; LLVM IR from ayush-tulsyan/ACM-ICPC-Handbook :: code/DFS.ll (Z3DFSi)

; 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::vector" = type { %"struct.std::_Vector_base" }
%"struct.std::_Vector_base" = type { %"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl" }
%"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl" = type { %"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl_data" }
%"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl_data" = type { ptr, ptr, ptr }

@Alist = external dso_local global [101000 x %"class.std::vector"], align 16
@ComNum = external dso_local global [101000 x i32], align 16
@visited = external dso_local global [101000 x i8], align 16

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: mustprogress uwtable
define dso_local void @_Z3DFSi(i32 noundef %0) #1 {
  %2 = alloca i32, align 4
  %3 = alloca i64, align 8
  %4 = alloca i64, align 8
  store i32 %0, ptr %2, align 4, !tbaa !5
  %5 = load i32, ptr %2, align 4, !tbaa !5
  %6 = sext i32 %5 to i64
  %7 = getelementptr inbounds [101000 x i8], ptr @visited, i64 0, i64 %6
  store i8 1, ptr %7, align 1, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #3
  store i64 0, ptr %3, align 8, !tbaa !11
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #3
  %8 = load i32, ptr %2, align 4, !tbaa !5
  %9 = sext i32 %8 to i64
  %10 = getelementptr inbounds [101000 x %"class.std::vector"], ptr @Alist, i64 0, i64 %9
  %11 = call noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24) %10) #3
  store i64 %11, ptr %4, align 8, !tbaa !11
  br label %12

12:                                               ; preds = %48, %1
  %13 = load i64, ptr %3, align 8, !tbaa !11
  %14 = load i64, ptr %4, align 8, !tbaa !11
  %15 = icmp slt i64 %13, %14
  br i1 %15, label %17, label %16

16:                                               ; preds = %12
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #3
  br label %51

17:                                               ; preds = %12
  %18 = load i32, ptr %2, align 4, !tbaa !5
  %19 = sext i32 %18 to i64
  %20 = getelementptr inbounds [101000 x %"class.std::vector"], ptr @Alist, i64 0, i64 %19
  %21 = load i64, ptr %3, align 8, !tbaa !11
  %22 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24) %20, i64 noundef %21) #3
  %23 = load i32, ptr %22, align 4, !tbaa !5
  %24 = sext i32 %23 to i64
  %25 = getelementptr inbounds [101000 x i8], ptr @visited, i64 0, i64 %24
  %26 = load i8, ptr %25, align 1, !tbaa !9, !range !13, !noundef !14
  %27 = trunc i8 %26 to i1
  br i1 %27, label %47, label %28

28:                                               ; preds = %17
  %29 = load i32, ptr %2, align 4, !tbaa !5
  %30 = sext i32 %29 to i64
  %31 = getelementptr inbounds [101000 x i32], ptr @ComNum, i64 0, i64 %30
  %32 = load i32, ptr %31, align 4, !tbaa !5
  %33 = load i32, ptr %2, align 4, !tbaa !5
  %34 = sext i32 %33 to i64
  %35 = getelementptr inbounds [101000 x %"class.std::vector"], ptr @Alist, i64 0, i64 %34
  %36 = load i64, ptr %3, align 8, !tbaa !11
  %37 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24) %35, i64 noundef %36) #3
  %38 = load i32, ptr %37, align 4, !tbaa !5
  %39 = sext i32 %38 to i64
  %40 = getelementptr inbounds [101000 x i32], ptr @ComNum, i64 0, i64 %39
  store i32 %32, ptr %40, align 4, !tbaa !5
  %41 = load i32, ptr %2, align 4, !tbaa !5
  %42 = sext i32 %41 to i64
  %43 = getelementptr inbounds [101000 x %"class.std::vector"], ptr @Alist, i64 0, i64 %42
  %44 = load i64, ptr %3, align 8, !tbaa !11
  %45 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24) %43, i64 noundef %44) #3
  %46 = load i32, ptr %45, align 4, !tbaa !5
  call void @_Z3DFSi(i32 noundef %46)
  br label %47

47:                                               ; preds = %28, %17
  br label %48

48:                                               ; preds = %47
  %49 = load i64, ptr %3, align 8, !tbaa !11
  %50 = add nsw i64 %49, 1
  store i64 %50, ptr %3, align 8, !tbaa !11
  br label %12, !llvm.loop !15

51:                                               ; preds = %16
  ret void
}

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24)) #2 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24), i64 noundef) #2 align 2

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 #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 = !{!10, !10, i64 0}
!10 = !{!"bool", !7, i64 0}
!11 = !{!12, !12, i64 0}
!12 = !{!"long long", !7, i64 0}
!13 = !{i8 0, i8 2}
!14 = !{}
!15 = distinct !{!15, !16}
!16 = !{!"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::vector" = type { %"struct.std::_Vector_base" }
%"struct.std::_Vector_base" = type { %"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl" }
%"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl" = type { %"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl_data" }
%"struct.std::_Vector_base<int, std::allocator<int>>::_Vector_impl_data" = type { ptr, ptr, ptr }

@Alist = external dso_local global [101000 x %"class.std::vector"], align 16
@ComNum = external dso_local local_unnamed_addr global [101000 x i32], align 16
@visited = external dso_local local_unnamed_addr global [101000 x i8], align 16

; Function Attrs: mustprogress nounwind uwtable
define dso_local void @_Z3DFSi(i32 noundef %0) local_unnamed_addr #0 {
  %2 = sext i32 %0 to i64
  %3 = getelementptr inbounds [101000 x i8], ptr @visited, i64 0, i64 %2
  store i8 1, ptr %3, align 1, !tbaa !5
  %4 = getelementptr inbounds [101000 x %"class.std::vector"], ptr @Alist, i64 0, i64 %2
  %5 = tail call noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24) %4) #1
  %6 = icmp sgt i64 %5, 0
  br i1 %6, label %.lr.ph, label %._crit_edge

.lr.ph:                                           ; preds = %1
  %7 = getelementptr inbounds [101000 x i32], ptr @ComNum, i64 0, i64 %2
  br label %8

._crit_edge:                                      ; preds = %23, %1
  ret void

8:                                                ; preds = %.lr.ph, %23
  %.012 = phi i64 [ 0, %.lr.ph ], [ %24, %23 ]
  %9 = tail call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24) %4, i64 noundef %.012) #1
  %10 = load i32, ptr %9, align 4, !tbaa !9
  %11 = sext i32 %10 to i64
  %12 = getelementptr inbounds [101000 x i8], ptr @visited, i64 0, i64 %11
  %13 = load i8, ptr %12, align 1, !tbaa !5, !range !11, !noundef !12
  %14 = trunc nuw i8 %13 to i1
  br i1 %14, label %23, label %15

15:                                               ; preds = %8
  %16 = load i32, ptr %7, align 4, !tbaa !9
  %17 = tail call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24) %4, i64 noundef %.012) #1
  %18 = load i32, ptr %17, align 4, !tbaa !9
  %19 = sext i32 %18 to i64
  %20 = getelementptr inbounds [101000 x i32], ptr @ComNum, i64 0, i64 %19
  store i32 %16, ptr %20, align 4, !tbaa !9
  %21 = tail call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24) %4, i64 noundef %.012) #1
  %22 = load i32, ptr %21, align 4, !tbaa !9
  tail call void @_Z3DFSi(i32 noundef %22)
  br label %23

23:                                               ; preds = %8, %15
  %24 = add nuw nsw i64 %.012, 1
  %exitcond.not = icmp eq i64 %24, %5
  br i1 %exitcond.not, label %._crit_edge, label %8, !llvm.loop !13
}

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24)) local_unnamed_addr #0 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEEixEm(ptr noundef nonnull align 8 dereferenceable(24), 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" }
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 = !{!"bool", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = !{i8 0, i8 2}
!12 = !{}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}


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