; LLVM IR from Py-Contributors/AlgorithmsAndDataStructure :: C++/Data Structure/Disjoint Set Union (DisJointSetUnion)

; 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 }
%struct.dsu = type { ptr, ptr, ptr }

@n = external dso_local global i32, align 4
@m = external dso_local global i32, align 4
@x = external dso_local global i32, align 4
@y = external dso_local global i32, align 4
@_ZSt3cin = external global %"class.std::basic_istream", align 8

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() #0 {
  %1 = alloca i32, align 4
  %2 = alloca %struct.dsu, align 8
  %3 = alloca i32, align 4
  store i32 0, ptr %1, align 4
  %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) @n)
  %5 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) %4, ptr noundef nonnull align 4 dereferenceable(4) @m)
  %6 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) %5, ptr noundef nonnull align 4 dereferenceable(4) @x)
  %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) @y)
  call void @llvm.lifetime.start.p0(i64 24, ptr %2) #4
  %8 = load i32, ptr @n, align 4, !tbaa !5
  call void @_ZN3dsu4initEi(ptr noundef nonnull align 8 dereferenceable(24) %2, i32 noundef %8)
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #4
  store i32 0, ptr %3, align 4, !tbaa !5
  br label %9

9:                                                ; preds = %23, %0
  %10 = load i32, ptr %3, align 4, !tbaa !5
  %11 = load i32, ptr @m, align 4, !tbaa !5
  %12 = icmp slt i32 %10, %11
  br i1 %12, label %14, label %13

13:                                               ; preds = %9
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #4
  br label %26

14:                                               ; preds = %9
  %15 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) @x)
  %16 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) %15, ptr noundef nonnull align 4 dereferenceable(4) @y)
  %17 = load i32, ptr @x, align 4, !tbaa !5
  %18 = add nsw i32 %17, -1
  store i32 %18, ptr @x, align 4, !tbaa !5
  %19 = load i32, ptr @y, align 4, !tbaa !5
  %20 = add nsw i32 %19, -1
  store i32 %20, ptr @y, align 4, !tbaa !5
  %21 = load i32, ptr @x, align 4, !tbaa !5
  %22 = load i32, ptr @y, align 4, !tbaa !5
  call void @_ZN3dsu5uniteEii(ptr noundef nonnull align 8 dereferenceable(24) %2, i32 noundef %21, i32 noundef %22)
  br label %23

23:                                               ; preds = %14
  %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 %9, !llvm.loop !9

26:                                               ; preds = %13
  call void @llvm.lifetime.end.p0(i64 24, ptr %2) #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)) #1

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

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZN3dsu4initEi(ptr noundef nonnull align 8 dereferenceable(24), i32 noundef) #3 align 2

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZN3dsu5uniteEii(ptr noundef nonnull align 8 dereferenceable(24), i32 noundef, i32 noundef) #3 align 2

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


; 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 }
%struct.dsu = type { ptr, ptr, ptr }

@n = external dso_local global i32, align 4
@m = external dso_local global i32, align 4
@x = external dso_local global i32, align 4
@y = external dso_local global i32, align 4
@_ZSt3cin = external global %"class.std::basic_istream", align 8

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() local_unnamed_addr #0 {
  %1 = alloca %struct.dsu, align 8
  %2 = tail 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)
  %3 = tail call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) %2, ptr noundef nonnull align 4 dereferenceable(4) @m)
  %4 = tail call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) %3, ptr noundef nonnull align 4 dereferenceable(4) @x)
  %5 = tail call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) %4, ptr noundef nonnull align 4 dereferenceable(4) @y)
  call void @llvm.lifetime.start.p0(i64 24, ptr nonnull %1) #4
  %6 = load i32, ptr @n, align 4, !tbaa !5
  call void @_ZN3dsu4initEi(ptr noundef nonnull align 8 dereferenceable(24) %1, i32 noundef %6)
  %7 = load i32, ptr @m, align 4, !tbaa !5
  %8 = icmp sgt i32 %7, 0
  br i1 %8, label %.lr.ph, label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph, %0
  call void @llvm.lifetime.end.p0(i64 24, ptr nonnull %1) #4
  ret i32 0

.lr.ph:                                           ; preds = %0, %.lr.ph
  %.02 = phi i32 [ %15, %.lr.ph ], [ 0, %0 ]
  %9 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) @x)
  %10 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) %9, ptr noundef nonnull align 4 dereferenceable(4) @y)
  %11 = load i32, ptr @x, align 4, !tbaa !5
  %12 = add nsw i32 %11, -1
  store i32 %12, ptr @x, align 4, !tbaa !5
  %13 = load i32, ptr @y, align 4, !tbaa !5
  %14 = add nsw i32 %13, -1
  store i32 %14, ptr @y, align 4, !tbaa !5
  call void @_ZN3dsu5uniteEii(ptr noundef nonnull align 8 dereferenceable(24) %1, i32 noundef %12, i32 noundef %14)
  %15 = add nuw nsw i32 %.02, 1
  %16 = load i32, ptr @m, align 4, !tbaa !5
  %17 = icmp slt i32 %15, %16
  br i1 %17, label %.lr.ph, label %._crit_edge, !llvm.loop !9
}

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 #1

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

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZN3dsu4initEi(ptr noundef nonnull align 8 dereferenceable(24), i32 noundef) local_unnamed_addr #3 align 2

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZN3dsu5uniteEii(ptr noundef nonnull align 8 dereferenceable(24), i32 noundef, i32 noundef) local_unnamed_addr #3 align 2

; 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 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 = { "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 = { 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 = { 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"}


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