; LLVM IR from Tunghohin/Competitive_Coding :: Codeforces (cf1536_B)

; 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 [1000 x i8], align 16
@n = external dso_local global i32, align 4
@flag = external dso_local global i8, align 1
@_ZSt3cin = external global %"class.std::basic_istream", align 8

; 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
declare dso_local void @_Z3dfsii(i32 noundef, i32 noundef) #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
  %5 = alloca i32, align 4
  store i32 0, ptr %1, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #4
  %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)
  br label %7

7:                                                ; preds = %41, %0
  %8 = load i32, ptr %2, align 4, !tbaa !5
  %9 = add nsw i32 %8, -1
  store i32 %9, ptr %2, align 4, !tbaa !5
  %10 = icmp ne i32 %8, 0
  br i1 %10, label %11, label %42

11:                                               ; preds = %7
  %12 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) @n)
  store i8 1, ptr @flag, align 1, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #4
  store i32 1, ptr %3, align 4, !tbaa !5
  br label %13

13:                                               ; preds = %23, %11
  %14 = load i32, ptr %3, align 4, !tbaa !5
  %15 = load i32, ptr @n, align 4, !tbaa !5
  %16 = icmp sle i32 %14, %15
  br i1 %16, label %18, label %17

17:                                               ; preds = %13
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #4
  br label %26

18:                                               ; preds = %13
  %19 = load i32, ptr %3, align 4, !tbaa !5
  %20 = sext i32 %19 to i64
  %21 = getelementptr inbounds [1000 x i8], ptr @a, i64 0, i64 %20
  %22 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZStrsIcSt11char_traitsIcEERSt13basic_istreamIT_T0_ES6_RS3_(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 1 dereferenceable(1) %21)
  br label %23

23:                                               ; preds = %18
  %24 = load i32, ptr %3, align 4, !tbaa !5
  %25 = add nsw i32 %24, 1
  store i32 %25, ptr %3, align 4, !tbaa !5
  br label %13, !llvm.loop !11

26:                                               ; preds = %17
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #4
  store i32 1, ptr %4, align 4, !tbaa !5
  br label %27

27:                                               ; preds = %37, %26
  %28 = load i32, ptr %4, align 4, !tbaa !5
  %29 = icmp sle i32 %28, 1000
  br i1 %29, label %31, label %30

30:                                               ; preds = %27
  store i32 7, ptr %5, align 4
  br label %40

31:                                               ; preds = %27
  %32 = load i32, ptr %4, align 4, !tbaa !5
  call void @_Z3dfsii(i32 noundef 1, i32 noundef %32)
  %33 = load i8, ptr @flag, align 1, !tbaa !9, !range !13, !noundef !14
  %34 = trunc i8 %33 to i1
  br i1 %34, label %36, label %35

35:                                               ; preds = %31
  store i32 7, ptr %5, align 4
  br label %40

36:                                               ; preds = %31
  br label %37

37:                                               ; preds = %36
  %38 = load i32, ptr %4, align 4, !tbaa !5
  %39 = add nsw i32 %38, 1
  store i32 %39, ptr %4, align 4, !tbaa !5
  br label %27, !llvm.loop !15

40:                                               ; preds = %35, %30
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #4
  br label %41

41:                                               ; preds = %40
  br label %7, !llvm.loop !16

42:                                               ; preds = %7
  store i32 0, ptr %1, align 4
  store i32 1, ptr %5, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #4
  %43 = load i32, ptr %1, align 4
  ret i32 %43
}

declare noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 4 dereferenceable(4)) #3

declare noundef nonnull align 8 dereferenceable(16) ptr @_ZStrsIcSt11char_traitsIcEERSt13basic_istreamIT_T0_ES6_RS3_(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 1 dereferenceable(1)) #3

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 = { 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 = !{!10, !10, i64 0}
!10 = !{!"bool", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}
!13 = !{i8 0, i8 2}
!14 = !{}
!15 = distinct !{!15, !12}
!16 = distinct !{!16, !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 [1000 x i8], align 16
@n = external dso_local global i32, align 4
@flag = external dso_local local_unnamed_addr global i8, align 1
@_ZSt3cin = external global %"class.std::basic_istream", align 8

; 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 uwtable
declare dso_local void @_Z3dfsii(i32 noundef, i32 noundef) local_unnamed_addr #1

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() local_unnamed_addr #2 {
  %1 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %1) #4
  %2 = 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)
  %3 = load i32, ptr %1, align 4, !tbaa !5
  %4 = add nsw i32 %3, -1
  store i32 %4, ptr %1, align 4, !tbaa !5
  %.not12 = icmp eq i32 %3, 0
  br i1 %.not12, label %._crit_edge, label %.lr.ph13

.lr.ph13:                                         ; preds = %0, %15
  %5 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) @n)
  store i8 1, ptr @flag, align 1, !tbaa !9
  %6 = load i32, ptr @n, align 4, !tbaa !5
  %.not89 = icmp slt i32 %6, 1
  br i1 %.not89, label %.preheader.preheader, label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph13, %.lr.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ 1, %.lr.ph13 ]
  %7 = getelementptr inbounds [1000 x i8], ptr @a, i64 0, i64 %indvars.iv
  %8 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZStrsIcSt11char_traitsIcEERSt13basic_istreamIT_T0_ES6_RS3_(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 1 dereferenceable(1) %7)
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %9 = load i32, ptr @n, align 4, !tbaa !5
  %10 = sext i32 %9 to i64
  %.not8.not = icmp slt i64 %indvars.iv, %10
  br i1 %.not8.not, label %.lr.ph, label %.preheader.preheader, !llvm.loop !11

.preheader.preheader:                             ; preds = %.lr.ph, %.lr.ph13
  br label %.preheader

.preheader:                                       ; preds = %.preheader.preheader, %.preheader
  %.011 = phi i32 [ %13, %.preheader ], [ 1, %.preheader.preheader ]
  call void @_Z3dfsii(i32 noundef 1, i32 noundef %.011)
  %11 = load i8, ptr @flag, align 1, !tbaa !9, !range !13, !noundef !14
  %12 = trunc nuw i8 %11 to i1
  %13 = add nuw nsw i32 %.011, 1
  %14 = icmp ult i32 %.011, 1000
  %or.cond = and i1 %14, %12
  br i1 %or.cond, label %.preheader, label %15, !llvm.loop !15

15:                                               ; preds = %.preheader
  %16 = load i32, ptr %1, align 4, !tbaa !5
  %17 = add nsw i32 %16, -1
  store i32 %17, ptr %1, align 4, !tbaa !5
  %.not = icmp eq i32 %16, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph13, !llvm.loop !16

._crit_edge:                                      ; preds = %15, %0
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %1) #4
  ret i32 0
}

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 #3

declare noundef nonnull align 8 dereferenceable(16) ptr @_ZStrsIcSt11char_traitsIcEERSt13basic_istreamIT_T0_ES6_RS3_(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 1 dereferenceable(1)) local_unnamed_addr #3

attributes #0 = { mustprogress 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 = { 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 = !{!10, !10, i64 0}
!10 = !{!"bool", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}
!13 = !{i8 0, i8 2}
!14 = !{}
!15 = distinct !{!15, !12}
!16 = distinct !{!16, !12}


; Effective O3 passes: GlobalOptPass,IPSCCPPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopInstSimplifyPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,SROAPass,SimplifyCFGPass