; LLVM IR from tangjz/acm-icpc :: 51nod/1076.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"

%struct.Edge = type { i32, i32 }

@e = external dso_local global [100001 x %struct.Edge], align 16
@lnk = external dso_local global [50001 x i32], align 16
@cnt = external dso_local global i32, align 4
@bcc = external dso_local global [50001 x i32], align 16
@used = external dso_local global [100001 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 i32, align 4
  store i32 %0, ptr %2, align 4, !tbaa !5
  %4 = load i32, ptr @cnt, align 4, !tbaa !5
  %5 = load i32, ptr %2, align 4, !tbaa !5
  %6 = sext i32 %5 to i64
  %7 = getelementptr inbounds [50001 x i32], ptr @bcc, i64 0, i64 %6
  store i32 %4, ptr %7, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #2
  %8 = load i32, ptr %2, align 4, !tbaa !5
  %9 = sext i32 %8 to i64
  %10 = getelementptr inbounds [50001 x i32], ptr @lnk, i64 0, i64 %9
  %11 = load i32, ptr %10, align 4, !tbaa !5
  store i32 %11, ptr %3, align 4, !tbaa !5
  br label %12

12:                                               ; preds = %39, %1
  %13 = load i32, ptr %3, align 4, !tbaa !5
  %14 = icmp ne i32 %13, -1
  br i1 %14, label %16, label %15

15:                                               ; preds = %12
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #2
  br label %45

16:                                               ; preds = %12
  %17 = load i32, ptr %3, align 4, !tbaa !5
  %18 = sext i32 %17 to i64
  %19 = getelementptr inbounds [100001 x i8], ptr @used, i64 0, i64 %18
  %20 = load i8, ptr %19, align 1, !tbaa !9, !range !11, !noundef !12
  %21 = trunc i8 %20 to i1
  br i1 %21, label %38, label %22

22:                                               ; preds = %16
  %23 = load i32, ptr %3, align 4, !tbaa !5
  %24 = sext i32 %23 to i64
  %25 = getelementptr inbounds [100001 x %struct.Edge], ptr @e, i64 0, i64 %24
  %26 = getelementptr inbounds %struct.Edge, ptr %25, i32 0, i32 1
  %27 = load i32, ptr %26, align 4, !tbaa !13
  %28 = sext i32 %27 to i64
  %29 = getelementptr inbounds [50001 x i32], ptr @bcc, i64 0, i64 %28
  %30 = load i32, ptr %29, align 4, !tbaa !5
  %31 = icmp eq i32 %30, -1
  br i1 %31, label %32, label %38

32:                                               ; preds = %22
  %33 = load i32, ptr %3, align 4, !tbaa !5
  %34 = sext i32 %33 to i64
  %35 = getelementptr inbounds [100001 x %struct.Edge], ptr @e, i64 0, i64 %34
  %36 = getelementptr inbounds %struct.Edge, ptr %35, i32 0, i32 1
  %37 = load i32, ptr %36, align 4, !tbaa !13
  call void @_Z3dfsi(i32 noundef %37)
  br label %38

38:                                               ; preds = %32, %22, %16
  br label %39

39:                                               ; preds = %38
  %40 = load i32, ptr %3, align 4, !tbaa !5
  %41 = sext i32 %40 to i64
  %42 = getelementptr inbounds [100001 x %struct.Edge], ptr @e, i64 0, i64 %41
  %43 = getelementptr inbounds %struct.Edge, ptr %42, i32 0, i32 0
  %44 = load i32, ptr %43, align 8, !tbaa !15
  store i32 %44, ptr %3, align 4, !tbaa !5
  br label %12, !llvm.loop !16

45:                                               ; preds = %15
  ret void
}

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 = { 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 = !{i8 0, i8 2}
!12 = !{}
!13 = !{!14, !6, i64 4}
!14 = !{!"_ZTS4Edge", !6, i64 0, !6, i64 4}
!15 = !{!14, !6, i64 0}
!16 = distinct !{!16, !17}
!17 = !{!"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"

%struct.Edge = type { i32, i32 }

@e = external dso_local local_unnamed_addr global [100001 x %struct.Edge], align 16
@lnk = external dso_local local_unnamed_addr global [50001 x i32], align 16
@cnt = external dso_local local_unnamed_addr global i32, align 4
@bcc = external dso_local local_unnamed_addr global [50001 x i32], align 16
@used = external dso_local local_unnamed_addr global [100001 x i8], align 16

; Function Attrs: mustprogress nofree nosync nounwind memory(readwrite, argmem: none, inaccessiblemem: none) uwtable
define dso_local void @_Z3dfsi(i32 noundef %0) local_unnamed_addr #0 {
  %2 = load i32, ptr @cnt, align 4, !tbaa !5
  %3 = sext i32 %0 to i64
  %4 = getelementptr inbounds [50001 x i32], ptr @bcc, i64 0, i64 %3
  store i32 %2, ptr %4, align 4, !tbaa !5
  %5 = getelementptr inbounds [50001 x i32], ptr @lnk, i64 0, i64 %3
  %.07 = load i32, ptr %5, align 4, !tbaa !5
  %.not8 = icmp eq i32 %.07, -1
  br i1 %.not8, label %._crit_edge, label %.lr.ph

._crit_edge:                                      ; preds = %18, %1
  ret void

.lr.ph:                                           ; preds = %1, %18
  %.09 = phi i32 [ %.0, %18 ], [ %.07, %1 ]
  %6 = sext i32 %.09 to i64
  %7 = getelementptr inbounds [100001 x i8], ptr @used, i64 0, i64 %6
  %8 = load i8, ptr %7, align 1, !tbaa !9, !range !11, !noundef !12
  %9 = trunc nuw i8 %8 to i1
  br i1 %9, label %18, label %10

10:                                               ; preds = %.lr.ph
  %11 = getelementptr inbounds [100001 x %struct.Edge], ptr @e, i64 0, i64 %6, i32 1
  %12 = load i32, ptr %11, align 4, !tbaa !13
  %13 = sext i32 %12 to i64
  %14 = getelementptr inbounds [50001 x i32], ptr @bcc, i64 0, i64 %13
  %15 = load i32, ptr %14, align 4, !tbaa !5
  %16 = icmp eq i32 %15, -1
  br i1 %16, label %17, label %18

17:                                               ; preds = %10
  tail call void @_Z3dfsi(i32 noundef %12)
  br label %18

18:                                               ; preds = %.lr.ph, %10, %17
  %19 = getelementptr inbounds [100001 x %struct.Edge], ptr @e, i64 0, i64 %6
  %.0 = load i32, ptr %19, align 8, !tbaa !5
  %.not = icmp eq i32 %.0, -1
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !15
}

attributes #0 = { mustprogress nofree nosync nounwind memory(readwrite, argmem: none, inaccessiblemem: none) 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 = !{!10, !10, i64 0}
!10 = !{!"bool", !7, i64 0}
!11 = !{i8 0, i8 2}
!12 = !{}
!13 = !{!14, !6, i64 4}
!14 = !{!"_ZTS4Edge", !6, i64 0, !6, i64 4}
!15 = distinct !{!15, !16}
!16 = !{!"llvm.loop.mustprogress"}


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