; LLVM IR from lzyrapx/Competitive-Programming :: ACdream (1099（nth_element）)

; 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::basic_istream" = type { ptr, i64, %"class.std::basic_ios" }
%"class.std::basic_ios" = type { %"class.std::ios_base", ptr, i8, i8, ptr, ptr, ptr, ptr }
%"class.std::ios_base" = type { ptr, i64, i64, i32, i32, i32, ptr, %"struct.std::ios_base::_Words", [8 x %"struct.std::ios_base::_Words"], i32, ptr, %"class.std::locale" }
%"struct.std::ios_base::_Words" = type { ptr, i64 }
%"class.std::locale" = type { ptr }

@a = external dso_local global [5000010 x i32], align 16
@_ZSt3cin = external global %"class.std::basic_istream", align 8
@.str = external hidden unnamed_addr constant [3 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [4 x i8], align 1

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() #0 {
  %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
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #5
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #5
  br label %5

5:                                                ; preds = %27, %0
  %6 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %2)
  %7 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) %6, ptr noundef nonnull align 4 dereferenceable(4) %3)
  %8 = load ptr, ptr %7, align 8, !tbaa !5
  %9 = getelementptr i8, ptr %8, i64 -24
  %10 = load i64, ptr %9, align 8
  %11 = getelementptr inbounds i8, ptr %7, i64 %10
  %12 = call noundef zeroext i1 @_ZNKSt9basic_iosIcSt11char_traitsIcEEcvbEv(ptr noundef nonnull align 8 dereferenceable(264) %11)
  br i1 %12, label %13, label %45

13:                                               ; preds = %5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #5
  store i32 0, ptr %4, align 4, !tbaa !8
  br label %14

14:                                               ; preds = %24, %13
  %15 = load i32, ptr %4, align 4, !tbaa !8
  %16 = load i32, ptr %2, align 4, !tbaa !8
  %17 = icmp slt i32 %15, %16
  br i1 %17, label %19, label %18

18:                                               ; preds = %14
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #5
  br label %27

19:                                               ; preds = %14
  %20 = load i32, ptr %4, align 4, !tbaa !8
  %21 = sext i32 %20 to i64
  %22 = getelementptr inbounds [5000010 x i32], ptr @a, i64 0, i64 %21
  %23 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str, ptr noundef %22)
  br label %24

24:                                               ; preds = %19
  %25 = load i32, ptr %4, align 4, !tbaa !8
  %26 = add nsw i32 %25, 1
  store i32 %26, ptr %4, align 4, !tbaa !8
  br label %14, !llvm.loop !11

27:                                               ; preds = %18
  %28 = load i32, ptr %2, align 4, !tbaa !8
  %29 = sext i32 %28 to i64
  %30 = getelementptr inbounds i32, ptr @a, i64 %29
  %31 = load i32, ptr %3, align 4, !tbaa !8
  %32 = sext i32 %31 to i64
  %33 = sub i64 0, %32
  %34 = getelementptr inbounds i32, ptr %30, i64 %33
  %35 = load i32, ptr %2, align 4, !tbaa !8
  %36 = sext i32 %35 to i64
  %37 = getelementptr inbounds i32, ptr @a, i64 %36
  call void @_ZSt11nth_elementIPiEvT_S1_S1_(ptr noundef @a, ptr noundef %34, ptr noundef %37)
  %38 = load i32, ptr %2, align 4, !tbaa !8
  %39 = load i32, ptr %3, align 4, !tbaa !8
  %40 = sub nsw i32 %38, %39
  %41 = sext i32 %40 to i64
  %42 = getelementptr inbounds [5000010 x i32], ptr @a, i64 0, i64 %41
  %43 = load i32, ptr %42, align 4, !tbaa !8
  %44 = call i32 (ptr, ...) @printf(ptr noundef @.str.1, i32 noundef %43)
  br label %5, !llvm.loop !13

45:                                               ; preds = %5
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #5
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #5
  ret i32 0
}

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

declare noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 4 dereferenceable(4)) #2

; Function Attrs: mustprogress uwtable
declare noundef zeroext i1 @_ZNKSt9basic_iosIcSt11char_traitsIcEEcvbEv(ptr noundef nonnull align 8 dereferenceable(264)) #3 align 2

declare i32 @__isoc99_scanf(ptr noundef, ...) #2

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

; Function Attrs: inlinehint mustprogress uwtable
declare dso_local void @_ZSt11nth_elementIPiEvT_S1_S1_(ptr noundef, ptr noundef, ptr noundef) #4

declare i32 @printf(ptr noundef, ...) #2

attributes #0 = { 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 #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { "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 = { 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 #4 = { inlinehint 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 #5 = { 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 = !{!"vtable pointer", !7, i64 0}
!7 = !{!"Simple C++ TBAA"}
!8 = !{!9, !9, i64 0}
!9 = !{!"int", !10, i64 0}
!10 = !{!"omnipotent char", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}
!13 = distinct !{!13, !12}


; 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::basic_istream" = type { ptr, i64, %"class.std::basic_ios" }
%"class.std::basic_ios" = type { %"class.std::ios_base", ptr, i8, i8, ptr, ptr, ptr, ptr }
%"class.std::ios_base" = type { ptr, i64, i64, i32, i32, i32, ptr, %"struct.std::ios_base::_Words", [8 x %"struct.std::ios_base::_Words"], i32, ptr, %"class.std::locale" }
%"struct.std::ios_base::_Words" = type { ptr, i64 }
%"class.std::locale" = type { ptr }

@a = external dso_local global [5000010 x i32], align 16
@_ZSt3cin = external global %"class.std::basic_istream", align 8
@.str = external hidden unnamed_addr constant [3 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [4 x i8], align 1

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() local_unnamed_addr #0 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %1) #6
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %2) #6
  %3 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %1)
  %4 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) %3, ptr noundef nonnull align 4 dereferenceable(4) %2)
  %5 = load ptr, ptr %4, align 8, !tbaa !5
  %6 = getelementptr i8, ptr %5, i64 -24
  %7 = load i64, ptr %6, align 8
  %8 = getelementptr inbounds i8, ptr %4, i64 %7
  %9 = call noundef zeroext i1 @_ZNKSt9basic_iosIcSt11char_traitsIcEEcvbEv(ptr noundef nonnull align 8 dereferenceable(264) %8)
  br i1 %9, label %.preheader, label %._crit_edge5

.preheader:                                       ; preds = %0, %._crit_edge
  %10 = load i32, ptr %1, align 4, !tbaa !8
  %11 = icmp sgt i32 %10, 0
  br i1 %11, label %.lr.ph, label %.preheader.._crit_edge_crit_edge

.preheader.._crit_edge_crit_edge:                 ; preds = %.preheader
  %.pre = sext i32 %10 to i64
  br label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph, %.preheader.._crit_edge_crit_edge
  %.pre-phi = phi i64 [ %.pre, %.preheader.._crit_edge_crit_edge ], [ %34, %.lr.ph ]
  %12 = getelementptr inbounds i32, ptr @a, i64 %.pre-phi
  %13 = load i32, ptr %2, align 4, !tbaa !8
  %14 = sext i32 %13 to i64
  %15 = sub nsw i64 0, %14
  %16 = getelementptr inbounds i32, ptr %12, i64 %15
  call void @_ZSt11nth_elementIPiEvT_S1_S1_(ptr noundef nonnull @a, ptr noundef nonnull %16, ptr noundef nonnull %12)
  %17 = load i32, ptr %1, align 4, !tbaa !8
  %18 = load i32, ptr %2, align 4, !tbaa !8
  %19 = sub nsw i32 %17, %18
  %20 = sext i32 %19 to i64
  %21 = getelementptr inbounds [5000010 x i32], ptr @a, i64 0, i64 %20
  %22 = load i32, ptr %21, align 4, !tbaa !8
  %23 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.1, i32 noundef %22)
  %24 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %1)
  %25 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) %24, ptr noundef nonnull align 4 dereferenceable(4) %2)
  %26 = load ptr, ptr %25, align 8, !tbaa !5
  %27 = getelementptr i8, ptr %26, i64 -24
  %28 = load i64, ptr %27, align 8
  %29 = getelementptr inbounds i8, ptr %25, i64 %28
  %30 = call noundef zeroext i1 @_ZNKSt9basic_iosIcSt11char_traitsIcEEcvbEv(ptr noundef nonnull align 8 dereferenceable(264) %29)
  br i1 %30, label %.preheader, label %._crit_edge5, !llvm.loop !11

.lr.ph:                                           ; preds = %.preheader, %.lr.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ 0, %.preheader ]
  %31 = getelementptr inbounds [5000010 x i32], ptr @a, i64 0, i64 %indvars.iv
  %32 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef nonnull %31)
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %33 = load i32, ptr %1, align 4, !tbaa !8
  %34 = sext i32 %33 to i64
  %35 = icmp slt i64 %indvars.iv.next, %34
  br i1 %35, label %.lr.ph, label %._crit_edge, !llvm.loop !13

._crit_edge5:                                     ; preds = %._crit_edge, %0
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %2) #6
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %1) #6
  ret i32 0
}

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

declare noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 4 dereferenceable(4)) local_unnamed_addr #2

; Function Attrs: mustprogress uwtable
declare noundef zeroext i1 @_ZNKSt9basic_iosIcSt11char_traitsIcEEcvbEv(ptr noundef nonnull align 8 dereferenceable(264)) local_unnamed_addr #3 align 2

; Function Attrs: nofree nounwind
declare noundef i32 @__isoc99_scanf(ptr nocapture noundef readonly, ...) local_unnamed_addr #4

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

; Function Attrs: inlinehint mustprogress uwtable
declare dso_local void @_ZSt11nth_elementIPiEvT_S1_S1_(ptr noundef, ptr noundef, ptr noundef) local_unnamed_addr #5

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #4

attributes #0 = { 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 #1 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { "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 = { 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 #4 = { 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 #5 = { inlinehint 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 #6 = { 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 = !{!"vtable pointer", !7, i64 0}
!7 = !{!"Simple C++ TBAA"}
!8 = !{!9, !9, i64 0}
!9 = !{!"int", !10, i64 0}
!10 = !{!"omnipotent char", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}
!13 = distinct !{!13, !12}


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