; LLVM IR from UtkarshPathrabe/Competitive-Coding :: HackerRank Solutions/Algorithms/Warm Up (Alternating Characters)

; 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" }

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

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() #0 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca [100005 x i8], align 16
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  store i32 0, ptr %1, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #6
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #6
  call void @llvm.lifetime.start.p0(i64 100005, ptr %4) #6
  %8 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %2)
  br label %9

9:                                                ; preds = %52, %0
  %10 = load i32, ptr %2, align 4, !tbaa !5
  %11 = add nsw i32 %10, -1
  store i32 %11, ptr %2, align 4, !tbaa !5
  %12 = icmp ne i32 %10, 0
  br i1 %12, label %13, label %56

13:                                               ; preds = %9
  %14 = getelementptr inbounds [100005 x i8], ptr %4, i64 0, i64 0
  %15 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZStrsIcSt11char_traitsIcEERSt13basic_istreamIT_T0_ES6_PS3_(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef %14)
  %16 = getelementptr inbounds [100005 x i8], ptr %4, i64 0, i64 0
  %17 = call i64 @strlen(ptr noundef %16) #7
  %18 = trunc i64 %17 to i32
  store i32 %18, ptr %3, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #6
  store i32 0, ptr %5, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #6
  store i32 0, ptr %6, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #6
  store i32 1, ptr %7, align 4, !tbaa !5
  br label %19

19:                                               ; preds = %51, %13
  %20 = load i32, ptr %6, align 4, !tbaa !5
  %21 = load i32, ptr %3, align 4, !tbaa !5
  %22 = icmp slt i32 %20, %21
  br i1 %22, label %23, label %27

23:                                               ; preds = %19
  %24 = load i32, ptr %7, align 4, !tbaa !5
  %25 = load i32, ptr %3, align 4, !tbaa !5
  %26 = icmp slt i32 %24, %25
  br label %27

27:                                               ; preds = %23, %19
  %28 = phi i1 [ false, %19 ], [ %26, %23 ]
  br i1 %28, label %30, label %29

29:                                               ; preds = %27
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #6
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #6
  br label %52

30:                                               ; preds = %27
  %31 = load i32, ptr %6, align 4, !tbaa !5
  %32 = sext i32 %31 to i64
  %33 = getelementptr inbounds [100005 x i8], ptr %4, i64 0, i64 %32
  %34 = load i8, ptr %33, align 1, !tbaa !9
  %35 = sext i8 %34 to i32
  %36 = load i32, ptr %7, align 4, !tbaa !5
  %37 = sext i32 %36 to i64
  %38 = getelementptr inbounds [100005 x i8], ptr %4, i64 0, i64 %37
  %39 = load i8, ptr %38, align 1, !tbaa !9
  %40 = sext i8 %39 to i32
  %41 = icmp eq i32 %35, %40
  br i1 %41, label %42, label %47

42:                                               ; preds = %30
  %43 = load i32, ptr %5, align 4, !tbaa !5
  %44 = add nsw i32 %43, 1
  store i32 %44, ptr %5, align 4, !tbaa !5
  %45 = load i32, ptr %7, align 4, !tbaa !5
  %46 = add nsw i32 %45, 1
  store i32 %46, ptr %7, align 4, !tbaa !5
  br label %51

47:                                               ; preds = %30
  %48 = load i32, ptr %7, align 4, !tbaa !5
  store i32 %48, ptr %6, align 4, !tbaa !5
  %49 = load i32, ptr %6, align 4, !tbaa !5
  %50 = add nsw i32 %49, 1
  store i32 %50, ptr %7, align 4, !tbaa !5
  br label %51

51:                                               ; preds = %47, %42
  br label %19, !llvm.loop !10

52:                                               ; preds = %29
  %53 = load i32, ptr %5, align 4, !tbaa !5
  %54 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %53)
  %55 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) %54, ptr noundef @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #6
  br label %9, !llvm.loop !12

56:                                               ; preds = %9
  call void @llvm.lifetime.end.p0(i64 100005, ptr %4) #6
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #6
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #6
  ret i32 0
}

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

declare noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 4 dereferenceable(4)) #2

; Function Attrs: inlinehint mustprogress uwtable
declare dso_local noundef nonnull align 8 dereferenceable(16) ptr @_ZStrsIcSt11char_traitsIcEERSt13basic_istreamIT_T0_ES6_PS3_(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull) #3

; Function Attrs: nounwind willreturn memory(read)
declare i64 @strlen(ptr noundef) #4

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

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) #2

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) #5 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)) #3

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 = { "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 = { 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 #4 = { nounwind willreturn memory(read) "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 = { 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 }
attributes #7 = { nounwind willreturn memory(read) }

!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 = !{!7, !7, i64 0}
!10 = distinct !{!10, !11}
!11 = !{!"llvm.loop.mustprogress"}
!12 = distinct !{!12, !11}


; 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" }

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

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() local_unnamed_addr #0 {
  %1 = alloca i32, align 4
  %2 = alloca [100005 x i8], align 16
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %1) #6
  call void @llvm.lifetime.start.p0(i64 100005, ptr nonnull %2) #6
  %3 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %1)
  %4 = load i32, ptr %1, align 4, !tbaa !5
  %5 = add nsw i32 %4, -1
  store i32 %5, ptr %1, align 4, !tbaa !5
  %.not18 = icmp eq i32 %4, 0
  br i1 %.not18, label %._crit_edge21, label %.lr.ph20

.lr.ph20:                                         ; preds = %0, %._crit_edge
  %6 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZStrsIcSt11char_traitsIcEERSt13basic_istreamIT_T0_ES6_PS3_(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef %2)
  %7 = call i64 @strlen(ptr noundef nonnull dereferenceable(1) %2) #7
  %8 = trunc i64 %7 to i32
  %9 = icmp sgt i32 %8, 1
  br i1 %9, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %.lr.ph20
  %10 = and i64 %7, 2147483647
  br label %.lr.ph

._crit_edge:                                      ; preds = %.lr.ph, %.lr.ph20
  %.013.lcssa = phi i32 [ 0, %.lr.ph20 ], [ %.114, %.lr.ph ]
  %11 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %.013.lcssa)
  %12 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) %11, ptr noundef nonnull @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
  %13 = load i32, ptr %1, align 4, !tbaa !5
  %14 = add nsw i32 %13, -1
  store i32 %14, ptr %1, align 4, !tbaa !5
  %.not = icmp eq i32 %13, 0
  br i1 %.not, label %._crit_edge21, label %.lr.ph20, !llvm.loop !9

.lr.ph:                                           ; preds = %.lr.ph.preheader, %.lr.ph
  %indvars.iv = phi i64 [ 1, %.lr.ph.preheader ], [ %indvars.iv.next, %.lr.ph ]
  %.01116 = phi i32 [ 0, %.lr.ph.preheader ], [ %.112, %.lr.ph ]
  %.01315 = phi i32 [ 0, %.lr.ph.preheader ], [ %.114, %.lr.ph ]
  %15 = sext i32 %.01116 to i64
  %16 = getelementptr inbounds [100005 x i8], ptr %2, i64 0, i64 %15
  %17 = load i8, ptr %16, align 1, !tbaa !11
  %18 = getelementptr inbounds [100005 x i8], ptr %2, i64 0, i64 %indvars.iv
  %19 = load i8, ptr %18, align 1, !tbaa !11
  %20 = icmp eq i8 %17, %19
  %21 = zext i1 %20 to i32
  %.114 = add nuw nsw i32 %.01315, %21
  %22 = trunc nuw nsw i64 %indvars.iv to i32
  %.112 = select i1 %20, i32 %.01116, i32 %22
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %23 = icmp slt i32 %.112, %8
  %24 = icmp ult i64 %indvars.iv.next, %10
  %25 = select i1 %23, i1 %24, i1 false
  br i1 %25, label %.lr.ph, label %._crit_edge, !llvm.loop !12

._crit_edge21:                                    ; preds = %._crit_edge, %0
  call void @llvm.lifetime.end.p0(i64 100005, ptr nonnull %2) #6
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %1) #6
  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

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 #2

; Function Attrs: inlinehint mustprogress uwtable
declare dso_local noundef nonnull align 8 dereferenceable(16) ptr @_ZStrsIcSt11char_traitsIcEERSt13basic_istreamIT_T0_ES6_PS3_(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull) local_unnamed_addr #3

; Function Attrs: mustprogress nofree nounwind willreturn memory(argmem: read)
declare i64 @strlen(ptr nocapture noundef) local_unnamed_addr #4

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

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) local_unnamed_addr #2

; 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 #5 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)) #3

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 = { "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 = { 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 #4 = { mustprogress nofree nounwind willreturn memory(argmem: read) "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 = { 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 }
attributes #7 = { nounwind willreturn memory(read) }

!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"}
!11 = !{!7, !7, i64 0}
!12 = distinct !{!12, !10}


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