; LLVM IR from smv1999/CompetitiveProgrammingQuestionBank :: Data Structures/Linked Lists/Singly Linked List (middle_of_linkedlist)

; 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_ostream" = type { ptr, %"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 }
%"class.std::basic_istream" = type { ptr, i64, %"class.std::basic_ios" }
%struct.Node = type { i32, ptr }

@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@_ZSt3cin = external global %"class.std::basic_istream", align 8

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) #0

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() #1 personality ptr @__gxx_personality_v0 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca ptr, align 8
  %6 = alloca ptr, align 8
  %7 = alloca i32, align 4
  %8 = alloca ptr, align 8
  %9 = alloca i32, align 4
  store i32 0, ptr %1, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #8
  %10 = 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 %11

11:                                               ; preds = %49, %0
  %12 = load i32, ptr %2, align 4, !tbaa !5
  %13 = add nsw i32 %12, -1
  store i32 %13, ptr %2, align 4, !tbaa !5
  %14 = icmp ne i32 %12, 0
  br i1 %14, label %15, label %55

15:                                               ; preds = %11
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #8
  %16 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %3)
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #8
  %17 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %4)
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #8
  %18 = call noalias noundef nonnull ptr @_Znwm(i64 noundef 16) #9
  %19 = load i32, ptr %4, align 4, !tbaa !5
  invoke void @_ZN4NodeC2Ei(ptr noundef nonnull align 8 dereferenceable(16) %18, i32 noundef %19)
          to label %20 unwind label %28

20:                                               ; preds = %15
  store ptr %18, ptr %5, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %8) #8
  %21 = load ptr, ptr %5, align 8, !tbaa !9
  store ptr %21, ptr %8, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %9) #8
  store i32 0, ptr %9, align 4, !tbaa !5
  br label %22

22:                                               ; preds = %42, %20
  %23 = load i32, ptr %9, align 4, !tbaa !5
  %24 = load i32, ptr %3, align 4, !tbaa !5
  %25 = sub nsw i32 %24, 1
  %26 = icmp slt i32 %23, %25
  br i1 %26, label %32, label %27

27:                                               ; preds = %22
  call void @llvm.lifetime.end.p0(i64 4, ptr %9) #8
  br label %49

28:                                               ; preds = %15
  %29 = landingpad { ptr, i32 }
          cleanup
  %30 = extractvalue { ptr, i32 } %29, 0
  store ptr %30, ptr %6, align 8
  %31 = extractvalue { ptr, i32 } %29, 1
  store i32 %31, ptr %7, align 4
  call void @_ZdlPvm(ptr noundef %18, i64 noundef 16) #10
  br label %54

32:                                               ; preds = %22
  %33 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %4)
  %34 = call noalias noundef nonnull ptr @_Znwm(i64 noundef 16) #9
  %35 = load i32, ptr %4, align 4, !tbaa !5
  invoke void @_ZN4NodeC2Ei(ptr noundef nonnull align 8 dereferenceable(16) %34, i32 noundef %35)
          to label %36 unwind label %45

36:                                               ; preds = %32
  %37 = load ptr, ptr %8, align 8, !tbaa !9
  %38 = getelementptr inbounds %struct.Node, ptr %37, i32 0, i32 1
  store ptr %34, ptr %38, align 8, !tbaa !11
  %39 = load ptr, ptr %8, align 8, !tbaa !9
  %40 = getelementptr inbounds %struct.Node, ptr %39, i32 0, i32 1
  %41 = load ptr, ptr %40, align 8, !tbaa !11
  store ptr %41, ptr %8, align 8, !tbaa !9
  br label %42

42:                                               ; preds = %36
  %43 = load i32, ptr %9, align 4, !tbaa !5
  %44 = add nsw i32 %43, 1
  store i32 %44, ptr %9, align 4, !tbaa !5
  br label %22, !llvm.loop !13

45:                                               ; preds = %32
  %46 = landingpad { ptr, i32 }
          cleanup
  %47 = extractvalue { ptr, i32 } %46, 0
  store ptr %47, ptr %6, align 8
  %48 = extractvalue { ptr, i32 } %46, 1
  store i32 %48, ptr %7, align 4
  call void @_ZdlPvm(ptr noundef %34, i64 noundef 16) #10
  call void @llvm.lifetime.end.p0(i64 4, ptr %9) #8
  call void @llvm.lifetime.end.p0(i64 8, ptr %8) #8
  br label %54

49:                                               ; preds = %27
  %50 = load ptr, ptr %5, align 8, !tbaa !9
  %51 = call noundef i32 @_Z9getMiddleP4Node(ptr noundef %50)
  %52 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %51)
  %53 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) %52, ptr noundef @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
  call void @llvm.lifetime.end.p0(i64 8, ptr %8) #8
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #8
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #8
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #8
  br label %11, !llvm.loop !15

54:                                               ; preds = %45, %28
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #8
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #8
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #8
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #8
  br label %56

55:                                               ; preds = %11
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #8
  ret i32 0

56:                                               ; preds = %54
  %57 = load ptr, ptr %6, align 8
  %58 = load i32, ptr %7, align 4
  %59 = insertvalue { ptr, i32 } poison, ptr %57, 0
  %60 = insertvalue { ptr, i32 } %59, i32 %58, 1
  resume { ptr, i32 } %60
}

; 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)) #0

; Function Attrs: nobuiltin allocsize(0)
declare noundef nonnull ptr @_Znwm(i64 noundef) #3

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_ZN4NodeC2Ei(ptr noundef nonnull align 8 dereferenceable(16), i32 noundef) unnamed_addr #4 align 2

declare i32 @__gxx_personality_v0(...)

; Function Attrs: nobuiltin nounwind
declare void @_ZdlPvm(ptr noundef, i64 noundef) #5

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

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef i32 @_Z9getMiddleP4Node(ptr noundef) #4

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) #6 align 2

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_(ptr noundef nonnull align 8 dereferenceable(8)) #7

attributes #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 = { nobuiltin allocsize(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 = { mustprogress nounwind 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 = { nobuiltin 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 = { 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 #7 = { 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 #8 = { nounwind }
attributes #9 = { builtin allocsize(0) }
attributes #10 = { builtin 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 = !{!"any pointer", !7, i64 0}
!11 = !{!12, !10, i64 8}
!12 = !{!"_ZTS4Node", !6, i64 0, !10, i64 8}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}
!15 = distinct !{!15, !14}


; 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_ostream" = type { ptr, %"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 }
%"class.std::basic_istream" = type { ptr, i64, %"class.std::basic_ios" }

@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@_ZSt3cin = external global %"class.std::basic_istream", align 8

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() local_unnamed_addr #1 personality ptr @__gxx_personality_v0 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %1) #7
  %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) %1)
  %5 = load i32, ptr %1, align 4, !tbaa !5
  %6 = add nsw i32 %5, -1
  store i32 %6, ptr %1, align 4, !tbaa !5
  %.not8 = icmp eq i32 %5, 0
  br i1 %.not8, label %._crit_edge11, label %.lr.ph10

.lr.ph10:                                         ; preds = %0, %._crit_edge
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %2) #7
  %7 = 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)
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %3) #7
  %8 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %3)
  %9 = call noalias noundef nonnull dereferenceable(16) ptr @_Znwm(i64 noundef 16) #8
  %10 = load i32, ptr %3, align 4, !tbaa !5
  call void @_ZN4NodeC2Ei(ptr noundef nonnull align 8 dereferenceable(16) %9, i32 noundef %10)
  %11 = load i32, ptr %2, align 4, !tbaa !5
  %12 = icmp sgt i32 %11, 1
  br i1 %12, label %.lr.ph, label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph, %.lr.ph10
  %13 = call noundef i32 @_Z9getMiddleP4Node(ptr noundef nonnull %9)
  %14 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %13)
  %15 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) %14, ptr noundef nonnull @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %3) #7
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %2) #7
  %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_edge11, label %.lr.ph10, !llvm.loop !9

.lr.ph:                                           ; preds = %.lr.ph10, %.lr.ph
  %.07 = phi i32 [ %22, %.lr.ph ], [ 0, %.lr.ph10 ]
  %.056 = phi ptr [ %19, %.lr.ph ], [ %9, %.lr.ph10 ]
  %18 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %3)
  %19 = call noalias noundef nonnull dereferenceable(16) ptr @_Znwm(i64 noundef 16) #8
  %20 = load i32, ptr %3, align 4, !tbaa !5
  call void @_ZN4NodeC2Ei(ptr noundef nonnull align 8 dereferenceable(16) %19, i32 noundef %20)
  %21 = getelementptr inbounds i8, ptr %.056, i64 8
  store ptr %19, ptr %21, align 8, !tbaa !11
  %22 = add nuw nsw i32 %.07, 1
  %23 = load i32, ptr %2, align 4, !tbaa !5
  %24 = add nsw i32 %23, -1
  %25 = icmp slt i32 %22, %24
  br i1 %25, label %.lr.ph, label %._crit_edge, !llvm.loop !14

._crit_edge11:                                    ; preds = %._crit_edge, %0
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %1) #7
  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 #0

; Function Attrs: nobuiltin allocsize(0)
declare noundef nonnull ptr @_Znwm(i64 noundef) local_unnamed_addr #3

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_ZN4NodeC2Ei(ptr noundef nonnull align 8 dereferenceable(16), i32 noundef) unnamed_addr #4 align 2

declare i32 @__gxx_personality_v0(...)

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

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef i32 @_Z9getMiddleP4Node(ptr noundef) local_unnamed_addr #4

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) local_unnamed_addr #5 align 2

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_(ptr noundef nonnull align 8 dereferenceable(8)) #6

attributes #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 = { nobuiltin allocsize(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 = { mustprogress nounwind 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 = { 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 = { 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 #7 = { nounwind }
attributes #8 = { builtin allocsize(0) }

!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"}
!11 = !{!12, !13, i64 8}
!12 = !{!"_ZTS4Node", !6, i64 0, !13, i64 8}
!13 = !{!"any pointer", !7, i64 0}
!14 = distinct !{!14, !10}


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