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

; 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"

@n = external dso_local global i32, align 4

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: nounwind uwtable
define dso_local void @applyUnion(ptr noundef %0, i32 noundef %1, i32 noundef %2) #1 {
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !9
  store i32 %2, ptr %6, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #2
  store i32 0, ptr %7, align 4, !tbaa !9
  br label %8

8:                                                ; preds = %27, %3
  %9 = load i32, ptr %7, align 4, !tbaa !9
  %10 = load i32, ptr @n, align 4, !tbaa !9
  %11 = icmp slt i32 %9, %10
  br i1 %11, label %12, label %30

12:                                               ; preds = %8
  %13 = load ptr, ptr %4, align 8, !tbaa !5
  %14 = load i32, ptr %7, align 4, !tbaa !9
  %15 = sext i32 %14 to i64
  %16 = getelementptr inbounds i32, ptr %13, i64 %15
  %17 = load i32, ptr %16, align 4, !tbaa !9
  %18 = load i32, ptr %6, align 4, !tbaa !9
  %19 = icmp eq i32 %17, %18
  br i1 %19, label %20, label %26

20:                                               ; preds = %12
  %21 = load i32, ptr %5, align 4, !tbaa !9
  %22 = load ptr, ptr %4, align 8, !tbaa !5
  %23 = load i32, ptr %7, align 4, !tbaa !9
  %24 = sext i32 %23 to i64
  %25 = getelementptr inbounds i32, ptr %22, i64 %24
  store i32 %21, ptr %25, align 4, !tbaa !9
  br label %26

26:                                               ; preds = %20, %12
  br label %27

27:                                               ; preds = %26
  %28 = load i32, ptr %7, align 4, !tbaa !9
  %29 = add nsw i32 %28, 1
  store i32 %29, ptr %7, align 4, !tbaa !9
  br label %8, !llvm.loop !11

30:                                               ; preds = %8
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #2
  ret void
}

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #0

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 #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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !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"

@n = external dso_local local_unnamed_addr global i32, align 4

; Function Attrs: nofree norecurse nosync nounwind memory(read, argmem: readwrite, inaccessiblemem: none) uwtable
define dso_local void @applyUnion(ptr nocapture noundef %0, i32 noundef %1, i32 noundef %2) local_unnamed_addr #0 {
  %4 = load i32, ptr @n, align 4, !tbaa !5
  %5 = icmp sgt i32 %4, 0
  br i1 %5, label %.lr.ph, label %._crit_edge

.lr.ph:                                           ; preds = %3, %11
  %6 = phi i32 [ %12, %11 ], [ %4, %3 ]
  %indvars.iv = phi i64 [ %indvars.iv.next, %11 ], [ 0, %3 ]
  %7 = getelementptr inbounds i32, ptr %0, i64 %indvars.iv
  %8 = load i32, ptr %7, align 4, !tbaa !5
  %9 = icmp eq i32 %8, %2
  br i1 %9, label %10, label %11

10:                                               ; preds = %.lr.ph
  store i32 %1, ptr %7, align 4, !tbaa !5
  %.pre = load i32, ptr @n, align 4, !tbaa !5
  br label %11

11:                                               ; preds = %.lr.ph, %10
  %12 = phi i32 [ %6, %.lr.ph ], [ %.pre, %10 ]
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %13 = sext i32 %12 to i64
  %14 = icmp slt i64 %indvars.iv.next, %13
  br i1 %14, label %.lr.ph, label %._crit_edge, !llvm.loop !9

._crit_edge:                                      ; preds = %11, %3
  ret void
}

attributes #0 = { nofree norecurse nosync nounwind memory(read, argmem: readwrite, 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,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass