; LLVM IR from HarshCasper/NeoAlgo :: C-Plus-Plus/cp/remove_cycle.ll (Z10breakcycleP4NodeS0_)

; 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
define dso_local void @_Z10breakcycleP4NodeS0_(ptr noundef %0, ptr noundef %1) #1 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca ptr, align 8
  %7 = alloca ptr, align 8
  store ptr %0, ptr %3, align 8, !tbaa !5
  store ptr %1, ptr %4, align 8, !tbaa !5
  %8 = load ptr, ptr %4, align 8, !tbaa !5
  %9 = load ptr, ptr %3, align 8, !tbaa !5
  %10 = icmp eq ptr %8, %9
  br i1 %10, label %11, label %28

11:                                               ; preds = %2
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #2
  %12 = load ptr, ptr %3, align 8, !tbaa !5
  %13 = getelementptr inbounds %class.Node, ptr %12, i32 0, i32 1
  %14 = load ptr, ptr %13, align 8, !tbaa !9
  store ptr %14, ptr %5, align 8, !tbaa !5
  br label %15

15:                                               ; preds = %21, %11
  %16 = load ptr, ptr %5, align 8, !tbaa !5
  %17 = getelementptr inbounds %class.Node, ptr %16, i32 0, i32 1
  %18 = load ptr, ptr %17, align 8, !tbaa !9
  %19 = load ptr, ptr %3, align 8, !tbaa !5
  %20 = icmp ne ptr %18, %19
  br i1 %20, label %21, label %25

21:                                               ; preds = %15
  %22 = load ptr, ptr %5, align 8, !tbaa !5
  %23 = getelementptr inbounds %class.Node, 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 %15, !llvm.loop !12

25:                                               ; preds = %15
  %26 = load ptr, ptr %5, align 8, !tbaa !5
  %27 = getelementptr inbounds %class.Node, ptr %26, i32 0, i32 1
  store ptr null, ptr %27, align 8, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #2
  br label %46

28:                                               ; preds = %2
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #2
  %29 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %29, ptr %6, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #2
  %30 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %30, ptr %7, align 8, !tbaa !5
  br label %31

31:                                               ; preds = %35, %28
  %32 = load ptr, ptr %7, align 8, !tbaa !5
  %33 = load ptr, ptr %4, align 8, !tbaa !5
  %34 = icmp ne ptr %32, %33
  br i1 %34, label %35, label %43

35:                                               ; preds = %31
  %36 = load ptr, ptr %7, align 8, !tbaa !5
  %37 = getelementptr inbounds %class.Node, ptr %36, i32 0, i32 1
  %38 = load ptr, ptr %37, align 8, !tbaa !9
  store ptr %38, ptr %7, align 8, !tbaa !5
  %39 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %39, ptr %6, align 8, !tbaa !5
  %40 = load ptr, ptr %4, align 8, !tbaa !5
  %41 = getelementptr inbounds %class.Node, ptr %40, i32 0, i32 1
  %42 = load ptr, ptr %41, align 8, !tbaa !9
  store ptr %42, ptr %4, align 8, !tbaa !5
  br label %31, !llvm.loop !14

43:                                               ; preds = %31
  %44 = load ptr, ptr %6, align 8, !tbaa !5
  %45 = getelementptr inbounds %class.Node, ptr %44, i32 0, i32 1
  store ptr null, ptr %45, align 8, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #2
  br label %46

46:                                               ; preds = %43, %25
  ret void
}

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"}
!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: mustprogress nofree norecurse nosync nounwind memory(readwrite, inaccessiblemem: none) uwtable
define dso_local void @_Z10breakcycleP4NodeS0_(ptr noundef readonly %0, ptr noundef %1) local_unnamed_addr #0 {
  %3 = icmp eq ptr %1, %0
  br i1 %3, label %4, label %.preheader

4:                                                ; preds = %2
  %5 = getelementptr inbounds i8, ptr %0, i64 8
  %6 = load ptr, ptr %5, align 8, !tbaa !5
  br label %7

7:                                                ; preds = %7, %4
  %.016 = phi ptr [ %6, %4 ], [ %9, %7 ]
  %8 = getelementptr inbounds i8, ptr %.016, i64 8
  %9 = load ptr, ptr %8, align 8, !tbaa !5
  %.not21 = icmp eq ptr %9, %1
  br i1 %.not21, label %.loopexit, label %7, !llvm.loop !11

.preheader:                                       ; preds = %2, %.preheader
  %.023 = phi ptr [ %11, %.preheader ], [ %0, %2 ]
  %.01722 = phi ptr [ %13, %.preheader ], [ %1, %2 ]
  %10 = getelementptr inbounds i8, ptr %.023, i64 8
  %11 = load ptr, ptr %10, align 8, !tbaa !5
  %12 = getelementptr inbounds i8, ptr %.01722, i64 8
  %13 = load ptr, ptr %12, align 8, !tbaa !5
  %.not = icmp eq ptr %11, %13
  br i1 %.not, label %.loopexit, label %.preheader, !llvm.loop !13

.loopexit:                                        ; preds = %.preheader, %7
  %.01722.lcssa.sink = phi ptr [ %.016, %7 ], [ %.01722, %.preheader ]
  %14 = getelementptr inbounds i8, ptr %.01722.lcssa.sink, i64 8
  store ptr null, ptr %14, align 8, !tbaa !5
  ret void
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind memory(readwrite, 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 = !{!"_ZTS4Node", !7, i64 0, !10, i64 8}
!7 = !{!"int", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple 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,LCSSAPass,LICMPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass