; LLVM IR from gargarchit/Data_Structure_n_Algorithms :: Linked_List/Implementation.ll (Z11delete_tailRP4Node)

; 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 [11 x i8], align 1

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

; 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)) #2

; Function Attrs: mustprogress uwtable
define dso_local noundef ptr @_Z11delete_tailRP4Node(ptr noundef nonnull align 8 dereferenceable(8) %0) #3 {
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  store ptr %0, ptr %3, align 8, !tbaa !5
  %5 = load ptr, ptr %3, align 8, !tbaa !5
  %6 = load ptr, ptr %5, align 8, !tbaa !5
  %7 = icmp eq ptr %6, null
  br i1 %7, label %8, label %11

8:                                                ; preds = %1
  %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.2)
  %10 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) %9, ptr noundef @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
  store ptr null, ptr %2, align 8
  br label %48

11:                                               ; preds = %1
  %12 = load ptr, ptr %3, align 8, !tbaa !5
  %13 = load ptr, ptr %12, align 8, !tbaa !5
  %14 = getelementptr inbounds %class.Node, ptr %13, i32 0, i32 1
  %15 = load ptr, ptr %14, align 8, !tbaa !9
  %16 = icmp eq ptr %15, null
  br i1 %16, label %17, label %23

17:                                               ; preds = %11
  %18 = load ptr, ptr %3, align 8, !tbaa !5
  %19 = load ptr, ptr %18, align 8, !tbaa !5
  %20 = icmp eq ptr %19, null
  br i1 %20, label %22, label %21

21:                                               ; preds = %17
  call void @_ZdlPvm(ptr noundef %19, i64 noundef 16) #4
  br label %22

22:                                               ; preds = %21, %17
  store ptr null, ptr %2, align 8
  br label %48

23:                                               ; preds = %11
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #5
  %24 = load ptr, ptr %3, align 8, !tbaa !5
  %25 = load ptr, ptr %24, align 8, !tbaa !5
  store ptr %25, ptr %4, align 8, !tbaa !5
  br label %26

26:                                               ; preds = %33, %23
  %27 = load ptr, ptr %4, align 8, !tbaa !5
  %28 = getelementptr inbounds %class.Node, ptr %27, i32 0, i32 1
  %29 = load ptr, ptr %28, align 8, !tbaa !9
  %30 = getelementptr inbounds %class.Node, ptr %29, i32 0, i32 1
  %31 = load ptr, ptr %30, align 8, !tbaa !9
  %32 = icmp ne ptr %31, null
  br i1 %32, label %33, label %37

33:                                               ; preds = %26
  %34 = load ptr, ptr %4, align 8, !tbaa !5
  %35 = getelementptr inbounds %class.Node, ptr %34, i32 0, i32 1
  %36 = load ptr, ptr %35, align 8, !tbaa !9
  store ptr %36, ptr %4, align 8, !tbaa !5
  br label %26, !llvm.loop !12

37:                                               ; preds = %26
  %38 = load ptr, ptr %4, align 8, !tbaa !5
  %39 = getelementptr inbounds %class.Node, ptr %38, i32 0, i32 1
  %40 = load ptr, ptr %39, align 8, !tbaa !9
  %41 = icmp eq ptr %40, null
  br i1 %41, label %43, label %42

42:                                               ; preds = %37
  call void @_ZdlPvm(ptr noundef %40, i64 noundef 16) #4
  br label %43

43:                                               ; preds = %42, %37
  %44 = load ptr, ptr %4, align 8, !tbaa !5
  %45 = getelementptr inbounds %class.Node, ptr %44, i32 0, i32 1
  store ptr null, ptr %45, align 8, !tbaa !9
  %46 = load ptr, ptr %3, align 8, !tbaa !5
  %47 = load ptr, ptr %46, align 8, !tbaa !5
  store ptr %47, ptr %2, align 8
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #5
  br label %48

48:                                               ; preds = %43, %22, %8
  %49 = load ptr, ptr %2, align 8
  ret ptr %49
}

attributes #0 = { 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 #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 = { 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 = { builtin nounwind }
attributes #5 = { 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"}


; 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 [11 x i8], align 1

; Function Attrs: nobuiltin nounwind
declare void @_ZdlPvm(ptr noundef, i64 noundef) local_unnamed_addr #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) 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)) #1

; Function Attrs: mustprogress uwtable
define dso_local noundef ptr @_Z11delete_tailRP4Node(ptr nocapture noundef nonnull readonly align 8 dereferenceable(8) %0) local_unnamed_addr #2 {
  %2 = load ptr, ptr %0, align 8, !tbaa !5
  %3 = icmp eq ptr %2, null
  br i1 %3, label %4, label %7

4:                                                ; preds = %1
  %5 = 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)
  %6 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) %5, ptr noundef nonnull @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
  br label %18

7:                                                ; preds = %1
  %8 = getelementptr inbounds i8, ptr %2, i64 8
  %9 = load ptr, ptr %8, align 8, !tbaa !9
  %10 = icmp eq ptr %9, null
  br i1 %10, label %11, label %.preheader

11:                                               ; preds = %7
  tail call void @_ZdlPvm(ptr noundef nonnull %2, i64 noundef 16) #3
  br label %18

.preheader:                                       ; preds = %7, %.preheader
  %12 = phi ptr [ %14, %.preheader ], [ %9, %7 ]
  %.0 = phi ptr [ %12, %.preheader ], [ %2, %7 ]
  %13 = getelementptr inbounds i8, ptr %12, i64 8
  %14 = load ptr, ptr %13, align 8, !tbaa !9
  %.not = icmp eq ptr %14, null
  br i1 %.not, label %15, label %.preheader, !llvm.loop !12

15:                                               ; preds = %.preheader
  %16 = getelementptr inbounds i8, ptr %.0, i64 8
  tail call void @_ZdlPvm(ptr noundef nonnull %12, i64 noundef 16) #3
  store ptr null, ptr %16, align 8, !tbaa !9
  %17 = load ptr, ptr %0, align 8, !tbaa !5
  br label %18

18:                                               ; preds = %15, %11, %4
  %.010 = phi ptr [ null, %4 ], [ null, %11 ], [ %17, %15 ]
  ret ptr %.010
}

attributes #0 = { 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 #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 = { 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 = { 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 = !{!"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"}


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