; LLVM IR from mahendramahara/DSA-in-C-Programing :: DOUBLY-LINKED-LIST (BeginDeleteDoublyLinkedList)

; 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"

%struct.Node = type { i32, ptr, ptr }

@head = external dso_local global ptr, align 8
@.str = external hidden unnamed_addr constant [28 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [17 x i8], align 1

; Function Attrs: nounwind uwtable
define dso_local void @insert(i32 noundef %0) #0 {
  %2 = alloca i32, align 4
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  store i32 %0, ptr %2, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #4
  %5 = call noalias ptr @malloc(i64 noundef 24) #5
  store ptr %5, ptr %3, align 8, !tbaa !9
  %6 = load ptr, ptr %3, align 8, !tbaa !9
  %7 = icmp eq ptr %6, null
  br i1 %7, label %8, label %10

8:                                                ; preds = %1
  %9 = call i32 (ptr, ...) @printf(ptr noundef @.str)
  store i32 1, ptr %4, align 4
  br label %28

10:                                               ; preds = %1
  %11 = load i32, ptr %2, align 4, !tbaa !5
  %12 = load ptr, ptr %3, align 8, !tbaa !9
  %13 = getelementptr inbounds %struct.Node, ptr %12, i32 0, i32 0
  store i32 %11, ptr %13, align 8, !tbaa !11
  %14 = load ptr, ptr %3, align 8, !tbaa !9
  %15 = getelementptr inbounds %struct.Node, ptr %14, i32 0, i32 2
  store ptr null, ptr %15, align 8, !tbaa !13
  %16 = load ptr, ptr @head, align 8, !tbaa !9
  %17 = load ptr, ptr %3, align 8, !tbaa !9
  %18 = getelementptr inbounds %struct.Node, ptr %17, i32 0, i32 1
  store ptr %16, ptr %18, align 8, !tbaa !14
  %19 = load ptr, ptr @head, align 8, !tbaa !9
  %20 = icmp ne ptr %19, null
  br i1 %20, label %21, label %25

21:                                               ; preds = %10
  %22 = load ptr, ptr %3, align 8, !tbaa !9
  %23 = load ptr, ptr @head, align 8, !tbaa !9
  %24 = getelementptr inbounds %struct.Node, ptr %23, i32 0, i32 2
  store ptr %22, ptr %24, align 8, !tbaa !13
  br label %25

25:                                               ; preds = %21, %10
  %26 = load ptr, ptr %3, align 8, !tbaa !9
  store ptr %26, ptr @head, align 8, !tbaa !9
  %27 = call i32 (ptr, ...) @printf(ptr noundef @.str.1)
  store i32 0, ptr %4, align 4
  br label %28

28:                                               ; preds = %25, %8
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #4
  %29 = load i32, ptr %4, align 4
  switch i32 %29, label %31 [
    i32 0, label %30
    i32 1, label %30
  ]

30:                                               ; preds = %28, %28
  ret void

31:                                               ; preds = %28
  unreachable
}

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

; Function Attrs: nounwind allocsize(0)
declare noalias ptr @malloc(i64 noundef) #2

declare i32 @printf(ptr noundef, ...) #3

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

attributes #0 = { 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 #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { nounwind 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 = { "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 }
attributes #5 = { nounwind 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/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !7, i64 0}
!11 = !{!12, !6, i64 0}
!12 = !{!"Node", !6, i64 0, !10, i64 8, !10, i64 16}
!13 = !{!12, !10, i64 16}
!14 = !{!12, !10, 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"

@head = external dso_local local_unnamed_addr global ptr, align 8
@.str = external hidden unnamed_addr constant [28 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [17 x i8], align 1

; Function Attrs: nofree nounwind uwtable
define dso_local void @insert(i32 noundef %0) local_unnamed_addr #0 {
  %2 = tail call noalias dereferenceable_or_null(24) ptr @malloc(i64 noundef 24) #3
  %3 = icmp eq ptr %2, null
  br i1 %3, label %11, label %4

4:                                                ; preds = %1
  store i32 %0, ptr %2, align 8, !tbaa !5
  %5 = getelementptr inbounds i8, ptr %2, i64 16
  store ptr null, ptr %5, align 8, !tbaa !11
  %6 = load ptr, ptr @head, align 8, !tbaa !12
  %7 = getelementptr inbounds i8, ptr %2, i64 8
  store ptr %6, ptr %7, align 8, !tbaa !13
  %.not = icmp eq ptr %6, null
  br i1 %.not, label %10, label %8

8:                                                ; preds = %4
  %9 = getelementptr inbounds i8, ptr %6, i64 16
  store ptr %2, ptr %9, align 8, !tbaa !11
  br label %10

10:                                               ; preds = %8, %4
  store ptr %2, ptr @head, align 8, !tbaa !12
  br label %11

11:                                               ; preds = %1, %10
  %.str.1.sink = phi ptr [ @.str.1, %10 ], [ @.str, %1 ]
  %12 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) %.str.1.sink)
  ret void
}

; Function Attrs: mustprogress nofree nounwind willreturn allockind("alloc,uninitialized") allocsize(0) memory(inaccessiblemem: readwrite)
declare noalias noundef ptr @malloc(i64 noundef) local_unnamed_addr #1

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #2

attributes #0 = { nofree 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 #1 = { mustprogress nofree nounwind willreturn allockind("alloc,uninitialized") allocsize(0) memory(inaccessiblemem: readwrite) "alloc-family"="malloc" "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 = { nofree 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 #3 = { nounwind 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, !7, i64 0}
!6 = !{!"Node", !7, i64 0, !10, i64 8, !10, i64 16}
!7 = !{!"int", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C/C++ TBAA"}
!10 = !{!"any pointer", !8, i64 0}
!11 = !{!6, !10, i64 16}
!12 = !{!10, !10, i64 0}
!13 = !{!6, !10, i64 8}


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