; LLVM IR from ritikbanger/Hacktoberfest2022-DSA :: 10. Linked List/c lang/CircularDoublyLinkedList (Deleting)

; 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 }

@start = external dso_local global ptr, align 8
@.str = external hidden unnamed_addr constant [12 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [6 x i8], align 1
@.str.2 = external hidden unnamed_addr constant [7 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: nounwind uwtable
define dso_local void @display() #1 {
  %1 = alloca ptr, align 8
  %2 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 8, ptr %1) #3
  %3 = load ptr, ptr @start, align 8, !tbaa !5
  store ptr %3, ptr %1, align 8, !tbaa !5
  %4 = call i32 (ptr, ...) @printf(ptr noundef @.str)
  br label %5

5:                                                ; preds = %11, %0
  %6 = load ptr, ptr %1, align 8, !tbaa !5
  %7 = getelementptr inbounds %struct.node, ptr %6, i32 0, i32 2
  %8 = load ptr, ptr %7, align 8, !tbaa !9
  %9 = load ptr, ptr @start, align 8, !tbaa !5
  %10 = icmp ne ptr %8, %9
  br i1 %10, label %11, label %19

11:                                               ; preds = %5
  %12 = load ptr, ptr %1, align 8, !tbaa !5
  %13 = getelementptr inbounds %struct.node, ptr %12, i32 0, i32 0
  %14 = load i32, ptr %13, align 8, !tbaa !12
  %15 = call i32 (ptr, ...) @printf(ptr noundef @.str.1, i32 noundef %14)
  %16 = load ptr, ptr %1, align 8, !tbaa !5
  %17 = getelementptr inbounds %struct.node, ptr %16, i32 0, i32 2
  %18 = load ptr, ptr %17, align 8, !tbaa !9
  store ptr %18, ptr %1, align 8, !tbaa !5
  br label %5, !llvm.loop !13

19:                                               ; preds = %5
  %20 = load ptr, ptr %1, align 8, !tbaa !5
  %21 = getelementptr inbounds %struct.node, ptr %20, i32 0, i32 0
  %22 = load i32, ptr %21, align 8, !tbaa !12
  %23 = icmp eq i32 %22, 0
  br i1 %23, label %24, label %26

24:                                               ; preds = %19
  %25 = call i32 (ptr, ...) @printf(ptr noundef @.str.2)
  store i32 1, ptr %2, align 4
  br label %32

26:                                               ; preds = %19
  %27 = load ptr, ptr %1, align 8, !tbaa !5
  %28 = getelementptr inbounds %struct.node, ptr %27, i32 0, i32 0
  %29 = load i32, ptr %28, align 8, !tbaa !12
  %30 = call i32 (ptr, ...) @printf(ptr noundef @.str.1, i32 noundef %29)
  %31 = call i32 (ptr, ...) @printf(ptr noundef @.str.2)
  store i32 0, ptr %2, align 4
  br label %32

32:                                               ; preds = %26, %24
  call void @llvm.lifetime.end.p0(i64 8, ptr %1) #3
  %33 = load i32, ptr %2, align 4
  switch i32 %33, label %35 [
    i32 0, label %34
    i32 1, label %34
  ]

34:                                               ; preds = %32, %32
  ret void

35:                                               ; preds = %32
  unreachable
}

declare i32 @printf(ptr noundef, ...) #2

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

@start = external dso_local local_unnamed_addr global ptr, align 8
@.str = external hidden unnamed_addr constant [12 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [6 x i8], align 1
@.str.2 = external hidden unnamed_addr constant [7 x i8], align 1

; Function Attrs: nofree nounwind uwtable
define dso_local void @display() local_unnamed_addr #0 {
  %1 = load ptr, ptr @start, align 8, !tbaa !5
  %2 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str)
  %3 = getelementptr inbounds i8, ptr %1, i64 16
  %4 = load ptr, ptr %3, align 8, !tbaa !9
  %5 = load ptr, ptr @start, align 8, !tbaa !5
  %.not6 = icmp eq ptr %4, %5
  br i1 %.not6, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %0, %.lr.ph
  %6 = phi ptr [ %10, %.lr.ph ], [ %3, %0 ]
  %.07 = phi ptr [ %9, %.lr.ph ], [ %1, %0 ]
  %7 = load i32, ptr %.07, align 8, !tbaa !12
  %8 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.1, i32 noundef %7)
  %9 = load ptr, ptr %6, align 8, !tbaa !9
  %10 = getelementptr inbounds i8, ptr %9, i64 16
  %11 = load ptr, ptr %10, align 8, !tbaa !9
  %12 = load ptr, ptr @start, align 8, !tbaa !5
  %.not = icmp eq ptr %11, %12
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !13

._crit_edge:                                      ; preds = %.lr.ph, %0
  %.0.lcssa = phi ptr [ %1, %0 ], [ %9, %.lr.ph ]
  %13 = load i32, ptr %.0.lcssa, align 8, !tbaa !12
  %14 = icmp eq i32 %13, 0
  br i1 %14, label %17, label %15

15:                                               ; preds = %._crit_edge
  %16 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.1, i32 noundef %13)
  br label %17

17:                                               ; preds = %._crit_edge, %15
  %18 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.2)
  ret void
}

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #1

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 = { 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" }

!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/C++ TBAA"}
!9 = !{!10, !6, i64 16}
!10 = !{!"node", !11, i64 0, !6, i64 8, !6, i64 16}
!11 = !{!"int", !7, i64 0}
!12 = !{!10, !11, i64 0}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}


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