; LLVM IR from DionysiosB/CodeForces :: 0700-0799 (798A-MikeAndPalindrome)

; 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 [3 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [4 x i8], align 1

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() #0 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
  %5 = alloca i64, align 8
  %6 = alloca i8, align 1
  %7 = alloca i64, align 8
  %8 = alloca i64, align 8
  %9 = alloca i32, align 4
  store i32 0, ptr %1, align 4
  call void @llvm.lifetime.start.p0(i64 32, ptr %2) #4
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2Ev(ptr noundef nonnull align 8 dereferenceable(32) %2) #4
  %10 = 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) %2)
          to label %11 unwind label %19

11:                                               ; preds = %0
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #4
  store i64 -1, ptr %5, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 1, ptr %6) #4
  store i8 1, ptr %6, align 1, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #4
  %12 = call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(32) %2) #4
  store i64 %12, ptr %7, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %8) #4
  store i64 0, ptr %8, align 8, !tbaa !5
  br label %13

13:                                               ; preds = %50, %11
  %14 = load i64, ptr %8, align 8, !tbaa !5
  %15 = load i64, ptr %7, align 8, !tbaa !5
  %16 = udiv i64 %15, 2
  %17 = icmp ult i64 %14, %16
  br i1 %17, label %23, label %18

18:                                               ; preds = %13
  store i32 2, ptr %9, align 4
  br label %53

19:                                               ; preds = %0
  %20 = landingpad { ptr, i32 }
          cleanup
  %21 = extractvalue { ptr, i32 } %20, 0
  store ptr %21, ptr %3, align 8
  %22 = extractvalue { ptr, i32 } %20, 1
  store i32 %22, ptr %4, align 4
  br label %78

23:                                               ; preds = %13
  %24 = load i64, ptr %8, align 8, !tbaa !5
  %25 = invoke noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %2, i64 noundef %24)
          to label %26 unwind label %39

26:                                               ; preds = %23
  %27 = load i8, ptr %25, align 1, !tbaa !11
  %28 = sext i8 %27 to i32
  %29 = load i64, ptr %7, align 8, !tbaa !5
  %30 = sub i64 %29, 1
  %31 = load i64, ptr %8, align 8, !tbaa !5
  %32 = sub i64 %30, %31
  %33 = invoke noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %2, i64 noundef %32)
          to label %34 unwind label %39

34:                                               ; preds = %26
  %35 = load i8, ptr %33, align 1, !tbaa !11
  %36 = sext i8 %35 to i32
  %37 = icmp eq i32 %28, %36
  br i1 %37, label %38, label %43

38:                                               ; preds = %34
  br label %50

39:                                               ; preds = %26, %23
  %40 = landingpad { ptr, i32 }
          cleanup
  %41 = extractvalue { ptr, i32 } %40, 0
  store ptr %41, ptr %3, align 8
  %42 = extractvalue { ptr, i32 } %40, 1
  store i32 %42, ptr %4, align 4
  call void @llvm.lifetime.end.p0(i64 8, ptr %8) #4
  br label %77

43:                                               ; preds = %34
  %44 = load i64, ptr %5, align 8, !tbaa !5
  %45 = icmp slt i64 %44, 0
  br i1 %45, label %46, label %48

46:                                               ; preds = %43
  %47 = load i64, ptr %8, align 8, !tbaa !5
  store i64 %47, ptr %5, align 8, !tbaa !5
  br label %49

48:                                               ; preds = %43
  store i8 0, ptr %6, align 1, !tbaa !9
  store i32 2, ptr %9, align 4
  br label %53

49:                                               ; preds = %46
  br label %50

50:                                               ; preds = %49, %38
  %51 = load i64, ptr %8, align 8, !tbaa !5
  %52 = add nsw i64 %51, 1
  store i64 %52, ptr %8, align 8, !tbaa !5
  br label %13, !llvm.loop !12

53:                                               ; preds = %48, %18
  call void @llvm.lifetime.end.p0(i64 8, ptr %8) #4
  br label %54

54:                                               ; preds = %53
  %55 = load i8, ptr %6, align 1, !tbaa !9, !range !14, !noundef !15
  %56 = trunc i8 %55 to i1
  br i1 %56, label %57, label %66

57:                                               ; preds = %54
  %58 = load i64, ptr %5, align 8, !tbaa !5
  %59 = icmp slt i64 %58, 0
  br i1 %59, label %60, label %64

60:                                               ; preds = %57
  %61 = load i64, ptr %7, align 8, !tbaa !5
  %62 = urem i64 %61, 2
  %63 = icmp eq i64 %62, 0
  br label %64

64:                                               ; preds = %60, %57
  %65 = phi i1 [ false, %57 ], [ %63, %60 ]
  br label %66

66:                                               ; preds = %64, %54
  %67 = phi i1 [ true, %54 ], [ %65, %64 ]
  %68 = zext i1 %67 to i64
  %69 = select i1 %67, ptr @.str, ptr @.str.1
  %70 = invoke i32 @puts(ptr noundef %69)
          to label %71 unwind label %73

71:                                               ; preds = %66
  store i32 0, ptr %1, align 4
  store i32 1, ptr %9, align 4
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #4
  call void @llvm.lifetime.end.p0(i64 1, ptr %6) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #4
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %2) #4
  call void @llvm.lifetime.end.p0(i64 32, ptr %2) #4
  %72 = load i32, ptr %1, align 4
  ret i32 %72

73:                                               ; preds = %66
  %74 = landingpad { ptr, i32 }
          cleanup
  %75 = extractvalue { ptr, i32 } %74, 0
  store ptr %75, ptr %3, align 8
  %76 = extractvalue { ptr, i32 } %74, 1
  store i32 %76, ptr %4, align 4
  br label %77

77:                                               ; preds = %73, %39
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #4
  call void @llvm.lifetime.end.p0(i64 1, ptr %6) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #4
  br label %78

78:                                               ; preds = %77, %19
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %2) #4
  call void @llvm.lifetime.end.p0(i64 32, ptr %2) #4
  br label %79

79:                                               ; preds = %78
  %80 = load ptr, ptr %3, align 8
  %81 = load i32, ptr %4, align 4
  %82 = insertvalue { ptr, i32 } poison, ptr %80, 0
  %83 = insertvalue { ptr, i32 } %82, i32 %81, 1
  resume { ptr, i32 } %83
}

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2Ev(ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #2 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 noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(32)) #2 align 2

; Function Attrs: mustprogress nounwind uwtable
declare noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32), i64 noundef) #2 align 2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

declare i32 @puts(ptr noundef) #3

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

attributes #0 = { 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 #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = { 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 = !{!10, !10, i64 0}
!10 = !{!"bool", !7, i64 0}
!11 = !{!7, !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}
!14 = !{i8 0, i8 2}
!15 = !{}


; 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 [3 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [4 x i8], align 1

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() local_unnamed_addr #0 personality ptr @__gxx_personality_v0 {
  %1 = alloca %"class.std::__cxx11::basic_string", align 8
  call void @llvm.lifetime.start.p0(i64 32, ptr nonnull %1) #5
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2Ev(ptr noundef nonnull align 8 dereferenceable(32) %1) #5
  %2 = 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 %3 unwind label %6

3:                                                ; preds = %0
  %4 = call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(32) %1) #5
  %5 = lshr i64 %4, 1
  %.not16.not = icmp ult i64 %4, 2
  br i1 %.not16.not, label %.critedge, label %.lr.ph

6:                                                ; preds = %0
  %7 = landingpad { ptr, i32 }
          cleanup
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %1) #5
  call void @llvm.lifetime.end.p0(i64 32, ptr nonnull %1) #5
  resume { ptr, i32 } %7

.lr.ph:                                           ; preds = %3, %17
  %.018 = phi i64 [ %18, %17 ], [ 0, %3 ]
  %.01417 = phi i64 [ %.1, %17 ], [ -1, %3 ]
  %8 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %1, i64 noundef %.018)
  %9 = load i8, ptr %8, align 1, !tbaa !5
  %10 = xor i64 %.018, -1
  %11 = add i64 %4, %10
  %12 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %1, i64 noundef %11)
  %13 = load i8, ptr %12, align 1, !tbaa !5
  %14 = icmp eq i8 %9, %13
  br i1 %14, label %17, label %15

15:                                               ; preds = %.lr.ph
  %16 = icmp slt i64 %.01417, 0
  br i1 %16, label %17, label %.loopexit

17:                                               ; preds = %15, %.lr.ph
  %.1 = phi i64 [ %.01417, %.lr.ph ], [ %.018, %15 ]
  %18 = add nuw nsw i64 %.018, 1
  %exitcond.not = icmp eq i64 %18, %5
  br i1 %exitcond.not, label %.critedge.loopexit, label %.lr.ph, !llvm.loop !8

.critedge.loopexit:                               ; preds = %17
  %19 = icmp slt i64 %.1, 0
  br label %.critedge

.critedge:                                        ; preds = %.critedge.loopexit, %3
  %.014.lcssa = phi i1 [ true, %3 ], [ %19, %.critedge.loopexit ]
  %20 = and i64 %4, 1
  %21 = icmp eq i64 %20, 0
  %22 = and i1 %21, %.014.lcssa
  %23 = select i1 %22, ptr @.str, ptr @.str.1
  br label %.loopexit

.loopexit:                                        ; preds = %15, %.critedge
  %24 = phi ptr [ %23, %.critedge ], [ @.str, %15 ]
  %25 = call i32 @puts(ptr noundef nonnull dereferenceable(1) %24)
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %1) #5
  call void @llvm.lifetime.end.p0(i64 32, ptr nonnull %1) #5
  ret i32 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 nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2Ev(ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #2 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 noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(32)) local_unnamed_addr #2 align 2

; Function Attrs: mustprogress nounwind uwtable
declare noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32), i64 noundef) local_unnamed_addr #2 align 2

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: nofree nounwind
declare noundef i32 @puts(ptr nocapture noundef readonly) local_unnamed_addr #4

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

attributes #0 = { 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 #1 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = { 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 #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 = !{!"omnipotent char", !7, i64 0}
!7 = !{!"Simple C++ TBAA"}
!8 = distinct !{!8, !9}
!9 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: EarlyCSEPass,GVNPass,GlobalOptPass,IPSCCPPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LICMPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,ReassociatePass,SROAPass,SimplifyCFGPass