; 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

; Function Attrs: nounwind uwtable
declare dso_local void @dfs(i32 noundef, i32 noundef) #0

; 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

; Function Attrs: nounwind uwtable
define dso_local i32 @get_connected_components(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 0, ptr %3, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #2
  store i32 1, ptr %4, align 4, !tbaa !5
  br label %5

5:                                                ; preds = %22, %1
  %6 = load i32, ptr %4, align 4, !tbaa !5
  %7 = load i32, ptr %2, align 4, !tbaa !5
  %8 = icmp sle i32 %6, %7
  br i1 %8, label %10, label %9

9:                                                ; preds = %5
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  br label %25

10:                                               ; preds = %5
  %11 = load i32, ptr %4, align 4, !tbaa !5
  %12 = sext i32 %11 to i64
  %13 = getelementptr inbounds [10009 x i32], ptr @visited, i64 0, i64 %12
  %14 = load i32, ptr %13, align 4, !tbaa !5
  %15 = icmp eq i32 %14, 0
  br i1 %15, label %16, label %21

16:                                               ; preds = %10
  %17 = load i32, ptr %4, align 4, !tbaa !5
  %18 = load i32, ptr %2, align 4, !tbaa !5
  call void @dfs(i32 noundef %17, i32 noundef %18)
  %19 = load i32, ptr %3, align 4, !tbaa !5
  %20 = add nsw i32 %19, 1
  store i32 %20, ptr %3, align 4, !tbaa !5
  br label %21

21:                                               ; preds = %16, %10
  br label %22

22:                                               ; preds = %21
  %23 = load i32, ptr %4, align 4, !tbaa !5
  %24 = add nsw i32 %23, 1
  store i32 %24, ptr %4, align 4, !tbaa !5
  br label %5, !llvm.loop !9

25:                                               ; preds = %9
  %26 = load i32, ptr %3, align 4, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #2
  ret i32 %26
}

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

; Function Attrs: nounwind uwtable
declare dso_local void @dfs(i32 noundef, i32 noundef) local_unnamed_addr #0

; Function Attrs: nounwind uwtable
define dso_local i32 @get_connected_components(i32 noundef %0) local_unnamed_addr #0 {
  %.not10 = icmp slt i32 %0, 1
  br i1 %.not10, label %._crit_edge, label %.lr.ph.preheader

.lr.ph.preheader:                                 ; preds = %1
  %2 = add nuw i32 %0, 1
  %wide.trip.count = zext i32 %2 to i64
  br label %.lr.ph

._crit_edge:                                      ; preds = %9, %1
  %.08.lcssa = phi i32 [ 0, %1 ], [ %.1, %9 ]
  ret i32 %.08.lcssa

.lr.ph:                                           ; preds = %.lr.ph.preheader, %9
  %indvars.iv = phi i64 [ 1, %.lr.ph.preheader ], [ %indvars.iv.next, %9 ]
  %.0811 = phi i32 [ 0, %.lr.ph.preheader ], [ %.1, %9 ]
  %3 = getelementptr inbounds [10009 x i32], ptr @visited, i64 0, i64 %indvars.iv
  %4 = load i32, ptr %3, align 4, !tbaa !5
  %5 = icmp eq i32 %4, 0
  br i1 %5, label %6, label %9

6:                                                ; preds = %.lr.ph
  %7 = trunc nuw nsw i64 %indvars.iv to i32
  tail call void @dfs(i32 noundef %7, i32 noundef %0)
  %8 = add nsw i32 %.0811, 1
  br label %9

9:                                                ; preds = %.lr.ph, %6
  %.1 = phi i32 [ %8, %6 ], [ %.0811, %.lr.ph ]
  %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 = { 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" }

!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: GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,SROAPass,SimplifyCFGPass,TailCallElimPass