; LLVM IR from eyangch/competitive-programming :: Codeforces/946/e.ll/Z4sub1NSt7 (cxx1112basic_stringIcSt11char_traitsIcESaIcEEEx)

; 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] }

; Function Attrs: mustprogress uwtable
define dso_local void @_Z4sub1NSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEx(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8 %0, ptr noundef %1, i64 noundef %2) #0 {
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca i64, align 8
  %7 = alloca i64, align 8
  %8 = alloca i64, align 8
  store ptr %0, ptr %4, align 8
  store ptr %1, ptr %5, align 8, !tbaa !5
  store i64 %2, ptr %6, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #3
  store i64 1, ptr %7, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %8) #3
  %9 = load i64, ptr %6, align 8, !tbaa !9
  %10 = sub nsw i64 %9, 1
  store i64 %10, ptr %8, align 8, !tbaa !9
  br label %11

11:                                               ; preds = %32, %3
  %12 = load i64, ptr %8, align 8, !tbaa !9
  %13 = icmp sge i64 %12, 0
  br i1 %13, label %15, label %14

14:                                               ; preds = %11
  call void @llvm.lifetime.end.p0(i64 8, ptr %8) #3
  br label %35

15:                                               ; preds = %11
  %16 = load i64, ptr %7, align 8, !tbaa !9
  %17 = load i64, ptr %8, align 8, !tbaa !9
  %18 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %1, i64 noundef %17)
  %19 = load i8, ptr %18, align 1, !tbaa !11
  %20 = sext i8 %19 to i64
  %21 = sub nsw i64 %20, %16
  %22 = trunc i64 %21 to i8
  store i8 %22, ptr %18, align 1, !tbaa !11
  store i64 0, ptr %7, align 8, !tbaa !9
  %23 = load i64, ptr %8, align 8, !tbaa !9
  %24 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %1, i64 noundef %23)
  %25 = load i8, ptr %24, align 1, !tbaa !11
  %26 = sext i8 %25 to i32
  %27 = icmp slt i32 %26, 48
  br i1 %27, label %28, label %31

28:                                               ; preds = %15
  store i64 1, ptr %7, align 8, !tbaa !9
  %29 = load i64, ptr %8, align 8, !tbaa !9
  %30 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %1, i64 noundef %29)
  store i8 57, ptr %30, align 1, !tbaa !11
  br label %31

31:                                               ; preds = %28, %15
  br label %32

32:                                               ; preds = %31
  %33 = load i64, ptr %8, align 8, !tbaa !9
  %34 = add nsw i64 %33, -1
  store i64 %34, ptr %8, align 8, !tbaa !9
  br label %11, !llvm.loop !12

35:                                               ; preds = %14
  call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2EOS4_(ptr noundef nonnull align 8 dereferenceable(32) %0, ptr noundef nonnull align 8 dereferenceable(32) %1) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #3
  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

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2EOS4_(ptr noundef nonnull align 8 dereferenceable(32), ptr noundef nonnull align 8 dereferenceable(32)) unnamed_addr #2 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 = { 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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"long long", !7, i64 0}
!11 = !{!7, !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"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::__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] }

; Function Attrs: mustprogress nounwind uwtable
define dso_local void @_Z4sub1NSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEx(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8 %0, ptr noundef %1, i64 noundef %2) local_unnamed_addr #0 {
  %4 = icmp sgt i64 %2, 0
  br i1 %4, label %.lr.ph, label %._crit_edge

._crit_edge:                                      ; preds = %13, %3
  tail call void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2EOS4_(ptr noundef nonnull align 8 dereferenceable(32) %0, ptr noundef nonnull align 8 dereferenceable(32) %1) #1
  ret void

.lr.ph:                                           ; preds = %3, %13
  %.010.in = phi i64 [ %.010, %13 ], [ %2, %3 ]
  %.07.neg9 = phi i8 [ %.1.neg, %13 ], [ -1, %3 ]
  %.010 = add nsw i64 %.010.in, -1
  %5 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %1, i64 noundef %.010)
  %6 = load i8, ptr %5, align 1, !tbaa !5
  %7 = add i8 %6, %.07.neg9
  store i8 %7, ptr %5, align 1, !tbaa !5
  %8 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %1, i64 noundef %.010)
  %9 = load i8, ptr %8, align 1, !tbaa !5
  %10 = icmp slt i8 %9, 48
  br i1 %10, label %11, label %13

11:                                               ; preds = %.lr.ph
  %12 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %1, i64 noundef %.010)
  store i8 57, ptr %12, align 1, !tbaa !5
  br label %13

13:                                               ; preds = %.lr.ph, %11
  %.1.neg = phi i8 [ -1, %11 ], [ 0, %.lr.ph ]
  %14 = icmp ugt i64 %.010.in, 1
  br i1 %14, label %.lr.ph, label %._crit_edge, !llvm.loop !8
}

; 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

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2EOS4_(ptr noundef nonnull align 8 dereferenceable(32), ptr noundef nonnull align 8 dereferenceable(32)) 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" }
attributes #1 = { 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: CorrelatedValuePropagationPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass,TailCallElimPass