; LLVM IR from ritikbanger/Hacktoberfest2022-DSA :: 03. Recursion (reverselinkedlist_recursive)

; 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 void @recursiveReverse(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 i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  store ptr %1, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #2
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #2
  %8 = load ptr, ptr %3, align 8, !tbaa !5
  %9 = icmp eq ptr %8, null
  br i1 %9, label %10, label %11

10:                                               ; preds = %2
  store i32 1, ptr %7, align 4
  br label %29

11:                                               ; preds = %2
  %12 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %12, ptr %5, align 8, !tbaa !5
  %13 = load ptr, ptr %5, align 8, !tbaa !5
  %14 = getelementptr inbounds %struct.Node, ptr %13, i32 0, i32 1
  %15 = load ptr, ptr %14, align 8, !tbaa !9
  store ptr %15, ptr %6, align 8, !tbaa !5
  %16 = load ptr, ptr %6, align 8, !tbaa !5
  %17 = icmp eq ptr %16, null
  br i1 %17, label %18, label %21

18:                                               ; preds = %11
  %19 = load ptr, ptr %5, align 8, !tbaa !5
  %20 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %19, ptr %20, align 8, !tbaa !5
  store i32 1, ptr %7, align 4
  br label %29

21:                                               ; preds = %11
  %22 = load ptr, ptr %6, align 8, !tbaa !5
  %23 = load ptr, ptr %4, align 8, !tbaa !5
  call void @recursiveReverse(ptr noundef %22, ptr noundef %23)
  %24 = load ptr, ptr %5, align 8, !tbaa !5
  %25 = load ptr, ptr %6, align 8, !tbaa !5
  %26 = getelementptr inbounds %struct.Node, ptr %25, i32 0, i32 1
  store ptr %24, ptr %26, align 8, !tbaa !9
  %27 = load ptr, ptr %5, align 8, !tbaa !5
  %28 = getelementptr inbounds %struct.Node, ptr %27, i32 0, i32 1
  store ptr null, ptr %28, align 8, !tbaa !9
  store i32 0, ptr %7, align 4
  br label %29

29:                                               ; preds = %21, %18, %10
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #2
  %30 = load i32, ptr %7, align 4
  switch i32 %30, label %32 [
    i32 0, label %31
    i32 1, label %31
  ]

31:                                               ; preds = %29, %29
  ret void

32:                                               ; preds = %29
  unreachable
}

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}


; 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 nosync nounwind memory(readwrite, inaccessiblemem: none) uwtable
define dso_local void @recursiveReverse(ptr noundef %0, ptr nocapture noundef writeonly %1) local_unnamed_addr #0 {
  %3 = icmp eq ptr %0, null
  br i1 %3, label %common.ret12, 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, null
  br i1 %7, label %8, label %9

8:                                                ; preds = %4
  store ptr %0, ptr %1, align 8, !tbaa !11
  br label %common.ret12

common.ret12:                                     ; preds = %2, %8, %9
  ret void

9:                                                ; preds = %4
  tail call void @recursiveReverse(ptr noundef nonnull %6, ptr noundef %1)
  %10 = getelementptr inbounds i8, ptr %6, i64 8
  store ptr %0, ptr %10, align 8, !tbaa !5
  store ptr null, ptr %5, align 8, !tbaa !5
  br label %common.ret12
}

attributes #0 = { 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 = !{!"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 = !{!10, !10, i64 0}


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