; LLVM IR from DionysiosB/CodeForces :: 1600-1699 (1634A-ReverseAndConcatenate)

; 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] }

@_ZSt3cin = external global %"class.std::basic_istream", align 8
@.str = external hidden unnamed_addr constant [2 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [2 x i8], align 1

; Function Attrs: mustprogress uwtable
declare dso_local noundef zeroext i1 @_Z12isPalindromeNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr 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 norecurse uwtable
define dso_local noundef i32 @main() #2 personality ptr @__gxx_personality_v0 {
  %1 = alloca i32, align 4
  %2 = alloca i64, align 8
  %3 = alloca i64, align 8
  %4 = alloca i64, align 8
  %5 = alloca %"class.std::__cxx11::basic_string", align 8
  %6 = alloca ptr, align 8
  %7 = alloca i32, align 4
  %8 = alloca %"class.std::__cxx11::basic_string", align 8
  store i32 0, ptr %1, align 4
  call void @llvm.lifetime.start.p0(i64 8, ptr %2) #5
  %9 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERl(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 8 dereferenceable(8) %2)
  br label %10

10:                                               ; preds = %43, %0
  %11 = load i64, ptr %2, align 8, !tbaa !5
  %12 = add nsw i64 %11, -1
  store i64 %12, ptr %2, align 8, !tbaa !5
  %13 = icmp ne i64 %11, 0
  br i1 %13, label %14, label %45

14:                                               ; preds = %10
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #5
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #5
  %15 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERl(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 8 dereferenceable(8) %3)
  %16 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERl(ptr noundef nonnull align 8 dereferenceable(16) %15, ptr noundef nonnull align 8 dereferenceable(8) %4)
  call void @llvm.lifetime.start.p0(i64 32, ptr %5) #5
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2Ev(ptr noundef nonnull align 8 dereferenceable(32) %5) #5
  %17 = 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) %5)
          to label %18 unwind label %24

18:                                               ; preds = %14
  %19 = load i64, ptr %4, align 8, !tbaa !5
  %20 = icmp ne i64 %19, 0
  br i1 %20, label %28, label %21

21:                                               ; preds = %18
  %22 = invoke i32 @puts(ptr noundef @.str)
          to label %23 unwind label %24

23:                                               ; preds = %21
  br label %43

24:                                               ; preds = %39, %32, %28, %21, %14
  %25 = landingpad { ptr, i32 }
          cleanup
  %26 = extractvalue { ptr, i32 } %25, 0
  store ptr %26, ptr %6, align 8
  %27 = extractvalue { ptr, i32 } %25, 1
  store i32 %27, ptr %7, align 4
  br label %44

28:                                               ; preds = %18
  invoke void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2ERKS4_(ptr noundef nonnull align 8 dereferenceable(32) %8, ptr noundef nonnull align 8 dereferenceable(32) %5)
          to label %29 unwind label %24

29:                                               ; preds = %28
  %30 = invoke noundef zeroext i1 @_Z12isPalindromeNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr noundef %8)
          to label %31 unwind label %35

31:                                               ; preds = %29
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %8) #5
  br i1 %30, label %32, label %39

32:                                               ; preds = %31
  %33 = invoke i32 @puts(ptr noundef @.str)
          to label %34 unwind label %24

34:                                               ; preds = %32
  br label %42

35:                                               ; preds = %29
  %36 = landingpad { ptr, i32 }
          cleanup
  %37 = extractvalue { ptr, i32 } %36, 0
  store ptr %37, ptr %6, align 8
  %38 = extractvalue { ptr, i32 } %36, 1
  store i32 %38, ptr %7, align 4
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %8) #5
  br label %44

39:                                               ; preds = %31
  %40 = invoke i32 @puts(ptr noundef @.str.1)
          to label %41 unwind label %24

41:                                               ; preds = %39
  br label %42

42:                                               ; preds = %41, %34
  br label %43

43:                                               ; preds = %42, %23
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %5) #5
  call void @llvm.lifetime.end.p0(i64 32, ptr %5) #5
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #5
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #5
  br label %10, !llvm.loop !9

44:                                               ; preds = %35, %24
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %5) #5
  call void @llvm.lifetime.end.p0(i64 32, ptr %5) #5
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #5
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #5
  call void @llvm.lifetime.end.p0(i64 8, ptr %2) #5
  br label %47

45:                                               ; preds = %10
  call void @llvm.lifetime.end.p0(i64 8, ptr %2) #5
  %46 = load i32, ptr %1, align 4
  ret i32 %46

47:                                               ; preds = %44
  %48 = load ptr, ptr %6, align 8
  %49 = load i32, ptr %7, align 4
  %50 = insertvalue { ptr, i32 } poison, ptr %48, 0
  %51 = insertvalue { ptr, i32 } %50, i32 %49, 1
  resume { ptr, i32 } %51
}

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERl(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 8 dereferenceable(8)) #0 align 2

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2Ev(ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #3 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)) #4

declare i32 @__gxx_personality_v0(...)

declare i32 @puts(ptr noundef) #4

; Function Attrs: mustprogress uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2ERKS4_(ptr noundef nonnull align 8 dereferenceable(32), ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #0 align 2

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #3 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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { 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 #3 = { 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 #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 = !{!"long", !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] }

@_ZSt3cin = external global %"class.std::basic_istream", align 8
@.str = external hidden unnamed_addr constant [2 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [2 x i8], align 1

; Function Attrs: mustprogress uwtable
declare dso_local noundef zeroext i1 @_Z12isPalindromeNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr noundef) 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 norecurse uwtable
define dso_local noundef i32 @main() local_unnamed_addr #2 personality ptr @__gxx_personality_v0 {
  %1 = alloca i64, align 8
  %2 = alloca i64, align 8
  %3 = alloca i64, align 8
  %4 = alloca %"class.std::__cxx11::basic_string", align 8
  %5 = alloca %"class.std::__cxx11::basic_string", align 8
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %1) #6
  %6 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERl(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 8 dereferenceable(8) %1)
  %7 = load i64, ptr %1, align 8, !tbaa !5
  %8 = add nsw i64 %7, -1
  store i64 %8, ptr %1, align 8, !tbaa !5
  %.not5 = icmp eq i64 %7, 0
  br i1 %.not5, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %0, %22
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %2) #6
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %3) #6
  %9 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERl(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 8 dereferenceable(8) %2)
  %10 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERl(ptr noundef nonnull align 8 dereferenceable(16) %9, ptr noundef nonnull align 8 dereferenceable(8) %3)
  call void @llvm.lifetime.start.p0(i64 32, ptr nonnull %4) #6
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2Ev(ptr noundef nonnull align 8 dereferenceable(32) %4) #6
  %11 = 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) %4)
          to label %12 unwind label %14

12:                                               ; preds = %.lr.ph
  %13 = load i64, ptr %3, align 8, !tbaa !5
  %.not3 = icmp eq i64 %13, 0
  br i1 %.not3, label %22, label %16

14:                                               ; preds = %16, %.lr.ph
  %15 = landingpad { ptr, i32 }
          cleanup
  br label %26

16:                                               ; preds = %12
  invoke void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2ERKS4_(ptr noundef nonnull align 8 dereferenceable(32) %5, ptr noundef nonnull align 8 dereferenceable(32) %4)
          to label %17 unwind label %14

17:                                               ; preds = %16
  %18 = invoke noundef zeroext i1 @_Z12isPalindromeNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr noundef nonnull %5)
          to label %19 unwind label %20

19:                                               ; preds = %17
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %5) #6
  %.str..str.1 = select i1 %18, ptr @.str, ptr @.str.1
  br label %22

20:                                               ; preds = %17
  %21 = landingpad { ptr, i32 }
          cleanup
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %5) #6
  br label %26

22:                                               ; preds = %19, %12
  %.str.sink = phi ptr [ @.str, %12 ], [ %.str..str.1, %19 ]
  %23 = call i32 @puts(ptr noundef nonnull dereferenceable(1) %.str.sink)
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %4) #6
  call void @llvm.lifetime.end.p0(i64 32, ptr nonnull %4) #6
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %3) #6
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %2) #6
  %24 = load i64, ptr %1, align 8, !tbaa !5
  %25 = add nsw i64 %24, -1
  store i64 %25, ptr %1, align 8, !tbaa !5
  %.not = icmp eq i64 %24, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !9

26:                                               ; preds = %20, %14
  %.pn = phi { ptr, i32 } [ %21, %20 ], [ %15, %14 ]
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %4) #6
  call void @llvm.lifetime.end.p0(i64 32, ptr nonnull %4) #6
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %3) #6
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %2) #6
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %1) #6
  resume { ptr, i32 } %.pn

._crit_edge:                                      ; preds = %22, %0
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %1) #6
  ret i32 0
}

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERl(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 8 dereferenceable(8)) local_unnamed_addr #0 align 2

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2Ev(ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #3 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 #4

declare i32 @__gxx_personality_v0(...)

; Function Attrs: nofree nounwind
declare noundef i32 @puts(ptr nocapture noundef readonly) local_unnamed_addr #5

; Function Attrs: mustprogress uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2ERKS4_(ptr noundef nonnull align 8 dereferenceable(32), ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #0 align 2

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #3 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 nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { 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 #3 = { 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 #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 = { nofree nounwind "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 = !{!"long", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


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