; LLVM IR from smv1999/CompetitiveProgrammingQuestionBank :: Data Structures/Linked Lists/Circular Linked Lists (recursive_reverse)

; 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.cll_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 uwtable
define dso_local noundef ptr @_Z24recursive_reverse_helperP8cll_nodeS0_(ptr noundef %0, ptr noundef %1) #1 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca ptr, align 8
  %7 = alloca ptr, align 8
  store ptr %0, ptr %4, align 8, !tbaa !5
  store ptr %1, ptr %5, align 8, !tbaa !5
  %8 = load ptr, ptr %4, align 8, !tbaa !5
  %9 = icmp eq ptr %8, null
  br i1 %9, label %16, label %10

10:                                               ; preds = %2
  %11 = load ptr, ptr %4, align 8, !tbaa !5
  %12 = getelementptr inbounds %class.cll_node, ptr %11, i32 0, i32 1
  %13 = load ptr, ptr %12, align 8, !tbaa !9
  %14 = load ptr, ptr %4, align 8, !tbaa !5
  %15 = icmp eq ptr %13, %14
  br i1 %15, label %16, label %18

16:                                               ; preds = %10, %2
  %17 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %17, ptr %3, align 8
  br label %37

18:                                               ; preds = %10
  %19 = load ptr, ptr %4, align 8, !tbaa !5
  %20 = getelementptr inbounds %class.cll_node, ptr %19, i32 0, i32 1
  %21 = load ptr, ptr %20, align 8, !tbaa !9
  %22 = load ptr, ptr %5, align 8, !tbaa !5
  %23 = getelementptr inbounds %class.cll_node, ptr %22, i32 0, i32 1
  store ptr %21, ptr %23, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #2
  %24 = load ptr, ptr %4, align 8, !tbaa !5
  %25 = getelementptr inbounds %class.cll_node, ptr %24, i32 0, i32 1
  %26 = load ptr, ptr %25, align 8, !tbaa !9
  store ptr %26, ptr %6, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #2
  %27 = load ptr, ptr %6, align 8, !tbaa !5
  %28 = load ptr, ptr %5, align 8, !tbaa !5
  %29 = call noundef ptr @_Z24recursive_reverse_helperP8cll_nodeS0_(ptr noundef %27, ptr noundef %28)
  store ptr %29, ptr %7, align 8, !tbaa !5
  %30 = load ptr, ptr %4, align 8, !tbaa !5
  %31 = load ptr, ptr %6, align 8, !tbaa !5
  %32 = getelementptr inbounds %class.cll_node, ptr %31, i32 0, i32 1
  store ptr %30, ptr %32, align 8, !tbaa !9
  %33 = load ptr, ptr %7, align 8, !tbaa !5
  %34 = load ptr, ptr %4, align 8, !tbaa !5
  %35 = getelementptr inbounds %class.cll_node, ptr %34, i32 0, i32 1
  store ptr %33, ptr %35, align 8, !tbaa !9
  %36 = load ptr, ptr %7, align 8, !tbaa !5
  store ptr %36, ptr %3, align 8
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #2
  br label %37

37:                                               ; preds = %18, %16
  %38 = load ptr, ptr %3, align 8
  ret ptr %38
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { mustprogress 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 = !{!"_ZTS8cll_node", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}


; 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 nosync nounwind memory(readwrite, inaccessiblemem: none) uwtable
define dso_local noundef ptr @_Z24recursive_reverse_helperP8cll_nodeS0_(ptr noundef %0, ptr nocapture noundef writeonly %1) local_unnamed_addr #0 {
  %3 = icmp eq ptr %0, null
  br i1 %3, label %common.ret17, label %4

4:                                                ; preds = %2
  %5 = getelementptr inbounds i8, ptr %0, i64 8
  %6 = load ptr, ptr %5, align 8, !tbaa !5
  %7 = icmp eq ptr %6, %0
  br i1 %7, label %common.ret17, label %8

common.ret17:                                     ; preds = %2, %4, %8
  %common.ret17.op = phi ptr [ %11, %8 ], [ %0, %4 ], [ null, %2 ]
  ret ptr %common.ret17.op

8:                                                ; preds = %4
  %9 = getelementptr inbounds i8, ptr %1, i64 8
  store ptr %6, ptr %9, align 8, !tbaa !5
  %10 = load ptr, ptr %5, align 8, !tbaa !5
  %11 = tail call noundef ptr @_Z24recursive_reverse_helperP8cll_nodeS0_(ptr noundef %10, ptr noundef %1)
  %12 = getelementptr inbounds i8, ptr %10, i64 8
  store ptr %0, ptr %12, align 8, !tbaa !5
  store ptr %11, ptr %5, align 8, !tbaa !5
  br label %common.ret17
}

attributes #0 = { mustprogress nofree 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 = !{!"_ZTS8cll_node", !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}


; Effective O3 passes: CorrelatedValuePropagationPass,EarlyCSEPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass