; LLVM IR from upupming/algorithm :: acwing/算法竞赛进阶指南/0x02-递推与递归/94. 递归实现排列型枚举.ll (Z3dfsv)

; 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::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 }
%"class.std::vector" = type { %"struct.std::_Vector_base" }
%"struct.std::_Vector_base" = type { %"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl" }
%"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl" = type { %"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl_data" }
%"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl_data" = type { ptr, ptr, ptr }
%"struct.std::_Rb_tree_const_iterator" = type { ptr }
%"struct.std::pair" = type <{ %"struct.std::_Rb_tree_const_iterator", i8, [7 x i8] }>

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

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z5printv() #0

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

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

; 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 void @_Z3dfsv() #0 {
  %1 = alloca %"struct.std::_Rb_tree_const_iterator", align 8
  %2 = alloca %"struct.std::_Rb_tree_const_iterator", align 8
  %3 = alloca i32, align 4
  %4 = alloca %"struct.std::pair", align 8
  %5 = alloca { ptr, i8 }, align 8
  %6 = alloca %"struct.std::_Rb_tree_const_iterator", align 8
  %7 = call noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24) @chosen) #4
  %8 = load i32, ptr @n, align 4, !tbaa !5
  %9 = sext i32 %8 to i64
  %10 = icmp eq i64 %7, %9
  br i1 %10, label %11, label %12

11:                                               ; preds = %0
  call void @_Z5printv()
  br label %12

12:                                               ; preds = %11, %0
  call void @llvm.lifetime.start.p0(i64 8, ptr %1) #4
  %13 = call ptr @_ZNKSt3setIiSt4lessIiESaIiEE5beginEv(ptr noundef nonnull align 8 dereferenceable(48) @s) #4
  %14 = getelementptr inbounds %"struct.std::_Rb_tree_const_iterator", ptr %1, i32 0, i32 0
  store ptr %13, ptr %14, align 8
  br label %15

15:                                               ; preds = %26, %12
  call void @llvm.lifetime.start.p0(i64 8, ptr %2) #4
  %16 = call ptr @_ZNKSt3setIiSt4lessIiESaIiEE3endEv(ptr noundef nonnull align 8 dereferenceable(48) @s) #4
  %17 = getelementptr inbounds %"struct.std::_Rb_tree_const_iterator", ptr %2, i32 0, i32 0
  store ptr %16, ptr %17, align 8
  %18 = call noundef zeroext i1 @_ZStneRKSt23_Rb_tree_const_iteratorIiES2_(ptr noundef nonnull align 8 dereferenceable(8) %1, ptr noundef nonnull align 8 dereferenceable(8) %2) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %2) #4
  br i1 %18, label %20, label %19

19:                                               ; preds = %15
  call void @llvm.lifetime.end.p0(i64 8, ptr %1) #4
  br label %29

20:                                               ; preds = %15
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #4
  %21 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNKSt23_Rb_tree_const_iteratorIiEdeEv(ptr noundef nonnull align 8 dereferenceable(8) %1) #4
  %22 = load i32, ptr %21, align 4, !tbaa !5
  store i32 %22, ptr %3, align 4, !tbaa !5
  call void @_ZNSt6vectorIiSaIiEE9push_backERKi(ptr noundef nonnull align 8 dereferenceable(24) @chosen, ptr noundef nonnull align 4 dereferenceable(4) %3)
  %23 = call noundef i64 @_ZNSt3setIiSt4lessIiESaIiEE5eraseERKi(ptr noundef nonnull align 8 dereferenceable(48) @s, ptr noundef nonnull align 4 dereferenceable(4) %3)
  call void @_Z3dfsv()
  call void @_ZNSt6vectorIiSaIiEE8pop_backEv(ptr noundef nonnull align 8 dereferenceable(24) @chosen) #4
  call void @llvm.lifetime.start.p0(i64 16, ptr %4) #4
  %24 = call { ptr, i8 } @_ZNSt3setIiSt4lessIiESaIiEE6insertERKi(ptr noundef nonnull align 8 dereferenceable(48) @s, ptr noundef nonnull align 4 dereferenceable(4) %3)
  store { ptr, i8 } %24, ptr %5, align 8
  call void @llvm.memcpy.p0.p0.i64(ptr align 8 %4, ptr align 8 %5, i64 9, i1 false)
  %25 = getelementptr inbounds %"struct.std::pair", ptr %4, i32 0, i32 0
  call void @llvm.memcpy.p0.p0.i64(ptr align 8 %1, ptr align 8 %25, i64 8, i1 false), !tbaa.struct !9
  call void @llvm.lifetime.end.p0(i64 16, ptr %4) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #4
  br label %26

26:                                               ; preds = %20
  %27 = call ptr @_ZNSt23_Rb_tree_const_iteratorIiEppEi(ptr noundef nonnull align 8 dereferenceable(8) %1, i32 noundef 0) #4
  %28 = getelementptr inbounds %"struct.std::_Rb_tree_const_iterator", ptr %6, i32 0, i32 0
  store ptr %27, ptr %28, align 8
  br label %15, !llvm.loop !12

29:                                               ; preds = %19
  ret void
}

; Function Attrs: mustprogress nounwind uwtable
declare dso_local ptr @_ZNKSt3setIiSt4lessIiESaIiEE5beginEv(ptr noundef nonnull align 8 dereferenceable(48)) #2 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef zeroext i1 @_ZStneRKSt23_Rb_tree_const_iteratorIiES2_(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef nonnull align 8 dereferenceable(8)) #2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local ptr @_ZNKSt3setIiSt4lessIiESaIiEE3endEv(ptr noundef nonnull align 8 dereferenceable(48)) #2 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZNKSt23_Rb_tree_const_iteratorIiEdeEv(ptr noundef nonnull align 8 dereferenceable(8)) #2 align 2

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZNSt6vectorIiSaIiEE9push_backERKi(ptr noundef nonnull align 8 dereferenceable(24), ptr noundef nonnull align 4 dereferenceable(4)) #0 align 2

; Function Attrs: mustprogress uwtable
declare dso_local noundef i64 @_ZNSt3setIiSt4lessIiESaIiEE5eraseERKi(ptr noundef nonnull align 8 dereferenceable(48), ptr noundef nonnull align 4 dereferenceable(4)) #0 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_ZNSt6vectorIiSaIiEE8pop_backEv(ptr noundef nonnull align 8 dereferenceable(24)) #2 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 nounwind willreturn memory(argmem: readwrite)
declare void @llvm.memcpy.p0.p0.i64(ptr noalias nocapture writeonly, ptr noalias nocapture readonly, i64, i1 immarg) #3

; Function Attrs: mustprogress nounwind uwtable
declare dso_local ptr @_ZNSt23_Rb_tree_const_iteratorIiEppEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) #2 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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { 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 #3 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
attributes #4 = { 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 = !{i64 0, i64 8, !10}
!10 = !{!11, !11, i64 0}
!11 = !{!"any pointer", !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"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::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 }
%"class.std::vector" = type { %"struct.std::_Vector_base" }
%"struct.std::_Vector_base" = type { %"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl" }
%"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl" = type { %"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl_data" }
%"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl_data" = type { ptr, ptr, ptr }
%"struct.std::_Rb_tree_const_iterator" = type { ptr }

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

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z5printv() 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 nounwind uwtable
declare dso_local noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24)) local_unnamed_addr #2 align 2

; 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 void @_Z3dfsv() local_unnamed_addr #0 {
  %1 = alloca %"struct.std::_Rb_tree_const_iterator", align 8
  %2 = alloca %"struct.std::_Rb_tree_const_iterator", align 8
  %3 = alloca i32, align 4
  %4 = tail call noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24) @chosen) #3
  %5 = load i32, ptr @n, align 4, !tbaa !5
  %6 = sext i32 %5 to i64
  %7 = icmp eq i64 %4, %6
  br i1 %7, label %8, label %9

8:                                                ; preds = %0
  tail call void @_Z5printv()
  br label %9

9:                                                ; preds = %8, %0
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %1) #3
  %10 = tail call ptr @_ZNKSt3setIiSt4lessIiESaIiEE5beginEv(ptr noundef nonnull align 8 dereferenceable(48) @s) #3
  store ptr %10, ptr %1, align 8
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %2) #3
  %11 = tail call ptr @_ZNKSt3setIiSt4lessIiESaIiEE3endEv(ptr noundef nonnull align 8 dereferenceable(48) @s) #3
  store ptr %11, ptr %2, align 8
  %12 = call noundef zeroext i1 @_ZStneRKSt23_Rb_tree_const_iteratorIiES2_(ptr noundef nonnull align 8 dereferenceable(8) %1, ptr noundef nonnull align 8 dereferenceable(8) %2) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %2) #3
  br i1 %12, label %.lr.ph, label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph, %9
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %1) #3
  ret void

.lr.ph:                                           ; preds = %9, %.lr.ph
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %3) #3
  %13 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNKSt23_Rb_tree_const_iteratorIiEdeEv(ptr noundef nonnull align 8 dereferenceable(8) %1) #3
  %14 = load i32, ptr %13, align 4, !tbaa !5
  store i32 %14, ptr %3, align 4, !tbaa !5
  call void @_ZNSt6vectorIiSaIiEE9push_backERKi(ptr noundef nonnull align 8 dereferenceable(24) @chosen, ptr noundef nonnull align 4 dereferenceable(4) %3)
  %15 = call noundef i64 @_ZNSt3setIiSt4lessIiESaIiEE5eraseERKi(ptr noundef nonnull align 8 dereferenceable(48) @s, ptr noundef nonnull align 4 dereferenceable(4) %3)
  call void @_Z3dfsv()
  call void @_ZNSt6vectorIiSaIiEE8pop_backEv(ptr noundef nonnull align 8 dereferenceable(24) @chosen) #3
  %16 = call { ptr, i8 } @_ZNSt3setIiSt4lessIiESaIiEE6insertERKi(ptr noundef nonnull align 8 dereferenceable(48) @s, ptr noundef nonnull align 4 dereferenceable(4) %3)
  %.fca.0.extract = extractvalue { ptr, i8 } %16, 0
  store ptr %.fca.0.extract, ptr %1, align 8, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %3) #3
  %17 = call ptr @_ZNSt23_Rb_tree_const_iteratorIiEppEi(ptr noundef nonnull align 8 dereferenceable(8) %1, i32 noundef 0) #3
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %2) #3
  %18 = call ptr @_ZNKSt3setIiSt4lessIiESaIiEE3endEv(ptr noundef nonnull align 8 dereferenceable(48) @s) #3
  store ptr %18, ptr %2, align 8
  %19 = call noundef zeroext i1 @_ZStneRKSt23_Rb_tree_const_iteratorIiES2_(ptr noundef nonnull align 8 dereferenceable(8) %1, ptr noundef nonnull align 8 dereferenceable(8) %2) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %2) #3
  br i1 %19, label %.lr.ph, label %._crit_edge, !llvm.loop !11
}

; Function Attrs: mustprogress nounwind uwtable
declare dso_local ptr @_ZNKSt3setIiSt4lessIiESaIiEE5beginEv(ptr noundef nonnull align 8 dereferenceable(48)) local_unnamed_addr #2 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef zeroext i1 @_ZStneRKSt23_Rb_tree_const_iteratorIiES2_(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef nonnull align 8 dereferenceable(8)) local_unnamed_addr #2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local ptr @_ZNKSt3setIiSt4lessIiESaIiEE3endEv(ptr noundef nonnull align 8 dereferenceable(48)) local_unnamed_addr #2 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZNKSt23_Rb_tree_const_iteratorIiEdeEv(ptr noundef nonnull align 8 dereferenceable(8)) local_unnamed_addr #2 align 2

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZNSt6vectorIiSaIiEE9push_backERKi(ptr noundef nonnull align 8 dereferenceable(24), ptr noundef nonnull align 4 dereferenceable(4)) local_unnamed_addr #0 align 2

; Function Attrs: mustprogress uwtable
declare dso_local noundef i64 @_ZNSt3setIiSt4lessIiESaIiEE5eraseERKi(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 void @_ZNSt6vectorIiSaIiEE8pop_backEv(ptr noundef nonnull align 8 dereferenceable(24)) local_unnamed_addr #2 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 ptr @_ZNSt23_Rb_tree_const_iteratorIiEppEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) local_unnamed_addr #2 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 nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { 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 #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 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}


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