; LLVM IR from HarshCasper/NeoAlgo :: C/ds (detectLoopLL)

; 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"

%struct.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: nounwind uwtable
define dso_local i32 @detectLoop(ptr noundef %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
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #2
  %5 = load ptr, ptr %2, align 8, !tbaa !5
  store ptr %5, ptr %3, align 8, !tbaa !5
  store ptr %5, ptr %4, align 8, !tbaa !5
  br label %6

6:                                                ; preds = %33, %1
  %7 = load ptr, ptr %4, align 8, !tbaa !5
  %8 = getelementptr inbounds %struct.Node, ptr %7, i32 0, i32 1
  %9 = load ptr, ptr %8, align 8, !tbaa !9
  store ptr %9, ptr %4, align 8, !tbaa !5
  %10 = load ptr, ptr %3, align 8, !tbaa !5
  %11 = getelementptr inbounds %struct.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 %3, align 8, !tbaa !5
  %14 = icmp ne ptr %13, null
  br i1 %14, label %15, label %19

15:                                               ; preds = %6
  %16 = load ptr, ptr %3, align 8, !tbaa !5
  %17 = getelementptr inbounds %struct.Node, ptr %16, i32 0, i32 1
  %18 = load ptr, ptr %17, align 8, !tbaa !9
  br label %21

19:                                               ; preds = %6
  %20 = load ptr, ptr %3, align 8, !tbaa !5
  br label %21

21:                                               ; preds = %19, %15
  %22 = phi ptr [ %18, %15 ], [ %20, %19 ]
  store ptr %22, ptr %3, align 8, !tbaa !5
  br label %23

23:                                               ; preds = %21
  %24 = load ptr, ptr %3, align 8, !tbaa !5
  %25 = icmp ne ptr %24, null
  br i1 %25, label %26, label %33

26:                                               ; preds = %23
  %27 = load ptr, ptr %4, align 8, !tbaa !5
  %28 = icmp ne ptr %27, null
  br i1 %28, label %29, label %33

29:                                               ; preds = %26
  %30 = load ptr, ptr %3, align 8, !tbaa !5
  %31 = load ptr, ptr %4, align 8, !tbaa !5
  %32 = icmp ne ptr %30, %31
  br label %33

33:                                               ; preds = %29, %26, %23
  %34 = phi i1 [ false, %26 ], [ false, %23 ], [ %32, %29 ]
  br i1 %34, label %6, label %35, !llvm.loop !12

35:                                               ; preds = %33
  %36 = load ptr, ptr %4, align 8, !tbaa !5
  %37 = load ptr, ptr %3, align 8, !tbaa !5
  %38 = icmp eq ptr %36, %37
  %39 = zext i1 %38 to i32
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #2
  ret i32 %39
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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/C++ TBAA"}
!9 = !{!10, !6, i64 8}
!10 = !{!"Node", !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: nofree norecurse nosync nounwind memory(read, inaccessiblemem: none) uwtable
define dso_local range(i32 0, 2) i32 @detectLoop(ptr nocapture noundef readonly %0) local_unnamed_addr #0 {
  br label %2

2:                                                ; preds = %7, %1
  %.013 = phi ptr [ %0, %1 ], [ %9, %7 ]
  %.0 = phi ptr [ %0, %1 ], [ %4, %7 ]
  %3 = getelementptr inbounds i8, ptr %.0, i64 8
  %4 = load ptr, ptr %3, align 8, !tbaa !5
  %5 = getelementptr inbounds i8, ptr %.013, i64 8
  %6 = load ptr, ptr %5, align 8, !tbaa !5
  %.not = icmp eq ptr %6, null
  br i1 %.not, label %.thread, label %7

.thread:                                          ; preds = %2
  %.not1721 = icmp eq ptr %4, null
  br label %.critedge

7:                                                ; preds = %2
  %8 = getelementptr inbounds i8, ptr %6, i64 8
  %9 = load ptr, ptr %8, align 8, !tbaa !5
  %10 = icmp eq ptr %9, null
  %11 = icmp eq ptr %4, null
  %.not17 = icmp eq ptr %9, %4
  %12 = or i1 %11, %.not17
  %or.cond18 = select i1 %10, i1 true, i1 %12
  br i1 %or.cond18, label %.critedge, label %2, !llvm.loop !11

.critedge:                                        ; preds = %7, %.thread
  %.not1723 = phi i1 [ %.not1721, %.thread ], [ %.not17, %7 ]
  %13 = zext i1 %.not1723 to i32
  ret i32 %13
}

attributes #0 = { nofree norecurse nosync nounwind 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 = !{!"Node", !7, i64 0, !10, i64 8}
!7 = !{!"int", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C/C++ TBAA"}
!10 = !{!"any pointer", !8, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}


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