; LLVM IR from upupming/algorithm :: acwing/每日一题·夏季/Week 2/AcWing 3483. 2的幂次方 (main)

; 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::basic_ostream" = type { ptr, %"class.std::basic_ios" }
%"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
@_ZSt3cin = external global %"class.std::basic_istream", align 8
@_ZSt4cout = external global %"class.std::basic_ostream", align 8

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #0 align 2

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z3getB5cxx11i(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8, i32 noundef) #1

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

declare i32 @__gxx_personality_v0(...)

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

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() #3 personality ptr @__gxx_personality_v0 {
  %1 = alloca i32, align 4
  %2 = alloca %"class.std::__cxx11::basic_string", align 8
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  store i32 0, ptr %1, align 4
  br label %5

5:                                                ; preds = %17, %0
  %6 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) @n)
  %7 = load ptr, ptr %6, align 8, !tbaa !5
  %8 = getelementptr i8, ptr %7, i64 -24
  %9 = load i64, ptr %8, align 8
  %10 = getelementptr inbounds i8, ptr %6, i64 %9
  %11 = call noundef zeroext i1 @_ZNKSt9basic_iosIcSt11char_traitsIcEEcvbEv(ptr noundef nonnull align 8 dereferenceable(264) %10)
  br i1 %11, label %12, label %22

12:                                               ; preds = %5
  call void @llvm.lifetime.start.p0(i64 32, ptr %2) #6
  %13 = load i32, ptr @n, align 4, !tbaa !8
  call void @_Z3getB5cxx11i(ptr dead_on_unwind writable sret(%"class.std::__cxx11::basic_string") align 8 %2, i32 noundef %13)
  %14 = invoke noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsIcSt11char_traitsIcESaIcEERSt13basic_ostreamIT_T0_ES7_RKNSt7__cxx1112basic_stringIS4_S5_T1_EE(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef nonnull align 8 dereferenceable(32) %2)
          to label %15 unwind label %18

15:                                               ; preds = %12
  %16 = invoke noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) %14, ptr noundef @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
          to label %17 unwind label %18

17:                                               ; preds = %15
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %2) #6
  call void @llvm.lifetime.end.p0(i64 32, ptr %2) #6
  br label %5, !llvm.loop !11

18:                                               ; preds = %15, %12
  %19 = landingpad { ptr, i32 }
          cleanup
  %20 = extractvalue { ptr, i32 } %19, 0
  store ptr %20, ptr %3, align 8
  %21 = extractvalue { ptr, i32 } %19, 1
  store i32 %21, ptr %4, align 4
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %2) #6
  call void @llvm.lifetime.end.p0(i64 32, ptr %2) #6
  br label %23

22:                                               ; preds = %5
  ret i32 0

23:                                               ; preds = %18
  %24 = load ptr, ptr %3, align 8
  %25 = load i32, ptr %4, align 4
  %26 = insertvalue { ptr, i32 } poison, ptr %24, 0
  %27 = insertvalue { ptr, i32 } %26, i32 %25, 1
  resume { ptr, i32 } %27
}

declare noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 4 dereferenceable(4)) #4

; Function Attrs: mustprogress uwtable
declare noundef zeroext i1 @_ZNKSt9basic_iosIcSt11char_traitsIcEEcvbEv(ptr noundef nonnull align 8 dereferenceable(264)) #1 align 2

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsIcSt11char_traitsIcESaIcEERSt13basic_ostreamIT_T0_ES7_RKNSt7__cxx1112basic_stringIS4_S5_T1_EE(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef nonnull align 8 dereferenceable(32)) #5

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) #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)) #5

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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #3 = { mustprogress norecurse 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 = { 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 #6 = { 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 = !{!"vtable pointer", !7, i64 0}
!7 = !{!"Simple C++ TBAA"}
!8 = !{!9, !9, i64 0}
!9 = !{!"int", !10, i64 0}
!10 = !{!"omnipotent char", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"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::basic_ostream" = type { ptr, %"class.std::basic_ios" }
%"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
@_ZSt3cin = external global %"class.std::basic_istream", align 8
@_ZSt4cout = external global %"class.std::basic_ostream", align 8

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #0 align 2

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z3getB5cxx11i(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8, i32 noundef) local_unnamed_addr #1

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

declare i32 @__gxx_personality_v0(...)

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

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() local_unnamed_addr #3 personality ptr @__gxx_personality_v0 {
  %1 = alloca %"class.std::__cxx11::basic_string", align 8
  %2 = tail call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) @n)
  %3 = load ptr, ptr %2, align 8, !tbaa !5
  %4 = getelementptr i8, ptr %3, i64 -24
  %5 = load i64, ptr %4, align 8
  %6 = getelementptr inbounds i8, ptr %2, i64 %5
  %7 = tail call noundef zeroext i1 @_ZNKSt9basic_iosIcSt11char_traitsIcEEcvbEv(ptr noundef nonnull align 8 dereferenceable(264) %6)
  br i1 %7, label %.lr.ph, label %._crit_edge

.lr.ph:                                           ; preds = %0, %12
  call void @llvm.lifetime.start.p0(i64 32, ptr nonnull %1) #6
  %8 = load i32, ptr @n, align 4, !tbaa !8
  call void @_Z3getB5cxx11i(ptr dead_on_unwind nonnull writable sret(%"class.std::__cxx11::basic_string") align 8 %1, i32 noundef %8)
  %9 = invoke noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsIcSt11char_traitsIcESaIcEERSt13basic_ostreamIT_T0_ES7_RKNSt7__cxx1112basic_stringIS4_S5_T1_EE(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef nonnull align 8 dereferenceable(32) %1)
          to label %10 unwind label %19

10:                                               ; preds = %.lr.ph
  %11 = invoke noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) %9, ptr noundef nonnull @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
          to label %12 unwind label %19

12:                                               ; preds = %10
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %1) #6
  call void @llvm.lifetime.end.p0(i64 32, ptr nonnull %1) #6
  %13 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) @n)
  %14 = load ptr, ptr %13, align 8, !tbaa !5
  %15 = getelementptr i8, ptr %14, i64 -24
  %16 = load i64, ptr %15, align 8
  %17 = getelementptr inbounds i8, ptr %13, i64 %16
  %18 = call noundef zeroext i1 @_ZNKSt9basic_iosIcSt11char_traitsIcEEcvbEv(ptr noundef nonnull align 8 dereferenceable(264) %17)
  br i1 %18, label %.lr.ph, label %._crit_edge, !llvm.loop !11

19:                                               ; preds = %10, %.lr.ph
  %20 = landingpad { ptr, i32 }
          cleanup
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %1) #6
  call void @llvm.lifetime.end.p0(i64 32, ptr nonnull %1) #6
  resume { ptr, i32 } %20

._crit_edge:                                      ; preds = %12, %0
  ret i32 0
}

declare noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 4 dereferenceable(4)) local_unnamed_addr #4

; Function Attrs: mustprogress uwtable
declare noundef zeroext i1 @_ZNKSt9basic_iosIcSt11char_traitsIcEEcvbEv(ptr noundef nonnull align 8 dereferenceable(264)) local_unnamed_addr #1 align 2

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsIcSt11char_traitsIcESaIcEERSt13basic_ostreamIT_T0_ES7_RKNSt7__cxx1112basic_stringIS4_S5_T1_EE(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef nonnull align 8 dereferenceable(32)) local_unnamed_addr #5

; 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)) #5

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 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #3 = { mustprogress norecurse 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 = { 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 #6 = { 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 = !{!"vtable pointer", !7, i64 0}
!7 = !{!"Simple C++ TBAA"}
!8 = !{!9, !9, i64 0}
!9 = !{!"int", !10, i64 0}
!10 = !{!"omnipotent char", !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