; LLVM IR from UtkarshPathrabe/Competitive-Coding :: HackerRank Solutions/Data Structures/Linked Lists (Cycle Detection)

; 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.SinglyLinkedListNode = 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 @_Z9has_cycleP20SinglyLinkedListNode(ptr noundef %0) #1 {
  %2 = alloca i1, align 1
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #2
  %6 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %6, ptr %4, align 8, !tbaa !5
  br label %7

7:                                                ; preds = %30, %1
  %8 = load ptr, ptr %4, align 8, !tbaa !5
  %9 = icmp ne ptr %8, null
  br i1 %9, label %10, label %15

10:                                               ; preds = %7
  %11 = load ptr, ptr %4, align 8, !tbaa !5
  %12 = getelementptr inbounds %class.SinglyLinkedListNode, ptr %11, i32 0, i32 1
  %13 = load ptr, ptr %12, align 8, !tbaa !9
  %14 = icmp ne ptr %13, null
  br label %15

15:                                               ; preds = %10, %7
  %16 = phi i1 [ false, %7 ], [ %14, %10 ]
  br i1 %16, label %17, label %31

17:                                               ; preds = %15
  %18 = load ptr, ptr %4, align 8, !tbaa !5
  %19 = getelementptr inbounds %class.SinglyLinkedListNode, ptr %18, i32 0, i32 1
  %20 = load ptr, ptr %19, align 8, !tbaa !9
  %21 = getelementptr inbounds %class.SinglyLinkedListNode, ptr %20, i32 0, i32 1
  %22 = load ptr, ptr %21, align 8, !tbaa !9
  store ptr %22, ptr %4, align 8, !tbaa !5
  %23 = load ptr, ptr %3, align 8, !tbaa !5
  %24 = getelementptr inbounds %class.SinglyLinkedListNode, ptr %23, i32 0, i32 1
  %25 = load ptr, ptr %24, align 8, !tbaa !9
  store ptr %25, ptr %3, align 8, !tbaa !5
  %26 = load ptr, ptr %3, align 8, !tbaa !5
  %27 = load ptr, ptr %4, align 8, !tbaa !5
  %28 = icmp eq ptr %26, %27
  br i1 %28, label %29, label %30

29:                                               ; preds = %17
  store i1 true, ptr %2, align 1
  store i32 1, ptr %5, align 4
  br label %32

30:                                               ; preds = %17
  br label %7, !llvm.loop !12

31:                                               ; preds = %15
  store i1 false, ptr %2, align 1
  store i32 1, ptr %5, align 4
  br label %32

32:                                               ; preds = %31, %29
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #2
  %33 = load i1, ptr %2, align 1
  ret i1 %33
}

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 = !{!"_ZTS20SinglyLinkedListNode", !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 @_Z9has_cycleP20SinglyLinkedListNode(ptr noundef readonly %0) local_unnamed_addr #0 {
  br label %2

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

3:                                                ; preds = %2
  %4 = getelementptr inbounds i8, ptr %.0, i64 8
  %5 = load ptr, ptr %4, align 8, !tbaa !5
  %.not13 = icmp eq ptr %5, null
  br i1 %.not13, 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 %.08, i64 8
  %10 = load ptr, ptr %9, align 8, !tbaa !5
  %11 = icmp eq ptr %10, %8
  br i1 %11, label %.critedge, label %2, !llvm.loop !11

.critedge:                                        ; preds = %3, %2, %6
  %.09 = phi i1 [ true, %6 ], [ false, %2 ], [ false, %3 ]
  ret i1 %.09
}

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 = !{!"_ZTS20SinglyLinkedListNode", !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,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass