; LLVM IR from VastoLorde95/Competitive-Programming :: Codeforces/236 Division 1/Problem C/C.ll (Z4dfs2ii)

; 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 }

@visited = external dso_local global [2000 x i32], align 16
@rev = external dso_local global [2000 x %"class.std::vector"], align 16
@scc = external dso_local global [2000 x %"class.std::vector"], align 16

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24)) #1 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24), i64 noundef) #1 align 2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: mustprogress uwtable
define dso_local void @_Z4dfs2ii(i32 noundef %0, i32 noundef %1) #2 {
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !5
  %6 = load i32, ptr %3, align 4, !tbaa !5
  %7 = sext i32 %6 to i64
  %8 = getelementptr inbounds [2000 x i32], ptr @visited, i64 0, i64 %7
  %9 = load i32, ptr %8, align 4, !tbaa !5
  %10 = icmp eq i32 %9, 1
  br i1 %10, label %11, label %12

11:                                               ; preds = %2
  br label %41

12:                                               ; preds = %2
  %13 = load i32, ptr %3, align 4, !tbaa !5
  %14 = sext i32 %13 to i64
  %15 = getelementptr inbounds [2000 x i32], ptr @visited, i64 0, i64 %14
  store i32 1, ptr %15, align 4, !tbaa !5
  %16 = load i32, ptr %4, align 4, !tbaa !5
  %17 = sext i32 %16 to i64
  %18 = getelementptr inbounds [2000 x %"class.std::vector"], ptr @scc, i64 0, i64 %17
  call void @_ZNSt6vectorIiSaIiEE9push_backERKi(ptr noundef nonnull align 8 dereferenceable(24) %18, ptr noundef nonnull align 4 dereferenceable(4) %3)
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #3
  store i32 0, ptr %5, align 4, !tbaa !5
  br label %19

19:                                               ; preds = %37, %12
  %20 = load i32, ptr %5, align 4, !tbaa !5
  %21 = sext i32 %20 to i64
  %22 = load i32, ptr %3, align 4, !tbaa !5
  %23 = sext i32 %22 to i64
  %24 = getelementptr inbounds [2000 x %"class.std::vector"], ptr @rev, i64 0, i64 %23
  %25 = call noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24) %24) #3
  %26 = icmp ult i64 %21, %25
  br i1 %26, label %28, label %27

27:                                               ; preds = %19
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #3
  br label %40

28:                                               ; preds = %19
  %29 = load i32, ptr %3, align 4, !tbaa !5
  %30 = sext i32 %29 to i64
  %31 = getelementptr inbounds [2000 x %"class.std::vector"], ptr @rev, i64 0, i64 %30
  %32 = load i32, ptr %5, align 4, !tbaa !5
  %33 = sext i32 %32 to i64
  %34 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24) %31, i64 noundef %33) #3
  %35 = load i32, ptr %34, align 4, !tbaa !5
  %36 = load i32, ptr %4, align 4, !tbaa !5
  call void @_Z4dfs2ii(i32 noundef %35, i32 noundef %36)
  br label %37

37:                                               ; preds = %28
  %38 = load i32, ptr %5, align 4, !tbaa !5
  %39 = add nsw i32 %38, 1
  store i32 %39, ptr %5, align 4, !tbaa !5
  br label %19, !llvm.loop !9

40:                                               ; preds = %27
  br label %41

41:                                               ; preds = %40, %11
  ret void
}

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZNSt6vectorIiSaIiEE9push_backERKi(ptr noundef nonnull align 8 dereferenceable(24), ptr noundef nonnull align 4 dereferenceable(4)) #2 align 2

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 #2 = { 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 #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 = 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<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 }

@visited = external dso_local local_unnamed_addr global [2000 x i32], align 16
@rev = external dso_local global [2000 x %"class.std::vector"], align 16
@scc = external dso_local global [2000 x %"class.std::vector"], align 16

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24)) local_unnamed_addr #0 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24), i64 noundef) local_unnamed_addr #0 align 2

; Function Attrs: mustprogress uwtable
define dso_local void @_Z4dfs2ii(i32 noundef %0, i32 noundef %1) local_unnamed_addr #1 {
  %3 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  %4 = sext i32 %0 to i64
  %5 = getelementptr inbounds [2000 x i32], ptr @visited, i64 0, i64 %4
  %6 = load i32, ptr %5, align 4, !tbaa !5
  %7 = icmp eq i32 %6, 1
  br i1 %7, label %.loopexit, label %8

8:                                                ; preds = %2
  store i32 1, ptr %5, align 4, !tbaa !5
  %9 = sext i32 %1 to i64
  %10 = getelementptr inbounds [2000 x %"class.std::vector"], ptr @scc, i64 0, i64 %9
  call void @_ZNSt6vectorIiSaIiEE9push_backERKi(ptr noundef nonnull align 8 dereferenceable(24) %10, ptr noundef nonnull align 4 dereferenceable(4) %3)
  %11 = load i32, ptr %3, align 4, !tbaa !5
  %12 = sext i32 %11 to i64
  %13 = getelementptr inbounds [2000 x %"class.std::vector"], ptr @rev, i64 0, i64 %12
  %14 = call noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24) %13) #2
  %.not = icmp eq i64 %14, 0
  br i1 %.not, label %.loopexit, label %.lr.ph

.lr.ph:                                           ; preds = %8, %.lr.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ 0, %8 ]
  %15 = load i32, ptr %3, align 4, !tbaa !5
  %16 = sext i32 %15 to i64
  %17 = getelementptr inbounds [2000 x %"class.std::vector"], ptr @rev, i64 0, i64 %16
  %18 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24) %17, i64 noundef %indvars.iv) #2
  %19 = load i32, ptr %18, align 4, !tbaa !5
  call void @_Z4dfs2ii(i32 noundef %19, i32 noundef %1)
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %20 = load i32, ptr %3, align 4, !tbaa !5
  %21 = sext i32 %20 to i64
  %22 = getelementptr inbounds [2000 x %"class.std::vector"], ptr @rev, i64 0, i64 %21
  %23 = call noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24) %22) #2
  %24 = icmp ugt i64 %23, %indvars.iv.next
  br i1 %24, label %.lr.ph, label %.loopexit, !llvm.loop !9

.loopexit:                                        ; preds = %.lr.ph, %8, %2
  ret void
}

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZNSt6vectorIiSaIiEE9push_backERKi(ptr noundef nonnull align 8 dereferenceable(24), ptr noundef nonnull align 4 dereferenceable(4)) local_unnamed_addr #1 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 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 #2 = { 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 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


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