; LLVM IR from int32bit/leetcode :: algorithms/LinkedListCycle2 (solve)

; 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: 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 uwtable
define dso_local ptr @detectCycle(ptr noundef %0) #1 {
  %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
  %7 = load ptr, ptr %3, align 8, !tbaa !5
  %8 = icmp eq ptr %7, null
  br i1 %8, label %9, label %10

9:                                                ; preds = %1
  store ptr null, ptr %2, align 8
  br label %53

10:                                               ; preds = %1
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #2
  %11 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %11, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #2
  %12 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %12, ptr %5, align 8, !tbaa !5
  br label %13

13:                                               ; preds = %50, %10
  %14 = load ptr, ptr %4, align 8, !tbaa !5
  %15 = icmp ne ptr %14, null
  br i1 %15, label %16, label %21

16:                                               ; preds = %13
  %17 = load ptr, ptr %4, align 8, !tbaa !5
  %18 = getelementptr inbounds %struct.ListNode, ptr %17, i32 0, i32 1
  %19 = load ptr, ptr %18, align 8, !tbaa !9
  %20 = icmp ne ptr %19, null
  br label %21

21:                                               ; preds = %16, %13
  %22 = phi i1 [ false, %13 ], [ %20, %16 ]
  br i1 %22, label %23, label %51

23:                                               ; preds = %21
  %24 = load ptr, ptr %4, align 8, !tbaa !5
  %25 = getelementptr inbounds %struct.ListNode, ptr %24, i32 0, i32 1
  %26 = load ptr, ptr %25, align 8, !tbaa !9
  %27 = getelementptr inbounds %struct.ListNode, ptr %26, i32 0, i32 1
  %28 = load ptr, ptr %27, align 8, !tbaa !9
  store ptr %28, ptr %4, align 8, !tbaa !5
  %29 = load ptr, ptr %5, align 8, !tbaa !5
  %30 = getelementptr inbounds %struct.ListNode, ptr %29, i32 0, i32 1
  %31 = load ptr, ptr %30, align 8, !tbaa !9
  store ptr %31, ptr %5, align 8, !tbaa !5
  %32 = load ptr, ptr %4, align 8, !tbaa !5
  %33 = load ptr, ptr %5, align 8, !tbaa !5
  %34 = icmp eq ptr %32, %33
  br i1 %34, label %35, label %50

35:                                               ; preds = %23
  %36 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %36, ptr %4, align 8, !tbaa !5
  br label %37

37:                                               ; preds = %41, %35
  %38 = load ptr, ptr %4, align 8, !tbaa !5
  %39 = load ptr, ptr %5, align 8, !tbaa !5
  %40 = icmp ne ptr %38, %39
  br i1 %40, label %41, label %48

41:                                               ; preds = %37
  %42 = load ptr, ptr %4, align 8, !tbaa !5
  %43 = getelementptr inbounds %struct.ListNode, ptr %42, i32 0, i32 1
  %44 = load ptr, ptr %43, align 8, !tbaa !9
  store ptr %44, ptr %4, align 8, !tbaa !5
  %45 = load ptr, ptr %5, align 8, !tbaa !5
  %46 = getelementptr inbounds %struct.ListNode, ptr %45, i32 0, i32 1
  %47 = load ptr, ptr %46, align 8, !tbaa !9
  store ptr %47, ptr %5, align 8, !tbaa !5
  br label %37, !llvm.loop !12

48:                                               ; preds = %37
  %49 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %49, ptr %2, align 8
  store i32 1, ptr %6, align 4
  br label %52

50:                                               ; preds = %23
  br label %13, !llvm.loop !14

51:                                               ; preds = %21
  store ptr null, ptr %2, align 8
  store i32 1, ptr %6, align 4
  br label %52

52:                                               ; preds = %51, %48
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #2
  br label %53

53:                                               ; preds = %52, %9
  %54 = load ptr, ptr %2, align 8
  ret ptr %54
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 #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 {
  %2 = icmp eq ptr %0, null
  br i1 %2, label %.critedge, label %.preheader27

.preheader27:                                     ; preds = %1, %6
  %.016 = phi ptr [ %8, %6 ], [ %0, %1 ]
  %.0 = phi ptr [ %10, %6 ], [ %0, %1 ]
  %.not = icmp eq ptr %.016, null
  br i1 %.not, label %.critedge, label %3

3:                                                ; preds = %.preheader27
  %4 = getelementptr inbounds i8, ptr %.016, i64 8
  %5 = load ptr, ptr %4, align 8, !tbaa !5
  %.not25 = icmp eq ptr %5, null
  br i1 %.not25, label %.critedge, label %6

6:                                                ; preds = %3
  %7 = getelementptr inbounds i8, ptr %5, 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
  %11 = icmp eq ptr %8, %10
  br i1 %11, label %.preheader, label %.preheader27, !llvm.loop !11

.preheader:                                       ; preds = %6
  %.not2629 = icmp eq ptr %8, %0
  br i1 %.not2629, label %.critedge, label %.lr.ph

.lr.ph:                                           ; preds = %.preheader, %.lr.ph
  %.131 = phi ptr [ %15, %.lr.ph ], [ %10, %.preheader ]
  %.11730 = phi ptr [ %13, %.lr.ph ], [ %0, %.preheader ]
  %12 = getelementptr inbounds i8, ptr %.11730, i64 8
  %13 = load ptr, ptr %12, align 8, !tbaa !5
  %14 = getelementptr inbounds i8, ptr %.131, i64 8
  %15 = load ptr, ptr %14, align 8, !tbaa !5
  %.not26 = icmp eq ptr %13, %15
  br i1 %.not26, label %.critedge, label %.lr.ph, !llvm.loop !13

.critedge:                                        ; preds = %.preheader27, %3, %.lr.ph, %.preheader, %1
  %.119 = phi ptr [ null, %1 ], [ %0, %.preheader ], [ %13, %.lr.ph ], [ null, %3 ], [ null, %.preheader27 ]
  ret ptr %.119
}

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