; LLVM IR from HarshCasper/NeoAlgo :: C/graphs (number_of_connected_components)

; 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"

@visited = external dso_local global [10009 x i32], align 16
@adj = external dso_local global [10009 x [1009 x i32]], align 16

; Function Attrs: nounwind uwtable
define dso_local void @dfs(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 = sext i32 %6 to i64
  %8 = getelementptr inbounds [10009 x i32], ptr @visited, i64 0, i64 %7
  store i32 1, ptr %8, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #2
  store i32 1, ptr %5, align 4, !tbaa !5
  br label %9

9:                                                ; preds = %33, %2
  %10 = load i32, ptr %5, align 4, !tbaa !5
  %11 = load i32, ptr %4, align 4, !tbaa !5
  %12 = icmp sle i32 %10, %11
  br i1 %12, label %14, label %13

13:                                               ; preds = %9
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  br label %36

14:                                               ; preds = %9
  %15 = load i32, ptr %3, align 4, !tbaa !5
  %16 = sext i32 %15 to i64
  %17 = getelementptr inbounds [10009 x [1009 x i32]], ptr @adj, i64 0, i64 %16
  %18 = load i32, ptr %5, align 4, !tbaa !5
  %19 = sext i32 %18 to i64
  %20 = getelementptr inbounds [1009 x i32], ptr %17, i64 0, i64 %19
  %21 = load i32, ptr %20, align 4, !tbaa !5
  %22 = icmp ne i32 %21, 0
  br i1 %22, label %23, label %32

23:                                               ; preds = %14
  %24 = load i32, ptr %5, align 4, !tbaa !5
  %25 = sext i32 %24 to i64
  %26 = getelementptr inbounds [10009 x i32], ptr @visited, i64 0, i64 %25
  %27 = load i32, ptr %26, align 4, !tbaa !5
  %28 = icmp eq i32 %27, 0
  br i1 %28, label %29, label %32

29:                                               ; preds = %23
  %30 = load i32, ptr %5, align 4, !tbaa !5
  %31 = load i32, ptr %4, align 4, !tbaa !5
  call void @dfs(i32 noundef %30, i32 noundef %31)
  br label %32

32:                                               ; preds = %29, %23, %14
  br label %33

33:                                               ; preds = %32
  %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 %9, !llvm.loop !9

36:                                               ; preds = %13
  ret void
}

; 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 = { 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 #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/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"

@visited = external dso_local local_unnamed_addr global [10009 x i32], align 16
@adj = external dso_local local_unnamed_addr global [10009 x [1009 x i32]], align 16

; Function Attrs: nofree nosync nounwind memory(readwrite, argmem: none, inaccessiblemem: none) uwtable
define dso_local void @dfs(i32 noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = sext i32 %0 to i64
  %4 = getelementptr inbounds [10009 x i32], ptr @visited, i64 0, i64 %3
  store i32 1, ptr %4, align 4, !tbaa !5
  %.not11 = icmp slt i32 %1, 1
  br i1 %.not11, label %._crit_edge, label %.lr.ph.preheader

.lr.ph.preheader:                                 ; preds = %2
  %5 = add nuw i32 %1, 1
  %wide.trip.count = zext i32 %5 to i64
  br label %.lr.ph

._crit_edge:                                      ; preds = %14, %2
  ret void

.lr.ph:                                           ; preds = %.lr.ph.preheader, %14
  %indvars.iv = phi i64 [ 1, %.lr.ph.preheader ], [ %indvars.iv.next, %14 ]
  %6 = getelementptr inbounds [10009 x [1009 x i32]], ptr @adj, i64 0, i64 %3, i64 %indvars.iv
  %7 = load i32, ptr %6, align 4, !tbaa !5
  %.not10 = icmp eq i32 %7, 0
  br i1 %.not10, label %14, label %8

8:                                                ; preds = %.lr.ph
  %9 = getelementptr inbounds [10009 x i32], ptr @visited, i64 0, i64 %indvars.iv
  %10 = load i32, ptr %9, align 4, !tbaa !5
  %11 = icmp eq i32 %10, 0
  br i1 %11, label %12, label %14

12:                                               ; preds = %8
  %13 = trunc nuw nsw i64 %indvars.iv to i32
  tail call void @dfs(i32 noundef %13, i32 noundef %1)
  br label %14

14:                                               ; preds = %.lr.ph, %8, %12
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next, %wide.trip.count
  br i1 %exitcond.not, label %._crit_edge, label %.lr.ph, !llvm.loop !9
}

attributes #0 = { 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/C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


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