; LLVM IR from wuzhouhui/leetcode :: 133_clone_graph (cloneGraph)

; 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.link_node = type { ptr, ptr }

@head = external hidden global ptr, align 8

; Function Attrs: nounwind uwtable
define dso_local ptr @cloneGraph(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 ne ptr %6, null
  br i1 %7, label %9, label %8

8:                                                ; preds = %1
  store ptr null, ptr %2, align 8
  br label %23

9:                                                ; preds = %1
  store ptr null, ptr @head, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #3
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #3
  %10 = load ptr, ptr %3, align 8, !tbaa !5
  %11 = call ptr @do_clone(ptr noundef %10)
  store ptr %11, ptr %5, align 8, !tbaa !5
  br label %12

12:                                               ; preds = %15, %9
  %13 = load ptr, ptr @head, align 8, !tbaa !5
  %14 = icmp ne ptr %13, null
  br i1 %14, label %15, label %21

15:                                               ; preds = %12
  %16 = load ptr, ptr @head, align 8, !tbaa !5
  store ptr %16, ptr %4, align 8, !tbaa !5
  %17 = load ptr, ptr @head, align 8, !tbaa !5
  %18 = getelementptr inbounds %struct.link_node, ptr %17, i32 0, i32 1
  %19 = load ptr, ptr %18, align 8, !tbaa !9
  store ptr %19, ptr @head, align 8, !tbaa !5
  %20 = load ptr, ptr %4, align 8, !tbaa !5
  call void @free(ptr noundef %20) #3
  br label %12, !llvm.loop !11

21:                                               ; preds = %12
  %22 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %22, ptr %2, align 8
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #3
  br label %23

23:                                               ; preds = %21, %8
  %24 = load ptr, ptr %2, align 8
  ret ptr %24
}

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

; Function Attrs: nounwind uwtable
declare hidden ptr @do_clone(ptr noundef) #0

; Function Attrs: nounwind
declare void @free(ptr noundef) #2

; 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 "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 = !{!"link_node", !6, i64 0, !6, i64 8}
!11 = distinct !{!11, !12}
!12 = !{!"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"

@head = external hidden local_unnamed_addr global ptr, align 8

; Function Attrs: nounwind uwtable
define dso_local ptr @cloneGraph(ptr noundef %0) local_unnamed_addr #0 {
  %.not = icmp eq ptr %0, null
  br i1 %.not, label %.loopexit, label %2

2:                                                ; preds = %1
  store ptr null, ptr @head, align 8, !tbaa !5
  %3 = tail call ptr @do_clone(ptr noundef nonnull %0)
  %4 = load ptr, ptr @head, align 8, !tbaa !5
  %.not78 = icmp eq ptr %4, null
  br i1 %.not78, label %.loopexit, label %.lr.ph

.lr.ph:                                           ; preds = %2, %.lr.ph
  %5 = phi ptr [ %8, %.lr.ph ], [ %4, %2 ]
  %6 = getelementptr inbounds i8, ptr %5, i64 8
  %7 = load ptr, ptr %6, align 8, !tbaa !9
  store ptr %7, ptr @head, align 8, !tbaa !5
  tail call void @free(ptr noundef nonnull %5) #2
  %8 = load ptr, ptr @head, align 8, !tbaa !5
  %.not7 = icmp eq ptr %8, null
  br i1 %.not7, label %.loopexit, label %.lr.ph, !llvm.loop !11

.loopexit:                                        ; preds = %.lr.ph, %2, %1
  %.0 = phi ptr [ null, %1 ], [ %3, %2 ], [ %3, %.lr.ph ]
  ret ptr %.0
}

; Function Attrs: nounwind uwtable
declare hidden ptr @do_clone(ptr noundef) local_unnamed_addr #0

; Function Attrs: mustprogress nounwind willreturn allockind("free") memory(argmem: readwrite, inaccessiblemem: readwrite)
declare void @free(ptr allocptr nocapture noundef) local_unnamed_addr #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 = { mustprogress nounwind willreturn allockind("free") memory(argmem: readwrite, 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 = { 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 = !{!"link_node", !6, i64 0, !6, i64 8}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}


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