; LLVM IR from HarshCasper/NeoAlgo :: C/ds (StackUsingQueue)

; 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 }

@front = external dso_local global ptr, align 8
@rear = external dso_local global ptr, align 8
@qsize = external dso_local global i32, align 4

; Function Attrs: nounwind uwtable
declare dso_local i32 @isEmpty(ptr noundef) #0

; 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

; Function Attrs: nounwind uwtable
define dso_local i32 @deQueue() #0 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #2
  %4 = load ptr, ptr @front, align 8, !tbaa !5
  %5 = call i32 @isEmpty(ptr noundef %4)
  %6 = icmp ne i32 %5, 0
  br i1 %6, label %7, label %8

7:                                                ; preds = %0
  store i32 -1, ptr %1, align 4
  store i32 1, ptr %3, align 4
  br label %26

8:                                                ; preds = %0
  %9 = load ptr, ptr @front, align 8, !tbaa !5
  %10 = getelementptr inbounds %struct.Node, ptr %9, i32 0, i32 0
  %11 = load i32, ptr %10, align 8, !tbaa !9
  store i32 %11, ptr %2, align 4, !tbaa !12
  %12 = load ptr, ptr @front, align 8, !tbaa !5
  %13 = getelementptr inbounds %struct.Node, ptr %12, i32 0, i32 1
  %14 = load ptr, ptr %13, align 8, !tbaa !13
  store ptr %14, ptr @front, align 8, !tbaa !5
  %15 = load ptr, ptr @front, align 8, !tbaa !5
  %16 = icmp eq ptr %15, null
  br i1 %16, label %17, label %21

17:                                               ; preds = %8
  %18 = load ptr, ptr @rear, align 8, !tbaa !5
  %19 = icmp eq ptr %18, null
  %20 = zext i1 %19 to i32
  br label %21

21:                                               ; preds = %17, %8
  %22 = load i32, ptr @qsize, align 4, !tbaa !12
  %23 = add nsw i32 %22, -1
  store i32 %23, ptr @qsize, align 4, !tbaa !12
  br label %24

24:                                               ; preds = %21
  %25 = load i32, ptr %2, align 4, !tbaa !12
  store i32 %25, ptr %1, align 4
  store i32 1, ptr %3, align 4
  br label %26

26:                                               ; preds = %24, %7
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #2
  %27 = load i32, ptr %1, align 4
  ret i32 %27
}

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, !11, i64 0}
!10 = !{!"Node", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = !{!11, !11, i64 0}
!13 = !{!10, !6, i64 8}


; 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"

@front = external dso_local local_unnamed_addr global ptr, align 8
@qsize = external dso_local local_unnamed_addr global i32, align 4

; Function Attrs: nounwind uwtable
declare dso_local i32 @isEmpty(ptr noundef) local_unnamed_addr #0

; Function Attrs: nounwind uwtable
define dso_local i32 @deQueue() local_unnamed_addr #0 {
  %1 = load ptr, ptr @front, align 8, !tbaa !5
  %2 = tail call i32 @isEmpty(ptr noundef %1)
  %.not = icmp eq i32 %2, 0
  br i1 %.not, label %3, label %10

3:                                                ; preds = %0
  %4 = load ptr, ptr @front, align 8, !tbaa !5
  %5 = load i32, ptr %4, align 8, !tbaa !9
  %6 = getelementptr inbounds i8, ptr %4, i64 8
  %7 = load ptr, ptr %6, align 8, !tbaa !12
  store ptr %7, ptr @front, align 8, !tbaa !5
  %8 = load i32, ptr @qsize, align 4, !tbaa !13
  %9 = add nsw i32 %8, -1
  store i32 %9, ptr @qsize, align 4, !tbaa !13
  br label %10

10:                                               ; preds = %0, %3
  %.0 = phi i32 [ %5, %3 ], [ -1, %0 ]
  ret i32 %.0
}

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" }

!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, !11, i64 0}
!10 = !{!"Node", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = !{!10, !6, i64 8}
!13 = !{!11, !11, i64 0}


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