; LLVM IR from div-bargali/Data-Structures-and-Algorithms :: C++/Data-Structures/LinkedList/DoublyLinkedList.ll (Z9deleteposPP4Nodei)

; 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 }

; 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: mustprogress nounwind uwtable
declare dso_local void @_Z10deleteNodePP4NodeS0_(ptr noundef, ptr noundef) #1

; Function Attrs: mustprogress nounwind uwtable
define dso_local void @_Z9deleteposPP4Nodei(ptr noundef %0, i32 noundef %1) #1 {
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = alloca ptr, align 8
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  %8 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !9
  %9 = load ptr, ptr %3, align 8, !tbaa !5
  %10 = load ptr, ptr %9, align 8, !tbaa !5
  %11 = icmp eq ptr %10, null
  br i1 %11, label %15, label %12

12:                                               ; preds = %2
  %13 = load i32, ptr %4, align 4, !tbaa !9
  %14 = icmp sle i32 %13, 0
  br i1 %14, label %15, label %16

15:                                               ; preds = %12, %2
  br label %45

16:                                               ; preds = %12
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #2
  %17 = load ptr, ptr %3, align 8, !tbaa !5
  %18 = load ptr, ptr %17, align 8, !tbaa !5
  store ptr %18, ptr %5, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #2
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #2
  store i32 1, ptr %7, align 4, !tbaa !9
  br label %19

19:                                               ; preds = %33, %16
  %20 = load ptr, ptr %5, align 8, !tbaa !5
  %21 = icmp ne ptr %20, null
  br i1 %21, label %22, label %26

22:                                               ; preds = %19
  %23 = load i32, ptr %7, align 4, !tbaa !9
  %24 = load i32, ptr %4, align 4, !tbaa !9
  %25 = icmp slt i32 %23, %24
  br label %26

26:                                               ; preds = %22, %19
  %27 = phi i1 [ false, %19 ], [ %25, %22 ]
  br i1 %27, label %29, label %28

28:                                               ; preds = %26
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #2
  br label %36

29:                                               ; preds = %26
  %30 = load ptr, ptr %5, align 8, !tbaa !5
  %31 = getelementptr inbounds %struct.Node, ptr %30, i32 0, i32 1
  %32 = load ptr, ptr %31, align 8, !tbaa !11
  store ptr %32, ptr %5, align 8, !tbaa !5
  br label %33

33:                                               ; preds = %29
  %34 = load i32, ptr %7, align 4, !tbaa !9
  %35 = add nsw i32 %34, 1
  store i32 %35, ptr %7, align 4, !tbaa !9
  br label %19, !llvm.loop !13

36:                                               ; preds = %28
  %37 = load ptr, ptr %5, align 8, !tbaa !5
  %38 = icmp eq ptr %37, null
  br i1 %38, label %39, label %40

39:                                               ; preds = %36
  store i32 1, ptr %8, align 4
  br label %43

40:                                               ; preds = %36
  %41 = load ptr, ptr %3, align 8, !tbaa !5
  %42 = load ptr, ptr %5, align 8, !tbaa !5
  call void @_Z10deleteNodePP4NodeS0_(ptr noundef %41, ptr noundef %42)
  store i32 0, ptr %8, align 4
  br label %43

43:                                               ; preds = %40, %39
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #2
  %44 = load i32, ptr %8, align 4
  switch i32 %44, label %46 [
    i32 0, label %45
    i32 1, label %45
  ]

45:                                               ; preds = %43, %43, %15
  ret void

46:                                               ; preds = %43
  unreachable
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 #2 = { 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 8}
!12 = !{!"_ZTS4Node", !10, i64 0, !6, i64 8, !6, i64 16}
!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"

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_Z10deleteNodePP4NodeS0_(ptr noundef, ptr noundef) local_unnamed_addr #0

; Function Attrs: mustprogress nounwind uwtable
define dso_local void @_Z9deleteposPP4Nodei(ptr noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = load ptr, ptr %0, align 8, !tbaa !5
  %4 = icmp eq ptr %3, null
  %5 = icmp slt i32 %1, 1
  %or.cond = or i1 %5, %4
  br i1 %or.cond, label %14, label %.preheader

.preheader:                                       ; preds = %2
  %6 = icmp ugt i32 %1, 1
  br i1 %6, label %.lr.ph, label %._crit_edge.thread

._crit_edge:                                      ; preds = %.lr.ph
  %7 = icmp eq ptr %9, null
  br i1 %7, label %14, label %._crit_edge.thread

.lr.ph:                                           ; preds = %.preheader, %.lr.ph
  %.015 = phi i32 [ %10, %.lr.ph ], [ 1, %.preheader ]
  %.01114 = phi ptr [ %9, %.lr.ph ], [ %3, %.preheader ]
  %8 = getelementptr inbounds i8, ptr %.01114, i64 8
  %9 = load ptr, ptr %8, align 8, !tbaa !9
  %10 = add nuw nsw i32 %.015, 1
  %11 = icmp ne ptr %9, null
  %12 = icmp slt i32 %10, %1
  %13 = select i1 %11, i1 %12, i1 false
  br i1 %13, label %.lr.ph, label %._crit_edge, !llvm.loop !12

._crit_edge.thread:                               ; preds = %.preheader, %._crit_edge
  %.011.lcssa17 = phi ptr [ %9, %._crit_edge ], [ %3, %.preheader ]
  tail call void @_Z10deleteNodePP4NodeS0_(ptr noundef nonnull %0, ptr noundef nonnull %.011.lcssa17)
  br label %14

14:                                               ; preds = %._crit_edge.thread, %._crit_edge, %2
  ret void
}

attributes #0 = { 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" }

!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, !6, i64 16}
!11 = !{!"int", !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}


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