; LLVM IR from Izaron/ACM-ICPC :: Timus Online Judge/Volume 7/1685. Orthography.ll (Z3dfsii)

; 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::__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] }

@_Z1sB5cxx11 = external dso_local global %"class.std::__cxx11::basic_string", align 8
@_Z3kekB5cxx11 = external dso_local global %"class.std::__cxx11::basic_string", align 8
@curr = external dso_local global i32, align 4

; Function Attrs: mustprogress uwtable
define dso_local void @_Z3dfsii(i32 noundef %0, i32 noundef %1) #0 {
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !5
  %6 = load i32, ptr %3, align 4, !tbaa !5
  %7 = load i32, ptr %4, align 4, !tbaa !5
  %8 = icmp sgt i32 %6, %7
  br i1 %8, label %9, label %10

9:                                                ; preds = %2
  br label %30

10:                                               ; preds = %2
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #3
  %11 = load i32, ptr %3, align 4, !tbaa !5
  %12 = load i32, ptr %4, align 4, !tbaa !5
  %13 = add nsw i32 %11, %12
  %14 = sdiv i32 %13, 2
  store i32 %14, ptr %5, align 4, !tbaa !5
  %15 = load i32, ptr @curr, align 4, !tbaa !5
  %16 = sext i32 %15 to i64
  %17 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) @_Z1sB5cxx11, i64 noundef %16)
  %18 = load i8, ptr %17, align 1, !tbaa !9
  %19 = load i32, ptr %5, align 4, !tbaa !5
  %20 = sext i32 %19 to i64
  %21 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) @_Z3kekB5cxx11, i64 noundef %20)
  store i8 %18, ptr %21, align 1, !tbaa !9
  %22 = load i32, ptr @curr, align 4, !tbaa !5
  %23 = add nsw i32 %22, 1
  store i32 %23, ptr @curr, align 4, !tbaa !5
  %24 = load i32, ptr %3, align 4, !tbaa !5
  %25 = load i32, ptr %5, align 4, !tbaa !5
  %26 = sub nsw i32 %25, 1
  call void @_Z3dfsii(i32 noundef %24, i32 noundef %26)
  %27 = load i32, ptr %5, align 4, !tbaa !5
  %28 = add nsw i32 %27, 1
  %29 = load i32, ptr %4, align 4, !tbaa !5
  call void @_Z3dfsii(i32 noundef %28, i32 noundef %29)
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #3
  br label %30

30:                                               ; preds = %10, %9
  ret void
}

; 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 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

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 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 = { 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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!7, !7, i64 0}


; 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::__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] }

@_Z1sB5cxx11 = external dso_local global %"class.std::__cxx11::basic_string", align 8
@_Z3kekB5cxx11 = external dso_local global %"class.std::__cxx11::basic_string", align 8
@curr = external dso_local local_unnamed_addr global i32, align 4

; Function Attrs: mustprogress nounwind uwtable
define dso_local void @_Z3dfsii(i32 noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = icmp sgt i32 %0, %1
  br i1 %3, label %tailrecurse._crit_edge, label %tailrecurse

tailrecurse:                                      ; preds = %2, %tailrecurse
  %.tr11 = phi i32 [ %15, %tailrecurse ], [ %0, %2 ]
  %4 = add nsw i32 %.tr11, %1
  %5 = sdiv i32 %4, 2
  %6 = load i32, ptr @curr, align 4, !tbaa !5
  %7 = sext i32 %6 to i64
  %8 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) @_Z1sB5cxx11, i64 noundef %7)
  %9 = load i8, ptr %8, align 1, !tbaa !9
  %10 = sext i32 %5 to i64
  %11 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) @_Z3kekB5cxx11, i64 noundef %10)
  store i8 %9, ptr %11, align 1, !tbaa !9
  %12 = load i32, ptr @curr, align 4, !tbaa !5
  %13 = add nsw i32 %12, 1
  store i32 %13, ptr @curr, align 4, !tbaa !5
  %14 = add nsw i32 %5, -1
  tail call void @_Z3dfsii(i32 noundef %.tr11, i32 noundef %14)
  %15 = add nsw i32 %5, 1
  %.not = icmp slt i32 %5, %1
  br i1 %.not, label %tailrecurse, label %tailrecurse._crit_edge

tailrecurse._crit_edge:                           ; preds = %tailrecurse, %2
  ret void
}

; 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 #0 align 2

attributes #0 = { 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" }

!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}


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