; LLVM IR from upupming/algorithm :: CCCC-GPLT/L2-026. 小字辈.ll (Z3dfsii)

; 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"

%"class.std::vector" = type { %"struct.std::_Vector_base" }
%"struct.std::_Vector_base" = type { %"struct.std::_Vector_base<std::vector<int>, std::allocator<std::vector<int>>>::_Vector_impl" }
%"struct.std::_Vector_base<std::vector<int>, std::allocator<std::vector<int>>>::_Vector_impl" = type { %"struct.std::_Vector_base<std::vector<int>, std::allocator<std::vector<int>>>::_Vector_impl_data" }
%"struct.std::_Vector_base<std::vector<int>, std::allocator<std::vector<int>>>::_Vector_impl_data" = type { ptr, ptr, ptr }
%"class.std::set" = type { %"class.std::_Rb_tree" }
%"class.std::_Rb_tree" = type { %"struct.std::_Rb_tree<int, int, std::_Identity<int>, std::less<int>>::_Rb_tree_impl" }
%"struct.std::_Rb_tree<int, int, std::_Identity<int>, std::less<int>>::_Rb_tree_impl" = type { [8 x i8], %"struct.std::_Rb_tree_header" }
%"struct.std::_Rb_tree_header" = type { %"struct.std::_Rb_tree_node_base", i64 }
%"struct.std::_Rb_tree_node_base" = type { i32, ptr, ptr, ptr }
%"struct.std::pair" = type <{ %"struct.std::_Rb_tree_const_iterator", i8, [7 x i8] }>
%"struct.std::_Rb_tree_const_iterator" = type { ptr }

@maxlevel = external dso_local global i32, align 4
@v = external dso_local global %"class.std::vector", align 8
@s = external dso_local global %"class.std::set", align 8

; Function Attrs: mustprogress uwtable
define dso_local void @_Z3dfsii(i32 noundef %0, i32 noundef %1) #0 {
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca %"struct.std::pair", align 8
  %6 = alloca %"struct.std::pair", align 8
  %7 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !5
  %8 = load i32, ptr %4, align 4, !tbaa !5
  %9 = load i32, ptr @maxlevel, align 4, !tbaa !5
  %10 = icmp sgt i32 %8, %9
  br i1 %10, label %11, label %18

11:                                               ; preds = %2
  %12 = load i32, ptr %4, align 4, !tbaa !5
  store i32 %12, ptr @maxlevel, align 4, !tbaa !5
  call void @_ZNSt3setIiSt4lessIiESaIiEE5clearEv(ptr noundef nonnull align 8 dereferenceable(48) @s) #3
  %13 = call { ptr, i8 } @_ZNSt3setIiSt4lessIiESaIiEE6insertERKi(ptr noundef nonnull align 8 dereferenceable(48) @s, ptr noundef nonnull align 4 dereferenceable(4) %3)
  %14 = getelementptr inbounds { ptr, i8 }, ptr %5, i32 0, i32 0
  %15 = extractvalue { ptr, i8 } %13, 0
  store ptr %15, ptr %14, align 8
  %16 = getelementptr inbounds { ptr, i8 }, ptr %5, i32 0, i32 1
  %17 = extractvalue { ptr, i8 } %13, 1
  store i8 %17, ptr %16, align 8
  br label %29

18:                                               ; preds = %2
  %19 = load i32, ptr %4, align 4, !tbaa !5
  %20 = load i32, ptr @maxlevel, align 4, !tbaa !5
  %21 = icmp eq i32 %19, %20
  br i1 %21, label %22, label %28

22:                                               ; preds = %18
  %23 = call { ptr, i8 } @_ZNSt3setIiSt4lessIiESaIiEE6insertERKi(ptr noundef nonnull align 8 dereferenceable(48) @s, ptr noundef nonnull align 4 dereferenceable(4) %3)
  %24 = getelementptr inbounds { ptr, i8 }, ptr %6, i32 0, i32 0
  %25 = extractvalue { ptr, i8 } %23, 0
  store ptr %25, ptr %24, align 8
  %26 = getelementptr inbounds { ptr, i8 }, ptr %6, i32 0, i32 1
  %27 = extractvalue { ptr, i8 } %23, 1
  store i8 %27, ptr %26, align 8
  br label %28

28:                                               ; preds = %22, %18
  br label %29

29:                                               ; preds = %28, %11
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #3
  store i32 0, ptr %7, align 4, !tbaa !5
  br label %30

30:                                               ; preds = %49, %29
  %31 = load i32, ptr %7, align 4, !tbaa !5
  %32 = sext i32 %31 to i64
  %33 = load i32, ptr %3, align 4, !tbaa !5
  %34 = sext i32 %33 to i64
  %35 = call noundef nonnull align 8 dereferenceable(24) ptr @_ZNSt6vectorIS_IiSaIiEESaIS1_EEixEm(ptr noundef nonnull align 8 dereferenceable(24) @v, i64 noundef %34) #3
  %36 = call noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24) %35) #3
  %37 = icmp ult i64 %32, %36
  br i1 %37, label %39, label %38

38:                                               ; preds = %30
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #3
  br label %52

39:                                               ; preds = %30
  %40 = load i32, ptr %3, align 4, !tbaa !5
  %41 = sext i32 %40 to i64
  %42 = call noundef nonnull align 8 dereferenceable(24) ptr @_ZNSt6vectorIS_IiSaIiEESaIS1_EEixEm(ptr noundef nonnull align 8 dereferenceable(24) @v, i64 noundef %41) #3
  %43 = load i32, ptr %7, align 4, !tbaa !5
  %44 = sext i32 %43 to i64
  %45 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24) %42, i64 noundef %44) #3
  %46 = load i32, ptr %45, align 4, !tbaa !5
  %47 = load i32, ptr %4, align 4, !tbaa !5
  %48 = add nsw i32 %47, 1
  call void @_Z3dfsii(i32 noundef %46, i32 noundef %48)
  br label %49

49:                                               ; preds = %39
  %50 = load i32, ptr %7, align 4, !tbaa !5
  %51 = add nsw i32 %50, 1
  store i32 %51, ptr %7, align 4, !tbaa !5
  br label %30, !llvm.loop !9

52:                                               ; preds = %38
  ret void
}

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_ZNSt3setIiSt4lessIiESaIiEE5clearEv(ptr noundef nonnull align 8 dereferenceable(48)) #1 align 2

; Function Attrs: mustprogress uwtable
declare dso_local { ptr, i8 } @_ZNSt3setIiSt4lessIiESaIiEE6insertERKi(ptr noundef nonnull align 8 dereferenceable(48), ptr noundef nonnull align 4 dereferenceable(4)) #0 align 2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 8 dereferenceable(24) ptr @_ZNSt6vectorIS_IiSaIiEESaIS1_EEixEm(ptr noundef nonnull align 8 dereferenceable(24), i64 noundef) #1 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24)) #1 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24), i64 noundef) #1 align 2

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

%"class.std::vector" = type { %"struct.std::_Vector_base" }
%"struct.std::_Vector_base" = type { %"struct.std::_Vector_base<std::vector<int>, std::allocator<std::vector<int>>>::_Vector_impl" }
%"struct.std::_Vector_base<std::vector<int>, std::allocator<std::vector<int>>>::_Vector_impl" = type { %"struct.std::_Vector_base<std::vector<int>, std::allocator<std::vector<int>>>::_Vector_impl_data" }
%"struct.std::_Vector_base<std::vector<int>, std::allocator<std::vector<int>>>::_Vector_impl_data" = type { ptr, ptr, ptr }
%"class.std::set" = type { %"class.std::_Rb_tree" }
%"class.std::_Rb_tree" = type { %"struct.std::_Rb_tree<int, int, std::_Identity<int>, std::less<int>>::_Rb_tree_impl" }
%"struct.std::_Rb_tree<int, int, std::_Identity<int>, std::less<int>>::_Rb_tree_impl" = type { [8 x i8], %"struct.std::_Rb_tree_header" }
%"struct.std::_Rb_tree_header" = type { %"struct.std::_Rb_tree_node_base", i64 }
%"struct.std::_Rb_tree_node_base" = type { i32, ptr, ptr, ptr }

@maxlevel = external dso_local local_unnamed_addr global i32, align 4
@v = external dso_local global %"class.std::vector", align 8
@s = external dso_local global %"class.std::set", align 8

; Function Attrs: mustprogress uwtable
define dso_local void @_Z3dfsii(i32 noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  %4 = load i32, ptr @maxlevel, align 4, !tbaa !5
  %5 = icmp slt i32 %4, %1
  br i1 %5, label %6, label %7

6:                                                ; preds = %2
  store i32 %1, ptr @maxlevel, align 4, !tbaa !5
  tail call void @_ZNSt3setIiSt4lessIiESaIiEE5clearEv(ptr noundef nonnull align 8 dereferenceable(48) @s) #2
  br label %.sink.split

7:                                                ; preds = %2
  %8 = icmp eq i32 %4, %1
  br i1 %8, label %.sink.split, label %10

.sink.split:                                      ; preds = %7, %6
  %9 = call { ptr, i8 } @_ZNSt3setIiSt4lessIiESaIiEE6insertERKi(ptr noundef nonnull align 8 dereferenceable(48) @s, ptr noundef nonnull align 4 dereferenceable(4) %3)
  br label %10

10:                                               ; preds = %.sink.split, %7
  %11 = load i32, ptr %3, align 4, !tbaa !5
  %12 = sext i32 %11 to i64
  %13 = call noundef nonnull align 8 dereferenceable(24) ptr @_ZNSt6vectorIS_IiSaIiEESaIS1_EEixEm(ptr noundef nonnull align 8 dereferenceable(24) @v, i64 noundef %12) #2
  %14 = call noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24) %13) #2
  %.not = icmp eq i64 %14, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %10
  %15 = add nsw i32 %1, 1
  br label %16

._crit_edge:                                      ; preds = %16, %10
  ret void

16:                                               ; preds = %.lr.ph, %16
  %indvars.iv = phi i64 [ 0, %.lr.ph ], [ %indvars.iv.next, %16 ]
  %17 = load i32, ptr %3, align 4, !tbaa !5
  %18 = sext i32 %17 to i64
  %19 = call noundef nonnull align 8 dereferenceable(24) ptr @_ZNSt6vectorIS_IiSaIiEESaIS1_EEixEm(ptr noundef nonnull align 8 dereferenceable(24) @v, i64 noundef %18) #2
  %20 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24) %19, i64 noundef %indvars.iv) #2
  %21 = load i32, ptr %20, align 4, !tbaa !5
  call void @_Z3dfsii(i32 noundef %21, i32 noundef %15)
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %22 = load i32, ptr %3, align 4, !tbaa !5
  %23 = sext i32 %22 to i64
  %24 = call noundef nonnull align 8 dereferenceable(24) ptr @_ZNSt6vectorIS_IiSaIiEESaIS1_EEixEm(ptr noundef nonnull align 8 dereferenceable(24) @v, i64 noundef %23) #2
  %25 = call noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24) %24) #2
  %26 = icmp ugt i64 %25, %indvars.iv.next
  br i1 %26, label %16, label %._crit_edge, !llvm.loop !9
}

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_ZNSt3setIiSt4lessIiESaIiEE5clearEv(ptr noundef nonnull align 8 dereferenceable(48)) local_unnamed_addr #1 align 2

; Function Attrs: mustprogress uwtable
declare dso_local { ptr, i8 } @_ZNSt3setIiSt4lessIiESaIiEE6insertERKi(ptr noundef nonnull align 8 dereferenceable(48), ptr noundef nonnull align 4 dereferenceable(4)) local_unnamed_addr #0 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 8 dereferenceable(24) ptr @_ZNSt6vectorIS_IiSaIiEESaIS1_EEixEm(ptr noundef nonnull align 8 dereferenceable(24), i64 noundef) local_unnamed_addr #1 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24)) local_unnamed_addr #1 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24), i64 noundef) local_unnamed_addr #1 align 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 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 }

!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"}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LICMPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,SROAPass,SimplifyCFGPass,TailCallElimPass