; LLVM IR from HarshCasper/NeoAlgo :: C-Plus-Plus/ds/linked_list_middle_element.ll (Z11MiddleNode2P4Node)

; 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.Node = type { i32, ptr }

@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@.str.2 = external hidden unnamed_addr constant [29 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: 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) #1

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) #2

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) #3 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)) #1

; Function Attrs: mustprogress uwtable
define dso_local void @_Z11MiddleNode2P4Node(ptr noundef %0) #3 {
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  store ptr %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #4
  %4 = load ptr, ptr %2, align 8, !tbaa !5
  store ptr %4, ptr %3, align 8, !tbaa !5
  br label %5

5:                                                ; preds = %25, %1
  %6 = load ptr, ptr %3, align 8, !tbaa !5
  %7 = icmp ne ptr %6, null
  br i1 %7, label %8, label %26

8:                                                ; preds = %5
  %9 = load ptr, ptr %3, align 8, !tbaa !5
  %10 = getelementptr inbounds %class.Node, ptr %9, i32 0, i32 1
  %11 = load ptr, ptr %10, align 8, !tbaa !9
  store ptr %11, ptr %3, align 8, !tbaa !5
  %12 = load ptr, ptr %3, align 8, !tbaa !5
  %13 = icmp ne ptr %12, null
  br i1 %13, label %14, label %18

14:                                               ; preds = %8
  %15 = load ptr, ptr %3, align 8, !tbaa !5
  %16 = getelementptr inbounds %class.Node, ptr %15, i32 0, i32 1
  %17 = load ptr, ptr %16, align 8, !tbaa !9
  store ptr %17, ptr %3, align 8, !tbaa !5
  br label %18

18:                                               ; preds = %14, %8
  %19 = load ptr, ptr %3, align 8, !tbaa !5
  %20 = icmp ne ptr %19, null
  br i1 %20, label %21, label %25

21:                                               ; preds = %18
  %22 = load ptr, ptr %2, align 8, !tbaa !5
  %23 = getelementptr inbounds %class.Node, ptr %22, i32 0, i32 1
  %24 = load ptr, ptr %23, align 8, !tbaa !9
  store ptr %24, ptr %2, align 8, !tbaa !5
  br label %25

25:                                               ; preds = %21, %18
  br label %5, !llvm.loop !12

26:                                               ; preds = %5
  %27 = 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)
  %28 = load ptr, ptr %2, align 8, !tbaa !5
  %29 = getelementptr inbounds %class.Node, ptr %28, i32 0, i32 0
  %30 = load i32, ptr %29, align 8, !tbaa !14
  %31 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) %27, i32 noundef %30)
  %32 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) %31, ptr noundef @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #4
  ret void
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 #2 = { "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 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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!10, !6, i64 8}
!10 = !{!"_ZTS4Node", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}
!14 = !{!10, !11, i64 0}


; 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 }

@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@.str.2 = external hidden unnamed_addr constant [29 x i8], align 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 #0

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) local_unnamed_addr #1

; 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 #2 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)) #0

; Function Attrs: mustprogress uwtable
define dso_local void @_Z11MiddleNode2P4Node(ptr noundef readonly %0) local_unnamed_addr #2 {
  %.not17 = icmp eq ptr %0, null
  br i1 %.not17, label %._crit_edge, label %.lr.ph.preheader

.lr.ph.preheader:                                 ; preds = %1
  %2 = getelementptr inbounds i8, ptr %0, i64 8
  %3 = load ptr, ptr %2, align 8, !tbaa !5
  %.not1224 = icmp eq ptr %3, null
  br i1 %.not1224, label %._crit_edge, label %.lr.ph26

.lr.ph26:                                         ; preds = %.lr.ph.preheader, %.thread
  %4 = phi ptr [ %10, %.thread ], [ %3, %.lr.ph.preheader ]
  %.081825 = phi ptr [ %8, %.thread ], [ %0, %.lr.ph.preheader ]
  %5 = getelementptr inbounds i8, ptr %4, i64 8
  %6 = load ptr, ptr %5, align 8, !tbaa !5
  %.not13 = icmp eq ptr %6, null
  br i1 %.not13, label %._crit_edge, label %.thread

.thread:                                          ; preds = %.lr.ph26
  %7 = getelementptr inbounds i8, ptr %.081825, i64 8
  %8 = load ptr, ptr %7, align 8, !tbaa !5
  %9 = getelementptr inbounds i8, ptr %6, i64 8
  %10 = load ptr, ptr %9, align 8, !tbaa !5
  %.not12 = icmp eq ptr %10, null
  br i1 %.not12, label %._crit_edge, label %.lr.ph26, !llvm.loop !11

._crit_edge:                                      ; preds = %.lr.ph26, %.thread, %.lr.ph.preheader, %1
  %.08.lcssa = phi ptr [ null, %1 ], [ %0, %.lr.ph.preheader ], [ %8, %.thread ], [ %.081825, %.lr.ph26 ]
  %11 = 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.2)
  %12 = load i32, ptr %.08.lcssa, align 8, !tbaa !13
  %13 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) %11, i32 noundef %12)
  %14 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) %13, ptr noundef nonnull @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
  ret void
}

attributes #0 = { 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 #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 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" }

!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, !10, i64 8}
!6 = !{!"_ZTS4Node", !7, i64 0, !10, i64 8}
!7 = !{!"int", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C++ TBAA"}
!10 = !{!"any pointer", !8, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}
!13 = !{!6, !7, i64 0}


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