; LLVM IR from div-bargali/Data-Structures-and-Algorithms :: C++/Data-Structures/Graph/ConnectedComponents.ll (Z12Is_Connectedi)

; 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"

@vis1 = external dso_local global [100000 x i8], align 16
@vis2 = external dso_local global [100000 x i8], align 16

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z4dfs1i(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: mustprogress uwtable
declare dso_local void @_Z4dfs2i(i32 noundef) #0

; Function Attrs: mustprogress uwtable
define dso_local noundef zeroext i1 @_Z12Is_Connectedi(i32 noundef %0) #0 {
  %2 = alloca i1, align 1
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  store i32 %0, ptr %3, align 4, !tbaa !5
  call void @llvm.memset.p0.i64(ptr align 16 @vis1, i8 0, i64 100000, i1 false)
  call void @_Z4dfs1i(i32 noundef 1)
  call void @llvm.memset.p0.i64(ptr align 16 @vis2, i8 0, i64 100000, i1 false)
  call void @_Z4dfs2i(i32 noundef 1)
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #3
  store i32 1, ptr %4, align 4, !tbaa !5
  br label %6

6:                                                ; preds = %25, %1
  %7 = load i32, ptr %4, align 4, !tbaa !5
  %8 = load i32, ptr %3, align 4, !tbaa !5
  %9 = icmp sle i32 %7, %8
  br i1 %9, label %11, label %10

10:                                               ; preds = %6
  store i32 2, ptr %5, align 4
  br label %28

11:                                               ; preds = %6
  %12 = load i32, ptr %4, align 4, !tbaa !5
  %13 = sext i32 %12 to i64
  %14 = getelementptr inbounds [100000 x i8], ptr @vis1, i64 0, i64 %13
  %15 = load i8, ptr %14, align 1, !tbaa !9, !range !11, !noundef !12
  %16 = trunc i8 %15 to i1
  br i1 %16, label %24, label %17

17:                                               ; preds = %11
  %18 = load i32, ptr %4, align 4, !tbaa !5
  %19 = sext i32 %18 to i64
  %20 = getelementptr inbounds [100000 x i8], ptr @vis2, i64 0, i64 %19
  %21 = load i8, ptr %20, align 1, !tbaa !9, !range !11, !noundef !12
  %22 = trunc i8 %21 to i1
  br i1 %22, label %24, label %23

23:                                               ; preds = %17
  store i1 false, ptr %2, align 1
  store i32 1, ptr %5, align 4
  br label %28

24:                                               ; preds = %17, %11
  br label %25

25:                                               ; preds = %24
  %26 = load i32, ptr %4, align 4, !tbaa !5
  %27 = add nsw i32 %26, 1
  store i32 %27, ptr %4, align 4, !tbaa !5
  br label %6, !llvm.loop !13

28:                                               ; preds = %23, %10
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #3
  %29 = load i32, ptr %5, align 4
  switch i32 %29, label %33 [
    i32 2, label %30
    i32 1, label %31
  ]

30:                                               ; preds = %28
  store i1 true, ptr %2, align 1
  br label %31

31:                                               ; preds = %30, %28
  %32 = load i1, ptr %2, align 1
  ret i1 %32

33:                                               ; preds = %28
  unreachable
}

; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: write)
declare void @llvm.memset.p0.i64(ptr nocapture writeonly, i8, i64, i1 immarg) #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 nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { nocallback nofree nounwind willreturn memory(argmem: write) }
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 = !{!10, !10, i64 0}
!10 = !{!"bool", !7, i64 0}
!11 = !{i8 0, i8 2}
!12 = !{}
!13 = distinct !{!13, !14}
!14 = !{!"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"

@vis1 = external dso_local local_unnamed_addr global [100000 x i8], align 16
@vis2 = external dso_local local_unnamed_addr global [100000 x i8], align 16

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z4dfs1i(i32 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z4dfs2i(i32 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress uwtable
define dso_local noundef zeroext i1 @_Z12Is_Connectedi(i32 noundef %0) local_unnamed_addr #0 {
  tail call void @llvm.memset.p0.i64(ptr noundef nonnull align 16 dereferenceable(100000) @vis1, i8 0, i64 100000, i1 false)
  tail call void @_Z4dfs1i(i32 noundef 1)
  tail call void @llvm.memset.p0.i64(ptr noundef nonnull align 16 dereferenceable(100000) @vis2, i8 0, i64 100000, i1 false)
  tail call void @_Z4dfs2i(i32 noundef 1)
  %.not8 = icmp slt i32 %0, 1
  br i1 %.not8, label %._crit_edge, label %.lr.ph.preheader

.lr.ph.preheader:                                 ; preds = %1
  %2 = zext nneg i32 %0 to i64
  %3 = add nuw i32 %0, 1
  %wide.trip.count = zext i32 %3 to i64
  br label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph.preheader, %11
  %indvars.iv = phi i64 [ 1, %.lr.ph.preheader ], [ %indvars.iv.next, %11 ]
  %.not10 = phi i1 [ false, %.lr.ph.preheader ], [ %.not, %11 ]
  %4 = getelementptr inbounds [100000 x i8], ptr @vis1, i64 0, i64 %indvars.iv
  %5 = load i8, ptr %4, align 1, !tbaa !5, !range !9, !noundef !10
  %6 = trunc nuw i8 %5 to i1
  br i1 %6, label %11, label %7

7:                                                ; preds = %.lr.ph
  %8 = getelementptr inbounds [100000 x i8], ptr @vis2, i64 0, i64 %indvars.iv
  %9 = load i8, ptr %8, align 1, !tbaa !5, !range !9, !noundef !10
  %10 = trunc nuw i8 %9 to i1
  br i1 %10, label %11, label %._crit_edge

11:                                               ; preds = %.lr.ph, %7
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %.not = icmp uge i64 %indvars.iv, %2
  %exitcond = icmp eq i64 %indvars.iv.next, %wide.trip.count
  br i1 %exitcond, label %._crit_edge, label %.lr.ph, !llvm.loop !11

._crit_edge:                                      ; preds = %11, %7, %1
  %.not.lcssa = phi i1 [ true, %1 ], [ %.not10, %7 ], [ %.not, %11 ]
  ret i1 %.not.lcssa
}

; Function Attrs: mustprogress nocallback nofree nounwind willreturn memory(argmem: write)
declare void @llvm.memset.p0.i64(ptr nocapture writeonly, i8, i64, i1 immarg) #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 = { mustprogress nocallback nofree nounwind willreturn memory(argmem: write) }

!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 = !{!"bool", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{i8 0, i8 2}
!10 = !{}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: CorrelatedValuePropagationPass,EarlyCSEPass,GVNPass,GlobalOptPass,IPSCCPPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,SROAPass,SimplifyCFGPass,TailCallElimPass