; LLVM IR from gargarchit/Data_Structure_n_Algorithms :: Binary_Tree (Level_order_traversal)

; 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.Qnode = type { ptr, ptr }

@last = external dso_local global ptr, align 8

; 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 ptr @dequeue() #1 {
  %1 = alloca ptr, align 8
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = load ptr, ptr @last, align 8, !tbaa !5
  %6 = icmp eq ptr %5, null
  br i1 %6, label %7, label %8

7:                                                ; preds = %0
  store ptr null, ptr %1, align 8
  br label %36

8:                                                ; preds = %0
  %9 = load ptr, ptr @last, align 8, !tbaa !5
  %10 = getelementptr inbounds %struct.Qnode, ptr %9, i32 0, i32 1
  %11 = load ptr, ptr %10, align 8, !tbaa !9
  %12 = load ptr, ptr @last, align 8, !tbaa !5
  %13 = icmp eq ptr %11, %12
  br i1 %13, label %14, label %20

14:                                               ; preds = %8
  call void @llvm.lifetime.start.p0(i64 8, ptr %2) #3
  %15 = load ptr, ptr @last, align 8, !tbaa !5
  %16 = getelementptr inbounds %struct.Qnode, ptr %15, i32 0, i32 0
  %17 = load ptr, ptr %16, align 8, !tbaa !11
  store ptr %17, ptr %2, align 8, !tbaa !5
  %18 = load ptr, ptr @last, align 8, !tbaa !5
  call void @free(ptr noundef %18) #3
  store ptr null, ptr @last, align 8, !tbaa !5
  %19 = load ptr, ptr %2, align 8, !tbaa !5
  store ptr %19, ptr %1, align 8
  call void @llvm.lifetime.end.p0(i64 8, ptr %2) #3
  br label %36

20:                                               ; preds = %8
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #3
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #3
  %21 = load ptr, ptr @last, align 8, !tbaa !5
  %22 = getelementptr inbounds %struct.Qnode, ptr %21, i32 0, i32 1
  %23 = load ptr, ptr %22, align 8, !tbaa !9
  store ptr %23, ptr %4, align 8, !tbaa !5
  %24 = load ptr, ptr @last, align 8, !tbaa !5
  %25 = getelementptr inbounds %struct.Qnode, ptr %24, i32 0, i32 1
  %26 = load ptr, ptr %25, align 8, !tbaa !9
  %27 = getelementptr inbounds %struct.Qnode, ptr %26, i32 0, i32 1
  %28 = load ptr, ptr %27, align 8, !tbaa !9
  %29 = load ptr, ptr @last, align 8, !tbaa !5
  %30 = getelementptr inbounds %struct.Qnode, ptr %29, i32 0, i32 1
  store ptr %28, ptr %30, align 8, !tbaa !9
  %31 = load ptr, ptr %4, align 8, !tbaa !5
  %32 = getelementptr inbounds %struct.Qnode, ptr %31, i32 0, i32 0
  %33 = load ptr, ptr %32, align 8, !tbaa !11
  store ptr %33, ptr %3, align 8, !tbaa !5
  %34 = load ptr, ptr %4, align 8, !tbaa !5
  call void @free(ptr noundef %34) #3
  %35 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %35, ptr %1, align 8
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #3
  br label %36

36:                                               ; preds = %20, %14, %7
  %37 = load ptr, ptr %1, align 8
  ret ptr %37
}

; Function Attrs: nounwind
declare void @free(ptr noundef) #2

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 "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 #3 = { 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 = !{!"Qnode", !6, i64 0, !6, i64 8}
!11 = !{!10, !6, 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"

@last = external dso_local local_unnamed_addr global ptr, align 8

; Function Attrs: mustprogress nounwind willreturn uwtable
define dso_local ptr @dequeue() local_unnamed_addr #0 {
  %1 = load ptr, ptr @last, align 8, !tbaa !5
  %2 = icmp eq ptr %1, null
  br i1 %2, label %13, label %3

3:                                                ; preds = %0
  %4 = getelementptr inbounds i8, ptr %1, i64 8
  %5 = load ptr, ptr %4, align 8, !tbaa !9
  %6 = icmp eq ptr %5, %1
  br i1 %6, label %7, label %9

7:                                                ; preds = %3
  %8 = load ptr, ptr %1, align 8, !tbaa !11
  tail call void @free(ptr noundef nonnull %1) #2
  store ptr null, ptr @last, align 8, !tbaa !5
  br label %13

9:                                                ; preds = %3
  %10 = getelementptr inbounds i8, ptr %5, i64 8
  %11 = load ptr, ptr %10, align 8, !tbaa !9
  store ptr %11, ptr %4, align 8, !tbaa !9
  %12 = load ptr, ptr %5, align 8, !tbaa !11
  tail call void @free(ptr noundef %5) #2
  br label %13

13:                                               ; preds = %0, %9, %7
  %.0 = phi ptr [ %8, %7 ], [ %12, %9 ], [ null, %0 ]
  ret ptr %.0
}

; Function Attrs: mustprogress nounwind willreturn allockind("free") memory(argmem: readwrite, inaccessiblemem: readwrite)
declare void @free(ptr allocptr nocapture noundef) local_unnamed_addr #1

attributes #0 = { mustprogress nounwind willreturn 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 = { mustprogress nounwind willreturn allockind("free") memory(argmem: readwrite, inaccessiblemem: readwrite) "alloc-family"="malloc" "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 = !{!"Qnode", !6, i64 0, !6, i64 8}
!11 = !{!10, !6, i64 0}


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