; LLVM IR from upupming/algorithm :: acwing/算法竞赛进阶指南/0x02-递推与递归/93. 递归实现组合型枚举.ll (Z5solvev)

; 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::basic_ostream" = type { ptr, %"class.std::basic_ios" }
%"class.std::basic_ios" = type { %"class.std::ios_base", ptr, i8, i8, ptr, ptr, ptr, ptr }
%"class.std::ios_base" = type { ptr, i64, i64, i32, i32, i32, ptr, %"struct.std::ios_base::_Words", [8 x %"struct.std::ios_base::_Words"], i32, ptr, %"class.std::locale" }
%"struct.std::ios_base::_Words" = type { ptr, i64 }
%"class.std::locale" = type { ptr }

@n = external dso_local global i32, align 4
@m = external dso_local global i32, align 4
@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@.str = external hidden unnamed_addr constant [2 x i8], align 1

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef i32 @_Z4pow2i(i32 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: mustprogress nounwind uwtable
declare dso_local noundef i32 @_Z7bitsSumi(i32 noundef) #0

; Function Attrs: mustprogress uwtable
define dso_local void @_Z5solvev() #2 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr %1) #5
  store i32 0, ptr %1, align 4, !tbaa !5
  br label %6

6:                                                ; preds = %49, %0
  %7 = load i32, ptr %1, align 4, !tbaa !5
  %8 = load i32, ptr @n, align 4, !tbaa !5
  %9 = call noundef i32 @_Z4pow2i(i32 noundef %8)
  %10 = icmp slt i32 %7, %9
  br i1 %10, label %12, label %11

11:                                               ; preds = %6
  store i32 2, ptr %2, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %1) #5
  br label %52

12:                                               ; preds = %6
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #5
  %13 = load i32, ptr %1, align 4, !tbaa !5
  store i32 %13, ptr %3, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #5
  store i32 0, ptr %4, align 4, !tbaa !5
  %14 = load i32, ptr %1, align 4, !tbaa !5
  %15 = call noundef i32 @_Z7bitsSumi(i32 noundef %14)
  %16 = load i32, ptr @m, align 4, !tbaa !5
  %17 = icmp ne i32 %15, %16
  br i1 %17, label %18, label %19

18:                                               ; preds = %12
  store i32 4, ptr %2, align 4
  br label %46

19:                                               ; preds = %12
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #5
  store i32 1, ptr %5, align 4, !tbaa !5
  br label %20

20:                                               ; preds = %41, %19
  %21 = load i32, ptr %3, align 4, !tbaa !5
  %22 = icmp sgt i32 %21, 0
  br i1 %22, label %24, label %23

23:                                               ; preds = %20
  store i32 5, ptr %2, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #5
  br label %44

24:                                               ; preds = %20
  %25 = load i32, ptr %3, align 4, !tbaa !5
  %26 = and i32 %25, 1
  %27 = icmp ne i32 %26, 0
  br i1 %27, label %28, label %38

28:                                               ; preds = %24
  %29 = load i32, ptr %4, align 4, !tbaa !5
  %30 = icmp ne i32 %29, 0
  br i1 %30, label %31, label %33

31:                                               ; preds = %28
  %32 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef @.str)
  br label %33

33:                                               ; preds = %31, %28
  %34 = load i32, ptr %5, align 4, !tbaa !5
  %35 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %34)
  %36 = load i32, ptr %4, align 4, !tbaa !5
  %37 = add nsw i32 %36, 1
  store i32 %37, ptr %4, align 4, !tbaa !5
  br label %38

38:                                               ; preds = %33, %24
  %39 = load i32, ptr %3, align 4, !tbaa !5
  %40 = ashr i32 %39, 1
  store i32 %40, ptr %3, align 4, !tbaa !5
  br label %41

41:                                               ; preds = %38
  %42 = load i32, ptr %5, align 4, !tbaa !5
  %43 = add nsw i32 %42, 1
  store i32 %43, ptr %5, align 4, !tbaa !5
  br label %20, !llvm.loop !9

44:                                               ; preds = %23
  %45 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
  store i32 0, ptr %2, align 4
  br label %46

46:                                               ; preds = %44, %18
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #5
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #5
  %47 = load i32, ptr %2, align 4
  switch i32 %47, label %53 [
    i32 0, label %48
    i32 4, label %49
  ]

48:                                               ; preds = %46
  br label %49

49:                                               ; preds = %48, %46
  %50 = load i32, ptr %1, align 4, !tbaa !5
  %51 = add nsw i32 %50, 1
  store i32 %51, ptr %1, align 4, !tbaa !5
  br label %6, !llvm.loop !11

52:                                               ; preds = %11
  ret void

53:                                               ; preds = %46
  unreachable
}

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) #3

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) #4

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) #2 align 2

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_(ptr noundef nonnull align 8 dereferenceable(8)) #3

attributes #0 = { 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 #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { 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 #3 = { inlinehint 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 #4 = { "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 #5 = { 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"}
!11 = distinct !{!11, !10}


; 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::basic_ostream" = type { ptr, %"class.std::basic_ios" }
%"class.std::basic_ios" = type { %"class.std::ios_base", ptr, i8, i8, ptr, ptr, ptr, ptr }
%"class.std::ios_base" = type { ptr, i64, i64, i32, i32, i32, ptr, %"struct.std::ios_base::_Words", [8 x %"struct.std::ios_base::_Words"], i32, ptr, %"class.std::locale" }
%"struct.std::ios_base::_Words" = type { ptr, i64 }
%"class.std::locale" = type { ptr }

@n = external dso_local local_unnamed_addr global i32, align 4
@m = external dso_local local_unnamed_addr global i32, align 4
@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@.str = external hidden unnamed_addr constant [2 x i8], align 1

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef i32 @_Z4pow2i(i32 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef i32 @_Z7bitsSumi(i32 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress uwtable
define dso_local void @_Z5solvev() local_unnamed_addr #1 {
  %1 = load i32, ptr @n, align 4, !tbaa !5
  %2 = tail call noundef i32 @_Z4pow2i(i32 noundef %1)
  %3 = icmp sgt i32 %2, 0
  br i1 %3, label %.lr.ph24, label %._crit_edge25

._crit_edge25:                                    ; preds = %17, %0
  ret void

.lr.ph24:                                         ; preds = %0, %17
  %.01321 = phi i32 [ %18, %17 ], [ 0, %0 ]
  %4 = tail call noundef i32 @_Z7bitsSumi(i32 noundef %.01321)
  %5 = load i32, ptr @m, align 4, !tbaa !5
  %.not = icmp eq i32 %4, %5
  br i1 %.not, label %.preheader, label %17

.preheader:                                       ; preds = %.lr.ph24
  %.not1417 = icmp eq i32 %.01321, 0
  br i1 %.not1417, label %._crit_edge, label %.lr.ph

._crit_edge:                                      ; preds = %14, %.preheader
  %6 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef nonnull @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
  br label %17

.lr.ph:                                           ; preds = %.preheader, %14
  %.020 = phi i32 [ %16, %14 ], [ 1, %.preheader ]
  %.01119 = phi i32 [ %.1, %14 ], [ 0, %.preheader ]
  %.01218 = phi i32 [ %15, %14 ], [ %.01321, %.preheader ]
  %7 = and i32 %.01218, 1
  %.not15 = icmp eq i32 %7, 0
  br i1 %.not15, label %14, label %8

8:                                                ; preds = %.lr.ph
  %.not16 = icmp eq i32 %.01119, 0
  br i1 %.not16, label %11, label %9

9:                                                ; preds = %8
  %10 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef nonnull @.str)
  br label %11

11:                                               ; preds = %9, %8
  %12 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %.020)
  %13 = add nsw i32 %.01119, 1
  br label %14

14:                                               ; preds = %11, %.lr.ph
  %.1 = phi i32 [ %13, %11 ], [ %.01119, %.lr.ph ]
  %15 = lshr i32 %.01218, 1
  %16 = add nuw nsw i32 %.020, 1
  %.not14 = icmp ult i32 %.01218, 2
  br i1 %.not14, label %._crit_edge, label %.lr.ph, !llvm.loop !9

17:                                               ; preds = %.lr.ph24, %._crit_edge
  %18 = add nuw nsw i32 %.01321, 1
  %19 = load i32, ptr @n, align 4, !tbaa !5
  %20 = tail call noundef i32 @_Z4pow2i(i32 noundef %19)
  %21 = icmp slt i32 %18, %20
  br i1 %21, label %.lr.ph24, label %._crit_edge25, !llvm.loop !11
}

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) local_unnamed_addr #2

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) local_unnamed_addr #3

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) local_unnamed_addr #1 align 2

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_(ptr noundef nonnull align 8 dereferenceable(8)) #2

attributes #0 = { 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 #1 = { 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 #2 = { inlinehint 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 #3 = { "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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}
!11 = distinct !{!11, !10}


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