; LLVM IR from lzyrapx/Competitive-Programming :: HDUOJ (1501（dfs）)

; 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 }

@vis = external dso_local global [567 x [567 x i8]], align 16
@s1 = external dso_local global [567 x i8], align 16
@s2 = external dso_local global [567 x i8], align 16
@s3 = external dso_local global [567 x i8], align 16
@flag = external dso_local global i8, align 1
@_ZSt3cin = external global %"class.std::basic_istream", align 8
@.str = external hidden unnamed_addr constant [7 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [14 x i8], align 1
@.str.2 = external hidden unnamed_addr constant [4 x i8], align 1
@.str.3 = external hidden unnamed_addr constant [3 x i8], align 1

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z3dfsiii(i32 noundef, i32 noundef, i32 noundef) #0

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() #1 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  %3 = 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
  store i32 1, ptr %3, align 4, !tbaa !5
  %4 = 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 %5

5:                                                ; preds = %20, %0
  %6 = load i32, ptr %2, align 4, !tbaa !5
  %7 = add nsw i32 %6, -1
  store i32 %7, ptr %2, align 4, !tbaa !5
  %8 = icmp ne i32 %6, 0
  br i1 %8, label %9, label %21

9:                                                ; preds = %5
  store i8 0, ptr @flag, align 1, !tbaa !9
  call void @llvm.memset.p0.i64(ptr align 16 @vis, i8 0, i64 321489, i1 false)
  %10 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str, ptr noundef @s1, ptr noundef @s2, ptr noundef @s3)
  call void @_Z3dfsiii(i32 noundef 0, i32 noundef 0, i32 noundef 0)
  %11 = load i32, ptr %3, align 4, !tbaa !5
  %12 = add nsw i32 %11, 1
  store i32 %12, ptr %3, align 4, !tbaa !5
  %13 = call i32 (ptr, ...) @printf(ptr noundef @.str.1, i32 noundef %11)
  %14 = load i8, ptr @flag, align 1, !tbaa !9, !range !11, !noundef !12
  %15 = trunc i8 %14 to i1
  br i1 %15, label %16, label %18

16:                                               ; preds = %9
  %17 = call i32 @puts(ptr noundef @.str.2)
  br label %20

18:                                               ; preds = %9
  %19 = call i32 @puts(ptr noundef @.str.3)
  br label %20

20:                                               ; preds = %18, %16
  br label %5, !llvm.loop !13

21:                                               ; 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) #2

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

; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: write)
declare void @llvm.memset.p0.i64(ptr nocapture writeonly, i8, i64, i1 immarg) #4

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

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

declare i32 @puts(ptr noundef) #3

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #2

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 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 #2 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = { nocallback nofree nounwind willreturn memory(argmem: write) }
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 = !{!"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 = !{i8 0, i8 2}
!12 = !{}
!13 = distinct !{!13, !14}
!14 = !{!"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"

%"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 }

@vis = external dso_local local_unnamed_addr global [567 x [567 x i8]], align 16
@s1 = external dso_local global [567 x i8], align 16
@s2 = external dso_local global [567 x i8], align 16
@s3 = external dso_local global [567 x i8], align 16
@flag = external dso_local local_unnamed_addr global i8, align 1
@_ZSt3cin = external global %"class.std::basic_istream", align 8
@.str = external hidden unnamed_addr constant [7 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [14 x i8], align 1
@.str.2 = external hidden unnamed_addr constant [4 x i8], align 1
@.str.3 = external hidden unnamed_addr constant [3 x i8], align 1

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z3dfsiii(i32 noundef, i32 noundef, i32 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() local_unnamed_addr #1 {
  %1 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %1) #6
  %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
  %.not1 = icmp eq i32 %3, 0
  br i1 %.not1, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %0, %.lr.ph
  %.02 = phi i32 [ %6, %.lr.ph ], [ 1, %0 ]
  store i8 0, ptr @flag, align 1, !tbaa !9
  call void @llvm.memset.p0.i64(ptr noundef nonnull align 16 dereferenceable(321489) @vis, i8 0, i64 321489, i1 false)
  %5 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef nonnull @s1, ptr noundef nonnull @s2, ptr noundef nonnull @s3)
  call void @_Z3dfsiii(i32 noundef 0, i32 noundef 0, i32 noundef 0)
  %6 = add nuw nsw i32 %.02, 1
  %7 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.1, i32 noundef %.02)
  %8 = load i8, ptr @flag, align 1, !tbaa !9, !range !11, !noundef !12
  %9 = trunc nuw i8 %8 to i1
  %.str.2..str.3 = select i1 %9, ptr @.str.2, ptr @.str.3
  %10 = call i32 @puts(ptr noundef nonnull dereferenceable(1) %.str.2..str.3)
  %11 = load i32, ptr %1, align 4, !tbaa !5
  %12 = add nsw i32 %11, -1
  store i32 %12, ptr %1, align 4, !tbaa !5
  %.not = icmp eq i32 %11, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !13

._crit_edge:                                      ; preds = %.lr.ph, %0
  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) #2

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

; Function Attrs: mustprogress nocallback nofree nounwind willreturn memory(argmem: write)
declare void @llvm.memset.p0.i64(ptr nocapture writeonly, i8, i64, i1 immarg) #4

; Function Attrs: nofree nounwind
declare noundef i32 @__isoc99_scanf(ptr nocapture noundef readonly, ...) local_unnamed_addr #5

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #5

; Function Attrs: nofree nounwind
declare noundef i32 @puts(ptr nocapture noundef readonly) local_unnamed_addr #5

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #2

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 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 #2 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = { mustprogress nocallback nofree nounwind willreturn memory(argmem: write) }
attributes #5 = { 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 #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 = !{!"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 = !{i8 0, i8 2}
!12 = !{}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}


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