; LLVM IR from IsaacAsante/HackerRank :: Problem Solving/Algorithms/Implementation/Viral Advertising (viral advertising)

; 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"

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z16viralAdvertisingi(i32 noundef %0) #0 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = 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 5, ptr %3, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #2
  store i32 2, ptr %4, align 4, !tbaa !5
  %6 = load i32, ptr %2, align 4, !tbaa !5
  %7 = icmp sgt i32 %6, 1
  br i1 %7, label %8, label %26

8:                                                ; preds = %1
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #2
  store i32 2, ptr %5, align 4, !tbaa !5
  br label %9

9:                                                ; preds = %22, %8
  %10 = load i32, ptr %5, align 4, !tbaa !5
  %11 = load i32, ptr %2, 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 %25

14:                                               ; preds = %9
  %15 = load i32, ptr %3, align 4, !tbaa !5
  %16 = sdiv i32 %15, 2
  %17 = mul nsw i32 %16, 3
  store i32 %17, ptr %3, align 4, !tbaa !5
  %18 = load i32, ptr %3, align 4, !tbaa !5
  %19 = sdiv i32 %18, 2
  %20 = load i32, ptr %4, align 4, !tbaa !5
  %21 = add nsw i32 %20, %19
  store i32 %21, ptr %4, align 4, !tbaa !5
  br label %22

22:                                               ; preds = %14
  %23 = load i32, ptr %5, align 4, !tbaa !5
  %24 = add nsw i32 %23, 1
  store i32 %24, ptr %5, align 4, !tbaa !5
  br label %9, !llvm.loop !9

25:                                               ; preds = %13
  br label %26

26:                                               ; preds = %25, %1
  %27 = load i32, ptr %4, align 4, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #2
  ret i32 %27
}

; 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 = { 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 = { 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++ 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"

; Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none) uwtable
define dso_local noundef i32 @_Z16viralAdvertisingi(i32 noundef %0) local_unnamed_addr #0 {
  %2 = icmp sgt i32 %0, 1
  br i1 %2, label %.preheader.preheader, label %.loopexit

.preheader.preheader:                             ; preds = %1
  %3 = add nsw i32 %0, -1
  %xtraiter = and i32 %3, 1
  %4 = icmp eq i32 %0, 2
  br i1 %4, label %.loopexit.loopexit.unr-lcssa, label %.preheader.preheader.new

.preheader.preheader.new:                         ; preds = %.preheader.preheader
  %unroll_iter = and i32 %3, -2
  br label %.preheader

.preheader:                                       ; preds = %.preheader, %.preheader.preheader.new
  %.0812 = phi i32 [ 2, %.preheader.preheader.new ], [ %12, %.preheader ]
  %.0911 = phi i32 [ 5, %.preheader.preheader.new ], [ %10, %.preheader ]
  %niter = phi i32 [ 0, %.preheader.preheader.new ], [ %niter.next.1, %.preheader ]
  %5 = sdiv i32 %.0911, 2
  %6 = mul nsw i32 %5, 3
  %7 = sdiv i32 %6, 2
  %8 = add nsw i32 %7, %.0812
  %9 = sdiv i32 %6, 2
  %10 = mul nsw i32 %9, 3
  %11 = sdiv i32 %10, 2
  %12 = add nsw i32 %11, %8
  %niter.next.1 = add i32 %niter, 2
  %niter.ncmp.1 = icmp eq i32 %niter.next.1, %unroll_iter
  br i1 %niter.ncmp.1, label %.loopexit.loopexit.unr-lcssa.loopexit, label %.preheader, !llvm.loop !5

.loopexit.loopexit.unr-lcssa.loopexit:            ; preds = %.preheader
  %13 = sdiv i32 %10, 2
  %14 = mul nsw i32 %13, 3
  %15 = sdiv i32 %14, 2
  br label %.loopexit.loopexit.unr-lcssa

.loopexit.loopexit.unr-lcssa:                     ; preds = %.loopexit.loopexit.unr-lcssa.loopexit, %.preheader.preheader
  %.lcssa.ph = phi i32 [ poison, %.preheader.preheader ], [ %12, %.loopexit.loopexit.unr-lcssa.loopexit ]
  %.0812.unr = phi i32 [ 2, %.preheader.preheader ], [ %12, %.loopexit.loopexit.unr-lcssa.loopexit ]
  %.0911.unr = phi i32 [ 3, %.preheader.preheader ], [ %15, %.loopexit.loopexit.unr-lcssa.loopexit ]
  %lcmp.mod.not = icmp eq i32 %xtraiter, 0
  %16 = add nsw i32 %.0911.unr, %.0812.unr
  %.lcssa = select i1 %lcmp.mod.not, i32 %.lcssa.ph, i32 %16
  br label %.loopexit

.loopexit:                                        ; preds = %.loopexit.loopexit.unr-lcssa, %1
  %.1 = phi i32 [ 2, %1 ], [ %.lcssa, %.loopexit.loopexit.unr-lcssa ]
  ret i32 %.1
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(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 = distinct !{!5, !6}
!6 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass