; LLVM IR from tangjz/acm-icpc :: lydsy/3004.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 }

@pre = external dso_local global [1200001 x i32], align 16
@cnt = external dso_local global [1200001 x i32], align 16
@e = external dso_local global [1200001 x %struct.Edge], align 16

; Function Attrs: mustprogress uwtable
define dso_local noundef i32 @_Z3dfsi(i32 noundef %0) #0 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  store i32 %0, ptr %2, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #2
  store i32 1, ptr %3, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #2
  %5 = load i32, ptr %2, align 4, !tbaa !5
  %6 = sext i32 %5 to i64
  %7 = getelementptr inbounds [1200001 x i32], ptr @pre, i64 0, i64 %6
  %8 = load i32, ptr %7, align 4, !tbaa !5
  store i32 %8, ptr %4, align 4, !tbaa !5
  br label %9

9:                                                ; preds = %22, %1
  %10 = load i32, ptr %4, align 4, !tbaa !5
  %11 = icmp ne i32 %10, 0
  br i1 %11, label %13, label %12

12:                                               ; preds = %9
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  br label %28

13:                                               ; preds = %9
  %14 = load i32, ptr %4, align 4, !tbaa !5
  %15 = sext i32 %14 to i64
  %16 = getelementptr inbounds [1200001 x %struct.Edge], ptr @e, i64 0, i64 %15
  %17 = getelementptr inbounds %struct.Edge, ptr %16, i32 0, i32 1
  %18 = load i32, ptr %17, align 4, !tbaa !9
  %19 = call noundef i32 @_Z3dfsi(i32 noundef %18)
  %20 = load i32, ptr %3, align 4, !tbaa !5
  %21 = add nsw i32 %20, %19
  store i32 %21, ptr %3, align 4, !tbaa !5
  br label %22

22:                                               ; preds = %13
  %23 = load i32, ptr %4, align 4, !tbaa !5
  %24 = sext i32 %23 to i64
  %25 = getelementptr inbounds [1200001 x %struct.Edge], ptr @e, i64 0, i64 %24
  %26 = getelementptr inbounds %struct.Edge, ptr %25, i32 0, i32 0
  %27 = load i32, ptr %26, align 8, !tbaa !11
  store i32 %27, ptr %4, align 4, !tbaa !5
  br label %9, !llvm.loop !12

28:                                               ; preds = %12
  %29 = load i32, ptr %3, align 4, !tbaa !5
  %30 = sext i32 %29 to i64
  %31 = getelementptr inbounds [1200001 x i32], ptr @cnt, i64 0, i64 %30
  %32 = load i32, ptr %31, align 4, !tbaa !5
  %33 = add nsw i32 %32, 1
  store i32 %33, ptr %31, align 4, !tbaa !5
  %34 = load i32, ptr %3, align 4, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #2
  ret i32 %34
}

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; 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 = { 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, !6, i64 4}
!10 = !{!"_ZTS4Edge", !6, i64 0, !6, i64 4}
!11 = !{!10, !6, 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"

%struct.Edge = type { i32, i32 }

@pre = external dso_local local_unnamed_addr global [1200001 x i32], align 16
@cnt = external dso_local local_unnamed_addr global [1200001 x i32], align 16
@e = external dso_local local_unnamed_addr global [1200001 x %struct.Edge], align 16

; Function Attrs: mustprogress nofree nosync nounwind memory(readwrite, argmem: none, inaccessiblemem: none) uwtable
define dso_local noundef i32 @_Z3dfsi(i32 noundef %0) local_unnamed_addr #0 {
  %2 = sext i32 %0 to i64
  %3 = getelementptr inbounds [1200001 x i32], ptr @pre, i64 0, i64 %2
  %.08 = load i32, ptr %3, align 4, !tbaa !5
  %.not9 = icmp eq i32 %.08, 0
  br i1 %.not9, label %._crit_edge, label %.lr.ph

._crit_edge:                                      ; preds = %.lr.ph, %1
  %.07.lcssa = phi i32 [ 1, %1 ], [ %13, %.lr.ph ]
  %4 = sext i32 %.07.lcssa to i64
  %5 = getelementptr inbounds [1200001 x i32], ptr @cnt, i64 0, i64 %4
  %6 = load i32, ptr %5, align 4, !tbaa !5
  %7 = add nsw i32 %6, 1
  store i32 %7, ptr %5, align 4, !tbaa !5
  ret i32 %.07.lcssa

.lr.ph:                                           ; preds = %1, %.lr.ph
  %.011 = phi i32 [ %.0, %.lr.ph ], [ %.08, %1 ]
  %.0710 = phi i32 [ %13, %.lr.ph ], [ 1, %1 ]
  %8 = sext i32 %.011 to i64
  %9 = getelementptr inbounds [1200001 x %struct.Edge], ptr @e, i64 0, i64 %8
  %10 = getelementptr inbounds i8, ptr %9, i64 4
  %11 = load i32, ptr %10, align 4, !tbaa !9
  %12 = tail call noundef i32 @_Z3dfsi(i32 noundef %11)
  %13 = add nsw i32 %12, %.0710
  %.0 = load i32, ptr %9, align 8, !tbaa !5
  %.not = icmp eq i32 %.0, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !11
}

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, !6, i64 4}
!10 = !{!"_ZTS4Edge", !6, i64 0, !6, i64 4}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: EarlyCSEPass,GVNPass,GlobalOptPass,InferAlignmentPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass,TailCallElimPass