; LLVM IR from upupming/algorithm :: acwing/算法竞赛进阶指南/0x02-递推与递归/92. 递归实现指数型枚举.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
@_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 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 = %40, %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 %43

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
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #5
  store i32 1, ptr %5, align 4, !tbaa !5
  br label %14

14:                                               ; preds = %35, %12
  %15 = load i32, ptr %3, align 4, !tbaa !5
  %16 = icmp sgt i32 %15, 0
  br i1 %16, label %18, label %17

17:                                               ; preds = %14
  store i32 5, ptr %2, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #5
  br label %38

18:                                               ; preds = %14
  %19 = load i32, ptr %3, align 4, !tbaa !5
  %20 = and i32 %19, 1
  %21 = icmp ne i32 %20, 0
  br i1 %21, label %22, label %32

22:                                               ; preds = %18
  %23 = load i32, ptr %4, align 4, !tbaa !5
  %24 = icmp ne i32 %23, 0
  br i1 %24, label %25, label %27

25:                                               ; preds = %22
  %26 = 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 %27

27:                                               ; preds = %25, %22
  %28 = load i32, ptr %5, align 4, !tbaa !5
  %29 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %28)
  %30 = load i32, ptr %4, align 4, !tbaa !5
  %31 = add nsw i32 %30, 1
  store i32 %31, ptr %4, align 4, !tbaa !5
  br label %32

32:                                               ; preds = %27, %18
  %33 = load i32, ptr %3, align 4, !tbaa !5
  %34 = ashr i32 %33, 1
  store i32 %34, ptr %3, align 4, !tbaa !5
  br label %35

35:                                               ; preds = %32
  %36 = load i32, ptr %5, align 4, !tbaa !5
  %37 = add nsw i32 %36, 1
  store i32 %37, ptr %5, align 4, !tbaa !5
  br label %14, !llvm.loop !9

38:                                               ; preds = %17
  %39 = 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_)
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #5
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #5
  br label %40

40:                                               ; preds = %38
  %41 = load i32, ptr %1, align 4, !tbaa !5
  %42 = add nsw i32 %41, 1
  store i32 %42, ptr %1, align 4, !tbaa !5
  br label %6, !llvm.loop !11

43:                                               ; preds = %11
  ret void
}

; 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
@_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 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 %.preheader, label %._crit_edge20

.preheader:                                       ; preds = %0, %._crit_edge
  %.01219 = phi i32 [ %5, %._crit_edge ], [ 0, %0 ]
  %.not15 = icmp eq i32 %.01219, 0
  br i1 %.not15, label %._crit_edge, label %.lr.ph

._crit_edge20:                                    ; preds = %._crit_edge, %0
  ret void

._crit_edge:                                      ; preds = %16, %.preheader
  %4 = 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_)
  %5 = add nuw nsw i32 %.01219, 1
  %6 = load i32, ptr @n, align 4, !tbaa !5
  %7 = tail call noundef i32 @_Z4pow2i(i32 noundef %6)
  %8 = icmp slt i32 %5, %7
  br i1 %8, label %.preheader, label %._crit_edge20, !llvm.loop !9

.lr.ph:                                           ; preds = %.preheader, %16
  %.018 = phi i32 [ %18, %16 ], [ 1, %.preheader ]
  %.01017 = phi i32 [ %.1, %16 ], [ 0, %.preheader ]
  %.01116 = phi i32 [ %17, %16 ], [ %.01219, %.preheader ]
  %9 = and i32 %.01116, 1
  %.not13 = icmp eq i32 %9, 0
  br i1 %.not13, label %16, label %10

10:                                               ; preds = %.lr.ph
  %.not14 = icmp eq i32 %.01017, 0
  br i1 %.not14, label %13, label %11

11:                                               ; preds = %10
  %12 = 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 %13

13:                                               ; preds = %11, %10
  %14 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %.018)
  %15 = add nsw i32 %.01017, 1
  br label %16

16:                                               ; preds = %13, %.lr.ph
  %.1 = phi i32 [ %15, %13 ], [ %.01017, %.lr.ph ]
  %17 = lshr i32 %.01116, 1
  %18 = add nuw nsw i32 %.018, 1
  %.not = icmp ult i32 %.01116, 2
  br i1 %.not, label %._crit_edge, label %.lr.ph, !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