; LLVM IR from smv1999/CompetitiveProgrammingQuestionBank :: Data Structures/Linked Lists/Doubly Linked List (reverse_a_double_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, ptr }

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

; Function Attrs: mustprogress uwtable
declare dso_local noundef ptr @_Z7newNodei(i32 noundef) #0

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z11displayListP4Node(ptr noundef) #0

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef ptr @_Z10reverseDLLP4Node(ptr noundef) #2

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

10:                                               ; preds = %40, %0
  %11 = load i32, ptr %2, align 4, !tbaa !5
  %12 = add nsw i32 %11, -1
  store i32 %12, ptr %2, align 4, !tbaa !5
  %13 = icmp ne i32 %11, 0
  br i1 %13, label %14, label %45

14:                                               ; preds = %10
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #6
  %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) %3)
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #6
  store ptr null, ptr %4, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #6
  store ptr null, ptr %5, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #6
  %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) %6)
  %17 = load i32, ptr %6, align 4, !tbaa !5
  %18 = call noundef ptr @_Z7newNodei(i32 noundef %17)
  store ptr %18, ptr %4, align 8, !tbaa !9
  %19 = load ptr, ptr %4, align 8, !tbaa !9
  store ptr %19, ptr %5, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #6
  store i32 0, ptr %7, align 4, !tbaa !5
  br label %20

20:                                               ; preds = %37, %14
  %21 = load i32, ptr %7, align 4, !tbaa !5
  %22 = load i32, ptr %3, align 4, !tbaa !5
  %23 = sub nsw i32 %22, 1
  %24 = icmp slt i32 %21, %23
  br i1 %24, label %26, label %25

25:                                               ; preds = %20
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #6
  br label %40

26:                                               ; preds = %20
  %27 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %6)
  call void @llvm.lifetime.start.p0(i64 8, ptr %8) #6
  %28 = load i32, ptr %6, align 4, !tbaa !5
  %29 = call noundef ptr @_Z7newNodei(i32 noundef %28)
  store ptr %29, ptr %8, align 8, !tbaa !9
  %30 = load ptr, ptr %8, align 8, !tbaa !9
  %31 = load ptr, ptr %5, align 8, !tbaa !9
  %32 = getelementptr inbounds %struct.Node, ptr %31, i32 0, i32 1
  store ptr %30, ptr %32, align 8, !tbaa !11
  %33 = load ptr, ptr %5, align 8, !tbaa !9
  %34 = load ptr, ptr %8, align 8, !tbaa !9
  %35 = getelementptr inbounds %struct.Node, ptr %34, i32 0, i32 2
  store ptr %33, ptr %35, align 8, !tbaa !13
  %36 = load ptr, ptr %8, align 8, !tbaa !9
  store ptr %36, ptr %5, align 8, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 8, ptr %8) #6
  br label %37

37:                                               ; preds = %26
  %38 = load i32, ptr %7, align 4, !tbaa !5
  %39 = add nsw i32 %38, 1
  store i32 %39, ptr %7, align 4, !tbaa !5
  br label %20, !llvm.loop !14

40:                                               ; preds = %25
  %41 = load ptr, ptr %4, align 8, !tbaa !9
  %42 = call noundef ptr @_Z10reverseDLLP4Node(ptr noundef %41)
  store ptr %42, ptr %4, align 8, !tbaa !9
  %43 = load ptr, ptr %4, align 8, !tbaa !9
  call void @_Z11displayListP4Node(ptr noundef %43)
  %44 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #6
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #6
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #6
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #6
  br label %10, !llvm.loop !16

45:                                               ; preds = %10
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #6
  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)) #4

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) #0 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)) #5

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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { 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 #3 = { 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 #4 = { "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 = { 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 #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 = !{!"any pointer", !7, i64 0}
!11 = !{!12, !10, i64 8}
!12 = !{!"_ZTS4Node", !6, i64 0, !10, i64 8, !10, i64 16}
!13 = !{!12, !10, i64 16}
!14 = distinct !{!14, !15}
!15 = !{!"llvm.loop.mustprogress"}
!16 = distinct !{!16, !15}


; 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

; Function Attrs: mustprogress uwtable
declare dso_local noundef ptr @_Z7newNodei(i32 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z11displayListP4Node(ptr noundef) local_unnamed_addr #0

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef ptr @_Z10reverseDLLP4Node(ptr noundef) local_unnamed_addr #2

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() local_unnamed_addr #3 {
  %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) #6
  %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
  %.not12 = icmp eq i32 %5, 0
  br i1 %.not12, label %._crit_edge15, label %.lr.ph14

.lr.ph14:                                         ; preds = %0, %._crit_edge
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %2) #6
  %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) #6
  %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 = load i32, ptr %3, align 4, !tbaa !5
  %10 = call noundef ptr @_Z7newNodei(i32 noundef %9)
  %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.ph14
  %13 = call noundef ptr @_Z10reverseDLLP4Node(ptr noundef %10)
  call void @_Z11displayListP4Node(ptr noundef %13)
  %14 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef nonnull @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %3) #6
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %2) #6
  %15 = load i32, ptr %1, align 4, !tbaa !5
  %16 = add nsw i32 %15, -1
  store i32 %16, ptr %1, align 4, !tbaa !5
  %.not = icmp eq i32 %15, 0
  br i1 %.not, label %._crit_edge15, label %.lr.ph14, !llvm.loop !9

.lr.ph:                                           ; preds = %.lr.ph14, %.lr.ph
  %.011 = phi i32 [ %22, %.lr.ph ], [ 0, %.lr.ph14 ]
  %.0910 = phi ptr [ %19, %.lr.ph ], [ %10, %.lr.ph14 ]
  %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) %3)
  %18 = load i32, ptr %3, align 4, !tbaa !5
  %19 = call noundef ptr @_Z7newNodei(i32 noundef %18)
  %20 = getelementptr inbounds i8, ptr %.0910, i64 8
  store ptr %19, ptr %20, align 8, !tbaa !11
  %21 = getelementptr inbounds i8, ptr %19, i64 16
  store ptr %.0910, ptr %21, align 8, !tbaa !14
  %22 = add nuw nsw i32 %.011, 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 !15

._crit_edge15:                                    ; preds = %._crit_edge, %0
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %1) #6
  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 #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 #0 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)) #5

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 nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { 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 #3 = { 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 #4 = { "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 = { 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 #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 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}
!11 = !{!12, !13, i64 8}
!12 = !{!"_ZTS4Node", !6, i64 0, !13, i64 8, !13, i64 16}
!13 = !{!"any pointer", !7, i64 0}
!14 = !{!12, !13, i64 16}
!15 = distinct !{!15, !10}


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