; LLVM IR from tangjz/acm-icpc :: lydsy/1907.ll (Z3dfsii)

; 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 }

@f = external dso_local global [10001 x i32], align 16
@e = external dso_local global [10001 x %"class.std::vector"], align 16
@flag = external dso_local global [10001 x i8], align 16

; Function Attrs: mustprogress uwtable
define dso_local void @_Z3dfsii(i32 noundef %0, i32 noundef %1) #0 {
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  %6 = alloca %"class.__gnu_cxx::__normal_iterator", align 8
  %7 = alloca %"class.__gnu_cxx::__normal_iterator", align 8
  store i32 %0, ptr %3, align 4, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !5
  %8 = load i32, ptr %3, align 4, !tbaa !5
  %9 = sext i32 %8 to i64
  %10 = getelementptr inbounds [10001 x i32], ptr @f, i64 0, i64 %9
  store i32 1, ptr %10, align 4, !tbaa !5
  %11 = load i32, ptr %3, align 4, !tbaa !5
  %12 = sext i32 %11 to i64
  %13 = getelementptr inbounds [10001 x i8], ptr @flag, i64 0, i64 %12
  store i8 0, ptr %13, align 1, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #4
  store i32 0, ptr %5, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #4
  %14 = load i32, ptr %3, align 4, !tbaa !5
  %15 = sext i32 %14 to i64
  %16 = getelementptr inbounds [10001 x %"class.std::vector"], ptr @e, i64 0, i64 %15
  %17 = call ptr @_ZNSt6vectorIiSaIiEE5beginEv(ptr noundef nonnull align 8 dereferenceable(24) %16) #4
  %18 = getelementptr inbounds %"class.__gnu_cxx::__normal_iterator", ptr %6, i32 0, i32 0
  store ptr %17, ptr %18, align 8
  br label %19

19:                                               ; preds = %57, %2
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #4
  %20 = load i32, ptr %3, align 4, !tbaa !5
  %21 = sext i32 %20 to i64
  %22 = getelementptr inbounds [10001 x %"class.std::vector"], ptr @e, i64 0, i64 %21
  %23 = call ptr @_ZNSt6vectorIiSaIiEE3endEv(ptr noundef nonnull align 8 dereferenceable(24) %22) #4
  %24 = getelementptr inbounds %"class.__gnu_cxx::__normal_iterator", ptr %7, i32 0, i32 0
  store ptr %23, ptr %24, align 8
  %25 = call noundef zeroext i1 @_ZN9__gnu_cxxneIPiSt6vectorIiSaIiEEEEbRKNS_17__normal_iteratorIT_T0_EESA_(ptr noundef nonnull align 8 dereferenceable(8) %6, ptr noundef nonnull align 8 dereferenceable(8) %7) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #4
  br i1 %25, label %27, label %26

26:                                               ; preds = %19
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #4
  br label %59

27:                                               ; preds = %19
  %28 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNK9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEdeEv(ptr noundef nonnull align 8 dereferenceable(8) %6) #4
  %29 = load i32, ptr %28, align 4, !tbaa !5
  %30 = load i32, ptr %4, align 4, !tbaa !5
  %31 = icmp eq i32 %29, %30
  br i1 %31, label %32, label %33

32:                                               ; preds = %27
  br label %57

33:                                               ; preds = %27
  %34 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNK9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEdeEv(ptr noundef nonnull align 8 dereferenceable(8) %6) #4
  %35 = load i32, ptr %34, align 4, !tbaa !5
  %36 = load i32, ptr %3, align 4, !tbaa !5
  call void @_Z3dfsii(i32 noundef %35, i32 noundef %36)
  %37 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNK9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEdeEv(ptr noundef nonnull align 8 dereferenceable(8) %6) #4
  %38 = load i32, ptr %37, align 4, !tbaa !5
  %39 = sext i32 %38 to i64
  %40 = getelementptr inbounds [10001 x i32], ptr @f, i64 0, i64 %39
  %41 = load i32, ptr %40, align 4, !tbaa !5
  %42 = load i32, ptr %3, align 4, !tbaa !5
  %43 = sext i32 %42 to i64
  %44 = getelementptr inbounds [10001 x i32], ptr @f, i64 0, i64 %43
  %45 = load i32, ptr %44, align 4, !tbaa !5
  %46 = add nsw i32 %45, %41
  store i32 %46, ptr %44, align 4, !tbaa !5
  %47 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNK9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEdeEv(ptr noundef nonnull align 8 dereferenceable(8) %6) #4
  %48 = load i32, ptr %47, align 4, !tbaa !5
  %49 = sext i32 %48 to i64
  %50 = getelementptr inbounds [10001 x i8], ptr @flag, i64 0, i64 %49
  %51 = load i8, ptr %50, align 1, !tbaa !9, !range !11, !noundef !12
  %52 = trunc i8 %51 to i1
  br i1 %52, label %56, label %53

53:                                               ; preds = %33
  %54 = load i32, ptr %5, align 4, !tbaa !5
  %55 = add nsw i32 %54, 1
  store i32 %55, ptr %5, align 4, !tbaa !5
  br label %56

56:                                               ; preds = %53, %33
  br label %57

57:                                               ; preds = %56, %32
  %58 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZN9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEppEv(ptr noundef nonnull align 8 dereferenceable(8) %6) #4
  br label %19, !llvm.loop !13

59:                                               ; preds = %26
  %60 = load i32, ptr %5, align 4, !tbaa !5
  %61 = icmp sge i32 %60, 2
  br i1 %61, label %62, label %71

62:                                               ; preds = %59
  %63 = load i32, ptr %3, align 4, !tbaa !5
  %64 = sext i32 %63 to i64
  %65 = getelementptr inbounds [10001 x i32], ptr @f, i64 0, i64 %64
  %66 = load i32, ptr %65, align 4, !tbaa !5
  %67 = sub nsw i32 %66, 2
  store i32 %67, ptr %65, align 4, !tbaa !5
  %68 = load i32, ptr %3, align 4, !tbaa !5
  %69 = sext i32 %68 to i64
  %70 = getelementptr inbounds [10001 x i8], ptr @flag, i64 0, i64 %69
  store i8 1, ptr %70, align 1, !tbaa !9
  br label %81

71:                                               ; preds = %59
  %72 = load i32, ptr %5, align 4, !tbaa !5
  %73 = icmp eq i32 %72, 1
  br i1 %73, label %74, label %80

74:                                               ; preds = %71
  %75 = load i32, ptr %3, align 4, !tbaa !5
  %76 = sext i32 %75 to i64
  %77 = getelementptr inbounds [10001 x i32], ptr @f, i64 0, i64 %76
  %78 = load i32, ptr %77, align 4, !tbaa !5
  %79 = add nsw i32 %78, -1
  store i32 %79, ptr %77, align 4, !tbaa !5
  br label %80

80:                                               ; preds = %74, %71
  br label %81

81:                                               ; preds = %80, %62
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #4
  ret void
}

; 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: 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 ptr @_ZNSt6vectorIiSaIiEE3endEv(ptr noundef nonnull align 8 dereferenceable(24)) #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 4 dereferenceable(4) ptr @_ZNK9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEdeEv(ptr noundef nonnull align 8 dereferenceable(8)) #2 align 2

; 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 = !{!"bool", !7, i64 0}
!11 = !{i8 0, i8 2}
!12 = !{}
!13 = distinct !{!13, !14}
!14 = !{!"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.__gnu_cxx::__normal_iterator" = type { ptr }

@f = external dso_local local_unnamed_addr global [10001 x i32], align 16
@e = external dso_local global [10001 x %"class.std::vector"], align 16
@flag = external dso_local local_unnamed_addr global [10001 x i8], align 16

; Function Attrs: mustprogress nounwind uwtable
define dso_local void @_Z3dfsii(i32 noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = alloca %"class.__gnu_cxx::__normal_iterator", align 8
  %4 = alloca %"class.__gnu_cxx::__normal_iterator", align 8
  %5 = sext i32 %0 to i64
  %6 = getelementptr inbounds [10001 x i32], ptr @f, i64 0, i64 %5
  store i32 1, ptr %6, align 4, !tbaa !5
  %7 = getelementptr inbounds [10001 x i8], ptr @flag, i64 0, i64 %5
  store i8 0, ptr %7, align 1, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %3) #3
  %8 = getelementptr inbounds [10001 x %"class.std::vector"], ptr @e, i64 0, i64 %5
  %9 = tail call ptr @_ZNSt6vectorIiSaIiEE5beginEv(ptr noundef nonnull align 8 dereferenceable(24) %8) #3
  store ptr %9, ptr %3, align 8
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %4) #3
  %10 = tail call ptr @_ZNSt6vectorIiSaIiEE3endEv(ptr noundef nonnull align 8 dereferenceable(24) %8) #3
  store ptr %10, ptr %4, align 8
  %11 = call noundef zeroext i1 @_ZN9__gnu_cxxneIPiSt6vectorIiSaIiEEEEbRKNS_17__normal_iteratorIT_T0_EESA_(ptr noundef nonnull align 8 dereferenceable(8) %3, ptr noundef nonnull align 8 dereferenceable(8) %4) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %4) #3
  br i1 %11, label %.lr.ph, label %.thread

.thread:                                          ; preds = %2
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %3) #3
  br label %44

._crit_edge:                                      ; preds = %32
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %3) #3
  %12 = icmp sgt i32 %.1, 1
  br i1 %12, label %36, label %39

.lr.ph:                                           ; preds = %2, %32
  %.013 = phi i32 [ %.1, %32 ], [ 0, %2 ]
  %13 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNK9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEdeEv(ptr noundef nonnull align 8 dereferenceable(8) %3) #3
  %14 = load i32, ptr %13, align 4, !tbaa !5
  %15 = icmp eq i32 %14, %1
  br i1 %15, label %32, label %16

16:                                               ; preds = %.lr.ph
  %17 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNK9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEdeEv(ptr noundef nonnull align 8 dereferenceable(8) %3) #3
  %18 = load i32, ptr %17, align 4, !tbaa !5
  call void @_Z3dfsii(i32 noundef %18, i32 noundef %0)
  %19 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNK9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEdeEv(ptr noundef nonnull align 8 dereferenceable(8) %3) #3
  %20 = load i32, ptr %19, align 4, !tbaa !5
  %21 = sext i32 %20 to i64
  %22 = getelementptr inbounds [10001 x i32], ptr @f, i64 0, i64 %21
  %23 = load i32, ptr %22, align 4, !tbaa !5
  %24 = load i32, ptr %6, align 4, !tbaa !5
  %25 = add nsw i32 %24, %23
  store i32 %25, ptr %6, align 4, !tbaa !5
  %26 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNK9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEdeEv(ptr noundef nonnull align 8 dereferenceable(8) %3) #3
  %27 = load i32, ptr %26, align 4, !tbaa !5
  %28 = sext i32 %27 to i64
  %29 = getelementptr inbounds [10001 x i8], ptr @flag, i64 0, i64 %28
  %30 = load i8, ptr %29, align 1, !tbaa !9, !range !11, !noundef !12
  %31 = xor i8 %30, 1
  %not. = zext nneg i8 %31 to i32
  %spec.select = add nsw i32 %.013, %not.
  br label %32

32:                                               ; preds = %16, %.lr.ph
  %.1 = phi i32 [ %.013, %.lr.ph ], [ %spec.select, %16 ]
  %33 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZN9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEppEv(ptr noundef nonnull align 8 dereferenceable(8) %3) #3
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %4) #3
  %34 = call ptr @_ZNSt6vectorIiSaIiEE3endEv(ptr noundef nonnull align 8 dereferenceable(24) %8) #3
  store ptr %34, ptr %4, align 8
  %35 = call noundef zeroext i1 @_ZN9__gnu_cxxneIPiSt6vectorIiSaIiEEEEbRKNS_17__normal_iteratorIT_T0_EESA_(ptr noundef nonnull align 8 dereferenceable(8) %3, ptr noundef nonnull align 8 dereferenceable(8) %4) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %4) #3
  br i1 %35, label %.lr.ph, label %._crit_edge, !llvm.loop !13

36:                                               ; preds = %._crit_edge
  %37 = load i32, ptr %6, align 4, !tbaa !5
  %38 = add nsw i32 %37, -2
  store i32 %38, ptr %6, align 4, !tbaa !5
  store i8 1, ptr %7, align 1, !tbaa !9
  br label %44

39:                                               ; preds = %._crit_edge
  %40 = icmp eq i32 %.1, 1
  br i1 %40, label %41, label %44

41:                                               ; preds = %39
  %42 = load i32, ptr %6, align 4, !tbaa !5
  %43 = add nsw i32 %42, -1
  store i32 %43, ptr %6, align 4, !tbaa !5
  br label %44

44:                                               ; preds = %.thread, %39, %41, %36
  ret void
}

; 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: 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 ptr @_ZNSt6vectorIiSaIiEE3endEv(ptr noundef nonnull align 8 dereferenceable(24)) 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 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 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"}
!9 = !{!10, !10, i64 0}
!10 = !{!"bool", !7, i64 0}
!11 = !{i8 0, i8 2}
!12 = !{}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: CorrelatedValuePropagationPass,EarlyCSEPass,GVNPass,GlobalOptPass,IPSCCPPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass,TailCallElimPass