; LLVM IR from Izaron/ACM-ICPC :: Google Code Jam/markdown.ll (Z9read_lineB5cxx11v)

; 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

; Function Attrs: mustprogress uwtable
define dso_local void @_Z9read_lineB5cxx11v(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8 %0) #0 personality ptr @__gxx_personality_v0 {
  %2 = alloca ptr, align 8
  %3 = alloca i1, align 1
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  store ptr %0, ptr %2, align 8
  store i1 false, ptr %3, align 1
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2Ev(ptr noundef nonnull align 8 dereferenceable(32) %0) #3
  br label %6

6:                                                ; preds = %22, %1
  %7 = invoke noundef nonnull align 8 dereferenceable(16) ptr @_ZSt7getlineIcSt11char_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) %0)
          to label %8 unwind label %18

8:                                                ; preds = %6
  %9 = load ptr, ptr %7, align 8, !tbaa !5
  %10 = getelementptr i8, ptr %9, i64 -24
  %11 = load i64, ptr %10, align 8
  %12 = getelementptr inbounds i8, ptr %7, i64 %11
  %13 = invoke noundef zeroext i1 @_ZNKSt9basic_iosIcSt11char_traitsIcEEcvbEv(ptr noundef nonnull align 8 dereferenceable(264) %12)
          to label %14 unwind label %18

14:                                               ; preds = %8
  br i1 %13, label %15, label %23

15:                                               ; preds = %14
  %16 = call noundef zeroext i1 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE5emptyEv(ptr noundef nonnull align 8 dereferenceable(32) %0) #3
  br i1 %16, label %22, label %17

17:                                               ; preds = %15
  br label %23

18:                                               ; preds = %8, %6
  %19 = landingpad { ptr, i32 }
          cleanup
  %20 = extractvalue { ptr, i32 } %19, 0
  store ptr %20, ptr %4, align 8
  %21 = extractvalue { ptr, i32 } %19, 1
  store i32 %21, ptr %5, align 4
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %0) #3
  br label %27

22:                                               ; preds = %15
  br label %6, !llvm.loop !8

23:                                               ; preds = %17, %14
  store i1 true, ptr %3, align 1
  %24 = load i1, ptr %3, align 1
  br i1 %24, label %26, label %25

25:                                               ; preds = %23
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %0) #3
  br label %26

26:                                               ; preds = %25, %23
  ret void

27:                                               ; preds = %18
  %28 = load ptr, ptr %4, align 8
  %29 = load i32, ptr %5, align 4
  %30 = insertvalue { ptr, i32 } poison, ptr %28, 0
  %31 = insertvalue { ptr, i32 } %30, i32 %29, 1
  resume { ptr, i32 } %31
}

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2Ev(ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #1 align 2

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(16) ptr @_ZSt7getlineIcSt11char_traitsIcESaIcEERSt13basic_istreamIT_T0_ES7_RNSt7__cxx1112basic_stringIS4_S5_T1_EE(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 8 dereferenceable(32)) #2

declare i32 @__gxx_personality_v0(...)

; Function Attrs: mustprogress uwtable
declare noundef zeroext i1 @_ZNKSt9basic_iosIcSt11char_traitsIcEEcvbEv(ptr noundef nonnull align 8 dereferenceable(264)) #0 align 2

; Function Attrs: mustprogress nounwind uwtable
declare noundef zeroext i1 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE5emptyEv(ptr noundef nonnull align 8 dereferenceable(32)) #1 align 2

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #1 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 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 #2 = { 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 #3 = { 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 = distinct !{!8, !9}
!9 = !{!"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

; Function Attrs: mustprogress uwtable
define dso_local void @_Z9read_lineB5cxx11v(ptr dead_on_unwind noalias nonnull writable sret(%"class.std::__cxx11::basic_string") align 8 %0) local_unnamed_addr #0 personality ptr @__gxx_personality_v0 {
  tail call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2Ev(ptr noundef nonnull align 8 dereferenceable(32) %0) #3
  br label %2

2:                                                ; preds = %11, %1
  %3 = invoke noundef nonnull align 8 dereferenceable(16) ptr @_ZSt7getlineIcSt11char_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) %0)
          to label %4 unwind label %13

4:                                                ; preds = %2
  %5 = load ptr, ptr %3, align 8, !tbaa !5
  %6 = getelementptr i8, ptr %5, i64 -24
  %7 = load i64, ptr %6, align 8
  %8 = getelementptr inbounds i8, ptr %3, i64 %7
  %9 = invoke noundef zeroext i1 @_ZNKSt9basic_iosIcSt11char_traitsIcEEcvbEv(ptr noundef nonnull align 8 dereferenceable(264) %8)
          to label %10 unwind label %13

10:                                               ; preds = %4
  br i1 %9, label %11, label %15

11:                                               ; preds = %10
  %12 = tail call noundef zeroext i1 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE5emptyEv(ptr noundef nonnull align 8 dereferenceable(32) %0) #3
  br i1 %12, label %2, label %15, !llvm.loop !8

13:                                               ; preds = %4, %2
  %14 = landingpad { ptr, i32 }
          cleanup
  tail call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32) %0) #3
  resume { ptr, i32 } %14

15:                                               ; preds = %10, %11
  ret void
}

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2Ev(ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #1 align 2

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(16) ptr @_ZSt7getlineIcSt11char_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 #2

declare i32 @__gxx_personality_v0(...)

; Function Attrs: mustprogress uwtable
declare noundef zeroext i1 @_ZNKSt9basic_iosIcSt11char_traitsIcEEcvbEv(ptr noundef nonnull align 8 dereferenceable(264)) local_unnamed_addr #0 align 2

; Function Attrs: mustprogress nounwind uwtable
declare noundef zeroext i1 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE5emptyEv(ptr noundef nonnull align 8 dereferenceable(32)) local_unnamed_addr #1 align 2

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEED2Ev(ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #1 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 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 #2 = { 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 #3 = { 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 = distinct !{!8, !9}
!9 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,IPSCCPPass,InstCombinePass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass