; LLVM IR from sunkafei/xcpc-algorithm-templates :: 算法/图论/欧拉回路.ll (ZN12direct_graph3dfsEi)

; 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 }
%"class.std::vector.0" = type { %"struct.std::_Vector_base.1" }
%"struct.std::_Vector_base.1" = type { %"struct.std::_Vector_base<std::pair<int, int>, std::allocator<std::pair<int, int>>>::_Vector_impl" }
%"struct.std::_Vector_base<std::pair<int, int>, std::allocator<std::pair<int, int>>>::_Vector_impl" = type { %"struct.std::_Vector_base<std::pair<int, int>, std::allocator<std::pair<int, int>>>::_Vector_impl_data" }
%"struct.std::_Vector_base<std::pair<int, int>, std::allocator<std::pair<int, int>>>::_Vector_impl_data" = type { ptr, ptr, ptr }

@_ZN12direct_graph1GE = external dso_local global [110000 x %"class.std::vector"], align 16
@_ZN12direct_graph6resultE = external dso_local global %"class.std::vector.0", align 8

; Function Attrs: mustprogress uwtable
define dso_local void @_ZN12direct_graph3dfsEi(i32 noundef %0) #0 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  store i32 %0, ptr %2, align 4, !tbaa !5
  br label %4

4:                                                ; preds = %10, %1
  %5 = load i32, ptr %2, align 4, !tbaa !5
  %6 = sext i32 %5 to i64
  %7 = getelementptr inbounds [110000 x %"class.std::vector"], ptr @_ZN12direct_graph1GE, i64 0, i64 %6
  %8 = call noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24) %7) #3
  %9 = icmp ne i64 %8, 0
  br i1 %9, label %10, label %21

10:                                               ; preds = %4
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #3
  %11 = load i32, ptr %2, align 4, !tbaa !5
  %12 = sext i32 %11 to i64
  %13 = getelementptr inbounds [110000 x %"class.std::vector"], ptr @_ZN12direct_graph1GE, i64 0, i64 %12
  %14 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEE4backEv(ptr noundef nonnull align 8 dereferenceable(24) %13) #3
  %15 = load i32, ptr %14, align 4, !tbaa !5
  store i32 %15, ptr %3, align 4, !tbaa !5
  %16 = load i32, ptr %2, align 4, !tbaa !5
  %17 = sext i32 %16 to i64
  %18 = getelementptr inbounds [110000 x %"class.std::vector"], ptr @_ZN12direct_graph1GE, i64 0, i64 %17
  call void @_ZNSt6vectorIiSaIiEE8pop_backEv(ptr noundef nonnull align 8 dereferenceable(24) %18) #3
  %19 = load i32, ptr %3, align 4, !tbaa !5
  call void @_ZN12direct_graph3dfsEi(i32 noundef %19)
  %20 = call noundef nonnull align 4 dereferenceable(8) ptr @_ZNSt6vectorISt4pairIiiESaIS1_EE12emplace_backIJRiS5_EEERS1_DpOT_(ptr noundef nonnull align 8 dereferenceable(24) @_ZN12direct_graph6resultE, ptr noundef nonnull align 4 dereferenceable(4) %2, ptr noundef nonnull align 4 dereferenceable(4) %3)
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #3
  br label %4, !llvm.loop !9

21:                                               ; preds = %4
  ret void
}

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24)) #1 align 2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEE4backEv(ptr noundef nonnull align 8 dereferenceable(24)) #1 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_ZNSt6vectorIiSaIiEE8pop_backEv(ptr noundef nonnull align 8 dereferenceable(24)) #1 align 2

; Function Attrs: mustprogress uwtable
declare dso_local noundef nonnull align 4 dereferenceable(8) ptr @_ZNSt6vectorISt4pairIiiESaIS1_EE12emplace_backIJRiS5_EEERS1_DpOT_(ptr noundef nonnull align 8 dereferenceable(24), ptr noundef nonnull align 4 dereferenceable(4), ptr noundef nonnull align 4 dereferenceable(4)) #0 align 2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = distinct !{!9, !10}
!10 = !{!"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 }
%"class.std::vector.0" = type { %"struct.std::_Vector_base.1" }
%"struct.std::_Vector_base.1" = type { %"struct.std::_Vector_base<std::pair<int, int>, std::allocator<std::pair<int, int>>>::_Vector_impl" }
%"struct.std::_Vector_base<std::pair<int, int>, std::allocator<std::pair<int, int>>>::_Vector_impl" = type { %"struct.std::_Vector_base<std::pair<int, int>, std::allocator<std::pair<int, int>>>::_Vector_impl_data" }
%"struct.std::_Vector_base<std::pair<int, int>, std::allocator<std::pair<int, int>>>::_Vector_impl_data" = type { ptr, ptr, ptr }

@_ZN12direct_graph1GE = external dso_local global [110000 x %"class.std::vector"], align 16
@_ZN12direct_graph6resultE = external dso_local global %"class.std::vector.0", align 8

; Function Attrs: mustprogress uwtable
define dso_local void @_ZN12direct_graph3dfsEi(i32 noundef %0) local_unnamed_addr #0 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  store i32 %0, ptr %2, align 4, !tbaa !5
  %4 = sext i32 %0 to i64
  %5 = getelementptr inbounds [110000 x %"class.std::vector"], ptr @_ZN12direct_graph1GE, i64 0, i64 %4
  %6 = tail call noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24) %5) #3
  %.not1 = icmp eq i64 %6, 0
  br i1 %.not1, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %1, %.lr.ph
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %3) #3
  %7 = load i32, ptr %2, align 4, !tbaa !5
  %8 = sext i32 %7 to i64
  %9 = getelementptr inbounds [110000 x %"class.std::vector"], ptr @_ZN12direct_graph1GE, i64 0, i64 %8
  %10 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEE4backEv(ptr noundef nonnull align 8 dereferenceable(24) %9) #3
  %11 = load i32, ptr %10, align 4, !tbaa !5
  store i32 %11, ptr %3, align 4, !tbaa !5
  %12 = load i32, ptr %2, align 4, !tbaa !5
  %13 = sext i32 %12 to i64
  %14 = getelementptr inbounds [110000 x %"class.std::vector"], ptr @_ZN12direct_graph1GE, i64 0, i64 %13
  call void @_ZNSt6vectorIiSaIiEE8pop_backEv(ptr noundef nonnull align 8 dereferenceable(24) %14) #3
  %15 = load i32, ptr %3, align 4, !tbaa !5
  call void @_ZN12direct_graph3dfsEi(i32 noundef %15)
  %16 = call noundef nonnull align 4 dereferenceable(8) ptr @_ZNSt6vectorISt4pairIiiESaIS1_EE12emplace_backIJRiS5_EEERS1_DpOT_(ptr noundef nonnull align 8 dereferenceable(24) @_ZN12direct_graph6resultE, ptr noundef nonnull align 4 dereferenceable(4) %2, ptr noundef nonnull align 4 dereferenceable(4) %3)
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %3) #3
  %17 = load i32, ptr %2, align 4, !tbaa !5
  %18 = sext i32 %17 to i64
  %19 = getelementptr inbounds [110000 x %"class.std::vector"], ptr @_ZN12direct_graph1GE, i64 0, i64 %18
  %20 = call noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24) %19) #3
  %.not = icmp eq i64 %20, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !9

._crit_edge:                                      ; preds = %.lr.ph, %1
  ret void
}

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef i64 @_ZNKSt6vectorIiSaIiEE4sizeEv(ptr noundef nonnull align 8 dereferenceable(24)) local_unnamed_addr #1 align 2

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt6vectorIiSaIiEE4backEv(ptr noundef nonnull align 8 dereferenceable(24)) local_unnamed_addr #1 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_ZNSt6vectorIiSaIiEE8pop_backEv(ptr noundef nonnull align 8 dereferenceable(24)) local_unnamed_addr #1 align 2

; Function Attrs: mustprogress uwtable
declare dso_local noundef nonnull align 4 dereferenceable(8) ptr @_ZNSt6vectorISt4pairIiiESaIS1_EE12emplace_backIJRiS5_EEERS1_DpOT_(ptr noundef nonnull align 8 dereferenceable(24), ptr noundef nonnull align 4 dereferenceable(4), ptr noundef nonnull align 4 dereferenceable(4)) local_unnamed_addr #0 align 2

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #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 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


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