %33 = load i64, ptr %2, align 8, !tbaa !8
  %34 = icmp sle i64 %32, %33
  br i1 %34, label %36, label %35

35:                                               ; preds = %31
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #5
  br label %44

36:                                               ; preds = %31
  %37 = load i64, ptr %7, align 8, !tbaa !8
  %38 = getelementptr inbounds [100001 x i8], ptr @onstack, i64 0, i64 %37
  store i8 0, ptr %38, align 1, !tbaa !13
  %39 = load i64, ptr %7, align 8, !tbaa !8
  %40 = getelementptr inbounds [100001 x i8], ptr @vis, i64 0, i64 %39
  store i8 0, ptr %40, align 1, !tbaa !13
  br label %41

41:                                               ; preds = %36
  %42 = load i64, ptr %7, align 8, !tbaa !8
  %43 = add nsw i64 %42, 1
  store i64 %43, ptr %7, align 8, !tbaa !8
  br label %31, !llvm.loop !15

44:                                               ; preds = %35
  call void @llvm.lifetime.start.p0(i64 8, ptr %8) #5
  store i64 1, ptr %8, align 8, !tbaa !8
  br label %45

45:                                               ; preds = %60, %44
  %46 = load i64, ptr %8, align 8, !tbaa !8
  %47 = load i64, ptr %2, align 8, !tbaa !8
  %48 = icmp sle i64 %46, %47
  br i1 %48, label %50, label %49

49:                                               ; preds = %45
  call void @llvm.lifetime.end.p0(i64 8, ptr %8) #5
  br label %63

50:                                               ; preds = %45
  %51 = load i64, ptr %8, align 8, !tbaa !8
  %52 = getelementptr inbounds [100001 x i8], ptr @vis, i64 0, i64 %51
  %53 = load i8, ptr %52, align 1, !tbaa !13, !range !16, !noundef !17
  %54 = trunc i8 %53 to i1
  %55 = zext i1 %54 to i32
  %56 = icmp eq i32 %55, 0
  br i1 %56, label %57, label %59

57:                                               ; preds = %50
  %58 = load i64, ptr %8, align 8, !tbaa !8
  call void @_Z3dfsx(i64 noundef %58)
  br label %59

59:                                               ; preds = %57, %50
  br label %60

60:                                               ; preds = %59
  %61 = load i64, ptr %8, align 8, !tbaa !8
  %62 = add nsw i64 %61, 1
  store i64 %62, ptr %8, align 8, !tbaa !8
  br label %45, !llvm.loop !18

63:                                               ; preds = %49
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #5
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #5
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #5
  call void @llvm.lifetime.end.p0(i64 8, ptr %2) #5
  ret i32 0
}

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

; 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

; 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

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 = { 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 = !{!"long long", !10, i64 0}
!10 = !{!"omnipotent char", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}
!13 = !{!14, !14, i64 0}
!14 = !{!"bool", !10, i64 0}
!15 = distinct !{!15, !12}
!16 = !{i8 0, i8 2}
!17 = !{}
!18 = distinct !{!18, !12}


; 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 }

@graph = external dso_local global [100001 x %"class.std::vector"], align 16
@vis = external dso_local local_unnamed_addr global [100001 x i8], align 16
@onstack = external dso_local local_unnamed_addr global [100001 x i8], align 16
@_ZSt3cin = external global %"class.std::basic_istream", align 8

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z3dfsx(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 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
  %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)
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %1) #6
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %2) #6
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %3) #6
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %4) #6
  %11 = 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)
  %12 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERx(ptr noundef nonnull align 8 dereferenceable(16) %11, ptr noundef nonnull align 8 dereferenceable(8) %2)
  %13 = load i64, ptr %2, align 8, !tbaa !8
  %.not15 = icmp slt i64 %13, 1
  br i1 %.not15, label %.preheader14, label %.lr.ph

.preheader14:                                     ; preds = %.lr.ph, %0
  %14 = load i64, ptr %1, align 8, !tbaa !8
  %.not1217 = icmp slt i64 %14, 1
  br i1 %.not1217, label %._crit_edge, label %.lr.ph22.preheader

.lr.ph:                                           ; preds = %0, %.lr.ph
  %.01116 = phi i64 [ %19, %.lr.ph ], [ 1, %0 ]
  %15 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERx(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 8 dereferenceable(8) %3)
  %16 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERx(ptr noundef nonnull align 8 dereferenceable(16) %15, ptr noundef nonnull align 8 dereferenceable(8) %4)
  %17 = load i64, ptr %3, align 8, !tbaa !8
  %18 = getelementptr inbounds [100001 x %"class.std::vector"], ptr @graph, i64 0, i64 %17
  call void @_ZNSt6vectorIxSaIxEE9push_backERKx(ptr noundef nonnull align 8 dereferenceable(24) %18, ptr noundef nonnull align 8 dereferenceable(8) %4)
  %19 = add nuw nsw i64 %.01116, 1
  %20 = load i64, ptr %2, align 8, !tbaa !8
  %.not.not = icmp slt i64 %.01116, %20
  br i1 %.not.not, label %.lr.ph, label %.preheader14, !llvm.loop !11

.lr.ph22.preheader:                               ; preds = %.preheader14
  call void @llvm.memset.p0.i64(ptr nonnull align 1 getelementptr inbounds (i8, ptr @onstack, i64 1), i8 0, i64 %14, i1 false), !tbaa !13
  call void @llvm.memset.p0.i64(ptr nonnull align 1 getelementptr inbounds (i8, ptr @vis, i64 1), i8 0, i64 %14, i1 false), !tbaa !13
  br label %.lr.ph22

._crit_edge:                                      ; preds = %26, %.preheader14
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %4) #6
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %3) #6
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %2) #6
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %1) #6
  ret i32 0

.lr.ph22:                                         ; preds = %.lr.ph22.preheader, %26
  %21 = phi i64 [ %27, %26 ], [ %14, %.lr.ph22.preheader ]
  %.021 = phi i64 [ %28, %26 ], [ 1, %.lr.ph22.preheader ]
  %22 = getelementptr inbounds [100001 x i8], ptr @vis, i64 0, i64 %.021
  %23 = load i8, ptr %22, align 1, !tbaa !13, !range !15, !noundef !16
  %24 = icmp eq i8 %23, 0
  br i1 %24, label %25, label %26

25:                                               ; preds = %.lr.ph22
  call void @_Z3dfsx(i64 noundef %.021)
  %.pre = load i64, ptr %1, align 8, !tbaa !8
  br label %26

26:                                               ; preds = %.lr.ph22, %25
  %27 = phi i64 [ %21, %.lr.ph22 ], [ %.pre, %25 ]
  %28 = add nuw nsw i64 %.021, 1
  %.not13.not = icmp slt i64 %.021, %27
  br i1 %.not13.not, label %.lr.ph22, label %._crit_edge, !llvm.loop !17
}

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

; 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

; 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: nocallback nofree nounwind willreturn memory(argmem: write)
declare void @llvm.memset.p0.i64(ptr nocapture writeonly, i8, i64, i1 immarg) #5

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 = { nocallback nofree nounwind willreturn memory(argmem: write) }
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 = !{!"long long", !10, i64 0}
!10 = !{!"omnipotent char", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}
!13 = !{!14, !14, i64 0}
!14 = !{!"bool", !10, i64 0}
!15 = !{i8 0, i8 2}
!16 = !{}
!17 = distinct !{!17, !12}


; Effective O3 passes: GVNPass,GlobalOptPass,IPSCCPPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LICMPass,LoopIdiomRecognizePass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,SROAPass,SimplifyCFGPass,TailCallElimPass