; LLVM IR from codemistic/Data-Structures-and-Algorithms :: CPP/LINKED LIST/ALGORITHMIC PROBLEMS RELATED TO LINKEDLIST/find_begeningof_circle._3ef40d62 (nodeP4node)

; 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"

%class.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: mustprogress nounwind uwtable
declare dso_local noundef ptr @_Z11floyd_cycleRP4node(ptr noundef nonnull align 8 dereferenceable(8)) #1

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef ptr @_Z17get_starting_nodeP4node(ptr noundef %0) #1 {
  %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 eq ptr %6, null
  br i1 %7, label %8, label %9

8:                                                ; preds = %1
  store ptr null, ptr %2, align 8
  br label %25

9:                                                ; preds = %1
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #2
  %10 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %10, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #2
  %11 = call noundef ptr @_Z11floyd_cycleRP4node(ptr noundef nonnull align 8 dereferenceable(8) %3)
  store ptr %11, ptr %5, align 8, !tbaa !5
  br label %12

12:                                               ; preds = %16, %9
  %13 = load ptr, ptr %4, align 8, !tbaa !5
  %14 = load ptr, ptr %5, align 8, !tbaa !5
  %15 = icmp ne ptr %13, %14
  br i1 %15, label %16, label %23

16:                                               ; preds = %12
  %17 = load ptr, ptr %4, align 8, !tbaa !5
  %18 = getelementptr inbounds %class.node, ptr %17, i32 0, i32 1
  %19 = load ptr, ptr %18, align 8, !tbaa !9
  store ptr %19, ptr %4, align 8, !tbaa !5
  %20 = load ptr, ptr %5, align 8, !tbaa !5
  %21 = getelementptr inbounds %class.node, ptr %20, i32 0, i32 1
  %22 = load ptr, ptr %21, align 8, !tbaa !9
  store ptr %22, ptr %5, align 8, !tbaa !5
  br label %12, !llvm.loop !12

23:                                               ; preds = %12
  %24 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %24, ptr %2, align 8
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #2
  br label %25

25:                                               ; preds = %23, %8
  %26 = load ptr, ptr %2, align 8
  ret ptr %26
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { mustprogress 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++ TBAA"}
!9 = !{!10, !6, i64 8}
!10 = !{!"_ZTS4node", !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: mustprogress nounwind uwtable
declare dso_local noundef ptr @_Z11floyd_cycleRP4node(ptr noundef nonnull align 8 dereferenceable(8)) local_unnamed_addr #0

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef ptr @_Z17get_starting_nodeP4node(ptr noundef %0) local_unnamed_addr #0 {
  %2 = alloca ptr, align 8
  store ptr %0, ptr %2, align 8, !tbaa !5
  %3 = icmp eq ptr %0, null
  br i1 %3, label %.loopexit, label %4

4:                                                ; preds = %1
  %5 = call noundef ptr @_Z11floyd_cycleRP4node(ptr noundef nonnull align 8 dereferenceable(8) %2)
  %.not9 = icmp eq ptr %5, %0
  br i1 %.not9, label %.loopexit, label %.lr.ph

.lr.ph:                                           ; preds = %4, %.lr.ph
  %.011 = phi ptr [ %9, %.lr.ph ], [ %5, %4 ]
  %.0610 = phi ptr [ %7, %.lr.ph ], [ %0, %4 ]
  %6 = getelementptr inbounds i8, ptr %.0610, i64 8
  %7 = load ptr, ptr %6, align 8, !tbaa !9
  %8 = getelementptr inbounds i8, ptr %.011, i64 8
  %9 = load ptr, ptr %8, align 8, !tbaa !9
  %.not = icmp eq ptr %7, %9
  br i1 %.not, label %.loopexit, label %.lr.ph, !llvm.loop !12

.loopexit:                                        ; preds = %.lr.ph, %4, %1
  %.07 = phi ptr [ null, %1 ], [ %0, %4 ], [ %7, %.lr.ph ]
  ret ptr %.07
}

attributes #0 = { mustprogress 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" }

!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++ TBAA"}
!9 = !{!10, !6, i64 8}
!10 = !{!"_ZTS4node", !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,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,SROAPass,SimplifyCFGPass