; LLVM IR from codemistic/Data-Structures-and-Algorithms :: CPP/LINKED LIST/CIRCULAR LOOP CONCEPTS/checkcircular.ll (Z13circularcheckP4node)

; 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 @_Z13circularcheckP4node(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
  %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 i1 true, ptr %2, align 1
  br label %34

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

11:                                               ; preds = %22, %9
  %12 = load ptr, ptr %4, align 8, !tbaa !5
  %13 = getelementptr inbounds %class.node, ptr %12, i32 0, i32 1
  %14 = load ptr, ptr %13, align 8, !tbaa !9
  %15 = load ptr, ptr %3, align 8, !tbaa !5
  %16 = icmp ne ptr %14, %15
  br i1 %16, label %17, label %20

17:                                               ; preds = %11
  %18 = load ptr, ptr %4, align 8, !tbaa !5
  %19 = icmp ne ptr %18, null
  br label %20

20:                                               ; preds = %17, %11
  %21 = phi i1 [ false, %11 ], [ %19, %17 ]
  br i1 %21, label %22, label %26

22:                                               ; preds = %20
  %23 = load ptr, ptr %4, align 8, !tbaa !5
  %24 = getelementptr inbounds %class.node, ptr %23, i32 0, i32 1
  %25 = load ptr, ptr %24, align 8, !tbaa !9
  store ptr %25, ptr %4, align 8, !tbaa !5
  br label %11, !llvm.loop !12

26:                                               ; preds = %20
  %27 = load ptr, ptr %3, align 8, !tbaa !5
  %28 = load ptr, ptr %4, align 8, !tbaa !5
  %29 = getelementptr inbounds %class.node, ptr %28, i32 0, i32 1
  store ptr %27, ptr %29, align 8, !tbaa !9
  %30 = icmp ne ptr %27, null
  br i1 %30, label %31, label %32

31:                                               ; preds = %26
  store i1 true, ptr %2, align 1
  store i32 1, ptr %5, align 4
  br label %33

32:                                               ; preds = %26
  store i1 false, ptr %2, align 1
  store i32 1, ptr %5, align 4
  br label %33

33:                                               ; preds = %32, %31
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #2
  br label %34

34:                                               ; preds = %33, %8
  %35 = load i1, ptr %2, align 1
  ret i1 %35
}

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 memory(readwrite, inaccessiblemem: none) uwtable
define dso_local noundef zeroext i1 @_Z13circularcheckP4node(ptr noundef %0) local_unnamed_addr #0 {
  %2 = icmp eq ptr %0, null
  br i1 %2, label %10, label %.preheader

.preheader:                                       ; preds = %1, %.preheader
  %.0 = phi ptr [ %4, %.preheader ], [ %0, %1 ]
  %3 = getelementptr inbounds i8, ptr %.0, i64 8
  %4 = load ptr, ptr %3, align 8, !tbaa !5
  %5 = icmp ne ptr %4, %0
  %6 = icmp ne ptr %.0, null
  %7 = and i1 %6, %5
  br i1 %7, label %.preheader, label %8, !llvm.loop !11

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

10:                                               ; preds = %1, %8
  ret i1 true
}

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, !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,GVNPass,GlobalOptPass,IPSCCPPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,LCSSAPass,LICMPass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass