; LLVM IR from Lakhankumawat/LearnCPP :: L-LinkedList/S-SinglyLinkedList/DetectCycleInLinkedList.ll (Z11cycleDetectP4node)

; 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 noundef zeroext i1 @_Z11cycleDetectP4node(ptr noundef %0) #1 {
  %2 = alloca i1, align 1
  %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 i1 false, ptr %2, align 1
  br label %43

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 = %40, %10
  %14 = load ptr, ptr %4, align 8, !tbaa !5
  %15 = getelementptr inbounds %class.node, ptr %14, i32 0, i32 1
  %16 = load ptr, ptr %15, align 8, !tbaa !9
  %17 = icmp ne ptr %16, null
  br i1 %17, label %18, label %25

18:                                               ; preds = %13
  %19 = load ptr, ptr %4, align 8, !tbaa !5
  %20 = getelementptr inbounds %class.node, ptr %19, i32 0, i32 1
  %21 = load ptr, ptr %20, align 8, !tbaa !9
  %22 = getelementptr inbounds %class.node, ptr %21, i32 0, i32 1
  %23 = load ptr, ptr %22, align 8, !tbaa !9
  %24 = icmp ne ptr %23, null
  br label %25

25:                                               ; preds = %18, %13
  %26 = phi i1 [ false, %13 ], [ %24, %18 ]
  br i1 %26, label %27, label %41

27:                                               ; preds = %25
  %28 = load ptr, ptr %4, align 8, !tbaa !5
  %29 = getelementptr inbounds %class.node, ptr %28, i32 0, i32 1
  %30 = load ptr, ptr %29, align 8, !tbaa !9
  %31 = getelementptr inbounds %class.node, ptr %30, i32 0, i32 1
  %32 = load ptr, ptr %31, align 8, !tbaa !9
  store ptr %32, ptr %4, align 8, !tbaa !5
  %33 = load ptr, ptr %5, align 8, !tbaa !5
  %34 = getelementptr inbounds %class.node, ptr %33, i32 0, i32 1
  %35 = load ptr, ptr %34, align 8, !tbaa !9
  store ptr %35, ptr %5, align 8, !tbaa !5
  %36 = load ptr, ptr %4, align 8, !tbaa !5
  %37 = load ptr, ptr %5, align 8, !tbaa !5
  %38 = icmp eq ptr %36, %37
  br i1 %38, label %39, label %40

39:                                               ; preds = %27
  store i1 true, ptr %2, align 1
  store i32 1, ptr %6, align 4
  br label %42

40:                                               ; preds = %27
  br label %13, !llvm.loop !12

41:                                               ; preds = %25
  store i1 false, ptr %2, align 1
  store i32 1, ptr %6, align 4
  br label %42

42:                                               ; preds = %41, %39
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #2
  br label %43

43:                                               ; preds = %42, %9
  %44 = load i1, ptr %2, align 1
  ret i1 %44
}

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 nofree norecurse nosync nounwind willreturn memory(read, inaccessiblemem: none) uwtable
define dso_local noundef zeroext i1 @_Z11cycleDetectP4node(ptr noundef readonly %0) local_unnamed_addr #0 {
  %2 = icmp eq ptr %0, null
  br i1 %2, label %.critedge, label %.preheader

.preheader:                                       ; preds = %1, %8
  %.010 = phi ptr [ %7, %8 ], [ %0, %1 ]
  %.0 = phi ptr [ %10, %8 ], [ %0, %1 ]
  %3 = getelementptr inbounds i8, ptr %.010, i64 8
  %4 = load ptr, ptr %3, align 8, !tbaa !5
  %.not = icmp eq ptr %4, null
  br i1 %.not, label %.critedge, label %5

5:                                                ; preds = %.preheader
  %6 = getelementptr inbounds i8, ptr %4, i64 8
  %7 = load ptr, ptr %6, align 8, !tbaa !5
  %.not16 = icmp eq ptr %7, null
  br i1 %.not16, label %.critedge, label %8

8:                                                ; preds = %5
  %9 = getelementptr inbounds i8, ptr %.0, i64 8
  %10 = load ptr, ptr %9, align 8, !tbaa !5
  %11 = icmp eq ptr %7, %10
  br i1 %11, label %.critedge, label %.preheader, !llvm.loop !11

.critedge:                                        ; preds = %8, %.preheader, %5, %1
  %.1 = phi i1 [ false, %1 ], [ false, %5 ], [ false, %.preheader ], [ true, %8 ]
  ret i1 %.1
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn 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 = !{!"_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"}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass