; LLVM IR from tangjz/acm-icpc :: 51nod (1314)

; 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"

@n = external dso_local global i32, align 4
@ans = external dso_local global i32, align 4
@e = external dso_local global [51 x [52 x i8]], align 16
@.str = external hidden unnamed_addr constant [3 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [3 x i8], align 1
@.str.2 = external hidden unnamed_addr constant [4 x i8], align 1

; Function Attrs: mustprogress uwtable
declare dso_local noundef i32 @_Z3dfsiiRi(i32 noundef, i32 noundef, ptr noundef nonnull align 4 dereferenceable(4)) #0

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() #2 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  store i32 0, ptr %1, align 4
  %5 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str, ptr noundef @n)
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #4
  store i32 0, ptr %2, align 4, !tbaa !5
  br label %6

6:                                                ; preds = %17, %0
  %7 = load i32, ptr %2, align 4, !tbaa !5
  %8 = load i32, ptr @n, align 4, !tbaa !5
  %9 = icmp slt i32 %7, %8
  br i1 %9, label %11, label %10

10:                                               ; preds = %6
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #4
  br label %20

11:                                               ; preds = %6
  %12 = load i32, ptr %2, align 4, !tbaa !5
  %13 = sext i32 %12 to i64
  %14 = getelementptr inbounds [51 x [52 x i8]], ptr @e, i64 0, i64 %13
  %15 = getelementptr inbounds [52 x i8], ptr %14, i64 0, i64 0
  %16 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str.1, ptr noundef %15)
  br label %17

17:                                               ; preds = %11
  %18 = load i32, ptr %2, align 4, !tbaa !5
  %19 = add nsw i32 %18, 1
  store i32 %19, ptr %2, align 4, !tbaa !5
  br label %6, !llvm.loop !9

20:                                               ; preds = %10
  %21 = load i32, ptr @n, align 4, !tbaa !5
  %22 = icmp sgt i32 %21, 1
  br i1 %22, label %23, label %25

23:                                               ; preds = %20
  %24 = load i32, ptr @n, align 4, !tbaa !5
  br label %26

25:                                               ; preds = %20
  br label %26

26:                                               ; preds = %25, %23
  %27 = phi i32 [ %24, %23 ], [ 0, %25 ]
  store i32 %27, ptr @ans, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #4
  store i32 0, ptr %3, align 4, !tbaa !5
  br label %28

28:                                               ; preds = %42, %26
  %29 = load i32, ptr %3, align 4, !tbaa !5
  %30 = load i32, ptr @n, align 4, !tbaa !5
  %31 = icmp slt i32 %29, %30
  br i1 %31, label %33, label %32

32:                                               ; preds = %28
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #4
  br label %45

33:                                               ; preds = %28
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #4
  store i32 1, ptr %4, align 4, !tbaa !5
  %34 = load i32, ptr %3, align 4, !tbaa !5
  %35 = call noundef i32 @_Z3dfsiiRi(i32 noundef %34, i32 noundef -1, ptr noundef nonnull align 4 dereferenceable(4) %4)
  %36 = load i32, ptr @ans, align 4, !tbaa !5
  %37 = load i32, ptr %4, align 4, !tbaa !5
  %38 = icmp sgt i32 %36, %37
  br i1 %38, label %39, label %41

39:                                               ; preds = %33
  %40 = load i32, ptr %4, align 4, !tbaa !5
  store i32 %40, ptr @ans, align 4, !tbaa !5
  br label %41

41:                                               ; preds = %39, %33
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #4
  br label %42

42:                                               ; preds = %41
  %43 = load i32, ptr %3, align 4, !tbaa !5
  %44 = add nsw i32 %43, 1
  store i32 %44, ptr %3, align 4, !tbaa !5
  br label %28, !llvm.loop !11

45:                                               ; preds = %32
  %46 = load i32, ptr @ans, align 4, !tbaa !5
  %47 = call i32 (ptr, ...) @printf(ptr noundef @.str.2, i32 noundef %46)
  ret i32 0
}

declare i32 @__isoc99_scanf(ptr noundef, ...) #3

declare i32 @printf(ptr noundef, ...) #3

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 norecurse 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 = { "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 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}
!11 = distinct !{!11, !10}


; 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"

@n = external dso_local global i32, align 4
@ans = external dso_local local_unnamed_addr global i32, align 4
@e = external dso_local global [51 x [52 x i8]], align 16
@.str = external hidden unnamed_addr constant [3 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [3 x i8], align 1
@.str.2 = external hidden unnamed_addr constant [4 x i8], align 1

; Function Attrs: mustprogress uwtable
declare dso_local noundef i32 @_Z3dfsiiRi(i32 noundef, i32 noundef, ptr noundef nonnull align 4 dereferenceable(4)) local_unnamed_addr #0

; 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 nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() local_unnamed_addr #2 {
  %1 = alloca i32, align 4
  %2 = tail call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef nonnull @n)
  %3 = load i32, ptr @n, align 4
  %4 = icmp sgt i32 %3, 0
  br i1 %4, label %.lr.ph, label %._crit_edge.thread

._crit_edge.thread:                               ; preds = %0
  store i32 0, ptr @ans, align 4, !tbaa !5
  br label %._crit_edge13

._crit_edge:                                      ; preds = %.lr.ph
  %5 = icmp sgt i32 %10, 1
  %6 = select i1 %5, i32 %10, i32 0
  store i32 %6, ptr @ans, align 4, !tbaa !5
  %7 = icmp sgt i32 %10, 0
  br i1 %7, label %.lr.ph12, label %._crit_edge13

.lr.ph:                                           ; preds = %0, %.lr.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ 0, %0 ]
  %8 = getelementptr inbounds [51 x [52 x i8]], ptr @e, i64 0, i64 %indvars.iv
  %9 = tail call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str.1, ptr noundef nonnull %8)
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %10 = load i32, ptr @n, align 4
  %11 = sext i32 %10 to i64
  %12 = icmp slt i64 %indvars.iv.next, %11
  br i1 %12, label %.lr.ph, label %._crit_edge, !llvm.loop !9

._crit_edge13:                                    ; preds = %20, %._crit_edge.thread, %._crit_edge
  %13 = phi i32 [ %6, %._crit_edge ], [ 0, %._crit_edge.thread ], [ %21, %20 ]
  %14 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.2, i32 noundef %13)
  ret i32 0

.lr.ph12:                                         ; preds = %._crit_edge, %20
  %.010 = phi i32 [ %22, %20 ], [ 0, %._crit_edge ]
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %1) #4
  store i32 1, ptr %1, align 4, !tbaa !5
  %15 = call noundef i32 @_Z3dfsiiRi(i32 noundef %.010, i32 noundef -1, ptr noundef nonnull align 4 dereferenceable(4) %1)
  %16 = load i32, ptr @ans, align 4, !tbaa !5
  %17 = load i32, ptr %1, align 4, !tbaa !5
  %18 = icmp sgt i32 %16, %17
  br i1 %18, label %19, label %20

19:                                               ; preds = %.lr.ph12
  store i32 %17, ptr @ans, align 4, !tbaa !5
  br label %20

20:                                               ; preds = %19, %.lr.ph12
  %21 = phi i32 [ %17, %19 ], [ %16, %.lr.ph12 ]
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %1) #4
  %22 = add nuw nsw i32 %.010, 1
  %23 = load i32, ptr @n, align 4, !tbaa !5
  %24 = icmp slt i32 %22, %23
  br i1 %24, label %.lr.ph12, label %._crit_edge13, !llvm.loop !11
}

; Function Attrs: nofree nounwind
declare noundef i32 @__isoc99_scanf(ptr nocapture noundef readonly, ...) local_unnamed_addr #3

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #3

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 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { mustprogress norecurse 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 = { nofree nounwind "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 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}
!11 = distinct !{!11, !10}


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