; LLVM IR from gargarchit/Data_Structure_n_Algorithms :: Linked_List (6_Append)

; 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: 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
declare void @free(ptr noundef) #1

; Function Attrs: nounwind uwtable
define dso_local void @Append(ptr noundef %0, ptr noundef %1) #2 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  store ptr %1, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #3
  %7 = load ptr, ptr %3, align 8, !tbaa !5
  %8 = load ptr, ptr %7, align 8, !tbaa !5
  %9 = icmp eq ptr %8, null
  br i1 %9, label %10, label %14

10:                                               ; preds = %2
  %11 = load ptr, ptr %4, align 8, !tbaa !5
  %12 = load ptr, ptr %11, align 8, !tbaa !5
  %13 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %12, ptr %13, align 8, !tbaa !5
  store i32 1, ptr %6, align 4
  br label %35

14:                                               ; preds = %2
  %15 = load ptr, ptr %3, align 8, !tbaa !5
  %16 = load ptr, ptr %15, align 8, !tbaa !5
  store ptr %16, ptr %5, align 8, !tbaa !5
  br label %17

17:                                               ; preds = %22, %14
  %18 = load ptr, ptr %5, align 8, !tbaa !5
  %19 = getelementptr inbounds %struct.node, ptr %18, i32 0, i32 1
  %20 = load ptr, ptr %19, align 8, !tbaa !9
  %21 = icmp ne ptr %20, null
  br i1 %21, label %22, label %26

22:                                               ; preds = %17
  %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
  store ptr %25, ptr %5, align 8, !tbaa !5
  br label %17, !llvm.loop !12

26:                                               ; preds = %17
  %27 = load ptr, ptr %4, align 8, !tbaa !5
  %28 = load ptr, ptr %27, align 8, !tbaa !5
  %29 = load ptr, ptr %5, align 8, !tbaa !5
  %30 = getelementptr inbounds %struct.node, ptr %29, i32 0, i32 1
  store ptr %28, ptr %30, align 8, !tbaa !9
  %31 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr null, ptr %31, align 8, !tbaa !5
  %32 = load ptr, ptr %4, align 8, !tbaa !5
  %33 = load ptr, ptr %32, align 8, !tbaa !5
  call void @free(ptr noundef %33) #3
  br label %34

34:                                               ; preds = %26
  store i32 0, ptr %6, align 4
  br label %35

35:                                               ; preds = %34, %10
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #3
  %36 = load i32, ptr %6, align 4
  switch i32 %36, label %38 [
    i32 0, label %37
    i32 1, label %37
  ]

37:                                               ; preds = %35, %35
  ret void

38:                                               ; preds = %35
  unreachable
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 = { 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 = { 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 8}
!10 = !{!"node", !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: nofree norecurse nosync nounwind memory(readwrite, inaccessiblemem: none) uwtable
define dso_local void @Append(ptr nocapture noundef %0, ptr nocapture noundef %1) local_unnamed_addr #0 {
  %3 = load ptr, ptr %0, align 8, !tbaa !5
  %4 = icmp eq ptr %3, null
  br i1 %4, label %5, label %.preheader

5:                                                ; preds = %2
  %6 = load ptr, ptr %1, align 8, !tbaa !5
  store ptr %6, ptr %0, align 8, !tbaa !5
  br label %12

.preheader:                                       ; preds = %2, %.preheader
  %.0 = phi ptr [ %8, %.preheader ], [ %3, %2 ]
  %7 = getelementptr inbounds i8, ptr %.0, i64 8
  %8 = load ptr, ptr %7, align 8, !tbaa !9
  %.not = icmp eq ptr %8, null
  br i1 %.not, label %9, label %.preheader, !llvm.loop !12

9:                                                ; preds = %.preheader
  %10 = getelementptr inbounds i8, ptr %.0, i64 8
  %11 = load ptr, ptr %1, align 8, !tbaa !5
  store ptr %11, ptr %10, align 8, !tbaa !9
  store ptr null, ptr %1, align 8, !tbaa !5
  br label %12

12:                                               ; preds = %9, %5
  ret void
}

attributes #0 = { nofree norecurse nosync nounwind memory(readwrite, inaccessiblemem: none) 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/C++ TBAA"}
!9 = !{!10, !6, i64 8}
!10 = !{!"node", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}


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