; LLVM IR from JessonYue/LeetCodeLearning :: Array/linchuanxin/Algorithm/day25_0625_环路检测 (day25_leetcode_interview28)

; 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.ListNode = type { i32, ptr }

; Function Attrs: nounwind uwtable
define dso_local ptr @detectCycle(ptr noundef %0) #0 {
  %2 = alloca ptr, align 8
  %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
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #2
  %7 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %7, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #2
  %8 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %8, ptr %5, align 8, !tbaa !5
  br label %9

9:                                                ; preds = %33, %1
  %10 = load ptr, ptr %4, align 8, !tbaa !5
  %11 = icmp ne ptr %10, null
  br i1 %11, label %12, label %34

12:                                               ; preds = %9
  %13 = load ptr, ptr %4, align 8, !tbaa !5
  %14 = getelementptr inbounds %struct.ListNode, ptr %13, i32 0, i32 1
  %15 = load ptr, ptr %14, align 8, !tbaa !9
  store ptr %15, ptr %4, align 8, !tbaa !5
  %16 = load ptr, ptr %4, align 8, !tbaa !5
  %17 = icmp ne ptr %16, null
  br i1 %17, label %18, label %28

18:                                               ; preds = %12
  %19 = load ptr, ptr %5, align 8, !tbaa !5
  %20 = icmp ne ptr %19, null
  br i1 %20, label %21, label %28

21:                                               ; preds = %18
  %22 = load ptr, ptr %4, align 8, !tbaa !5
  %23 = getelementptr inbounds %struct.ListNode, ptr %22, i32 0, i32 1
  %24 = load ptr, ptr %23, align 8, !tbaa !9
  store ptr %24, ptr %4, align 8, !tbaa !5
  %25 = load ptr, ptr %5, align 8, !tbaa !5
  %26 = getelementptr inbounds %struct.ListNode, ptr %25, i32 0, i32 1
  %27 = load ptr, ptr %26, align 8, !tbaa !9
  store ptr %27, ptr %5, align 8, !tbaa !5
  br label %28

28:                                               ; preds = %21, %18, %12
  %29 = load ptr, ptr %4, align 8, !tbaa !5
  %30 = load ptr, ptr %5, align 8, !tbaa !5
  %31 = icmp eq ptr %29, %30
  br i1 %31, label %32, label %33

32:                                               ; preds = %28
  br label %34

33:                                               ; preds = %28
  br label %9, !llvm.loop !12

34:                                               ; preds = %32, %9
  %35 = load ptr, ptr %4, align 8, !tbaa !5
  %36 = load ptr, ptr %5, align 8, !tbaa !5
  %37 = icmp ne ptr %35, %36
  br i1 %37, label %38, label %39

38:                                               ; preds = %34
  store ptr null, ptr %2, align 8
  store i32 1, ptr %6, align 4
  br label %54

39:                                               ; preds = %34
  %40 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %40, ptr %4, align 8, !tbaa !5
  br label %41

41:                                               ; preds = %45, %39
  %42 = load ptr, ptr %4, align 8, !tbaa !5
  %43 = load ptr, ptr %5, align 8, !tbaa !5
  %44 = icmp ne ptr %42, %43
  br i1 %44, label %45, label %52

45:                                               ; preds = %41
  %46 = load ptr, ptr %4, align 8, !tbaa !5
  %47 = getelementptr inbounds %struct.ListNode, ptr %46, i32 0, i32 1
  %48 = load ptr, ptr %47, align 8, !tbaa !9
  store ptr %48, ptr %4, align 8, !tbaa !5
  %49 = load ptr, ptr %5, align 8, !tbaa !5
  %50 = getelementptr inbounds %struct.ListNode, ptr %49, i32 0, i32 1
  %51 = load ptr, ptr %50, align 8, !tbaa !9
  store ptr %51, ptr %5, align 8, !tbaa !5
  br label %41, !llvm.loop !14

52:                                               ; preds = %41
  %53 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %53, ptr %2, align 8
  store i32 1, ptr %6, align 4
  br label %54

54:                                               ; preds = %52, %38
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #2
  %55 = load ptr, ptr %2, align 8
  ret ptr %55
}

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

; 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 }

!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 = !{!"ListNode", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}
!14 = distinct !{!14, !13}


; 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(read, inaccessiblemem: none) uwtable
define dso_local ptr @detectCycle(ptr noundef readonly %0) local_unnamed_addr #0 {
  %.old2.not = icmp eq ptr %0, null
  br i1 %.old2.not, label %.preheader, label %.preheader31

.preheader31:                                     ; preds = %1, %11
  %.022 = phi ptr [ %.123, %11 ], [ %0, %1 ]
  %.0 = phi ptr [ %.1, %11 ], [ %0, %1 ]
  %2 = getelementptr inbounds i8, ptr %.022, i64 8
  %3 = load ptr, ptr %2, align 8, !tbaa !5
  %4 = icmp ne ptr %3, null
  %5 = icmp ne ptr %.0, null
  %or.cond = and i1 %5, %4
  br i1 %or.cond, label %6, label %11

6:                                                ; preds = %.preheader31
  %7 = getelementptr inbounds i8, ptr %3, i64 8
  %8 = load ptr, ptr %7, align 8, !tbaa !5
  %9 = getelementptr inbounds i8, ptr %.0, i64 8
  %10 = load ptr, ptr %9, align 8, !tbaa !5
  br label %11

11:                                               ; preds = %6, %.preheader31
  %.123 = phi ptr [ %8, %6 ], [ %3, %.preheader31 ]
  %.1 = phi ptr [ %10, %6 ], [ %.0, %.preheader31 ]
  %12 = icmp ne ptr %.123, %.1
  %13 = icmp ne ptr %.123, null
  %or.cond3 = and i1 %13, %12
  br i1 %or.cond3, label %.preheader31, label %.loopexit32, !llvm.loop !11

.loopexit32:                                      ; preds = %11
  %.not = icmp eq ptr %.123, %.1
  br i1 %.not, label %.preheader, label %.loopexit

.preheader:                                       ; preds = %1, %.loopexit32
  %.240 = phi ptr [ %.1, %.loopexit32 ], [ null, %1 ]
  %.22439 = phi ptr [ %.123, %.loopexit32 ], [ null, %1 ]
  %.not3033 = icmp eq ptr %.22439, %0
  br i1 %.not3033, label %.loopexit, label %.lr.ph

.lr.ph:                                           ; preds = %.preheader, %.lr.ph
  %.335 = phi ptr [ %17, %.lr.ph ], [ %.240, %.preheader ]
  %.32534 = phi ptr [ %15, %.lr.ph ], [ %0, %.preheader ]
  %14 = getelementptr inbounds i8, ptr %.32534, i64 8
  %15 = load ptr, ptr %14, align 8, !tbaa !5
  %16 = getelementptr inbounds i8, ptr %.335, i64 8
  %17 = load ptr, ptr %16, align 8, !tbaa !5
  %.not30 = icmp eq ptr %15, %17
  br i1 %.not30, label %.loopexit, label %.lr.ph, !llvm.loop !13

.loopexit:                                        ; preds = %.lr.ph, %.preheader, %.loopexit32
  %.026 = phi ptr [ null, %.loopexit32 ], [ %0, %.preheader ], [ %15, %.lr.ph ]
  ret ptr %.026
}

attributes #0 = { nofree norecurse nosync nounwind memory(read, 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, !10, i64 8}
!6 = !{!"ListNode", !7, i64 0, !10, i64 8}
!7 = !{!"int", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C/C++ TBAA"}
!10 = !{!"any pointer", !8, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}
!13 = distinct !{!13, !12}


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