; LLVM IR from tangjz/acm-icpc :: lydsy/1165.ll (Z4dfs2i)

; 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 }

@m = external dso_local global i32, align 4
@tot = external dso_local global i32, align 4
@suf = external dso_local global [1000001 x i32], align 16
@lnk = external dso_local global [1000001 x i32], align 16
@scc = external dso_local global [1000001 x i32], align 16
@e = external dso_local global [4000005 x %struct.Edge], align 16
@vis = external dso_local global [1000001 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 @_Z4dfs2i(i32 noundef %0) #1 {
  %2 = alloca i32, align 4
  %3 = alloca %struct.Edge, align 4
  %4 = alloca i32, align 4
  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 [1000001 x i8], ptr @vis, i64 0, i64 %6
  store i8 1, ptr %7, align 1, !tbaa !9
  %8 = load i32, ptr @tot, align 4, !tbaa !5
  %9 = load i32, ptr %2, align 4, !tbaa !5
  %10 = sext i32 %9 to i64
  %11 = getelementptr inbounds [1000001 x i32], ptr @scc, i64 0, i64 %10
  store i32 %8, ptr %11, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #3
  %12 = getelementptr inbounds %struct.Edge, ptr %3, i32 0, i32 0
  %13 = load i32, ptr @tot, align 4, !tbaa !5
  %14 = sext i32 %13 to i64
  %15 = getelementptr inbounds [1000001 x i32], ptr @lnk, i64 0, i64 %14
  %16 = load i32, ptr %15, align 4, !tbaa !5
  store i32 %16, ptr %12, align 4, !tbaa !11
  %17 = getelementptr inbounds %struct.Edge, ptr %3, i32 0, i32 1
  %18 = load i32, ptr %2, align 4, !tbaa !5
  store i32 %18, ptr %17, align 4, !tbaa !13
  %19 = load i32, ptr @m, align 4, !tbaa !5
  %20 = sext i32 %19 to i64
  %21 = getelementptr inbounds [4000005 x %struct.Edge], ptr @e, i64 0, i64 %20
  call void @llvm.memcpy.p0.p0.i64(ptr align 8 %21, ptr align 4 %3, i64 8, i1 false), !tbaa.struct !14
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #3
  %22 = load i32, ptr @m, align 4, !tbaa !5
  %23 = add nsw i32 %22, 1
  store i32 %23, ptr @m, align 4, !tbaa !5
  %24 = load i32, ptr @tot, align 4, !tbaa !5
  %25 = sext i32 %24 to i64
  %26 = getelementptr inbounds [1000001 x i32], ptr @lnk, i64 0, i64 %25
  store i32 %22, ptr %26, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #3
  %27 = load i32, ptr %2, align 4, !tbaa !5
  %28 = sext i32 %27 to i64
  %29 = getelementptr inbounds [1000001 x i32], ptr @suf, i64 0, i64 %28
  %30 = load i32, ptr %29, align 4, !tbaa !5
  store i32 %30, ptr %4, align 4, !tbaa !5
  br label %31

31:                                               ; preds = %52, %1
  %32 = load i32, ptr %4, align 4, !tbaa !5
  %33 = icmp ne i32 %32, -1
  br i1 %33, label %35, label %34

34:                                               ; preds = %31
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #3
  br label %58

35:                                               ; preds = %31
  %36 = load i32, ptr %4, align 4, !tbaa !5
  %37 = sext i32 %36 to i64
  %38 = getelementptr inbounds [4000005 x %struct.Edge], ptr @e, i64 0, i64 %37
  %39 = getelementptr inbounds %struct.Edge, ptr %38, i32 0, i32 1
  %40 = load i32, ptr %39, align 4, !tbaa !13
  %41 = sext i32 %40 to i64
  %42 = getelementptr inbounds [1000001 x i8], ptr @vis, i64 0, i64 %41
  %43 = load i8, ptr %42, align 1, !tbaa !9, !range !15, !noundef !16
  %44 = trunc i8 %43 to i1
  br i1 %44, label %51, label %45

45:                                               ; preds = %35
  %46 = load i32, ptr %4, align 4, !tbaa !5
  %47 = sext i32 %46 to i64
  %48 = getelementptr inbounds [4000005 x %struct.Edge], ptr @e, i64 0, i64 %47
  %49 = getelementptr inbounds %struct.Edge, ptr %48, i32 0, i32 1
  %50 = load i32, ptr %49, align 4, !tbaa !13
  call void @_Z4dfs2i(i32 noundef %50)
  br label %51

51:                                               ; preds = %45, %35
  br label %52

52:                                               ; preds = %51
  %53 = load i32, ptr %4, align 4, !tbaa !5
  %54 = sext i32 %53 to i64
  %55 = getelementptr inbounds [4000005 x %struct.Edge], ptr @e, i64 0, i64 %54
  %56 = getelementptr inbounds %struct.Edge, ptr %55, i32 0, i32 0
  %57 = load i32, ptr %56, align 8, !tbaa !11
  store i32 %57, ptr %4, align 4, !tbaa !5
  br label %31, !llvm.loop !17

58:                                               ; preds = %34
  ret void
}

; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
declare void @llvm.memcpy.p0.p0.i64(ptr noalias nocapture writeonly, ptr noalias nocapture readonly, i64, i1 immarg) #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 = { nocallback nofree 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 = !{!10, !10, i64 0}
!10 = !{!"bool", !7, i64 0}
!11 = !{!12, !6, i64 0}
!12 = !{!"_ZTS4Edge", !6, i64 0, !6, i64 4}
!13 = !{!12, !6, i64 4}
!14 = !{i64 0, i64 4, !5, i64 4, i64 4, !5}
!15 = !{i8 0, i8 2}
!16 = !{}
!17 = distinct !{!17, !18}
!18 = !{!"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 }

@m = external dso_local local_unnamed_addr global i32, align 4
@tot = external dso_local local_unnamed_addr global i32, align 4
@suf = external dso_local local_unnamed_addr global [1000001 x i32], align 16
@lnk = external dso_local local_unnamed_addr global [1000001 x i32], align 16
@scc = external dso_local local_unnamed_addr global [1000001 x i32], align 16
@e = external dso_local local_unnamed_addr global [4000005 x %struct.Edge], align 16
@vis = external dso_local local_unnamed_addr global [1000001 x i8], align 16

; Function Attrs: mustprogress nofree nosync nounwind memory(readwrite, argmem: none, inaccessiblemem: none) uwtable
define dso_local void @_Z4dfs2i(i32 noundef %0) local_unnamed_addr #0 {
  %2 = sext i32 %0 to i64
  %3 = getelementptr inbounds [1000001 x i8], ptr @vis, i64 0, i64 %2
  store i8 1, ptr %3, align 1, !tbaa !5
  %4 = load i32, ptr @tot, align 4, !tbaa !9
  %5 = getelementptr inbounds [1000001 x i32], ptr @scc, i64 0, i64 %2
  store i32 %4, ptr %5, align 4, !tbaa !9
  %6 = sext i32 %4 to i64
  %7 = getelementptr inbounds [1000001 x i32], ptr @lnk, i64 0, i64 %6
  %8 = load i32, ptr %7, align 4, !tbaa !9
  %9 = load i32, ptr @m, align 4, !tbaa !9
  %10 = sext i32 %9 to i64
  %11 = getelementptr inbounds [4000005 x %struct.Edge], ptr @e, i64 0, i64 %10
  store i32 %8, ptr %11, align 8, !tbaa !9
  %.sroa.4.0..sroa_idx = getelementptr inbounds i8, ptr %11, i64 4
  store i32 %0, ptr %.sroa.4.0..sroa_idx, align 4, !tbaa !9
  %12 = add nsw i32 %9, 1
  store i32 %12, ptr @m, align 4, !tbaa !9
  store i32 %9, ptr %7, align 4, !tbaa !9
  %13 = getelementptr inbounds [1000001 x i32], ptr @suf, i64 0, i64 %2
  %.08 = load i32, ptr %13, align 4, !tbaa !9
  %.not9 = icmp eq i32 %.08, -1
  br i1 %.not9, label %._crit_edge, label %.lr.ph

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

.lr.ph:                                           ; preds = %1, %23
  %.010 = phi i32 [ %.0, %23 ], [ %.08, %1 ]
  %14 = sext i32 %.010 to i64
  %15 = getelementptr inbounds [4000005 x %struct.Edge], ptr @e, i64 0, i64 %14
  %16 = getelementptr inbounds i8, ptr %15, i64 4
  %17 = load i32, ptr %16, align 4, !tbaa !11
  %18 = sext i32 %17 to i64
  %19 = getelementptr inbounds [1000001 x i8], ptr @vis, i64 0, i64 %18
  %20 = load i8, ptr %19, align 1, !tbaa !5, !range !13, !noundef !14
  %21 = trunc nuw i8 %20 to i1
  br i1 %21, label %23, label %22

22:                                               ; preds = %.lr.ph
  tail call void @_Z4dfs2i(i32 noundef %17)
  br label %23

23:                                               ; preds = %.lr.ph, %22
  %.0 = load i32, ptr %15, align 8, !tbaa !9
  %.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 = !{!"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 = !{!12, !10, i64 4}
!12 = !{!"_ZTS4Edge", !10, i64 0, !10, i64 4}
!13 = !{i8 0, i8 2}
!14 = !{}
!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