; LLVM IR from JessonYue/LeetCodeLearning :: Array/linchuanxin/Algorithm/day33_0703_面试题_02_08_环路检测 (detectCycle)

; 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 = %30, %1
  %10 = load ptr, ptr %4, align 8, !tbaa !5
  %11 = icmp ne ptr %10, null
  br i1 %11, label %12, label %31

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 %25

18:                                               ; preds = %12
  %19 = load ptr, ptr %4, align 8, !tbaa !5
  %20 = getelementptr inbounds %struct.ListNode, ptr %19, i32 0, i32 1
  %21 = load ptr, ptr %20, align 8, !tbaa !9
  store ptr %21, ptr %4, align 8, !tbaa !5
  %22 = load ptr, ptr %5, 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 %5, align 8, !tbaa !5
  br label %25

25:                                               ; preds = %18, %12
  %26 = load ptr, ptr %4, align 8, !tbaa !5
  %27 = load ptr, ptr %5, align 8, !tbaa !5
  %28 = icmp eq ptr %26, %27
  br i1 %28, label %29, label %30

29:                                               ; preds = %25
  br label %31

30:                                               ; preds = %25
  br label %9, !llvm.loop !12

31:                                               ; preds = %29, %9
  %32 = load ptr, ptr %4, align 8, !tbaa !5
  %33 = load ptr, ptr %5, align 8, !tbaa !5
  %34 = icmp ne ptr %32, %33
  br i1 %34, label %35, label %36

35:                                               ; preds = %31
  store ptr null, ptr %2, align 8
  store i32 1, ptr %6, align 4
  br label %51

36:                                               ; preds = %31
  %37 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %37, ptr %4, align 8, !tbaa !5
  br label %38

38:                                               ; preds = %42, %36
  %39 = load ptr, ptr %4, align 8, !tbaa !5
  %40 = load ptr, ptr %5, align 8, !tbaa !5
  %41 = icmp ne ptr %39, %40
  br i1 %41, label %42, label %49

42:                                               ; preds = %38
  %43 = load ptr, ptr %4, align 8, !tbaa !5
  %44 = getelementptr inbounds %struct.ListNode, ptr %43, i32 0, i32 1
  %45 = load ptr, ptr %44, align 8, !tbaa !9
  store ptr %45, ptr %4, align 8, !tbaa !5
  %46 = load ptr, ptr %5, 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 %5, align 8, !tbaa !5
  br label %38, !llvm.loop !14

49:                                               ; preds = %38
  %50 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %50, ptr %2, align 8
  store i32 1, ptr %6, align 4
  br label %51

51:                                               ; preds = %49, %35
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #2
  %52 = load ptr, ptr %2, align 8
  ret ptr %52
}

; 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 {
  %.old1.not = icmp eq ptr %0, null
  br i1 %.old1.not, label %.preheader, label %.preheader33

.preheader33:                                     ; preds = %1, %4
  %.019 = phi ptr [ %6, %4 ], [ %0, %1 ]
  %.0 = phi ptr [ %8, %4 ], [ %0, %1 ]
  %2 = getelementptr inbounds i8, ptr %.019, i64 8
  %3 = load ptr, ptr %2, align 8, !tbaa !5
  %.not = icmp eq ptr %3, null
  br i1 %.not, label %.thread, label %4

4:                                                ; preds = %.preheader33
  %5 = getelementptr inbounds i8, ptr %3, i64 8
  %6 = load ptr, ptr %5, align 8, !tbaa !5
  %7 = getelementptr inbounds i8, ptr %.0, i64 8
  %8 = load ptr, ptr %7, align 8, !tbaa !5
  %9 = icmp ne ptr %6, %8
  %10 = icmp ne ptr %6, null
  %or.cond = and i1 %10, %9
  br i1 %or.cond, label %.preheader33, label %.thread, !llvm.loop !11

.thread:                                          ; preds = %.preheader33, %4
  %.221 = phi ptr [ %6, %4 ], [ null, %.preheader33 ]
  %.2 = phi ptr [ %8, %4 ], [ %.0, %.preheader33 ]
  %.not28 = icmp eq ptr %.221, %.2
  br i1 %.not28, label %.preheader, label %.loopexit

.preheader:                                       ; preds = %1, %.thread
  %.241 = phi ptr [ %.2, %.thread ], [ null, %1 ]
  %.22140 = phi ptr [ %.221, %.thread ], [ null, %1 ]
  %.not2934 = icmp eq ptr %.22140, %0
  br i1 %.not2934, label %.loopexit, label %.lr.ph

.lr.ph:                                           ; preds = %.preheader, %.lr.ph
  %.336 = phi ptr [ %14, %.lr.ph ], [ %.241, %.preheader ]
  %.32235 = phi ptr [ %12, %.lr.ph ], [ %0, %.preheader ]
  %11 = getelementptr inbounds i8, ptr %.32235, i64 8
  %12 = load ptr, ptr %11, align 8, !tbaa !5
  %13 = getelementptr inbounds i8, ptr %.336, i64 8
  %14 = load ptr, ptr %13, align 8, !tbaa !5
  %.not29 = icmp eq ptr %12, %14
  br i1 %.not29, label %.loopexit, label %.lr.ph, !llvm.loop !13

.loopexit:                                        ; preds = %.lr.ph, %.preheader, %.thread
  %.023 = phi ptr [ null, %.thread ], [ %.241, %.preheader ], [ %14, %.lr.ph ]
  ret ptr %.023
}

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: GVNPass,GlobalOptPass,IPSCCPPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass