; LLVM IR from ritikbanger/Hacktoberfest2022-DSA :: 10. Linked List/cpp/Linked List Complete.ll (Z11removeCycleRP4node)

; 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 @_Z11removeCycleRP4node(ptr noundef nonnull align 8 dereferenceable(8) %0) #1 {
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  store ptr %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #2
  %5 = load ptr, ptr %2, align 8, !tbaa !5
  %6 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %6, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #2
  %7 = load ptr, ptr %2, align 8, !tbaa !5
  %8 = load ptr, ptr %7, align 8, !tbaa !5
  store ptr %8, ptr %4, align 8, !tbaa !5
  br label %9

9:                                                ; preds = %18, %1
  %10 = load ptr, ptr %3, align 8, !tbaa !5
  %11 = getelementptr inbounds %class.node, ptr %10, i32 0, i32 1
  %12 = load ptr, ptr %11, align 8, !tbaa !9
  store ptr %12, ptr %3, align 8, !tbaa !5
  %13 = load ptr, ptr %4, align 8, !tbaa !5
  %14 = getelementptr inbounds %class.node, ptr %13, i32 0, i32 1
  %15 = load ptr, ptr %14, align 8, !tbaa !9
  %16 = getelementptr inbounds %class.node, ptr %15, i32 0, i32 1
  %17 = load ptr, ptr %16, align 8, !tbaa !9
  store ptr %17, ptr %4, align 8, !tbaa !5
  br label %18

18:                                               ; preds = %9
  %19 = load ptr, ptr %3, align 8, !tbaa !5
  %20 = load ptr, ptr %4, align 8, !tbaa !5
  %21 = icmp ne ptr %19, %20
  br i1 %21, label %9, label %22, !llvm.loop !12

22:                                               ; preds = %18
  %23 = load ptr, ptr %2, align 8, !tbaa !5
  %24 = load ptr, ptr %23, align 8, !tbaa !5
  store ptr %24, ptr %4, align 8, !tbaa !5
  br label %25

25:                                               ; preds = %33, %22
  %26 = load ptr, ptr %3, align 8, !tbaa !5
  %27 = getelementptr inbounds %class.node, ptr %26, i32 0, i32 1
  %28 = load ptr, ptr %27, align 8, !tbaa !9
  %29 = load ptr, ptr %4, align 8, !tbaa !5
  %30 = getelementptr inbounds %class.node, ptr %29, i32 0, i32 1
  %31 = load ptr, ptr %30, align 8, !tbaa !9
  %32 = icmp ne ptr %28, %31
  br i1 %32, label %33, label %40

33:                                               ; preds = %25
  %34 = load ptr, ptr %3, align 8, !tbaa !5
  %35 = getelementptr inbounds %class.node, ptr %34, i32 0, i32 1
  %36 = load ptr, ptr %35, align 8, !tbaa !9
  store ptr %36, ptr %3, align 8, !tbaa !5
  %37 = load ptr, ptr %4, align 8, !tbaa !5
  %38 = getelementptr inbounds %class.node, ptr %37, i32 0, i32 1
  %39 = load ptr, ptr %38, align 8, !tbaa !9
  store ptr %39, ptr %4, align 8, !tbaa !5
  br label %25, !llvm.loop !14

40:                                               ; preds = %25
  %41 = load ptr, ptr %3, align 8, !tbaa !5
  %42 = getelementptr inbounds %class.node, ptr %41, i32 0, i32 1
  store ptr null, ptr %42, align 8, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #2
  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 @_Z11removeCycleRP4node(ptr nocapture noundef nonnull readonly align 8 dereferenceable(8) %0) local_unnamed_addr #0 {
  %2 = load ptr, ptr %0, align 8, !tbaa !5
  br label %3

3:                                                ; preds = %3, %1
  %.012 = phi ptr [ %2, %1 ], [ %5, %3 ]
  %.0 = phi ptr [ %2, %1 ], [ %9, %3 ]
  %4 = getelementptr inbounds i8, ptr %.012, i64 8
  %5 = load ptr, ptr %4, align 8, !tbaa !9
  %6 = getelementptr inbounds i8, ptr %.0, i64 8
  %7 = load ptr, ptr %6, align 8, !tbaa !9
  %8 = getelementptr inbounds i8, ptr %7, i64 8
  %9 = load ptr, ptr %8, align 8, !tbaa !9
  %.not = icmp eq ptr %5, %9
  br i1 %.not, label %.preheader, label %3, !llvm.loop !12

.preheader:                                       ; preds = %3, %.preheader
  %.113 = phi ptr [ %11, %.preheader ], [ %5, %3 ]
  %.1 = phi ptr [ %13, %.preheader ], [ %2, %3 ]
  %10 = getelementptr inbounds i8, ptr %.113, i64 8
  %11 = load ptr, ptr %10, align 8, !tbaa !9
  %12 = getelementptr inbounds i8, ptr %.1, i64 8
  %13 = load ptr, ptr %12, align 8, !tbaa !9
  %.not17 = icmp eq ptr %11, %13
  br i1 %.not17, label %14, label %.preheader, !llvm.loop !14

14:                                               ; preds = %.preheader
  %15 = getelementptr inbounds i8, ptr %.113, i64 8
  store ptr null, ptr %15, align 8, !tbaa !9
  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, !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}


; Effective O3 passes: EarlyCSEPass,GVNPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,LCSSAPass,LICMPass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass