; LLVM IR from Tunghohin/Competitive_Coding :: Daimayuan/794.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"

%struct.edge = type { i32, i32 }

@timestamp = external dso_local global i32, align 4
@L = external dso_local global [200020 x i32], align 16
@R = external dso_local global [200020 x i32], align 16
@e = external dso_local global [400040 x %struct.edge], align 16
@head = external dso_local global [200020 x i32], 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 @_Z3dfsii(i32 noundef %0, i32 noundef %1) #1 {
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !5
  %8 = load i32, ptr @timestamp, align 4, !tbaa !5
  %9 = add nsw i32 %8, 1
  store i32 %9, ptr @timestamp, align 4, !tbaa !5
  %10 = load i32, ptr %3, align 4, !tbaa !5
  %11 = sext i32 %10 to i64
  %12 = getelementptr inbounds [200020 x i32], ptr @L, i64 0, i64 %11
  store i32 %9, ptr %12, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #2
  %13 = load i32, ptr %3, align 4, !tbaa !5
  %14 = sext i32 %13 to i64
  %15 = getelementptr inbounds [200020 x i32], ptr @head, i64 0, i64 %14
  %16 = load i32, ptr %15, align 4, !tbaa !5
  store i32 %16, ptr %5, align 4, !tbaa !5
  br label %17

17:                                               ; preds = %37, %2
  %18 = load i32, ptr %5, align 4, !tbaa !5
  %19 = icmp ne i32 %18, 0
  br i1 %19, label %21, label %20

20:                                               ; preds = %17
  store i32 2, ptr %6, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  br label %43

21:                                               ; preds = %17
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #2
  %22 = load i32, ptr %5, align 4, !tbaa !5
  %23 = sext i32 %22 to i64
  %24 = getelementptr inbounds [400040 x %struct.edge], ptr @e, i64 0, i64 %23
  %25 = getelementptr inbounds %struct.edge, ptr %24, i32 0, i32 0
  %26 = load i32, ptr %25, align 8, !tbaa !9
  store i32 %26, ptr %7, align 4, !tbaa !5
  %27 = load i32, ptr %7, align 4, !tbaa !5
  %28 = load i32, ptr %4, align 4, !tbaa !5
  %29 = icmp eq i32 %27, %28
  br i1 %29, label %30, label %31

30:                                               ; preds = %21
  store i32 4, ptr %6, align 4
  br label %34

31:                                               ; preds = %21
  %32 = load i32, ptr %7, align 4, !tbaa !5
  %33 = load i32, ptr %3, align 4, !tbaa !5
  call void @_Z3dfsii(i32 noundef %32, i32 noundef %33)
  store i32 0, ptr %6, align 4
  br label %34

34:                                               ; preds = %31, %30
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #2
  %35 = load i32, ptr %6, align 4
  switch i32 %35, label %48 [
    i32 0, label %36
    i32 4, label %37
  ]

36:                                               ; preds = %34
  br label %37

37:                                               ; preds = %36, %34
  %38 = load i32, ptr %5, align 4, !tbaa !5
  %39 = sext i32 %38 to i64
  %40 = getelementptr inbounds [400040 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 !11
  store i32 %42, ptr %5, align 4, !tbaa !5
  br label %17, !llvm.loop !12

43:                                               ; preds = %20
  %44 = load i32, ptr @timestamp, align 4, !tbaa !5
  %45 = load i32, ptr %3, align 4, !tbaa !5
  %46 = sext i32 %45 to i64
  %47 = getelementptr inbounds [200020 x i32], ptr @R, i64 0, i64 %46
  store i32 %44, ptr %47, align 4, !tbaa !5
  ret void

48:                                               ; preds = %34
  unreachable
}

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 0}
!10 = !{!"_ZTS4edge", !6, i64 0, !6, i64 4}
!11 = !{!10, !6, i64 4}
!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 }

@timestamp = external dso_local local_unnamed_addr global i32, align 4
@L = external dso_local local_unnamed_addr global [200020 x i32], align 16
@R = external dso_local local_unnamed_addr global [200020 x i32], align 16
@e = external dso_local local_unnamed_addr global [400040 x %struct.edge], align 16
@head = external dso_local local_unnamed_addr global [200020 x i32], align 16

; Function Attrs: mustprogress nofree nosync nounwind memory(readwrite, argmem: none, inaccessiblemem: none) uwtable
define dso_local void @_Z3dfsii(i32 noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = load i32, ptr @timestamp, align 4, !tbaa !5
  %4 = add nsw i32 %3, 1
  store i32 %4, ptr @timestamp, align 4, !tbaa !5
  %5 = sext i32 %0 to i64
  %6 = getelementptr inbounds [200020 x i32], ptr @L, i64 0, i64 %5
  store i32 %4, ptr %6, align 4, !tbaa !5
  %7 = getelementptr inbounds [200020 x i32], ptr @head, i64 0, i64 %5
  %.011 = load i32, ptr %7, align 4, !tbaa !5
  %.not12 = icmp eq i32 %.011, 0
  br i1 %.not12, label %._crit_edge, label %.lr.ph

._crit_edge.loopexit:                             ; preds = %15
  %.pre = load i32, ptr @timestamp, align 4, !tbaa !5
  br label %._crit_edge

._crit_edge:                                      ; preds = %._crit_edge.loopexit, %2
  %8 = phi i32 [ %.pre, %._crit_edge.loopexit ], [ %4, %2 ]
  %9 = getelementptr inbounds [200020 x i32], ptr @R, i64 0, i64 %5
  store i32 %8, ptr %9, align 4, !tbaa !5
  ret void

.lr.ph:                                           ; preds = %2, %15
  %.013 = phi i32 [ %.0, %15 ], [ %.011, %2 ]
  %10 = sext i32 %.013 to i64
  %11 = getelementptr inbounds [400040 x %struct.edge], ptr @e, i64 0, i64 %10
  %12 = load i32, ptr %11, align 8, !tbaa !9
  %13 = icmp eq i32 %12, %1
  br i1 %13, label %15, label %14

14:                                               ; preds = %.lr.ph
  tail call void @_Z3dfsii(i32 noundef %12, i32 noundef %0)
  br label %15

15:                                               ; preds = %.lr.ph, %14
  %16 = getelementptr inbounds i8, ptr %11, i64 4
  %.0 = load i32, ptr %16, align 4, !tbaa !5
  %.not = icmp eq i32 %.0, 0
  br i1 %.not, label %._crit_edge.loopexit, label %.lr.ph, !llvm.loop !11
}

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 0}
!10 = !{!"_ZTS4edge", !6, i64 0, !6, i64 4}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}


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