; LLVM IR from codemistic/Data-Structures-and-Algorithms :: CPP/LINKED LIST/ALGORITHMIC PROBLEMS RELATED TO LINKEDLIST/find_begeningof_circle._ff3f0d19 (circleP4node)

; 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
declare dso_local noundef ptr @_Z17get_starting_nodeP4node(ptr noundef) #1

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef ptr @_Z13remove_circleP4node(ptr noundef %0) #1 {
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  store ptr %0, ptr %3, align 8, !tbaa !5
  %6 = load ptr, ptr %3, align 8, !tbaa !5
  %7 = icmp eq ptr %6, null
  br i1 %7, label %8, label %9

8:                                                ; preds = %1
  store ptr null, ptr %2, align 8
  br label %28

9:                                                ; preds = %1
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #2
  %10 = load ptr, ptr %3, align 8, !tbaa !5
  %11 = call noundef ptr @_Z17get_starting_nodeP4node(ptr noundef %10)
  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
  %13 = call noundef ptr @_Z17get_starting_nodeP4node(ptr noundef %12)
  store ptr %13, ptr %5, align 8, !tbaa !5
  br label %14

14:                                               ; preds = %20, %9
  %15 = load ptr, ptr %5, align 8, !tbaa !5
  %16 = getelementptr inbounds %class.node, ptr %15, i32 0, i32 1
  %17 = load ptr, ptr %16, align 8, !tbaa !9
  %18 = load ptr, ptr %4, align 8, !tbaa !5
  %19 = icmp ne ptr %17, %18
  br i1 %19, label %20, label %24

20:                                               ; preds = %14
  %21 = load ptr, ptr %5, align 8, !tbaa !5
  %22 = getelementptr inbounds %class.node, ptr %21, i32 0, i32 1
  %23 = load ptr, ptr %22, align 8, !tbaa !9
  store ptr %23, ptr %5, align 8, !tbaa !5
  br label %14, !llvm.loop !12

24:                                               ; preds = %14
  %25 = load ptr, ptr %5, align 8, !tbaa !5
  %26 = getelementptr inbounds %class.node, ptr %25, i32 0, i32 1
  store ptr null, ptr %26, align 8, !tbaa !9
  %27 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %27, ptr %2, align 8
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #2
  br label %28

28:                                               ; preds = %24, %8
  %29 = load ptr, ptr %2, align 8
  ret ptr %29
}

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 nounwind uwtable
declare dso_local noundef ptr @_Z17get_starting_nodeP4node(ptr noundef) local_unnamed_addr #0

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef ptr @_Z13remove_circleP4node(ptr noundef returned %0) local_unnamed_addr #0 {
  %2 = icmp eq ptr %0, null
  br i1 %2, label %11, label %3

3:                                                ; preds = %1
  %4 = tail call noundef ptr @_Z17get_starting_nodeP4node(ptr noundef nonnull %0)
  %5 = tail call noundef ptr @_Z17get_starting_nodeP4node(ptr noundef nonnull %0)
  br label %6

6:                                                ; preds = %6, %3
  %.0 = phi ptr [ %5, %3 ], [ %8, %6 ]
  %7 = getelementptr inbounds i8, ptr %.0, i64 8
  %8 = load ptr, ptr %7, align 8, !tbaa !5
  %.not = icmp eq ptr %8, %4
  br i1 %.not, label %9, label %6, !llvm.loop !11

9:                                                ; preds = %6
  %10 = getelementptr inbounds i8, ptr %.0, i64 8
  store ptr null, ptr %10, align 8, !tbaa !5
  br label %11

11:                                               ; preds = %1, %9
  ret ptr %0
}

attributes #0 = { 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" }

!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: CorrelatedValuePropagationPass,EarlyCSEPass,GVNPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,LCSSAPass,LICMPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass