; LLVM IR from kaynewbie/algorithm :: algorithm/CodingInterviews (question-27)

; 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.TreeNode = type { i32, ptr, ptr }

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

6:                                                ; preds = %1
  br label %37

7:                                                ; preds = %1
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #2
  %8 = load ptr, ptr %2, align 8, !tbaa !5
  %9 = getelementptr inbounds %struct.TreeNode, ptr %8, i32 0, i32 1
  %10 = load ptr, ptr %9, align 8, !tbaa !9
  store ptr %10, ptr %3, align 8, !tbaa !5
  %11 = load ptr, ptr %2, align 8, !tbaa !5
  %12 = getelementptr inbounds %struct.TreeNode, ptr %11, i32 0, i32 2
  %13 = load ptr, ptr %12, align 8, !tbaa !12
  %14 = load ptr, ptr %2, align 8, !tbaa !5
  %15 = getelementptr inbounds %struct.TreeNode, ptr %14, i32 0, i32 1
  store ptr %13, ptr %15, align 8, !tbaa !9
  %16 = load ptr, ptr %3, align 8, !tbaa !5
  %17 = load ptr, ptr %2, align 8, !tbaa !5
  %18 = getelementptr inbounds %struct.TreeNode, ptr %17, i32 0, i32 2
  store ptr %16, ptr %18, align 8, !tbaa !12
  %19 = load ptr, ptr %2, align 8, !tbaa !5
  %20 = getelementptr inbounds %struct.TreeNode, ptr %19, i32 0, i32 1
  %21 = load ptr, ptr %20, align 8, !tbaa !9
  %22 = icmp ne ptr %21, null
  br i1 %22, label %23, label %27

23:                                               ; preds = %7
  %24 = load ptr, ptr %2, align 8, !tbaa !5
  %25 = getelementptr inbounds %struct.TreeNode, ptr %24, i32 0, i32 1
  %26 = load ptr, ptr %25, align 8, !tbaa !9
  call void @mirrorBinary(ptr noundef %26)
  br label %27

27:                                               ; preds = %23, %7
  %28 = load ptr, ptr %2, align 8, !tbaa !5
  %29 = getelementptr inbounds %struct.TreeNode, ptr %28, i32 0, i32 2
  %30 = load ptr, ptr %29, align 8, !tbaa !12
  %31 = icmp ne ptr %30, null
  br i1 %31, label %32, label %36

32:                                               ; preds = %27
  %33 = load ptr, ptr %2, align 8, !tbaa !5
  %34 = getelementptr inbounds %struct.TreeNode, ptr %33, i32 0, i32 2
  %35 = load ptr, ptr %34, align 8, !tbaa !12
  call void @mirrorBinary(ptr noundef %35)
  br label %36

36:                                               ; preds = %32, %27
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #2
  br label %37

37:                                               ; preds = %36, %6
  ret void
}

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

attributes #0 = { 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 #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = !{!"TreeNode", !11, i64 0, !6, i64 8, !6, i64 16}
!11 = !{!"int", !7, i64 0}
!12 = !{!10, !6, i64 16}


; 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 @mirrorBinary(ptr noundef %0) local_unnamed_addr #0 {
  br label %tailrecurse

tailrecurse:                                      ; preds = %9, %1
  %.tr = phi ptr [ %0, %1 ], [ %10, %9 ]
  %2 = icmp eq ptr %.tr, null
  br i1 %2, label %11, label %3

3:                                                ; preds = %tailrecurse
  %4 = getelementptr inbounds i8, ptr %.tr, i64 8
  %5 = load ptr, ptr %4, align 8, !tbaa !5
  %6 = getelementptr inbounds i8, ptr %.tr, i64 16
  %7 = load ptr, ptr %6, align 8, !tbaa !11
  store ptr %7, ptr %4, align 8, !tbaa !5
  store ptr %5, ptr %6, align 8, !tbaa !11
  %.not = icmp eq ptr %7, null
  br i1 %.not, label %9, label %8

8:                                                ; preds = %3
  tail call void @mirrorBinary(ptr noundef nonnull %7)
  %.pr = load ptr, ptr %6, align 8, !tbaa !11
  br label %9

9:                                                ; preds = %8, %3
  %10 = phi ptr [ %.pr, %8 ], [ %5, %3 ]
  %.not12 = icmp eq ptr %10, null
  br i1 %.not12, label %11, label %tailrecurse

11:                                               ; preds = %9, %tailrecurse
  ret void
}

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 = !{!"TreeNode", !7, i64 0, !10, i64 8, !10, i64 16}
!7 = !{!"int", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C/C++ TBAA"}
!10 = !{!"any pointer", !8, i64 0}
!11 = !{!6, !10, i64 16}


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