; LLVM IR from tangjz/acm-icpc :: lydsy/3626.ll (Z3dfsi)

; 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"

%struct.Edge = type { i32, i32 }

@tot = external dso_local global i32, align 4
@lnk = external dso_local global [50001 x i32], align 16
@sz = external dso_local global [50001 x i32], align 16
@son = external dso_local global [50001 x i32], align 16
@top = external dso_local global [50001 x i32], align 16
@in = external dso_local global [50001 x i32], align 16
@out = external dso_local global [50001 x i32], align 16
@e = external dso_local global [50001 x %struct.Edge], 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: 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 @_Z3dfsi(i32 noundef %0) #1 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  store i32 %0, ptr %2, align 4, !tbaa !5
  %4 = load i32, ptr @tot, align 4, !tbaa !5
  %5 = add nsw i32 %4, 1
  store i32 %5, ptr @tot, align 4, !tbaa !5
  %6 = load i32, ptr %2, align 4, !tbaa !5
  %7 = sext i32 %6 to i64
  %8 = getelementptr inbounds [50001 x i32], ptr @in, i64 0, i64 %7
  store i32 %5, ptr %8, align 4, !tbaa !5
  %9 = load i32, ptr %2, align 4, !tbaa !5
  %10 = sext i32 %9 to i64
  %11 = getelementptr inbounds [50001 x i32], ptr @sz, i64 0, i64 %10
  %12 = load i32, ptr %11, align 4, !tbaa !5
  %13 = icmp sgt i32 %12, 1
  br i1 %13, label %14, label %74

14:                                               ; preds = %1
  %15 = load i32, ptr %2, align 4, !tbaa !5
  %16 = sext i32 %15 to i64
  %17 = getelementptr inbounds [50001 x i32], ptr @top, i64 0, i64 %16
  %18 = load i32, ptr %17, align 4, !tbaa !5
  %19 = load i32, ptr %2, align 4, !tbaa !5
  %20 = sext i32 %19 to i64
  %21 = getelementptr inbounds [50001 x i32], ptr @son, i64 0, i64 %20
  %22 = load i32, ptr %21, align 4, !tbaa !5
  %23 = sext i32 %22 to i64
  %24 = getelementptr inbounds [50001 x i32], ptr @top, i64 0, i64 %23
  store i32 %18, ptr %24, align 4, !tbaa !5
  %25 = load i32, ptr %2, align 4, !tbaa !5
  %26 = sext i32 %25 to i64
  %27 = getelementptr inbounds [50001 x i32], ptr @son, i64 0, i64 %26
  %28 = load i32, ptr %27, align 4, !tbaa !5
  call void @_Z3dfsi(i32 noundef %28)
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #2
  %29 = load i32, ptr %2, align 4, !tbaa !5
  %30 = sext i32 %29 to i64
  %31 = getelementptr inbounds [50001 x i32], ptr @lnk, i64 0, i64 %30
  %32 = load i32, ptr %31, align 4, !tbaa !5
  store i32 %32, ptr %3, align 4, !tbaa !5
  br label %33

33:                                               ; preds = %67, %14
  %34 = load i32, ptr %3, align 4, !tbaa !5
  %35 = icmp ne i32 %34, -1
  br i1 %35, label %37, label %36

36:                                               ; preds = %33
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #2
  br label %73

37:                                               ; preds = %33
  %38 = load i32, ptr %3, align 4, !tbaa !5
  %39 = sext i32 %38 to i64
  %40 = getelementptr inbounds [50001 x %struct.Edge], ptr @e, i64 0, i64 %39
  %41 = getelementptr inbounds %struct.Edge, ptr %40, i32 0, i32 1
  %42 = load i32, ptr %41, align 4, !tbaa !9
  %43 = load i32, ptr %2, align 4, !tbaa !5
  %44 = sext i32 %43 to i64
  %45 = getelementptr inbounds [50001 x i32], ptr @son, i64 0, i64 %44
  %46 = load i32, ptr %45, align 4, !tbaa !5
  %47 = icmp ne i32 %42, %46
  br i1 %47, label %48, label %66

48:                                               ; preds = %37
  %49 = load i32, ptr %3, align 4, !tbaa !5
  %50 = sext i32 %49 to i64
  %51 = getelementptr inbounds [50001 x %struct.Edge], ptr @e, i64 0, i64 %50
  %52 = getelementptr inbounds %struct.Edge, ptr %51, i32 0, i32 1
  %53 = load i32, ptr %52, align 4, !tbaa !9
  %54 = load i32, ptr %3, align 4, !tbaa !5
  %55 = sext i32 %54 to i64
  %56 = getelementptr inbounds [50001 x %struct.Edge], ptr @e, i64 0, i64 %55
  %57 = getelementptr inbounds %struct.Edge, ptr %56, i32 0, i32 1
  %58 = load i32, ptr %57, align 4, !tbaa !9
  %59 = sext i32 %58 to i64
  %60 = getelementptr inbounds [50001 x i32], ptr @top, i64 0, i64 %59
  store i32 %53, ptr %60, align 4, !tbaa !5
  %61 = load i32, ptr %3, align 4, !tbaa !5
  %62 = sext i32 %61 to i64
  %63 = getelementptr inbounds [50001 x %struct.Edge], ptr @e, i64 0, i64 %62
  %64 = getelementptr inbounds %struct.Edge, ptr %63, i32 0, i32 1
  %65 = load i32, ptr %64, align 4, !tbaa !9
  call void @_Z3dfsi(i32 noundef %65)
  br label %66

66:                                               ; preds = %48, %37
  br label %67

67:                                               ; preds = %66
  %68 = load i32, ptr %3, align 4, !tbaa !5
  %69 = sext i32 %68 to i64
  %70 = getelementptr inbounds [50001 x %struct.Edge], ptr @e, i64 0, i64 %69
  %71 = getelementptr inbounds %struct.Edge, ptr %70, i32 0, i32 0
  %72 = load i32, ptr %71, align 8, !tbaa !11
  store i32 %72, ptr %3, align 4, !tbaa !5
  br label %33, !llvm.loop !12

73:                                               ; preds = %36
  br label %74

74:                                               ; preds = %73, %1
  %75 = load i32, ptr @tot, align 4, !tbaa !5
  %76 = load i32, ptr %2, align 4, !tbaa !5
  %77 = sext i32 %76 to i64
  %78 = getelementptr inbounds [50001 x i32], ptr @out, i64 0, i64 %77
  store i32 %75, ptr %78, align 4, !tbaa !5
  ret void
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = !{!10, !6, i64 4}
!10 = !{!"_ZTS4Edge", !6, i64 0, !6, i64 4}
!11 = !{!10, !6, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"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"

%struct.Edge = type { i32, i32 }

@tot = external dso_local local_unnamed_addr global i32, align 4
@lnk = external dso_local local_unnamed_addr global [50001 x i32], align 16
@sz = external dso_local local_unnamed_addr global [50001 x i32], align 16
@son = external dso_local local_unnamed_addr global [50001 x i32], align 16
@top = external dso_local local_unnamed_addr global [50001 x i32], align 16
@in = external dso_local local_unnamed_addr global [50001 x i32], align 16
@out = external dso_local local_unnamed_addr global [50001 x i32], align 16
@e = external dso_local local_unnamed_addr global [50001 x %struct.Edge], align 16

; Function Attrs: mustprogress nofree nosync nounwind memory(readwrite, argmem: none, inaccessiblemem: none) uwtable
define dso_local void @_Z3dfsi(i32 noundef %0) local_unnamed_addr #0 {
  %2 = load i32, ptr @tot, align 4, !tbaa !5
  %3 = add nsw i32 %2, 1
  store i32 %3, ptr @tot, align 4, !tbaa !5
  %4 = sext i32 %0 to i64
  %5 = getelementptr inbounds [50001 x i32], ptr @in, i64 0, i64 %4
  store i32 %3, ptr %5, align 4, !tbaa !5
  %6 = getelementptr inbounds [50001 x i32], ptr @sz, i64 0, i64 %4
  %7 = load i32, ptr %6, align 4, !tbaa !5
  %8 = icmp sgt i32 %7, 1
  br i1 %8, label %9, label %.loopexit

9:                                                ; preds = %1
  %10 = getelementptr inbounds [50001 x i32], ptr @top, i64 0, i64 %4
  %11 = load i32, ptr %10, align 4, !tbaa !5
  %12 = getelementptr inbounds [50001 x i32], ptr @son, i64 0, i64 %4
  %13 = load i32, ptr %12, align 4, !tbaa !5
  %14 = sext i32 %13 to i64
  %15 = getelementptr inbounds [50001 x i32], ptr @top, i64 0, i64 %14
  store i32 %11, ptr %15, align 4, !tbaa !5
  tail call void @_Z3dfsi(i32 noundef %13)
  %16 = getelementptr inbounds [50001 x i32], ptr @lnk, i64 0, i64 %4
  %.016 = load i32, ptr %16, align 4, !tbaa !5
  %.not17 = icmp eq i32 %.016, -1
  br i1 %.not17, label %.loopexit, label %.lr.ph

.lr.ph:                                           ; preds = %9, %25
  %.018 = phi i32 [ %.0, %25 ], [ %.016, %9 ]
  %17 = sext i32 %.018 to i64
  %18 = getelementptr inbounds [50001 x %struct.Edge], ptr @e, i64 0, i64 %17
  %19 = getelementptr inbounds i8, ptr %18, i64 4
  %20 = load i32, ptr %19, align 4, !tbaa !9
  %21 = load i32, ptr %12, align 4, !tbaa !5
  %.not15 = icmp eq i32 %20, %21
  br i1 %.not15, label %25, label %22

22:                                               ; preds = %.lr.ph
  %23 = sext i32 %20 to i64
  %24 = getelementptr inbounds [50001 x i32], ptr @top, i64 0, i64 %23
  store i32 %20, ptr %24, align 4, !tbaa !5
  tail call void @_Z3dfsi(i32 noundef %20)
  br label %25

25:                                               ; preds = %.lr.ph, %22
  %.0 = load i32, ptr %18, align 8, !tbaa !5
  %.not = icmp eq i32 %.0, -1
  br i1 %.not, label %.loopexit, label %.lr.ph, !llvm.loop !11

.loopexit:                                        ; preds = %25, %9, %1
  %26 = load i32, ptr @tot, align 4, !tbaa !5
  %27 = getelementptr inbounds [50001 x i32], ptr @out, i64 0, i64 %4
  store i32 %26, ptr %27, align 4, !tbaa !5
  ret void
}

attributes #0 = { mustprogress nofree nosync nounwind memory(readwrite, argmem: none, inaccessiblemem: none) 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" }

!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, !6, i64 4}
!10 = !{!"_ZTS4Edge", !6, i64 0, !6, i64 4}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}


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