; LLVM IR from plskz/competitive-programming :: Junior Training Sheet/A (137)

; 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"

%"struct.std::pair" = type { i32, i32 }
%"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" }

@a = external dso_local global [101 x %"struct.std::pair"], align 16
@_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 i32, align 4
  store i32 0, ptr %1, align 4
  %5 = call noundef zeroext i1 @_ZNSt8ios_base15sync_with_stdioEb(i1 noundef zeroext false)
  %6 = load ptr, ptr @_ZSt3cin, align 8, !tbaa !5
  %7 = getelementptr i8, ptr %6, i64 -24
  %8 = load i64, ptr %7, align 8
  %9 = getelementptr inbounds i8, ptr @_ZSt3cin, i64 %8
  %10 = call noundef ptr @_ZNSt9basic_iosIcSt11char_traitsIcEE3tieEPSo(ptr noundef nonnull align 8 dereferenceable(264) %9, ptr noundef null)
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #5
  %11 = 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)
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #5
  store i32 0, ptr %3, align 4, !tbaa !8
  br label %12

12:                                               ; preds = %29, %0
  %13 = load i32, ptr %3, align 4, !tbaa !8
  %14 = load i32, ptr %2, align 4, !tbaa !8
  %15 = icmp slt i32 %13, %14
  br i1 %15, label %17, label %16

16:                                               ; preds = %12
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #5
  br label %32

17:                                               ; preds = %12
  %18 = load i32, ptr %3, align 4, !tbaa !8
  %19 = sext i32 %18 to i64
  %20 = getelementptr inbounds [101 x %"struct.std::pair"], ptr @a, i64 0, i64 %19
  %21 = getelementptr inbounds %"struct.std::pair", ptr %20, i32 0, i32 0
  %22 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %21)
  %23 = load i32, ptr %3, align 4, !tbaa !8
  %24 = add nsw i32 %23, 1
  %25 = load i32, ptr %3, align 4, !tbaa !8
  %26 = sext i32 %25 to i64
  %27 = getelementptr inbounds [101 x %"struct.std::pair"], ptr @a, i64 0, i64 %26
  %28 = getelementptr inbounds %"struct.std::pair", ptr %27, i32 0, i32 1
  store i32 %24, ptr %28, align 4, !tbaa !11
  br label %29

29:                                               ; preds = %17
  %30 = load i32, ptr %3, align 4, !tbaa !8
  %31 = add nsw i32 %30, 1
  store i32 %31, ptr %3, align 4, !tbaa !8
  br label %12, !llvm.loop !13

32:                                               ; preds = %16
  %33 = load i32, ptr %2, align 4, !tbaa !8
  %34 = sext i32 %33 to i64
  %35 = getelementptr inbounds %"struct.std::pair", ptr @a, i64 %34
  call void @_ZSt4sortIPSt4pairIiiEEvT_S3_(ptr noundef @a, ptr noundef %35)
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #5
  store i32 0, ptr %4, align 4, !tbaa !8
  br label %36

36:                                               ; preds = %60, %32
  %37 = load i32, ptr %4, align 4, !tbaa !8
  %38 = load i32, ptr %2, align 4, !tbaa !8
  %39 = sdiv i32 %38, 2
  %40 = icmp slt i32 %37, %39
  br i1 %40, label %42, label %41

41:                                               ; preds = %36
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #5
  br label %63

42:                                               ; preds = %36
  %43 = load i32, ptr %4, align 4, !tbaa !8
  %44 = sext i32 %43 to i64
  %45 = getelementptr inbounds [101 x %"struct.std::pair"], ptr @a, i64 0, i64 %44
  %46 = getelementptr inbounds %"struct.std::pair", ptr %45, i32 0, i32 1
  %47 = load i32, ptr %46, align 4, !tbaa !11
  %48 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %47)
  %49 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8) %48, i8 noundef signext 32)
  %50 = load i32, ptr %2, align 4, !tbaa !8
  %51 = load i32, ptr %4, align 4, !tbaa !8
  %52 = sub nsw i32 %50, %51
  %53 = sub nsw i32 %52, 1
  %54 = sext i32 %53 to i64
  %55 = getelementptr inbounds [101 x %"struct.std::pair"], ptr @a, i64 0, i64 %54
  %56 = getelementptr inbounds %"struct.std::pair", ptr %55, i32 0, i32 1
  %57 = load i32, ptr %56, align 4, !tbaa !11
  %58 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) %49, i32 noundef %57)
  %59 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8) %58, i8 noundef signext 10)
  br label %60

60:                                               ; preds = %42
  %61 = load i32, ptr %4, align 4, !tbaa !8
  %62 = add nsw i32 %61, 1
  store i32 %62, ptr %4, align 4, !tbaa !8
  br label %36, !llvm.loop !15

63:                                               ; preds = %41
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #5
  ret i32 0
}

declare noundef zeroext i1 @_ZNSt8ios_base15sync_with_stdioEb(i1 noundef zeroext) #1

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

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #3

declare noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 4 dereferenceable(4)) #1

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #3

; Function Attrs: inlinehint mustprogress uwtable
declare dso_local void @_ZSt4sortIPSt4pairIiiEEvT_S3_(ptr noundef, ptr noundef) #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) #4

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) #1

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 = { "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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #4 = { 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 #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 = !{!"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 = !{!12, !9, i64 4}
!12 = !{!"_ZTSSt4pairIiiE", !9, i64 0, !9, i64 4}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}
!15 = distinct !{!15, !14}


; 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"

%"struct.std::pair" = type { i32, i32 }
%"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" }

@a = external dso_local global [101 x %"struct.std::pair"], align 16
@_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 = tail call noundef zeroext i1 @_ZNSt8ios_base15sync_with_stdioEb(i1 noundef zeroext false)
  %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)
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %1) #5
  %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) %1)
  %9 = load i32, ptr %1, align 4, !tbaa !8
  %10 = icmp sgt i32 %9, 0
  br i1 %10, label %.lr.ph, label %.._crit_edge_crit_edge

.._crit_edge_crit_edge:                           ; preds = %0
  %.pre = sext i32 %9 to i64
  br label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph, %.._crit_edge_crit_edge
  %.pre-phi = phi i64 [ %.pre, %.._crit_edge_crit_edge ], [ %19, %.lr.ph ]
  %11 = getelementptr inbounds %"struct.std::pair", ptr @a, i64 %.pre-phi
  call void @_ZSt4sortIPSt4pairIiiEEvT_S3_(ptr noundef nonnull @a, ptr noundef nonnull %11)
  %12 = load i32, ptr %1, align 4, !tbaa !8
  %13 = icmp sgt i32 %12, 1
  br i1 %13, label %.lr.ph14, label %._crit_edge15

.lr.ph:                                           ; preds = %0, %.lr.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ 0, %0 ]
  %14 = getelementptr inbounds [101 x %"struct.std::pair"], ptr @a, i64 0, i64 %indvars.iv
  %15 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %14)
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %16 = getelementptr inbounds i8, ptr %14, i64 4
  %17 = trunc nuw nsw i64 %indvars.iv.next to i32
  store i32 %17, ptr %16, align 4, !tbaa !11
  %18 = load i32, ptr %1, align 4, !tbaa !8
  %19 = sext i32 %18 to i64
  %20 = icmp slt i64 %indvars.iv.next, %19
  br i1 %20, label %.lr.ph, label %._crit_edge, !llvm.loop !13

._crit_edge15:                                    ; preds = %.lr.ph14, %._crit_edge
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %1) #5
  ret i32 0

.lr.ph14:                                         ; preds = %._crit_edge, %.lr.ph14
  %indvars.iv18 = phi i64 [ %indvars.iv.next19, %.lr.ph14 ], [ 0, %._crit_edge ]
  %21 = getelementptr inbounds [101 x %"struct.std::pair"], ptr @a, i64 0, i64 %indvars.iv18, i32 1
  %22 = load i32, ptr %21, align 4, !tbaa !11
  %23 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %22)
  %24 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8) %23, i8 noundef signext 32)
  %25 = load i32, ptr %1, align 4, !tbaa !8
  %26 = trunc nuw nsw i64 %indvars.iv18 to i32
  %27 = xor i32 %26, -1
  %28 = add i32 %25, %27
  %29 = sext i32 %28 to i64
  %30 = getelementptr inbounds [101 x %"struct.std::pair"], ptr @a, i64 0, i64 %29, i32 1
  %31 = load i32, ptr %30, align 4, !tbaa !11
  %32 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) %24, i32 noundef %31)
  %33 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8) %32, i8 noundef signext 10)
  %indvars.iv.next19 = add nuw nsw i64 %indvars.iv18, 1
  %34 = load i32, ptr %1, align 4, !tbaa !8
  %35 = sdiv i32 %34, 2
  %36 = sext i32 %35 to i64
  %37 = icmp slt i64 %indvars.iv.next19, %36
  br i1 %37, label %.lr.ph14, label %._crit_edge15, !llvm.loop !15
}

declare noundef zeroext i1 @_ZNSt8ios_base15sync_with_stdioEb(i1 noundef zeroext) local_unnamed_addr #1

; 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

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #3

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 #1

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #3

; Function Attrs: inlinehint mustprogress uwtable
declare dso_local void @_ZSt4sortIPSt4pairIiiEEvT_S3_(ptr noundef, ptr noundef) local_unnamed_addr #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 #4

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) local_unnamed_addr #1

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 = { "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 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #4 = { 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 #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 = !{!"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 = !{!12, !9, i64 4}
!12 = !{!"_ZTSSt4pairIiiE", !9, i64 0, !9, i64 4}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}
!15 = distinct !{!15, !14}


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