; LLVM IR from Leet-Us-Code/DSA-A-Z-Practice :: Sid's Levels/Level - 1/LinkedList/deleteLastNode.ll (Z14removeLastNodeP4Node)

; 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 }

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef ptr @_Z14removeLastNodeP4Node(ptr noundef %0) #0 {
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  store ptr %0, ptr %3, align 8, !tbaa !5
  %6 = load ptr, ptr %3, align 8, !tbaa !5
  %7 = icmp eq ptr %6, null
  br i1 %7, label %8, label %9

8:                                                ; preds = %1
  store ptr null, ptr %2, align 8
  br label %40

9:                                                ; preds = %1
  %10 = load ptr, ptr %3, align 8, !tbaa !5
  %11 = getelementptr inbounds %struct.Node, ptr %10, i32 0, i32 1
  %12 = load ptr, ptr %11, align 8, !tbaa !9
  %13 = icmp eq ptr %12, null
  br i1 %13, label %14, label %19

14:                                               ; preds = %9
  %15 = load ptr, ptr %3, align 8, !tbaa !5
  %16 = icmp eq ptr %15, null
  br i1 %16, label %18, label %17

17:                                               ; preds = %14
  call void @_ZdlPvm(ptr noundef %15, i64 noundef 16) #3
  br label %18

18:                                               ; preds = %17, %14
  store ptr null, ptr %2, align 8
  br label %40

19:                                               ; preds = %9
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #4
  %20 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %20, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #4
  %21 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %21, ptr %5, align 8, !tbaa !5
  br label %22

22:                                               ; preds = %27, %19
  %23 = load ptr, ptr %5, align 8, !tbaa !5
  %24 = getelementptr inbounds %struct.Node, ptr %23, i32 0, i32 1
  %25 = load ptr, ptr %24, align 8, !tbaa !9
  %26 = icmp ne ptr %25, null
  br i1 %26, label %27, label %32

27:                                               ; preds = %22
  %28 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %28, ptr %4, align 8, !tbaa !5
  %29 = load ptr, ptr %5, align 8, !tbaa !5
  %30 = getelementptr inbounds %struct.Node, ptr %29, i32 0, i32 1
  %31 = load ptr, ptr %30, align 8, !tbaa !9
  store ptr %31, ptr %5, align 8, !tbaa !5
  br label %22, !llvm.loop !12

32:                                               ; preds = %22
  %33 = load ptr, ptr %4, align 8, !tbaa !5
  %34 = getelementptr inbounds %struct.Node, ptr %33, i32 0, i32 1
  store ptr null, ptr %34, align 8, !tbaa !9
  %35 = load ptr, ptr %5, align 8, !tbaa !5
  %36 = icmp eq ptr %35, null
  br i1 %36, label %38, label %37

37:                                               ; preds = %32
  call void @_ZdlPvm(ptr noundef %35, i64 noundef 16) #3
  br label %38

38:                                               ; preds = %37, %32
  %39 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %39, ptr %2, align 8
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #4
  br label %40

40:                                               ; preds = %38, %18, %8
  %41 = load ptr, ptr %2, align 8
  ret ptr %41
}

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

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #2

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" }
attributes #1 = { 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 #2 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #3 = { builtin nounwind }
attributes #4 = { 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"

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef ptr @_Z14removeLastNodeP4Node(ptr noundef %0) local_unnamed_addr #0 {
  %2 = icmp eq ptr %0, null
  br i1 %2, label %11, label %3

3:                                                ; preds = %1
  %4 = getelementptr inbounds i8, ptr %0, i64 8
  %5 = load ptr, ptr %4, align 8, !tbaa !5
  %6 = icmp eq ptr %5, null
  br i1 %6, label %.sink.split, label %.preheader

.preheader:                                       ; preds = %3, %.preheader
  %.012 = phi ptr [ %.0, %.preheader ], [ %0, %3 ]
  %.0 = phi ptr [ %8, %.preheader ], [ %0, %3 ]
  %7 = getelementptr inbounds i8, ptr %.0, i64 8
  %8 = load ptr, ptr %7, align 8, !tbaa !5
  %.not = icmp eq ptr %8, null
  br i1 %.not, label %9, label %.preheader, !llvm.loop !11

9:                                                ; preds = %.preheader
  %10 = getelementptr inbounds i8, ptr %.012, i64 8
  store ptr null, ptr %10, align 8, !tbaa !5
  br label %.sink.split

.sink.split:                                      ; preds = %3, %9
  %.0.lcssa.sink = phi ptr [ %.0, %9 ], [ %0, %3 ]
  %.013.ph = phi ptr [ %0, %9 ], [ null, %3 ]
  tail call void @_ZdlPvm(ptr noundef nonnull %.0.lcssa.sink, i64 noundef 16) #2
  br label %11

11:                                               ; preds = %.sink.split, %1
  %.013 = phi ptr [ null, %1 ], [ %.013.ph, %.sink.split ]
  ret ptr %.013
}

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

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" }
attributes #1 = { 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 #2 = { 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, !10, i64 8}
!6 = !{!"_ZTS4Node", !7, i64 0, !10, i64 8}
!7 = !{!"int", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C++ TBAA"}
!10 = !{!"any pointer", !8, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}


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