; LLVM IR from tangjz/acm-icpc :: lydsy/1026.ll/Z5checkNSt7 (cxx1112basic_stringIcSt11char_traitsIcESaIcEEE)

; 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"

; Function Attrs: mustprogress uwtable
define dso_local noundef zeroext i1 @_Z5checkNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr noundef %0) #0 {
  %2 = alloca i1, align 1
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #4
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #4
  %7 = call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32) %0) #4
  %8 = trunc i64 %7 to i32
  store i32 %8, ptr %5, align 4, !tbaa !9
  store i32 0, ptr %4, align 4, !tbaa !9
  br label %9

9:                                                ; preds = %31, %1
  %10 = load i32, ptr %4, align 4, !tbaa !9
  %11 = load i32, ptr %5, align 4, !tbaa !9
  %12 = sub nsw i32 %11, 1
  %13 = icmp slt i32 %10, %12
  br i1 %13, label %14, label %34

14:                                               ; preds = %9
  %15 = load i32, ptr %4, align 4, !tbaa !9
  %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) %0, i64 noundef %16)
  %18 = load i8, ptr %17, align 1, !tbaa !11
  %19 = sext i8 %18 to i32
  %20 = load i32, ptr %4, align 4, !tbaa !9
  %21 = add nsw i32 %20, 1
  %22 = sext i32 %21 to i64
  %23 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %22)
  %24 = load i8, ptr %23, align 1, !tbaa !11
  %25 = sext i8 %24 to i32
  %26 = sub nsw i32 %19, %25
  %27 = call i32 @llvm.abs.i32(i32 %26, i1 true)
  %28 = icmp slt i32 %27, 2
  br i1 %28, label %29, label %30

29:                                               ; preds = %14
  store i1 false, ptr %2, align 1
  store i32 1, ptr %6, align 4
  br label %35

30:                                               ; preds = %14
  br label %31

31:                                               ; preds = %30
  %32 = load i32, ptr %4, align 4, !tbaa !9
  %33 = add nsw i32 %32, 1
  store i32 %33, ptr %4, align 4, !tbaa !9
  br label %9, !llvm.loop !12

34:                                               ; preds = %9
  store i1 true, ptr %2, align 1
  store i32 1, ptr %6, align 4
  br label %35

35:                                               ; preds = %34, %29
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #4
  %36 = load i1, ptr %2, align 1
  ret i1 %36
}

; 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 i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32)) #2 align 2

; 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 speculatable willreturn memory(none)
declare i32 @llvm.abs.i32(i32, i1 immarg) #3

; 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 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
attributes #4 = { 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 = !{!"int", !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"

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef zeroext i1 @_Z5checkNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr noundef nonnull %0) local_unnamed_addr #0 {
  %2 = tail call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32) %0) #3
  %3 = trunc i64 %2 to i32
  %4 = add nsw i32 %3, -1
  %smax = tail call i32 @llvm.smax.i32(i32 %4, i32 0)
  %wide.trip.count = zext nneg i32 %smax to i64
  br label %5

5:                                                ; preds = %6, %1
  %indvars.iv = phi i64 [ %indvars.iv.next, %6 ], [ 0, %1 ]
  %exitcond = icmp eq i64 %indvars.iv, %wide.trip.count
  br i1 %exitcond, label %16, label %6

6:                                                ; preds = %5
  %7 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %indvars.iv)
  %8 = load i8, ptr %7, align 1, !tbaa !5
  %9 = sext i8 %8 to i32
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %10 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %indvars.iv.next)
  %11 = load i8, ptr %10, align 1, !tbaa !5
  %12 = sext i8 %11 to i32
  %13 = sub nsw i32 %9, %12
  %14 = tail call i32 @llvm.abs.i32(i32 %13, i1 true)
  %15 = icmp ult i32 %14, 2
  br i1 %15, label %16, label %5, !llvm.loop !8

16:                                               ; preds = %5, %6
  %17 = sext i32 %4 to i64
  %18 = icmp sge i64 %indvars.iv, %17
  ret i1 %18
}

; Function Attrs: mustprogress nounwind uwtable
declare noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32)) local_unnamed_addr #0 align 2

; 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 nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i32 @llvm.abs.i32(i32, i1 immarg) #1

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i32 @llvm.smax.i32(i32, i32) #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 = { mustprogress nocallback nofree nosync nounwind speculatable willreturn memory(none) }
attributes #2 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
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 = !{!"omnipotent char", !7, i64 0}
!7 = !{!"Simple C++ TBAA"}
!8 = distinct !{!8, !9}
!9 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: EarlyCSEPass,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,LCSSAPass,LICMPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SCCPPass,SROAPass,SimplifyCFGPass,TailCallElimPass