; LLVM IR from HarshCasper/NeoAlgo :: C-Plus-Plus/graphs/Largest_distance_between_2_nodes_in_a_tree.ll (Z5solvei)

; 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"

@visited = external dso_local global [40010 x i32], align 16
@mx = external dso_local global i32, align 4

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z3dfsiiRi(i32 noundef, i32 noundef, ptr noundef nonnull align 4 dereferenceable(4)) #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: mustprogress uwtable
define dso_local noundef i32 @_Z5solvei(i32 noundef %0) #0 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  %7 = load i32, ptr %3, align 4, !tbaa !5
  %8 = icmp eq i32 %7, 1
  br i1 %8, label %9, label %10

9:                                                ; preds = %1
  store i32 0, ptr %2, align 4
  br label %26

10:                                               ; preds = %1
  store i32 0, ptr @mx, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #2
  store i32 -1, ptr %4, align 4, !tbaa !5
  call void @_Z3dfsiiRi(i32 noundef 0, i32 noundef 0, ptr noundef nonnull align 4 dereferenceable(4) %4)
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #2
  store i32 0, ptr %5, align 4, !tbaa !5
  br label %11

11:                                               ; preds = %20, %10
  %12 = load i32, ptr %5, align 4, !tbaa !5
  %13 = load i32, ptr %3, align 4, !tbaa !5
  %14 = icmp slt i32 %12, %13
  br i1 %14, label %16, label %15

15:                                               ; preds = %11
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  br label %23

16:                                               ; preds = %11
  %17 = load i32, ptr %5, align 4, !tbaa !5
  %18 = sext i32 %17 to i64
  %19 = getelementptr inbounds [40010 x i32], ptr @visited, i64 0, i64 %18
  store i32 0, ptr %19, align 4, !tbaa !5
  br label %20

20:                                               ; preds = %16
  %21 = load i32, ptr %5, align 4, !tbaa !5
  %22 = add nsw i32 %21, 1
  store i32 %22, ptr %5, align 4, !tbaa !5
  br label %11, !llvm.loop !9

23:                                               ; preds = %15
  store i32 0, ptr @mx, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #2
  store i32 -1, ptr %6, align 4, !tbaa !5
  %24 = load i32, ptr %4, align 4, !tbaa !5
  call void @_Z3dfsiiRi(i32 noundef %24, i32 noundef 0, ptr noundef nonnull align 4 dereferenceable(4) %6)
  %25 = load i32, ptr @mx, align 4, !tbaa !5
  store i32 %25, ptr %2, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  br label %26

26:                                               ; preds = %23, %9
  %27 = load i32, ptr %2, align 4
  ret i32 %27
}

attributes #0 = { mustprogress 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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


; 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"

@visited = external dso_local local_unnamed_addr global [40010 x i32], align 16
@mx = external dso_local local_unnamed_addr global i32, align 4

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z3dfsiiRi(i32 noundef, i32 noundef, ptr noundef nonnull align 4 dereferenceable(4)) local_unnamed_addr #0

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

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

; Function Attrs: mustprogress uwtable
define dso_local noundef i32 @_Z5solvei(i32 noundef %0) local_unnamed_addr #0 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = icmp eq i32 %0, 1
  br i1 %4, label %11, label %5

5:                                                ; preds = %1
  store i32 0, ptr @mx, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %2) #3
  store i32 -1, ptr %2, align 4, !tbaa !5
  call void @_Z3dfsiiRi(i32 noundef 0, i32 noundef 0, ptr noundef nonnull align 4 dereferenceable(4) %2)
  %6 = icmp sgt i32 %0, 0
  br i1 %6, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %5
  %7 = zext nneg i32 %0 to i64
  %8 = shl nuw nsw i64 %7, 2
  call void @llvm.memset.p0.i64(ptr nonnull align 16 @visited, i8 0, i64 %8, i1 false), !tbaa !5
  br label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph.preheader, %5
  store i32 0, ptr @mx, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %3) #3
  store i32 -1, ptr %3, align 4, !tbaa !5
  %9 = load i32, ptr %2, align 4, !tbaa !5
  call void @_Z3dfsiiRi(i32 noundef %9, i32 noundef 0, ptr noundef nonnull align 4 dereferenceable(4) %3)
  %10 = load i32, ptr @mx, align 4, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %3) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %2) #3
  br label %11

11:                                               ; preds = %1, %._crit_edge
  %.06 = phi i32 [ %10, %._crit_edge ], [ 0, %1 ]
  ret i32 %.06
}

; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: write)
declare void @llvm.memset.p0.i64(ptr nocapture writeonly, i8, i64, i1 immarg) #2

attributes #0 = { mustprogress 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 nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { nocallback nofree nounwind willreturn memory(argmem: write) }
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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}


; Effective O3 passes: GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,LoopIdiomRecognizePass,LoopRotatePass,LoopSimplifyPass,SROAPass,SimplifyCFGPass