; LLVM IR from Hunterdii/GeeksforGeeks-POTD :: February 2025 GFG SOLUTION (February-05)

; 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.QueueNode = type { ptr, ptr }
%struct.Queue = type { ptr, ptr }

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: nounwind allocsize(0)
declare noalias ptr @malloc(i64 noundef) #1

; 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 @enqueue(ptr noundef %0, ptr noundef %1) #2 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = 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) #3
  %7 = call noalias ptr @malloc(i64 noundef 16) #4
  store ptr %7, ptr %5, align 8, !tbaa !5
  %8 = load ptr, ptr %4, align 8, !tbaa !5
  %9 = load ptr, ptr %5, align 8, !tbaa !5
  %10 = getelementptr inbounds %struct.QueueNode, ptr %9, i32 0, i32 0
  store ptr %8, ptr %10, align 8, !tbaa !9
  %11 = load ptr, ptr %5, align 8, !tbaa !5
  %12 = getelementptr inbounds %struct.QueueNode, ptr %11, i32 0, i32 1
  store ptr null, ptr %12, align 8, !tbaa !11
  %13 = load ptr, ptr %3, align 8, !tbaa !5
  %14 = getelementptr inbounds %struct.Queue, ptr %13, i32 0, i32 1
  %15 = load ptr, ptr %14, align 8, !tbaa !12
  %16 = icmp eq ptr %15, null
  br i1 %16, label %17, label %23

17:                                               ; preds = %2
  %18 = load ptr, ptr %5, align 8, !tbaa !5
  %19 = load ptr, ptr %3, align 8, !tbaa !5
  %20 = getelementptr inbounds %struct.Queue, ptr %19, i32 0, i32 1
  store ptr %18, ptr %20, align 8, !tbaa !12
  %21 = load ptr, ptr %3, align 8, !tbaa !5
  %22 = getelementptr inbounds %struct.Queue, ptr %21, i32 0, i32 0
  store ptr %18, ptr %22, align 8, !tbaa !14
  store i32 1, ptr %6, align 4
  br label %32

23:                                               ; preds = %2
  %24 = load ptr, ptr %5, align 8, !tbaa !5
  %25 = load ptr, ptr %3, align 8, !tbaa !5
  %26 = getelementptr inbounds %struct.Queue, ptr %25, i32 0, i32 1
  %27 = load ptr, ptr %26, align 8, !tbaa !12
  %28 = getelementptr inbounds %struct.QueueNode, ptr %27, i32 0, i32 1
  store ptr %24, ptr %28, align 8, !tbaa !11
  %29 = load ptr, ptr %5, align 8, !tbaa !5
  %30 = load ptr, ptr %3, align 8, !tbaa !5
  %31 = getelementptr inbounds %struct.Queue, ptr %30, i32 0, i32 1
  store ptr %29, ptr %31, align 8, !tbaa !12
  store i32 0, ptr %6, align 4
  br label %32

32:                                               ; preds = %23, %17
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #3
  %33 = load i32, ptr %6, align 4
  switch i32 %33, label %35 [
    i32 0, label %34
    i32 1, label %34
  ]

34:                                               ; preds = %32, %32
  ret void

35:                                               ; preds = %32
  unreachable
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { nounwind allocsize(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 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 #3 = { nounwind }
attributes #4 = { nounwind allocsize(0) }

!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 0}
!10 = !{!"QueueNode", !6, i64 0, !6, i64 8}
!11 = !{!10, !6, i64 8}
!12 = !{!13, !6, i64 8}
!13 = !{!"Queue", !6, i64 0, !6, i64 8}
!14 = !{!13, !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"

; Function Attrs: mustprogress nofree nounwind willreturn allockind("alloc,uninitialized") allocsize(0) memory(inaccessiblemem: readwrite)
declare noalias noundef ptr @malloc(i64 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress nofree nounwind willreturn memory(write, argmem: readwrite, inaccessiblemem: readwrite) uwtable
define dso_local void @enqueue(ptr nocapture noundef %0, ptr noundef %1) local_unnamed_addr #1 {
  %3 = tail call noalias dereferenceable_or_null(16) ptr @malloc(i64 noundef 16) #2
  store ptr %1, ptr %3, align 8, !tbaa !5
  %4 = getelementptr inbounds i8, ptr %3, i64 8
  store ptr null, ptr %4, align 8, !tbaa !10
  %5 = getelementptr inbounds i8, ptr %0, i64 8
  %6 = load ptr, ptr %5, align 8, !tbaa !11
  %7 = icmp eq ptr %6, null
  %8 = getelementptr inbounds i8, ptr %6, i64 8
  %.sink = select i1 %7, ptr %0, ptr %8
  store ptr %3, ptr %.sink, align 8, !tbaa !13
  store ptr %3, ptr %5, align 8
  ret void
}

attributes #0 = { mustprogress nofree nounwind willreturn allockind("alloc,uninitialized") allocsize(0) memory(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 #1 = { mustprogress nofree nounwind willreturn memory(write, argmem: readwrite, inaccessiblemem: readwrite) 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 allocsize(0) }

!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, !7, i64 0}
!6 = !{!"QueueNode", !7, i64 0, !7, i64 8}
!7 = !{!"any pointer", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C/C++ TBAA"}
!10 = !{!6, !7, i64 8}
!11 = !{!12, !7, i64 8}
!12 = !{!"Queue", !7, i64 0, !7, i64 8}
!13 = !{!7, !7, i64 0}


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