; LLVM IR from tangjz/acm-icpc :: self_training/2015-09-24/D.ll (Z3dfsii)

; 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.Node = type { [6 x i32] }

@e = external dso_local global [15504 x %struct.Node], align 16
@tmp = external dso_local global %struct.Node, align 4
@tot = external dso_local global i32, align 4

; Function Attrs: mustprogress uwtable
define dso_local void @_Z3dfsii(i32 noundef %0, i32 noundef %1) #0 {
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !5
  %6 = load i32, ptr %3, align 4, !tbaa !5
  %7 = icmp eq i32 %6, 5
  br i1 %7, label %8, label %17

8:                                                ; preds = %2
  %9 = load i32, ptr %4, align 4, !tbaa !5
  %10 = load i32, ptr %3, align 4, !tbaa !5
  %11 = sext i32 %10 to i64
  %12 = getelementptr inbounds [6 x i32], ptr @tmp, i64 0, i64 %11
  store i32 %9, ptr %12, align 4, !tbaa !5
  %13 = load i32, ptr @tot, align 4, !tbaa !5
  %14 = add nsw i32 %13, 1
  store i32 %14, ptr @tot, align 4, !tbaa !5
  %15 = sext i32 %13 to i64
  %16 = getelementptr inbounds [15504 x %struct.Node], ptr @e, i64 0, i64 %15
  call void @llvm.memcpy.p0.p0.i64(ptr align 8 %16, ptr align 4 @tmp, i64 24, i1 false), !tbaa.struct !9
  br label %36

17:                                               ; preds = %2
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #3
  store i32 0, ptr %5, align 4, !tbaa !5
  br label %18

18:                                               ; preds = %33, %17
  %19 = load i32, ptr %5, align 4, !tbaa !5
  %20 = load i32, ptr %4, align 4, !tbaa !5
  %21 = icmp sle i32 %19, %20
  br i1 %21, label %23, label %22

22:                                               ; preds = %18
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #3
  br label %36

23:                                               ; preds = %18
  %24 = load i32, ptr %5, align 4, !tbaa !5
  %25 = load i32, ptr %3, align 4, !tbaa !5
  %26 = sext i32 %25 to i64
  %27 = getelementptr inbounds [6 x i32], ptr @tmp, i64 0, i64 %26
  store i32 %24, ptr %27, align 4, !tbaa !5
  %28 = load i32, ptr %3, align 4, !tbaa !5
  %29 = add nsw i32 %28, 1
  %30 = load i32, ptr %4, align 4, !tbaa !5
  %31 = load i32, ptr %5, align 4, !tbaa !5
  %32 = sub nsw i32 %30, %31
  call void @_Z3dfsii(i32 noundef %29, i32 noundef %32)
  br label %33

33:                                               ; preds = %23
  %34 = load i32, ptr %5, align 4, !tbaa !5
  %35 = add nsw i32 %34, 1
  store i32 %35, ptr %5, align 4, !tbaa !5
  br label %18, !llvm.loop !11

36:                                               ; preds = %22, %8
  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) #1

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #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 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
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 = !{i64 0, i64 24, !10}
!10 = !{!7, !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"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.Node = type { [6 x i32] }

@e = external dso_local local_unnamed_addr global [15504 x %struct.Node], align 16
@tmp = external dso_local local_unnamed_addr global %struct.Node, align 4
@tot = external dso_local local_unnamed_addr global i32, align 4

; Function Attrs: mustprogress nofree nosync nounwind memory(readwrite, argmem: none, inaccessiblemem: none) uwtable
define dso_local void @_Z3dfsii(i32 noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = icmp eq i32 %0, 5
  br i1 %3, label %7, label %.preheader

.preheader:                                       ; preds = %2
  %.not13 = icmp slt i32 %1, 0
  br i1 %.not13, label %.loopexit, label %.lr.ph

.lr.ph:                                           ; preds = %.preheader
  %4 = sext i32 %0 to i64
  %5 = getelementptr inbounds [6 x i32], ptr @tmp, i64 0, i64 %4
  %6 = add nsw i32 %0, 1
  br label %12

7:                                                ; preds = %2
  store i32 %1, ptr getelementptr inbounds (i8, ptr @tmp, i64 20), align 4, !tbaa !5
  %8 = load i32, ptr @tot, align 4, !tbaa !5
  %9 = add nsw i32 %8, 1
  store i32 %9, ptr @tot, align 4, !tbaa !5
  %10 = sext i32 %8 to i64
  %11 = getelementptr inbounds [15504 x %struct.Node], ptr @e, i64 0, i64 %10
  tail call void @llvm.memcpy.p0.p0.i64(ptr noundef nonnull align 8 dereferenceable(24) %11, ptr noundef nonnull align 4 dereferenceable(24) @tmp, i64 24, i1 false), !tbaa.struct !9
  br label %.loopexit

12:                                               ; preds = %.lr.ph, %12
  %.014 = phi i32 [ 0, %.lr.ph ], [ %14, %12 ]
  store i32 %.014, ptr %5, align 4, !tbaa !5
  %13 = sub nsw i32 %1, %.014
  tail call void @_Z3dfsii(i32 noundef %6, i32 noundef %13)
  %14 = add nuw i32 %.014, 1
  %exitcond.not = icmp eq i32 %.014, %1
  br i1 %exitcond.not, label %.loopexit, label %12, !llvm.loop !11

.loopexit:                                        ; preds = %12, %.preheader, %7
  ret void
}

; Function Attrs: mustprogress 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) #1

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" }
attributes #1 = { mustprogress nocallback nofree nounwind willreturn memory(argmem: readwrite) }

!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 = !{i64 0, i64 24, !10}
!10 = !{!7, !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}


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