; LLVM IR from upupming/algorithm :: acwing/日常刷题/kick-start/561. 大按钮.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_istream" = type { ptr, i64, %"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 }
%"class.std::__cxx11::basic_string" = type { %"struct.std::__cxx11::basic_string<char>::_Alloc_hider", i64, %union.anon }
%"struct.std::__cxx11::basic_string<char>::_Alloc_hider" = type { ptr }
%union.anon = type { i64, [8 x i8] }

@n = external dso_local global i32, align 4
@p = external dso_local global i32, align 4
@_ZSt3cin = external global %"class.std::basic_istream", align 8

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_Z6insertRNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr noundef nonnull align 8 dereferenceable(32)) #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
declare dso_local noundef i64 @_Z3dfsii(i32 noundef, i32 noundef) #2

; Function Attrs: mustprogress uwtable
define dso_local noundef i64 @_Z5solvev() #2 personality ptr @__gxx_personality_v0 {
  %1 = alloca %"class.std::__cxx11::basic_string", align 8
  %2 = alloca ptr, align 8
  %3 = alloca i32, align 4
  br label %4

4:                                                ; preds = %10, %0
  %5 = load i32, ptr @p, align 4, !tbaa !5
  %6 = add nsw i32 %5, -1
  store i32 %6, ptr @p, align 4, !tbaa !5
  %7 = icmp ne i32 %5, 0
  br i1 %7, label %8, label %15

8:                                                ; preds = %4
  call void @llvm.lifetime.start.p0(i64 32, ptr %1) #4
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2Ev(ptr noundef nonnull align 8 dereferenceable(32) %1) #4
  %9 = invoke noundef nonnull align 8 dereferenceable(16) ptr @_ZStrsIcSt11char_traitsIcESaIcEERSt13basic_istreamIT_T0_ES7_RNSt7__cxx1112basic_stringIS4_S5_T1_EE(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 8 dereferenceable(32) %1)
          to label %10 unwind label %11

10:                                               ; preds = %8
  call void @_Z6insertRNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr noundef nonnull align 8 dereferenceable(32) %1)
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %1) #4
  call void @llvm.lifetime.end.p0(i64 32, ptr %1) #4
  br label %4, !llvm.loop !9

11:                                               ; preds = %8
  %12 = landingpad { ptr, i32 }
          cleanup
  %13 = extractvalue { ptr, i32 } %12, 0
  store ptr %13, ptr %2, align 8
  %14 = extractvalue { ptr, i32 } %12, 1
  store i32 %14, ptr %3, align 4
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %1) #4
  call void @llvm.lifetime.end.p0(i64 32, ptr %1) #4
  br label %21

15:                                               ; preds = %4
  %16 = load i32, ptr @n, align 4, !tbaa !5
  %17 = zext i32 %16 to i64
  %18 = shl i64 1, %17
  %19 = call noundef i64 @_Z3dfsii(i32 noundef 1, i32 noundef 0)
  %20 = sub nsw i64 %18, %19
  ret i64 %20

21:                                               ; preds = %11
  %22 = load ptr, ptr %2, align 8
  %23 = load i32, ptr %3, align 4
  %24 = insertvalue { ptr, i32 } poison, ptr %22, 0
  %25 = insertvalue { ptr, i32 } %24, i32 %23, 1
  resume { ptr, i32 } %25
}

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2Ev(ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #0 align 2

declare noundef nonnull align 8 dereferenceable(16) ptr @_ZStrsIcSt11char_traitsIcESaIcEERSt13basic_istreamIT_T0_ES7_RNSt7__cxx1112basic_stringIS4_S5_T1_EE(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 8 dereferenceable(32)) #3

declare i32 @__gxx_personality_v0(...)

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #0 align 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 = { 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 = { "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 = { 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::basic_istream" = type { ptr, i64, %"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 }
%"class.std::__cxx11::basic_string" = type { %"struct.std::__cxx11::basic_string<char>::_Alloc_hider", i64, %union.anon }
%"struct.std::__cxx11::basic_string<char>::_Alloc_hider" = type { ptr }
%union.anon = type { i64, [8 x i8] }

@n = external dso_local local_unnamed_addr global i32, align 4
@p = external dso_local local_unnamed_addr global i32, align 4
@_ZSt3cin = external global %"class.std::basic_istream", align 8

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_Z6insertRNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr noundef nonnull align 8 dereferenceable(32)) 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
declare dso_local noundef i64 @_Z3dfsii(i32 noundef, i32 noundef) local_unnamed_addr #2

; Function Attrs: mustprogress uwtable
define dso_local noundef i64 @_Z5solvev() local_unnamed_addr #2 personality ptr @__gxx_personality_v0 {
  %1 = alloca %"class.std::__cxx11::basic_string", align 8
  %2 = load i32, ptr @p, align 4, !tbaa !5
  %3 = add nsw i32 %2, -1
  store i32 %3, ptr @p, align 4, !tbaa !5
  %.not1 = icmp eq i32 %2, 0
  br i1 %.not1, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %0, %5
  call void @llvm.lifetime.start.p0(i64 32, ptr nonnull %1) #4
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2Ev(ptr noundef nonnull align 8 dereferenceable(32) %1) #4
  %4 = invoke noundef nonnull align 8 dereferenceable(16) ptr @_ZStrsIcSt11char_traitsIcESaIcEERSt13basic_istreamIT_T0_ES7_RNSt7__cxx1112basic_stringIS4_S5_T1_EE(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 8 dereferenceable(32) %1)
          to label %5 unwind label %8

5:                                                ; preds = %.lr.ph
  call void @_Z6insertRNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr noundef nonnull align 8 dereferenceable(32) %1)
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %1) #4
  call void @llvm.lifetime.end.p0(i64 32, ptr nonnull %1) #4
  %6 = load i32, ptr @p, align 4, !tbaa !5
  %7 = add nsw i32 %6, -1
  store i32 %7, ptr @p, align 4, !tbaa !5
  %.not = icmp eq i32 %6, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !9

8:                                                ; preds = %.lr.ph
  %9 = landingpad { ptr, i32 }
          cleanup
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %1) #4
  call void @llvm.lifetime.end.p0(i64 32, ptr nonnull %1) #4
  resume { ptr, i32 } %9

._crit_edge:                                      ; preds = %5, %0
  %10 = load i32, ptr @n, align 4, !tbaa !5
  %11 = zext nneg i32 %10 to i64
  %12 = shl nuw i64 1, %11
  %13 = call noundef i64 @_Z3dfsii(i32 noundef 1, i32 noundef 0)
  %14 = sub nsw i64 %12, %13
  ret i64 %14
}

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2Ev(ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #0 align 2

declare noundef nonnull align 8 dereferenceable(16) ptr @_ZStrsIcSt11char_traitsIcESaIcEERSt13basic_istreamIT_T0_ES7_RNSt7__cxx1112basic_stringIS4_S5_T1_EE(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 8 dereferenceable(32)) local_unnamed_addr #3

declare i32 @__gxx_personality_v0(...)

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #0 align 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 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 = { "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 = { 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,IPSCCPPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,SROAPass,SimplifyCFGPass