; LLVM IR from Mohammed-Shoaib/Coding-Problems :: Google/Kick Start/2020/Round C/A.ll (Z9countdowniiRSt6vectorIiSaIiEE)

; 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"

%"class.__gnu_cxx::__normal_iterator" = type { ptr }

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z9countdowniiRSt6vectorIiSaIiEE(i32 noundef %0, i32 noundef %1, ptr noundef nonnull align 8 dereferenceable(24) %2) #0 {
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  %6 = alloca ptr, align 8
  %7 = alloca i32, align 4
  %8 = alloca i32, align 4
  %9 = alloca ptr, align 8
  %10 = alloca %"class.__gnu_cxx::__normal_iterator", align 8
  %11 = alloca %"class.__gnu_cxx::__normal_iterator", align 8
  %12 = alloca ptr, align 8
  store i32 %0, ptr %4, align 4, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !5
  store ptr %2, ptr %6, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #3
  store i32 0, ptr %7, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #3
  %13 = load i32, ptr %5, align 4, !tbaa !5
  store i32 %13, ptr %8, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %9) #3
  %14 = load ptr, ptr %6, align 8, !tbaa !9
  store ptr %14, ptr %9, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %10) #3
  %15 = load ptr, ptr %9, align 8, !tbaa !9
  %16 = call ptr @_ZNSt6vectorIiSaIiEE5beginEv(ptr noundef nonnull align 8 dereferenceable(24) %15) #3
  %17 = getelementptr inbounds %"class.__gnu_cxx::__normal_iterator", ptr %10, i32 0, i32 0
  store ptr %16, ptr %17, align 8
  call void @llvm.lifetime.start.p0(i64 8, ptr %11) #3
  %18 = load ptr, ptr %9, align 8, !tbaa !9
  %19 = call ptr @_ZNSt6vectorIiSaIiEE3endEv(ptr noundef nonnull align 8 dereferenceable(24) %18) #3
  %20 = getelementptr inbounds %"class.__gnu_cxx::__normal_iterator", ptr %11, i32 0, i32 0
  store ptr %19, ptr %20, align 8
  br label %21

21:                                               ; preds = %47, %3
  %22 = call noundef zeroext i1 @_ZN9__gnu_cxxneIPiSt6vectorIiSaIiEEEEbRKNS_17__normal_iteratorIT_T0_EESA_(ptr noundef nonnull align 8 dereferenceable(8) %10, ptr noundef nonnull align 8 dereferenceable(8) %11) #3
  br i1 %22, label %24, label %23

23:                                               ; preds = %21
  call void @llvm.lifetime.end.p0(i64 8, ptr %11) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %10) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %9) #3
  br label %49

24:                                               ; preds = %21
  call void @llvm.lifetime.start.p0(i64 8, ptr %12) #3
  %25 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNK9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEdeEv(ptr noundef nonnull align 8 dereferenceable(8) %10) #3
  store ptr %25, ptr %12, align 8, !tbaa !9
  %26 = load ptr, ptr %12, align 8, !tbaa !9
  %27 = load i32, ptr %26, align 4, !tbaa !5
  %28 = load i32, ptr %8, align 4, !tbaa !5
  %29 = icmp ne i32 %27, %28
  br i1 %29, label %30, label %32

30:                                               ; preds = %24
  %31 = load i32, ptr %5, align 4, !tbaa !5
  store i32 %31, ptr %8, align 4, !tbaa !5
  br label %32

32:                                               ; preds = %30, %24
  %33 = load ptr, ptr %12, align 8, !tbaa !9
  %34 = load i32, ptr %33, align 4, !tbaa !5
  %35 = load i32, ptr %8, align 4, !tbaa !5
  %36 = icmp eq i32 %34, %35
  br i1 %36, label %37, label %46

37:                                               ; preds = %32
  %38 = load i32, ptr %8, align 4, !tbaa !5
  %39 = add nsw i32 %38, -1
  store i32 %39, ptr %8, align 4, !tbaa !5
  %40 = load i32, ptr %8, align 4, !tbaa !5
  %41 = icmp eq i32 %40, 0
  br i1 %41, label %42, label %45

42:                                               ; preds = %37
  %43 = load i32, ptr %7, align 4, !tbaa !5
  %44 = add nsw i32 %43, 1
  store i32 %44, ptr %7, align 4, !tbaa !5
  br label %45

45:                                               ; preds = %42, %37
  br label %46

46:                                               ; preds = %45, %32
  call void @llvm.lifetime.end.p0(i64 8, ptr %12) #3
  br label %47

47:                                               ; preds = %46
  %48 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZN9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEppEv(ptr noundef nonnull align 8 dereferenceable(8) %10) #3
  br label %21

49:                                               ; preds = %23
  %50 = load i32, ptr %7, align 4, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #3
  ret i32 %50
}

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: mustprogress nounwind uwtable
declare dso_local ptr @_ZNSt6vectorIiSaIiEE5beginEv(ptr noundef nonnull align 8 dereferenceable(24)) #0 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local ptr @_ZNSt6vectorIiSaIiEE3endEv(ptr noundef nonnull align 8 dereferenceable(24)) #0 align 2

; Function Attrs: inlinehint mustprogress nounwind uwtable
declare dso_local noundef zeroext i1 @_ZN9__gnu_cxxneIPiSt6vectorIiSaIiEEEEbRKNS_17__normal_iteratorIT_T0_EESA_(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef nonnull align 8 dereferenceable(8)) #2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZNK9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEdeEv(ptr noundef nonnull align 8 dereferenceable(8)) #0 align 2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 8 dereferenceable(8) ptr @_ZN9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEppEv(ptr noundef nonnull align 8 dereferenceable(8)) #0 align 2

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 = { 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 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !7, i64 0}


; 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"

%"class.__gnu_cxx::__normal_iterator" = type { ptr }

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z9countdowniiRSt6vectorIiSaIiEE(i32 noundef %0, i32 noundef %1, ptr noundef nonnull align 8 dereferenceable(24) %2) local_unnamed_addr #0 {
  %4 = alloca %"class.__gnu_cxx::__normal_iterator", align 8
  %5 = alloca %"class.__gnu_cxx::__normal_iterator", align 8
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %4) #3
  %6 = tail call ptr @_ZNSt6vectorIiSaIiEE5beginEv(ptr noundef nonnull align 8 dereferenceable(24) %2) #3
  store ptr %6, ptr %4, align 8
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %5) #3
  %7 = tail call ptr @_ZNSt6vectorIiSaIiEE3endEv(ptr noundef nonnull align 8 dereferenceable(24) %2) #3
  store ptr %7, ptr %5, align 8
  %8 = call noundef zeroext i1 @_ZN9__gnu_cxxneIPiSt6vectorIiSaIiEEEEbRKNS_17__normal_iteratorIT_T0_EESA_(ptr noundef nonnull align 8 dereferenceable(8) %4, ptr noundef nonnull align 8 dereferenceable(8) %5) #3
  br i1 %8, label %.lr.ph, label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph, %3
  %.0.lcssa = phi i32 [ 0, %3 ], [ %.1, %.lr.ph ]
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %5) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %4) #3
  ret i32 %.0.lcssa

.lr.ph:                                           ; preds = %3, %.lr.ph
  %.019 = phi i32 [ %.1, %.lr.ph ], [ 0, %3 ]
  %.01218 = phi i32 [ %.2, %.lr.ph ], [ %1, %3 ]
  %9 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNK9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEdeEv(ptr noundef nonnull align 8 dereferenceable(8) %4) #3
  %10 = load i32, ptr %9, align 4, !tbaa !5
  %.not = icmp eq i32 %10, %.01218
  %spec.select = select i1 %.not, i32 %.01218, i32 %1
  %11 = icmp eq i32 %10, %spec.select
  %12 = add nsw i32 %spec.select, -1
  %13 = icmp eq i32 %12, 0
  %.2 = select i1 %11, i32 %12, i32 %spec.select
  %narrow = select i1 %11, i1 %13, i1 false
  %spec.select17 = zext i1 %narrow to i32
  %.1 = add nuw nsw i32 %.019, %spec.select17
  %14 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZN9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEppEv(ptr noundef nonnull align 8 dereferenceable(8) %4) #3
  %15 = call noundef zeroext i1 @_ZN9__gnu_cxxneIPiSt6vectorIiSaIiEEEEbRKNS_17__normal_iteratorIT_T0_EESA_(ptr noundef nonnull align 8 dereferenceable(8) %4, ptr noundef nonnull align 8 dereferenceable(8) %5) #3
  br i1 %15, label %.lr.ph, label %._crit_edge
}

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: mustprogress nounwind uwtable
declare dso_local ptr @_ZNSt6vectorIiSaIiEE5beginEv(ptr noundef nonnull align 8 dereferenceable(24)) local_unnamed_addr #0 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local ptr @_ZNSt6vectorIiSaIiEE3endEv(ptr noundef nonnull align 8 dereferenceable(24)) local_unnamed_addr #0 align 2

; Function Attrs: inlinehint mustprogress nounwind uwtable
declare dso_local noundef zeroext i1 @_ZN9__gnu_cxxneIPiSt6vectorIiSaIiEEEEbRKNS_17__normal_iteratorIT_T0_EESA_(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef nonnull align 8 dereferenceable(8)) local_unnamed_addr #2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZNK9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEdeEv(ptr noundef nonnull align 8 dereferenceable(8)) local_unnamed_addr #0 align 2

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 8 dereferenceable(8) ptr @_ZN9__gnu_cxx17__normal_iteratorIPiSt6vectorIiSaIiEEEppEv(ptr noundef nonnull align 8 dereferenceable(8)) local_unnamed_addr #0 align 2

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 nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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"}


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