; LLVM IR from UtkarshPathrabe/Competitive-Coding :: HackerRank Solutions/Algorithms/Implementation/Cut The Sticks.ll (Z13DecreaseByMini)

; 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"

@arr = external dso_local global [1005 x i32], align 16

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

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

; Function Attrs: mustprogress uwtable
define dso_local noundef ptr @_Z13DecreaseByMini(i32 noundef %0) #1 {
  %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) #3
  store i32 2147483647, ptr %3, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #3
  store i32 0, ptr %4, align 4, !tbaa !5
  br label %6

6:                                                ; preds = %24, %1
  %7 = load i32, ptr %4, align 4, !tbaa !5
  %8 = load i32, ptr %2, 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) #3
  br label %27

11:                                               ; preds = %6
  %12 = load i32, ptr %4, align 4, !tbaa !5
  %13 = sext i32 %12 to i64
  %14 = getelementptr inbounds [1005 x i32], ptr @arr, i64 0, i64 %13
  %15 = load i32, ptr %14, align 4, !tbaa !5
  %16 = icmp sgt i32 %15, 0
  br i1 %16, label %17, label %23

17:                                               ; preds = %11
  %18 = load i32, ptr %4, align 4, !tbaa !5
  %19 = sext i32 %18 to i64
  %20 = getelementptr inbounds [1005 x i32], ptr @arr, i64 0, i64 %19
  %21 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZSt3minIiERKT_S2_S2_(ptr noundef nonnull align 4 dereferenceable(4) %3, ptr noundef nonnull align 4 dereferenceable(4) %20)
  %22 = load i32, ptr %21, align 4, !tbaa !5
  store i32 %22, ptr %3, align 4, !tbaa !5
  br label %23

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

24:                                               ; preds = %23
  %25 = load i32, ptr %4, align 4, !tbaa !5
  %26 = add nsw i32 %25, 1
  store i32 %26, ptr %4, align 4, !tbaa !5
  br label %6, !llvm.loop !9

27:                                               ; preds = %10
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #3
  store i32 0, ptr %5, align 4, !tbaa !5
  br label %28

28:                                               ; preds = %40, %27
  %29 = load i32, ptr %5, align 4, !tbaa !5
  %30 = load i32, ptr %2, align 4, !tbaa !5
  %31 = icmp slt i32 %29, %30
  br i1 %31, label %33, label %32

32:                                               ; preds = %28
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #3
  br label %43

33:                                               ; preds = %28
  %34 = load i32, ptr %3, align 4, !tbaa !5
  %35 = load i32, ptr %5, align 4, !tbaa !5
  %36 = sext i32 %35 to i64
  %37 = getelementptr inbounds [1005 x i32], ptr @arr, i64 0, i64 %36
  %38 = load i32, ptr %37, align 4, !tbaa !5
  %39 = sub nsw i32 %38, %34
  store i32 %39, ptr %37, align 4, !tbaa !5
  br label %40

40:                                               ; preds = %33
  %41 = load i32, ptr %5, align 4, !tbaa !5
  %42 = add nsw i32 %41, 1
  store i32 %42, ptr %5, align 4, !tbaa !5
  br label %28, !llvm.loop !11

43:                                               ; preds = %32
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #3
  ret ptr @arr
}

; Function Attrs: inlinehint mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZSt3minIiERKT_S2_S2_(ptr noundef nonnull align 4 dereferenceable(4), ptr noundef nonnull align 4 dereferenceable(4)) #2

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = { inlinehint 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 #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 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}
!11 = distinct !{!11, !10}


; 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"

@arr = external dso_local global [1005 x i32], align 16

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

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

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef nonnull ptr @_Z13DecreaseByMini(i32 noundef %0) local_unnamed_addr #1 {
  %2 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %2) #3
  store i32 2147483647, ptr %2, align 4, !tbaa !5
  %3 = icmp sgt i32 %0, 0
  br i1 %3, label %.lr.ph.preheader, label %._crit_edge

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

.preheader:                                       ; preds = %16
  br i1 %3, label %.lr.ph13, label %._crit_edge

.lr.ph13:                                         ; preds = %.preheader
  %wide.trip.count18 = zext nneg i32 %0 to i64
  %min.iters.check = icmp ult i32 %0, 8
  br i1 %min.iters.check, label %scalar.ph.preheader, label %vector.ph

scalar.ph.preheader:                              ; preds = %middle.block, %.lr.ph13
  %indvars.iv15.ph = phi i64 [ 0, %.lr.ph13 ], [ %n.vec, %middle.block ]
  br label %scalar.ph

vector.ph:                                        ; preds = %.lr.ph13
  %n.vec = and i64 %wide.trip.count, 2147483640
  %broadcast.splatinsert = insertelement <4 x i32> poison, i32 %17, i64 0
  %broadcast.splat = shufflevector <4 x i32> %broadcast.splatinsert, <4 x i32> poison, <4 x i32> zeroinitializer
  br label %vector.body

vector.body:                                      ; preds = %vector.body, %vector.ph
  %index = phi i64 [ 0, %vector.ph ], [ %index.next, %vector.body ]
  %4 = getelementptr inbounds [1005 x i32], ptr @arr, i64 0, i64 %index
  %5 = getelementptr inbounds i8, ptr %4, i64 16
  %wide.load = load <4 x i32>, ptr %4, align 16, !tbaa !5
  %wide.load20 = load <4 x i32>, ptr %5, align 16, !tbaa !5
  %6 = sub nsw <4 x i32> %wide.load, %broadcast.splat
  %7 = sub nsw <4 x i32> %wide.load20, %broadcast.splat
  store <4 x i32> %6, ptr %4, align 16, !tbaa !5
  store <4 x i32> %7, ptr %5, align 16, !tbaa !5
  %index.next = add nuw i64 %index, 8
  %8 = icmp eq i64 %index.next, %n.vec
  br i1 %8, label %middle.block, label %vector.body, !llvm.loop !9

middle.block:                                     ; preds = %vector.body
  %cmp.n = icmp eq i64 %n.vec, %wide.trip.count
  br i1 %cmp.n, label %._crit_edge, label %scalar.ph.preheader

.lr.ph:                                           ; preds = %.lr.ph.preheader, %16
  %9 = phi i32 [ 2147483647, %.lr.ph.preheader ], [ %17, %16 ]
  %indvars.iv = phi i64 [ 0, %.lr.ph.preheader ], [ %indvars.iv.next, %16 ]
  %10 = getelementptr inbounds [1005 x i32], ptr @arr, i64 0, i64 %indvars.iv
  %11 = load i32, ptr %10, align 4, !tbaa !5
  %12 = icmp sgt i32 %11, 0
  br i1 %12, label %13, label %16

13:                                               ; preds = %.lr.ph
  %14 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZSt3minIiERKT_S2_S2_(ptr noundef nonnull align 4 dereferenceable(4) %2, ptr noundef nonnull align 4 dereferenceable(4) %10)
  %15 = load i32, ptr %14, align 4, !tbaa !5
  store i32 %15, ptr %2, align 4, !tbaa !5
  br label %16

16:                                               ; preds = %.lr.ph, %13
  %17 = phi i32 [ %9, %.lr.ph ], [ %15, %13 ]
  %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 %.preheader, label %.lr.ph, !llvm.loop !13

._crit_edge:                                      ; preds = %scalar.ph, %middle.block, %1, %.preheader
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %2) #3
  ret ptr @arr

scalar.ph:                                        ; preds = %scalar.ph.preheader, %scalar.ph
  %indvars.iv15 = phi i64 [ %indvars.iv.next16, %scalar.ph ], [ %indvars.iv15.ph, %scalar.ph.preheader ]
  %18 = getelementptr inbounds [1005 x i32], ptr @arr, i64 0, i64 %indvars.iv15
  %19 = load i32, ptr %18, align 4, !tbaa !5
  %20 = sub nsw i32 %19, %17
  store i32 %20, ptr %18, align 4, !tbaa !5
  %indvars.iv.next16 = add nuw nsw i64 %indvars.iv15, 1
  %exitcond19.not = icmp eq i64 %indvars.iv.next16, %wide.trip.count18
  br i1 %exitcond19.not, label %._crit_edge, label %scalar.ph, !llvm.loop !14
}

; Function Attrs: inlinehint mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZSt3minIiERKT_S2_S2_(ptr noundef nonnull align 4 dereferenceable(4), ptr noundef nonnull align 4 dereferenceable(4)) local_unnamed_addr #2

attributes #0 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 #2 = { inlinehint 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 #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 = distinct !{!9, !10, !11, !12}
!10 = !{!"llvm.loop.mustprogress"}
!11 = !{!"llvm.loop.isvectorized", i32 1}
!12 = !{!"llvm.loop.unroll.runtime.disable"}
!13 = distinct !{!13, !10}
!14 = distinct !{!14, !10, !12, !11}


; Effective O3 passes: CorrelatedValuePropagationPass,EarlyCSEPass,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferAlignmentPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LICMPass,LoopLoadEliminationPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,LoopVectorizePass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass