; LLVM IR from devparthgarg/Data-Structures-and-Algorithms :: 11. Linked List/23 Circular Doubly Linked List (23 Circular Doubly Linked List)

; 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.Node = type { i32, ptr, ptr }

; Function Attrs: mustprogress uwtable
define dso_local noundef ptr @_Z12insertAtHeadRP4Nodei(ptr noundef nonnull align 8 dereferenceable(8) %0, i32 noundef %1) #0 personality ptr @__gxx_personality_v0 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca ptr, align 8
  %7 = alloca ptr, align 8
  %8 = alloca i32, align 4
  %9 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #5
  %10 = call noalias noundef nonnull ptr @_Znwm(i64 noundef 24) #6
  %11 = load i32, ptr %5, align 4, !tbaa !9
  invoke void @_ZN4NodeC2Ei(ptr noundef nonnull align 8 dereferenceable(24) %10, i32 noundef %11)
          to label %12 unwind label %24

12:                                               ; preds = %2
  store ptr %10, ptr %6, align 8, !tbaa !5
  %13 = load ptr, ptr %4, align 8, !tbaa !5
  %14 = load ptr, ptr %13, align 8, !tbaa !5
  %15 = icmp eq ptr %14, null
  br i1 %15, label %16, label %28

16:                                               ; preds = %12
  %17 = load ptr, ptr %6, align 8, !tbaa !5
  %18 = load ptr, ptr %6, align 8, !tbaa !5
  %19 = getelementptr inbounds %class.Node, ptr %18, i32 0, i32 2
  store ptr %17, ptr %19, align 8, !tbaa !11
  %20 = load ptr, ptr %6, align 8, !tbaa !5
  %21 = load ptr, ptr %6, align 8, !tbaa !5
  %22 = getelementptr inbounds %class.Node, ptr %21, i32 0, i32 1
  store ptr %20, ptr %22, align 8, !tbaa !13
  %23 = load ptr, ptr %6, align 8, !tbaa !5
  store ptr %23, ptr %3, align 8
  store i32 1, ptr %9, align 4
  br label %50

24:                                               ; preds = %2
  %25 = landingpad { ptr, i32 }
          cleanup
  %26 = extractvalue { ptr, i32 } %25, 0
  store ptr %26, ptr %7, align 8
  %27 = extractvalue { ptr, i32 } %25, 1
  store i32 %27, ptr %8, align 4
  call void @_ZdlPvm(ptr noundef %10, i64 noundef 24) #7
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #5
  br label %52

28:                                               ; preds = %12
  %29 = load ptr, ptr %4, align 8, !tbaa !5
  %30 = load ptr, ptr %29, align 8, !tbaa !5
  %31 = getelementptr inbounds %class.Node, ptr %30, i32 0, i32 1
  %32 = load ptr, ptr %31, align 8, !tbaa !13
  %33 = load ptr, ptr %6, align 8, !tbaa !5
  %34 = getelementptr inbounds %class.Node, ptr %33, i32 0, i32 1
  store ptr %32, ptr %34, align 8, !tbaa !13
  %35 = load ptr, ptr %4, align 8, !tbaa !5
  %36 = load ptr, ptr %35, align 8, !tbaa !5
  %37 = load ptr, ptr %6, align 8, !tbaa !5
  %38 = getelementptr inbounds %class.Node, ptr %37, i32 0, i32 2
  store ptr %36, ptr %38, align 8, !tbaa !11
  %39 = load ptr, ptr %6, align 8, !tbaa !5
  %40 = load ptr, ptr %4, align 8, !tbaa !5
  %41 = load ptr, ptr %40, align 8, !tbaa !5
  %42 = getelementptr inbounds %class.Node, ptr %41, i32 0, i32 1
  %43 = load ptr, ptr %42, align 8, !tbaa !13
  %44 = getelementptr inbounds %class.Node, ptr %43, i32 0, i32 2
  store ptr %39, ptr %44, align 8, !tbaa !11
  %45 = load ptr, ptr %6, align 8, !tbaa !5
  %46 = load ptr, ptr %4, align 8, !tbaa !5
  %47 = load ptr, ptr %46, align 8, !tbaa !5
  %48 = getelementptr inbounds %class.Node, ptr %47, i32 0, i32 1
  store ptr %45, ptr %48, align 8, !tbaa !13
  %49 = load ptr, ptr %6, align 8, !tbaa !5
  store ptr %49, ptr %3, align 8
  store i32 1, ptr %9, align 4
  br label %50

50:                                               ; preds = %28, %16
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #5
  %51 = load ptr, ptr %3, align 8
  ret ptr %51

52:                                               ; preds = %24
  %53 = load ptr, ptr %7, align 8
  %54 = load i32, ptr %8, align 4
  %55 = insertvalue { ptr, i32 } poison, ptr %53, 0
  %56 = insertvalue { ptr, i32 } %55, i32 %54, 1
  resume { ptr, i32 } %56
}

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

; Function Attrs: nobuiltin allocsize(0)
declare noundef nonnull ptr @_Znwm(i64 noundef) #2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_ZN4NodeC2Ei(ptr noundef nonnull align 8 dereferenceable(24), i32 noundef) unnamed_addr #3 align 2

declare i32 @__gxx_personality_v0(...)

; Function Attrs: nobuiltin nounwind
declare void @_ZdlPvm(ptr noundef, i64 noundef) #4

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

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 = { 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 #3 = { 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 #4 = { 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 #5 = { nounwind }
attributes #6 = { builtin allocsize(0) }
attributes #7 = { 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, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = !{!12, !6, i64 16}
!12 = !{!"_ZTS4Node", !10, i64 0, !6, i64 8, !6, i64 16}
!13 = !{!12, !6, i64 8}


; 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"

; Function Attrs: mustprogress uwtable
define dso_local noundef nonnull ptr @_Z12insertAtHeadRP4Nodei(ptr nocapture noundef nonnull readonly align 8 dereferenceable(8) %0, i32 noundef %1) local_unnamed_addr #0 personality ptr @__gxx_personality_v0 {
  %3 = tail call noalias noundef nonnull dereferenceable(24) ptr @_Znwm(i64 noundef 24) #3
  tail call void @_ZN4NodeC2Ei(ptr noundef nonnull align 8 dereferenceable(24) %3, i32 noundef %1)
  %4 = load ptr, ptr %0, align 8, !tbaa !5
  %5 = icmp eq ptr %4, null
  %6 = getelementptr inbounds i8, ptr %3, i64 8
  br i1 %5, label %7, label %9

7:                                                ; preds = %2
  %8 = getelementptr inbounds i8, ptr %3, i64 16
  store ptr %3, ptr %8, align 8, !tbaa !9
  br label %16

9:                                                ; preds = %2
  %10 = getelementptr inbounds i8, ptr %4, i64 8
  %11 = load ptr, ptr %10, align 8, !tbaa !12
  store ptr %11, ptr %6, align 8, !tbaa !12
  %12 = getelementptr inbounds i8, ptr %3, i64 16
  store ptr %4, ptr %12, align 8, !tbaa !9
  %13 = getelementptr inbounds i8, ptr %11, i64 16
  store ptr %3, ptr %13, align 8, !tbaa !9
  %14 = load ptr, ptr %0, align 8, !tbaa !5
  %15 = getelementptr inbounds i8, ptr %14, i64 8
  br label %16

16:                                               ; preds = %9, %7
  %.sink = phi ptr [ %15, %9 ], [ %6, %7 ]
  store ptr %3, ptr %.sink, align 8, !tbaa !12
  ret ptr %3
}

; Function Attrs: nobuiltin allocsize(0)
declare noundef nonnull ptr @_Znwm(i64 noundef) local_unnamed_addr #1

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_ZN4NodeC2Ei(ptr noundef nonnull align 8 dereferenceable(24), i32 noundef) unnamed_addr #2 align 2

declare i32 @__gxx_personality_v0(...)

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 = { 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 #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 = { 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, !6, i64 16}
!10 = !{!"_ZTS4Node", !11, i64 0, !6, i64 8, !6, i64 16}
!11 = !{!"int", !7, i64 0}
!12 = !{!10, !6, i64 8}


; Effective O3 passes: EarlyCSEPass,GVNPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass