; LLVM IR from tangjz/acm-icpc :: lydsy/5450.ll (Z4dfs3i)

; 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 }

@pre = external dso_local global [1000001 x i32], align 16
@f = external dso_local global [1000001 x i32], align 16
@e = external dso_local global [3000003 x %struct.Edge], align 16
@vis = external dso_local global [1000001 x i8], 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 @_Z4dfs3i(i32 noundef %0) #1 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  store i32 %0, ptr %2, align 4, !tbaa !5
  %5 = load i32, ptr %2, align 4, !tbaa !5
  %6 = sext i32 %5 to i64
  %7 = getelementptr inbounds [1000001 x i8], ptr @vis, i64 0, i64 %6
  store i8 1, ptr %7, align 1, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #3
  store i32 0, ptr %3, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #3
  %8 = load i32, ptr %2, align 4, !tbaa !5
  %9 = sext i32 %8 to i64
  %10 = getelementptr inbounds [1000001 x i32], ptr @pre, i64 0, i64 %9
  %11 = load i32, ptr %10, align 4, !tbaa !5
  store i32 %11, ptr %4, align 4, !tbaa !5
  br label %12

12:                                               ; preds = %42, %1
  %13 = load i32, ptr %4, align 4, !tbaa !5
  %14 = icmp ne i32 %13, -1
  br i1 %14, label %16, label %15

15:                                               ; preds = %12
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #3
  br label %48

16:                                               ; preds = %12
  %17 = load i32, ptr %4, align 4, !tbaa !5
  %18 = sext i32 %17 to i64
  %19 = getelementptr inbounds [3000003 x %struct.Edge], ptr @e, i64 0, i64 %18
  %20 = getelementptr inbounds %struct.Edge, ptr %19, i32 0, i32 1
  %21 = load i32, ptr %20, align 4, !tbaa !11
  %22 = sext i32 %21 to i64
  %23 = getelementptr inbounds [1000001 x i8], ptr @vis, i64 0, i64 %22
  %24 = load i8, ptr %23, align 1, !tbaa !9, !range !13, !noundef !14
  %25 = trunc i8 %24 to i1
  br i1 %25, label %32, label %26

26:                                               ; preds = %16
  %27 = load i32, ptr %4, align 4, !tbaa !5
  %28 = sext i32 %27 to i64
  %29 = getelementptr inbounds [3000003 x %struct.Edge], ptr @e, i64 0, i64 %28
  %30 = getelementptr inbounds %struct.Edge, ptr %29, i32 0, i32 1
  %31 = load i32, ptr %30, align 4, !tbaa !11
  call void @_Z4dfs3i(i32 noundef %31)
  br label %32

32:                                               ; preds = %26, %16
  %33 = load i32, ptr %4, align 4, !tbaa !5
  %34 = sext i32 %33 to i64
  %35 = getelementptr inbounds [3000003 x %struct.Edge], ptr @e, i64 0, i64 %34
  %36 = getelementptr inbounds %struct.Edge, ptr %35, i32 0, i32 1
  %37 = load i32, ptr %36, align 4, !tbaa !11
  %38 = sext i32 %37 to i64
  %39 = getelementptr inbounds [1000001 x i32], ptr @f, i64 0, i64 %38
  %40 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZSt3maxIiERKT_S2_S2_(ptr noundef nonnull align 4 dereferenceable(4) %3, ptr noundef nonnull align 4 dereferenceable(4) %39)
  %41 = load i32, ptr %40, align 4, !tbaa !5
  store i32 %41, ptr %3, align 4, !tbaa !5
  br label %42

42:                                               ; preds = %32
  %43 = load i32, ptr %4, align 4, !tbaa !5
  %44 = sext i32 %43 to i64
  %45 = getelementptr inbounds [3000003 x %struct.Edge], ptr @e, i64 0, i64 %44
  %46 = getelementptr inbounds %struct.Edge, ptr %45, i32 0, i32 0
  %47 = load i32, ptr %46, align 8, !tbaa !15
  store i32 %47, ptr %4, align 4, !tbaa !5
  br label %12, !llvm.loop !16

48:                                               ; preds = %15
  %49 = load i32, ptr %3, align 4, !tbaa !5
  %50 = load i32, ptr %2, align 4, !tbaa !5
  %51 = sext i32 %50 to i64
  %52 = getelementptr inbounds [1000001 x i32], ptr @f, i64 0, i64 %51
  %53 = load i32, ptr %52, align 4, !tbaa !5
  %54 = add nsw i32 %53, %49
  store i32 %54, ptr %52, align 4, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #3
  ret void
}

; Function Attrs: inlinehint mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZSt3maxIiERKT_S2_S2_(ptr noundef nonnull align 4 dereferenceable(4), ptr noundef nonnull align 4 dereferenceable(4)) #2

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 = { 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 = !{!12, !6, i64 4}
!12 = !{!"_ZTS4Edge", !6, i64 0, !6, i64 4}
!13 = !{i8 0, i8 2}
!14 = !{}
!15 = !{!12, !6, i64 0}
!16 = distinct !{!16, !17}
!17 = !{!"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 }

@pre = external dso_local local_unnamed_addr global [1000001 x i32], align 16
@f = external dso_local global [1000001 x i32], align 16
@e = external dso_local local_unnamed_addr global [3000003 x %struct.Edge], align 16
@vis = external dso_local local_unnamed_addr global [1000001 x i8], align 16

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

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

; Function Attrs: mustprogress nounwind uwtable
define dso_local void @_Z4dfs3i(i32 noundef %0) local_unnamed_addr #1 {
  %2 = alloca i32, align 4
  %3 = sext i32 %0 to i64
  %4 = getelementptr inbounds [1000001 x i8], ptr @vis, i64 0, i64 %3
  store i8 1, ptr %4, align 1, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %2) #3
  store i32 0, ptr %2, align 4, !tbaa !9
  %5 = getelementptr inbounds [1000001 x i32], ptr @pre, i64 0, i64 %3
  %.08 = load i32, ptr %5, align 4, !tbaa !9
  %.not9 = icmp eq i32 %.08, -1
  br i1 %.not9, label %._crit_edge, label %.lr.ph

._crit_edge:                                      ; preds = %19, %1
  %6 = phi i32 [ 0, %1 ], [ %22, %19 ]
  %7 = getelementptr inbounds [1000001 x i32], ptr @f, i64 0, i64 %3
  %8 = load i32, ptr %7, align 4, !tbaa !9
  %9 = add nsw i32 %8, %6
  store i32 %9, ptr %7, align 4, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %2) #3
  ret void

.lr.ph:                                           ; preds = %1, %19
  %.010 = phi i32 [ %.0, %19 ], [ %.08, %1 ]
  %10 = sext i32 %.010 to i64
  %11 = getelementptr inbounds [3000003 x %struct.Edge], ptr @e, i64 0, i64 %10
  %12 = getelementptr inbounds i8, ptr %11, i64 4
  %13 = load i32, ptr %12, align 4, !tbaa !11
  %14 = sext i32 %13 to i64
  %15 = getelementptr inbounds [1000001 x i8], ptr @vis, i64 0, i64 %14
  %16 = load i8, ptr %15, align 1, !tbaa !5, !range !13, !noundef !14
  %17 = trunc nuw i8 %16 to i1
  br i1 %17, label %19, label %18

18:                                               ; preds = %.lr.ph
  call void @_Z4dfs3i(i32 noundef %13)
  %.pre = load i32, ptr %12, align 4, !tbaa !11
  %.pre11 = sext i32 %.pre to i64
  br label %19

19:                                               ; preds = %18, %.lr.ph
  %.pre-phi = phi i64 [ %.pre11, %18 ], [ %14, %.lr.ph ]
  %20 = getelementptr inbounds [1000001 x i32], ptr @f, i64 0, i64 %.pre-phi
  %21 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZSt3maxIiERKT_S2_S2_(ptr noundef nonnull align 4 dereferenceable(4) %2, ptr noundef nonnull align 4 dereferenceable(4) %20)
  %22 = load i32, ptr %21, align 4, !tbaa !9
  store i32 %22, ptr %2, align 4, !tbaa !9
  %.0 = load i32, ptr %11, align 8, !tbaa !9
  %.not = icmp eq i32 %.0, -1
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !15
}

; Function Attrs: inlinehint mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZSt3maxIiERKT_S2_S2_(ptr noundef nonnull align 4 dereferenceable(4), ptr noundef nonnull align 4 dereferenceable(4)) local_unnamed_addr #2

attributes #0 = { mustprogress 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 = { 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 = !{!"bool", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = !{!12, !10, i64 4}
!12 = !{!"_ZTS4Edge", !10, i64 0, !10, i64 4}
!13 = !{i8 0, i8 2}
!14 = !{}
!15 = distinct !{!15, !16}
!16 = !{!"llvm.loop.mustprogress"}


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