; LLVM IR from Dev-XYS/Algorithms :: Biconnected-Component (main)

; 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"

@ivc = external dso_local global i32, align 4
@iec = external dso_local global i32, align 4
@.str = external hidden unnamed_addr constant [5 x i8], align 1

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_Z8add_edgeii(i32 noundef, i32 noundef) #0

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z3DFSii(i32 noundef, i32 noundef) #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

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() #3 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  store i32 0, ptr %1, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #5
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #5
  %5 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str, ptr noundef @ivc, ptr noundef @iec)
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #5
  store i32 0, ptr %4, align 4, !tbaa !5
  br label %6

6:                                                ; preds = %17, %0
  %7 = load i32, ptr %4, align 4, !tbaa !5
  %8 = load i32, ptr @iec, align 4, !tbaa !5
  %9 = icmp slt i32 %7, %8
  br i1 %9, label %11, label %10

10:                                               ; preds = %6
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #5
  br label %20

11:                                               ; preds = %6
  %12 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str, ptr noundef %2, ptr noundef %3)
  %13 = load i32, ptr %2, align 4, !tbaa !5
  %14 = load i32, ptr %3, align 4, !tbaa !5
  call void @_Z8add_edgeii(i32 noundef %13, i32 noundef %14)
  %15 = load i32, ptr %3, align 4, !tbaa !5
  %16 = load i32, ptr %2, align 4, !tbaa !5
  call void @_Z8add_edgeii(i32 noundef %15, i32 noundef %16)
  br label %17

17:                                               ; preds = %11
  %18 = load i32, ptr %4, align 4, !tbaa !5
  %19 = add nsw i32 %18, 1
  store i32 %19, ptr %4, align 4, !tbaa !5
  br label %6, !llvm.loop !9

20:                                               ; preds = %10
  call void @_Z3DFSii(i32 noundef 1, i32 noundef 0)
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #5
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #5
  ret i32 0
}

declare i32 @__isoc99_scanf(ptr noundef, ...) #4

attributes #0 = { mustprogress 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 = { 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 #2 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #3 = { mustprogress norecurse 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 #4 = { "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 #5 = { 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 = 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"

@ivc = external dso_local global i32, align 4
@iec = external dso_local global i32, align 4
@.str = external hidden unnamed_addr constant [5 x i8], align 1

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_Z8add_edgeii(i32 noundef, i32 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z3DFSii(i32 noundef, i32 noundef) local_unnamed_addr #1

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #2

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #2

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() local_unnamed_addr #3 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %1) #5
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %2) #5
  %3 = tail call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef nonnull @ivc, ptr noundef nonnull @iec)
  %4 = load i32, ptr @iec, align 4, !tbaa !5
  %5 = icmp sgt i32 %4, 0
  br i1 %5, label %.lr.ph, label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph, %0
  call void @_Z3DFSii(i32 noundef 1, i32 noundef 0)
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %2) #5
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %1) #5
  ret i32 0

.lr.ph:                                           ; preds = %0, %.lr.ph
  %.02 = phi i32 [ %11, %.lr.ph ], [ 0, %0 ]
  %6 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef nonnull %1, ptr noundef nonnull %2)
  %7 = load i32, ptr %1, align 4, !tbaa !5
  %8 = load i32, ptr %2, align 4, !tbaa !5
  call void @_Z8add_edgeii(i32 noundef %7, i32 noundef %8)
  %9 = load i32, ptr %2, align 4, !tbaa !5
  %10 = load i32, ptr %1, align 4, !tbaa !5
  call void @_Z8add_edgeii(i32 noundef %9, i32 noundef %10)
  %11 = add nuw nsw i32 %.02, 1
  %12 = load i32, ptr @iec, align 4, !tbaa !5
  %13 = icmp slt i32 %11, %12
  br i1 %13, label %.lr.ph, label %._crit_edge, !llvm.loop !9
}

; Function Attrs: nofree nounwind
declare noundef i32 @__isoc99_scanf(ptr nocapture noundef readonly, ...) local_unnamed_addr #4

attributes #0 = { mustprogress 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 = { 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 #2 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #3 = { mustprogress norecurse 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 #4 = { nofree nounwind "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 #5 = { 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 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


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