; LLVM IR from eyangch/competitive-programming :: Codeforces/981 (a)

; 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::__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] }
%"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" }

@_Z1SB5cxx11 = external dso_local global %"class.std::__cxx11::basic_string", align 8
@_ZSt3cin = external global %"class.std::basic_istream", align 8
@_ZSt4cout = external global %"class.std::basic_ostream", align 8

; Function Attrs: mustprogress uwtable
declare dso_local noundef zeroext i1 @_Z13is_palindromexx(i64 noundef, i64 noundef) #0

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() #1 {
  %1 = alloca i32, align 4
  %2 = alloca i64, align 8
  %3 = alloca i64, align 8
  %4 = alloca i32, align 4
  %5 = alloca i64, align 8
  %6 = alloca i64, align 8
  store i32 0, ptr %1, align 4
  %7 = load ptr, ptr @_ZSt3cin, align 8, !tbaa !5
  %8 = getelementptr i8, ptr %7, i64 -24
  %9 = load i64, ptr %8, align 8
  %10 = getelementptr inbounds i8, ptr @_ZSt3cin, i64 %9
  %11 = call noundef ptr @_ZNSt9basic_iosIcSt11char_traitsIcEE3tieEPSo(ptr noundef nonnull align 8 dereferenceable(264) %10, ptr noundef null)
  %12 = call noundef zeroext i1 @_ZNSt8ios_base15sync_with_stdioEb(i1 noundef zeroext false)
  %13 = call 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) @_Z1SB5cxx11)
  call void @llvm.lifetime.start.p0(i64 8, ptr %2) #7
  store i64 0, ptr %2, align 8, !tbaa !8
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #7
  store i64 0, ptr %3, align 8, !tbaa !8
  br label %14

14:                                               ; preds = %42, %0
  %15 = load i64, ptr %3, align 8, !tbaa !8
  %16 = call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32) @_Z1SB5cxx11) #7
  %17 = icmp ult i64 %15, %16
  br i1 %17, label %19, label %18

18:                                               ; preds = %14
  store i32 2, ptr %4, align 4
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #7
  br label %45

19:                                               ; preds = %14
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #7
  %20 = load i64, ptr %3, align 8, !tbaa !8
  store i64 %20, ptr %5, align 8, !tbaa !8
  br label %21

21:                                               ; preds = %38, %19
  %22 = load i64, ptr %5, align 8, !tbaa !8
  %23 = call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32) @_Z1SB5cxx11) #7
  %24 = icmp ult i64 %22, %23
  br i1 %24, label %26, label %25

25:                                               ; preds = %21
  store i32 5, ptr %4, align 4
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #7
  br label %41

26:                                               ; preds = %21
  %27 = load i64, ptr %3, align 8, !tbaa !8
  %28 = load i64, ptr %5, align 8, !tbaa !8
  %29 = call noundef zeroext i1 @_Z13is_palindromexx(i64 noundef %27, i64 noundef %28)
  br i1 %29, label %37, label %30

30:                                               ; preds = %26
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #7
  %31 = load i64, ptr %5, align 8, !tbaa !8
  %32 = load i64, ptr %3, align 8, !tbaa !8
  %33 = sub nsw i64 %31, %32
  %34 = add nsw i64 %33, 1
  store i64 %34, ptr %6, align 8, !tbaa !8
  %35 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZSt3maxIxERKT_S2_S2_(ptr noundef nonnull align 8 dereferenceable(8) %2, ptr noundef nonnull align 8 dereferenceable(8) %6)
  %36 = load i64, ptr %35, align 8, !tbaa !8
  store i64 %36, ptr %2, align 8, !tbaa !8
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #7
  br label %37

37:                                               ; preds = %30, %26
  br label %38

38:                                               ; preds = %37
  %39 = load i64, ptr %5, align 8, !tbaa !8
  %40 = add nsw i64 %39, 1
  store i64 %40, ptr %5, align 8, !tbaa !8
  br label %21, !llvm.loop !11

41:                                               ; preds = %25
  br label %42

42:                                               ; preds = %41
  %43 = load i64, ptr %3, align 8, !tbaa !8
  %44 = add nsw i64 %43, 1
  store i64 %44, ptr %3, align 8, !tbaa !8
  br label %14, !llvm.loop !13

45:                                               ; preds = %18
  %46 = load i64, ptr %2, align 8, !tbaa !8
  %47 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEx(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i64 noundef %46)
  %48 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8) %47, i8 noundef signext 10)
  call void @llvm.lifetime.end.p0(i64 8, ptr %2) #7
  %49 = load i32, ptr %1, align 4
  ret i32 %49
}

; Function Attrs: mustprogress nounwind uwtable
declare noundef ptr @_ZNSt9basic_iosIcSt11char_traitsIcEE3tieEPSo(ptr noundef nonnull align 8 dereferenceable(264), ptr noundef) #2 align 2

declare noundef zeroext i1 @_ZNSt8ios_base15sync_with_stdioEb(i1 noundef zeroext) #3

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

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #4

; Function Attrs: mustprogress nounwind uwtable
declare noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32)) #2 align 2

; Function Attrs: inlinehint mustprogress nounwind uwtable
declare dso_local noundef nonnull align 8 dereferenceable(8) ptr @_ZSt3maxIxERKT_S2_S2_(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef nonnull align 8 dereferenceable(8)) #5

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #4

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8), i8 noundef signext) #6

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEx(ptr noundef nonnull align 8 dereferenceable(8), i64 noundef) #0 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 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 #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 = { "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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #5 = { inlinehint 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 #6 = { 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 #7 = { 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 = !{!"long long", !10, i64 0}
!10 = !{!"omnipotent char", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}
!13 = distinct !{!13, !12}


; 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::__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] }
%"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" }

@_Z1SB5cxx11 = external dso_local global %"class.std::__cxx11::basic_string", align 8
@_ZSt3cin = external global %"class.std::basic_istream", align 8
@_ZSt4cout = external global %"class.std::basic_ostream", align 8

; Function Attrs: mustprogress uwtable
declare dso_local noundef zeroext i1 @_Z13is_palindromexx(i64 noundef, i64 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() local_unnamed_addr #1 {
  %1 = alloca i64, align 8
  %2 = alloca i64, align 8
  %3 = load ptr, ptr @_ZSt3cin, align 8, !tbaa !5
  %4 = getelementptr i8, ptr %3, i64 -24
  %5 = load i64, ptr %4, align 8
  %6 = getelementptr inbounds i8, ptr @_ZSt3cin, i64 %5
  %7 = tail call noundef ptr @_ZNSt9basic_iosIcSt11char_traitsIcEE3tieEPSo(ptr noundef nonnull align 8 dereferenceable(264) %6, ptr noundef null)
  %8 = tail call noundef zeroext i1 @_ZNSt8ios_base15sync_with_stdioEb(i1 noundef zeroext false)
  %9 = tail call 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) @_Z1SB5cxx11)
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %1) #7
  store i64 0, ptr %1, align 8, !tbaa !8
  %10 = tail call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32) @_Z1SB5cxx11) #7
  %.not = icmp eq i64 %10, 0
  br i1 %.not, label %._crit_edge13, label %.preheader

.preheader:                                       ; preds = %0, %._crit_edge
  %.01012 = phi i64 [ %16, %._crit_edge ], [ 0, %0 ]
  %11 = call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32) @_Z1SB5cxx11) #7
  %12 = icmp ult i64 %.01012, %11
  br i1 %12, label %.lr.ph, label %._crit_edge

._crit_edge13.loopexit:                           ; preds = %._crit_edge
  %.pre = load i64, ptr %1, align 8, !tbaa !8
  br label %._crit_edge13

._crit_edge13:                                    ; preds = %._crit_edge13.loopexit, %0
  %13 = phi i64 [ %.pre, %._crit_edge13.loopexit ], [ 0, %0 ]
  %14 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEx(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i64 noundef %13)
  %15 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8) %14, i8 noundef signext 10)
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %1) #7
  ret i32 0

._crit_edge:                                      ; preds = %24, %.preheader
  %16 = add nuw nsw i64 %.01012, 1
  %17 = call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32) @_Z1SB5cxx11) #7
  %18 = icmp ult i64 %16, %17
  br i1 %18, label %.preheader, label %._crit_edge13.loopexit, !llvm.loop !11

.lr.ph:                                           ; preds = %.preheader, %24
  %.011 = phi i64 [ %25, %24 ], [ %.01012, %.preheader ]
  %19 = call noundef zeroext i1 @_Z13is_palindromexx(i64 noundef %.01012, i64 noundef %.011)
  br i1 %19, label %24, label %20

20:                                               ; preds = %.lr.ph
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %2) #7
  %reass.sub = sub nuw nsw i64 %.011, %.01012
  %21 = add nuw i64 %reass.sub, 1
  store i64 %21, ptr %2, align 8, !tbaa !8
  %22 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZSt3maxIxERKT_S2_S2_(ptr noundef nonnull align 8 dereferenceable(8) %1, ptr noundef nonnull align 8 dereferenceable(8) %2)
  %23 = load i64, ptr %22, align 8, !tbaa !8
  store i64 %23, ptr %1, align 8, !tbaa !8
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %2) #7
  br label %24

24:                                               ; preds = %.lr.ph, %20
  %25 = add nuw nsw i64 %.011, 1
  %26 = call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32) @_Z1SB5cxx11) #7
  %27 = icmp ult i64 %25, %26
  br i1 %27, label %.lr.ph, label %._crit_edge, !llvm.loop !13
}

; Function Attrs: mustprogress nounwind uwtable
declare noundef ptr @_ZNSt9basic_iosIcSt11char_traitsIcEE3tieEPSo(ptr noundef nonnull align 8 dereferenceable(264), ptr noundef) local_unnamed_addr #2 align 2

declare noundef zeroext i1 @_ZNSt8ios_base15sync_with_stdioEb(i1 noundef zeroext) local_unnamed_addr #3

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

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #4

; Function Attrs: mustprogress nounwind uwtable
declare noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32)) local_unnamed_addr #2 align 2

; Function Attrs: inlinehint mustprogress nounwind uwtable
declare dso_local noundef nonnull align 8 dereferenceable(8) ptr @_ZSt3maxIxERKT_S2_S2_(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef nonnull align 8 dereferenceable(8)) local_unnamed_addr #5

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #4

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8), i8 noundef signext) local_unnamed_addr #6

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEx(ptr noundef nonnull align 8 dereferenceable(8), i64 noundef) local_unnamed_addr #0 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 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 #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 = { "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 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #5 = { inlinehint 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 #6 = { 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 #7 = { 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 = !{!"long long", !10, i64 0}
!10 = !{!"omnipotent char", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}
!13 = distinct !{!13, !12}


; Effective O3 passes: GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LICMPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,ReassociatePass,SROAPass,SimplifyCFGPass,TailCallElimPass