; LLVM IR from ahampriyanshu/algo-ds-101 :: Data-Structures/LinkedList/Singly_Linked_List (MiddleElementLL)

; 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 }

@head = external dso_local global ptr, align 8
@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@.str = external hidden unnamed_addr constant [27 x i8], align 1
@_ZSt3cin = external global %"class.std::basic_istream", align 8
@.str.1 = external hidden unnamed_addr constant [21 x i8], align 1
@.str.2 = external hidden unnamed_addr constant [19 x i8], align 1

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() #0 {
  %1 = alloca i32, align 4
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  %8 = alloca i32, align 4
  store i32 0, ptr %1, align 4
  call void @llvm.lifetime.start.p0(i64 8, ptr %2) #6
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #6
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #6
  store ptr null, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #6
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #6
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #6
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #6
  store i32 0, ptr %8, align 4, !tbaa !9
  %9 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef @.str)
  %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) %5)
  %11 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef @.str.1)
  store i32 0, ptr %7, align 4, !tbaa !9
  br label %12

12:                                               ; preds = %48, %0
  %13 = load i32, ptr %7, align 4, !tbaa !9
  %14 = load i32, ptr %5, align 4, !tbaa !9
  %15 = icmp slt i32 %13, %14
  br i1 %15, label %16, label %51

16:                                               ; preds = %12
  %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) %6)
  %18 = call noalias noundef nonnull ptr @_Znwm(i64 noundef 16) #7
  store ptr %18, ptr %2, align 8, !tbaa !5
  %19 = load i32, ptr %6, align 4, !tbaa !9
  %20 = load ptr, ptr %2, align 8, !tbaa !5
  %21 = getelementptr inbounds %struct.Node, ptr %20, i32 0, i32 0
  store i32 %19, ptr %21, align 8, !tbaa !11
  %22 = load ptr, ptr %2, align 8, !tbaa !5
  %23 = getelementptr inbounds %struct.Node, ptr %22, i32 0, i32 1
  store ptr null, ptr %23, align 8, !tbaa !13
  %24 = load ptr, ptr @head, align 8, !tbaa !5
  %25 = icmp eq ptr %24, null
  br i1 %25, label %26, label %30

26:                                               ; preds = %16
  %27 = load ptr, ptr %2, align 8, !tbaa !5
  store ptr %27, ptr @head, align 8, !tbaa !5
  %28 = load ptr, ptr @head, align 8, !tbaa !5
  store ptr %28, ptr %4, align 8, !tbaa !5
  %29 = load ptr, ptr @head, align 8, !tbaa !5
  store ptr %29, ptr %3, align 8, !tbaa !5
  br label %47

30:                                               ; preds = %16
  %31 = load ptr, ptr %2, align 8, !tbaa !5
  %32 = load ptr, ptr %4, align 8, !tbaa !5
  %33 = getelementptr inbounds %struct.Node, ptr %32, i32 0, i32 1
  store ptr %31, ptr %33, align 8, !tbaa !13
  %34 = load ptr, ptr %2, align 8, !tbaa !5
  store ptr %34, ptr %4, align 8, !tbaa !5
  %35 = load i32, ptr %7, align 4, !tbaa !9
  %36 = sdiv i32 %35, 2
  %37 = load i32, ptr %8, align 4, !tbaa !9
  %38 = icmp eq i32 %36, %37
  br i1 %38, label %39, label %40

39:                                               ; preds = %30
  br label %48

40:                                               ; preds = %30
  %41 = load ptr, ptr %3, align 8, !tbaa !5
  %42 = getelementptr inbounds %struct.Node, ptr %41, i32 0, i32 1
  %43 = load ptr, ptr %42, align 8, !tbaa !13
  store ptr %43, ptr %3, align 8, !tbaa !5
  %44 = load i32, ptr %8, align 4, !tbaa !9
  %45 = add nsw i32 %44, 1
  store i32 %45, ptr %8, align 4, !tbaa !9
  br label %46

46:                                               ; preds = %40
  br label %47

47:                                               ; preds = %46, %26
  br label %48

48:                                               ; preds = %47, %39
  %49 = load i32, ptr %7, align 4, !tbaa !9
  %50 = add nsw i32 %49, 1
  store i32 %50, ptr %7, align 4, !tbaa !9
  br label %12, !llvm.loop !14

51:                                               ; preds = %12
  %52 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef @.str.2)
  %53 = load ptr, ptr %3, align 8, !tbaa !5
  %54 = getelementptr inbounds %struct.Node, ptr %53, i32 0, i32 0
  %55 = load i32, ptr %54, align 8, !tbaa !11
  %56 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) %52, i32 noundef %55)
  %57 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) %56, ptr noundef @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #6
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #6
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #6
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #6
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #6
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #6
  call void @llvm.lifetime.end.p0(i64 8, ptr %2) #6
  ret i32 0
}

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

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) #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: nobuiltin allocsize(0)
declare noundef nonnull ptr @_Znwm(i64 noundef) #4

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) #3

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

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

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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { 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 #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 = { 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 #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 = { nounwind }
attributes #7 = { 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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = !{!12, !10, i64 0}
!12 = !{!"_ZTS4Node", !10, i64 0, !6, i64 8}
!13 = !{!12, !6, i64 8}
!14 = distinct !{!14, !15}
!15 = !{!"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_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" }

@head = external dso_local local_unnamed_addr global ptr, align 8
@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@.str = external hidden unnamed_addr constant [27 x i8], align 1
@_ZSt3cin = external global %"class.std::basic_istream", align 8
@.str.1 = external hidden unnamed_addr constant [21 x i8], align 1
@.str.2 = external hidden unnamed_addr constant [19 x i8], align 1

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() local_unnamed_addr #0 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %1) #6
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %2) #6
  %3 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef nonnull @.str)
  %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 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef nonnull @.str.1)
  %6 = load i32, ptr %1, align 4, !tbaa !5
  %7 = icmp sgt i32 %6, 0
  br i1 %7, label %.lr.ph, label %._crit_edge

.lr.ph:                                           ; preds = %0, %23
  %.020 = phi i32 [ %.1, %23 ], [ 0, %0 ]
  %.01219 = phi i32 [ %24, %23 ], [ 0, %0 ]
  %.01318 = phi ptr [ %9, %23 ], [ null, %0 ]
  %.01517 = phi ptr [ %.116, %23 ], [ undef, %0 ]
  %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) %2)
  %9 = call noalias noundef nonnull dereferenceable(16) ptr @_Znwm(i64 noundef 16) #7
  %10 = load i32, ptr %2, align 4, !tbaa !5
  store i32 %10, ptr %9, align 8, !tbaa !9
  %11 = getelementptr inbounds i8, ptr %9, i64 8
  store ptr null, ptr %11, align 8, !tbaa !12
  %12 = load ptr, ptr @head, align 8, !tbaa !13
  %13 = icmp eq ptr %12, null
  br i1 %13, label %14, label %15

14:                                               ; preds = %.lr.ph
  store ptr %9, ptr @head, align 8, !tbaa !13
  br label %23

15:                                               ; preds = %.lr.ph
  %16 = getelementptr inbounds i8, ptr %.01318, i64 8
  store ptr %9, ptr %16, align 8, !tbaa !12
  %17 = lshr i32 %.01219, 1
  %18 = icmp eq i32 %17, %.020
  br i1 %18, label %23, label %19

19:                                               ; preds = %15
  %20 = getelementptr inbounds i8, ptr %.01517, i64 8
  %21 = load ptr, ptr %20, align 8, !tbaa !12
  %22 = add nsw i32 %.020, 1
  br label %23

23:                                               ; preds = %14, %19, %15
  %.116 = phi ptr [ %9, %14 ], [ %.01517, %15 ], [ %21, %19 ]
  %.1 = phi i32 [ %.020, %14 ], [ %.020, %15 ], [ %22, %19 ]
  %24 = add nuw nsw i32 %.01219, 1
  %25 = load i32, ptr %1, align 4, !tbaa !5
  %26 = icmp slt i32 %24, %25
  br i1 %26, label %.lr.ph, label %._crit_edge, !llvm.loop !14

._crit_edge:                                      ; preds = %23, %0
  %.015.lcssa = phi ptr [ undef, %0 ], [ %.116, %23 ]
  %27 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef nonnull @.str.2)
  %28 = load i32, ptr %.015.lcssa, align 8, !tbaa !9
  %29 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) %27, i32 noundef %28)
  %30 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) %29, ptr noundef nonnull @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %2) #6
  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) #1

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) local_unnamed_addr #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: nobuiltin allocsize(0)
declare noundef nonnull ptr @_Znwm(i64 noundef) local_unnamed_addr #4

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) local_unnamed_addr #3

; 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)) #2

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

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


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