; LLVM IR from ahr9n/psolving-paradigms :: 1.brute-force/1.2.recursive-brute-force-(backtracking)/CodeForces 121A - Lucky Sum._8e00865f (Z3nxti)

; 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.std::vector" = type { %"struct.std::_Vector_base" }
%"struct.std::_Vector_base" = type { %"struct.std::_Vector_base<long long, std::allocator<long long>>::_Vector_impl" }
%"struct.std::_Vector_base<long long, std::allocator<long long>>::_Vector_impl" = type { %"struct.std::_Vector_base<long long, std::allocator<long long>>::_Vector_impl_data" }
%"struct.std::_Vector_base<long long, std::allocator<long long>>::_Vector_impl_data" = type { ptr, ptr, ptr }

@lucky = external dso_local global %"class.std::vector", align 8

; 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 nounwind uwtable
define dso_local noundef i32 @_Z3nxti(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 %3, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #2
  store i32 0, ptr %4, align 4, !tbaa !5
  br label %6

6:                                                ; preds = %21, %1
  %7 = load i32, ptr %4, align 4, !tbaa !5
  %8 = icmp slt i32 %7, 1024
  br i1 %8, label %10, label %9

9:                                                ; preds = %6
  store i32 2, ptr %5, align 4
  br label %24

10:                                               ; preds = %6
  %11 = load i32, ptr %4, align 4, !tbaa !5
  %12 = sext i32 %11 to i64
  %13 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSt6vectorIxSaIxEEixEm(ptr noundef nonnull align 8 dereferenceable(24) @lucky, i64 noundef %12) #2
  %14 = load i64, ptr %13, align 8, !tbaa !9
  %15 = load i32, ptr %3, align 4, !tbaa !5
  %16 = sext i32 %15 to i64
  %17 = icmp sge i64 %14, %16
  br i1 %17, label %18, label %20

18:                                               ; preds = %10
  %19 = load i32, ptr %4, align 4, !tbaa !5
  store i32 %19, ptr %2, align 4
  store i32 1, ptr %5, align 4
  br label %24

20:                                               ; preds = %10
  br label %21

21:                                               ; preds = %20
  %22 = load i32, ptr %4, align 4, !tbaa !5
  %23 = add nsw i32 %22, 1
  store i32 %23, ptr %4, align 4, !tbaa !5
  br label %6, !llvm.loop !11

24:                                               ; preds = %18, %9
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  %25 = load i32, ptr %5, align 4
  switch i32 %25, label %29 [
    i32 2, label %26
    i32 1, label %27
  ]

26:                                               ; preds = %24
  unreachable

27:                                               ; preds = %24
  %28 = load i32, ptr %2, align 4
  ret i32 %28

29:                                               ; preds = %24
  unreachable
}

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 8 dereferenceable(8) ptr @_ZNSt6vectorIxSaIxEEixEm(ptr noundef nonnull align 8 dereferenceable(24), i64 noundef) #1 align 2

attributes #0 = { 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 = { 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 = !{!"long long", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"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"

%"class.std::vector" = type { %"struct.std::_Vector_base" }
%"struct.std::_Vector_base" = type { %"struct.std::_Vector_base<long long, std::allocator<long long>>::_Vector_impl" }
%"struct.std::_Vector_base<long long, std::allocator<long long>>::_Vector_impl" = type { %"struct.std::_Vector_base<long long, std::allocator<long long>>::_Vector_impl_data" }
%"struct.std::_Vector_base<long long, std::allocator<long long>>::_Vector_impl_data" = type { ptr, ptr, ptr }

@lucky = external dso_local global %"class.std::vector", align 8

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z3nxti(i32 noundef %0) local_unnamed_addr #0 {
  %2 = sext i32 %0 to i64
  br label %3

3:                                                ; preds = %1, %6
  %indvars.iv = phi i64 [ 0, %1 ], [ %indvars.iv.next, %6 ]
  %4 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSt6vectorIxSaIxEEixEm(ptr noundef nonnull align 8 dereferenceable(24) @lucky, i64 noundef %indvars.iv) #1
  %5 = load i64, ptr %4, align 8, !tbaa !5
  %.not = icmp slt i64 %5, %2
  br i1 %.not, label %6, label %.split.loop.exit

6:                                                ; preds = %3
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next, 1024
  br i1 %exitcond.not, label %.split.loop.exit9, label %3, !llvm.loop !9

.split.loop.exit:                                 ; preds = %3
  %7 = trunc nuw nsw i64 %indvars.iv to i32
  br label %.split.loop.exit9

.split.loop.exit9:                                ; preds = %6, %.split.loop.exit
  %.0.lcssa = phi i32 [ %7, %.split.loop.exit ], [ 1024, %6 ]
  ret i32 %.0.lcssa
}

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef nonnull align 8 dereferenceable(8) ptr @_ZNSt6vectorIxSaIxEEixEm(ptr noundef nonnull align 8 dereferenceable(24), i64 noundef) 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 = { 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 = !{!"long long", !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,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,LCSSAPass,LICMPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,SROAPass,SimplifyCFGPass,TailCallElimPass