; LLVM IR from tangjz/acm-icpc :: 51nod (1204)

; 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
@m = external dso_local global i32, align 4
@dsu = external dso_local global [100001 x i32], align 16
@.str = external hidden unnamed_addr constant [5 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [7 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: 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 noundef zeroext i1 @_Z9dsu_mergeiii(i32 noundef, 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
  %6 = alloca [5 x i8], align 1
  store i32 0, ptr %1, align 4
  %7 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str, ptr noundef @n, ptr noundef @m)
  %8 = load i32, ptr @n, align 4, !tbaa !5
  %9 = add nsw i32 %8, 1
  %10 = sext i32 %9 to i64
  %11 = mul i64 %10, 4
  call void @llvm.memset.p0.i64(ptr align 16 @dsu, i8 -1, i64 %11, i1 false)
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #5
  store i32 1, ptr %2, align 4, !tbaa !5
  br label %12

12:                                               ; preds = %36, %0
  %13 = load i32, ptr %2, align 4, !tbaa !5
  %14 = load i32, ptr @m, align 4, !tbaa !5
  %15 = icmp sle i32 %13, %14
  br i1 %15, label %17, label %16

16:                                               ; preds = %12
  store i32 2, ptr %3, align 4
  br label %39

17:                                               ; preds = %12
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #5
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #5
  call void @llvm.lifetime.start.p0(i64 5, ptr %6) #5
  %18 = getelementptr inbounds [5 x i8], ptr %6, i64 0, i64 0
  %19 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str.1, ptr noundef %4, ptr noundef %5, ptr noundef %18)
  %20 = load i32, ptr %4, align 4, !tbaa !5
  %21 = sub nsw i32 %20, 1
  %22 = load i32, ptr %5, align 4, !tbaa !5
  %23 = getelementptr inbounds [5 x i8], ptr %6, i64 0, i64 0
  %24 = load i8, ptr %23, align 1, !tbaa !9
  %25 = sext i8 %24 to i32
  %26 = icmp eq i32 %25, 111
  %27 = zext i1 %26 to i32
  %28 = call noundef zeroext i1 @_Z9dsu_mergeiii(i32 noundef %21, i32 noundef %22, i32 noundef %27)
  br i1 %28, label %32, label %29

29:                                               ; preds = %17
  %30 = load i32, ptr %2, align 4, !tbaa !5
  %31 = call i32 (ptr, ...) @printf(ptr noundef @.str.2, i32 noundef %30)
  store i32 0, ptr %1, align 4
  store i32 1, ptr %3, align 4
  br label %33

32:                                               ; preds = %17
  store i32 0, ptr %3, align 4
  br label %33

33:                                               ; preds = %32, %29
  call void @llvm.lifetime.end.p0(i64 5, ptr %6) #5
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #5
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #5
  %34 = load i32, ptr %3, align 4
  switch i32 %34, label %39 [
    i32 0, label %35
  ]

35:                                               ; preds = %33
  br label %36

36:                                               ; preds = %35
  %37 = load i32, ptr %2, align 4, !tbaa !5
  %38 = add nsw i32 %37, 1
  store i32 %38, ptr %2, align 4, !tbaa !5
  br label %12, !llvm.loop !10

39:                                               ; preds = %33, %16
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #5
  %40 = load i32, ptr %3, align 4
  switch i32 %40, label %45 [
    i32 2, label %41
    i32 1, label %43
  ]

41:                                               ; preds = %39
  %42 = call i32 @puts(ptr noundef @.str.3)
  store i32 0, ptr %1, align 4
  br label %43

43:                                               ; preds = %41, %39
  %44 = load i32, ptr %1, align 4
  ret i32 %44

45:                                               ; preds = %39
  unreachable
}

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

declare i32 @puts(ptr noundef) #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 = { 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 = !{!7, !7, i64 0}
!10 = distinct !{!10, !11}
!11 = !{!"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"

@n = external dso_local global i32, align 4
@m = external dso_local global i32, align 4
@dsu = external dso_local local_unnamed_addr global [100001 x i32], align 16
@.str = external hidden unnamed_addr constant [5 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [7 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 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 noundef zeroext i1 @_Z9dsu_mergeiii(i32 noundef, 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
  %2 = alloca i32, align 4
  %3 = alloca [5 x i8], align 1
  %4 = tail call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef nonnull @n, ptr noundef nonnull @m)
  %5 = load i32, ptr @n, align 4, !tbaa !5
  %6 = add nsw i32 %5, 1
  %7 = sext i32 %6 to i64
  %8 = shl nsw i64 %7, 2
  tail call void @llvm.memset.p0.i64(ptr nonnull align 16 @dsu, i8 -1, i64 %8, i1 false)
  %9 = load i32, ptr @m, align 4, !tbaa !5
  %.not13 = icmp slt i32 %9, 1
  br i1 %.not13, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %0, %.critedge
  %.0614 = phi i32 [ %18, %.critedge ], [ 1, %0 ]
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %1) #5
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %2) #5
  call void @llvm.lifetime.start.p0(i64 5, ptr nonnull %3) #5
  %10 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str.1, ptr noundef nonnull %1, ptr noundef nonnull %2, ptr noundef nonnull %3)
  %11 = load i32, ptr %1, align 4, !tbaa !5
  %12 = add nsw i32 %11, -1
  %13 = load i32, ptr %2, align 4, !tbaa !5
  %14 = load i8, ptr %3, align 1, !tbaa !9
  %15 = icmp eq i8 %14, 111
  %16 = zext i1 %15 to i32
  %17 = call noundef zeroext i1 @_Z9dsu_mergeiii(i32 noundef %12, i32 noundef %13, i32 noundef %16)
  br i1 %17, label %.critedge, label %20

.critedge:                                        ; preds = %.lr.ph
  call void @llvm.lifetime.end.p0(i64 5, ptr nonnull %3) #5
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %2) #5
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %1) #5
  %18 = add nuw nsw i32 %.0614, 1
  %19 = load i32, ptr @m, align 4, !tbaa !5
  %.not.not = icmp slt i32 %.0614, %19
  br i1 %.not.not, label %.lr.ph, label %._crit_edge, !llvm.loop !10

20:                                               ; preds = %.lr.ph
  %21 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.2, i32 noundef %.0614)
  call void @llvm.lifetime.end.p0(i64 5, ptr nonnull %3) #5
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %2) #5
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %1) #5
  br label %23

._crit_edge:                                      ; preds = %.critedge, %0
  %22 = call i32 @puts(ptr noundef nonnull dereferenceable(1) @.str.3)
  br label %23

23:                                               ; preds = %20, %._crit_edge
  ret i32 0
}

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

; Function Attrs: nofree nounwind
declare noundef i32 @puts(ptr nocapture noundef readonly) 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 = { 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 = { mustprogress 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 = !{!7, !7, i64 0}
!10 = distinct !{!10, !11}
!11 = !{!"llvm.loop.mustprogress"}


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