; LLVM IR from tangjz/acm-icpc :: 51nod (1344)

; 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"

@n = external dso_local global i32, align 4
@x = external dso_local global i32, align 4
@sum = external dso_local global i64, align 8
@ans = external dso_local global i64, align 8
@.str = external hidden unnamed_addr constant [3 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [6 x i8], align 1

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() #0 {
  %1 = alloca i32, align 4
  store i32 0, ptr %1, align 4
  %2 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str, ptr noundef @n)
  br label %3

3:                                                ; preds = %19, %0
  %4 = load i32, ptr @n, align 4, !tbaa !5
  %5 = add nsw i32 %4, -1
  store i32 %5, ptr @n, align 4, !tbaa !5
  %6 = icmp ne i32 %4, 0
  br i1 %6, label %7, label %21

7:                                                ; preds = %3
  %8 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str, ptr noundef @x)
  %9 = load i32, ptr @x, align 4, !tbaa !5
  %10 = sext i32 %9 to i64
  %11 = load i64, ptr @sum, align 8, !tbaa !9
  %12 = add nsw i64 %11, %10
  store i64 %12, ptr @sum, align 8, !tbaa !9
  %13 = load i64, ptr @ans, align 8, !tbaa !9
  %14 = load i64, ptr @sum, align 8, !tbaa !9
  %15 = icmp sgt i64 %13, %14
  br i1 %15, label %16, label %19

16:                                               ; preds = %7
  %17 = load i64, ptr @sum, align 8, !tbaa !9
  store i64 %17, ptr @ans, align 8, !tbaa !9
  %18 = icmp ne i64 %17, 0
  br label %19

19:                                               ; preds = %16, %7
  %20 = phi i1 [ false, %7 ], [ %18, %16 ]
  br label %3, !llvm.loop !11

21:                                               ; preds = %3
  %22 = load i64, ptr @ans, align 8, !tbaa !9
  %23 = sub nsw i64 0, %22
  %24 = call i32 (ptr, ...) @printf(ptr noundef @.str.1, i64 noundef %23)
  ret i32 0
}

declare i32 @__isoc99_scanf(ptr noundef, ...) #1

declare i32 @printf(ptr noundef, ...) #1

attributes #0 = { 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 #1 = { "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 = !{!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"

@n = external dso_local global i32, align 4
@x = external dso_local global i32, align 4
@sum = external dso_local local_unnamed_addr global i64, align 8
@ans = external dso_local local_unnamed_addr global i64, align 8
@.str = external hidden unnamed_addr constant [3 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [6 x i8], align 1

; Function Attrs: mustprogress nofree norecurse nounwind uwtable
define dso_local noundef i32 @main() local_unnamed_addr #0 {
  %1 = tail call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef nonnull @n)
  %2 = load i32, ptr @n, align 4, !tbaa !5
  %3 = add nsw i32 %2, -1
  store i32 %3, ptr @n, align 4, !tbaa !5
  %.not1 = icmp eq i32 %2, 0
  br i1 %.not1, label %.._crit_edge_crit_edge, label %.lr.ph

.._crit_edge_crit_edge:                           ; preds = %0
  %.pre = load i64, ptr @ans, align 8, !tbaa !9
  br label %._crit_edge

.lr.ph:                                           ; preds = %0, %12
  %4 = tail call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef nonnull @x)
  %5 = load i32, ptr @x, align 4, !tbaa !5
  %6 = sext i32 %5 to i64
  %7 = load i64, ptr @sum, align 8, !tbaa !9
  %8 = add nsw i64 %7, %6
  store i64 %8, ptr @sum, align 8, !tbaa !9
  %9 = load i64, ptr @ans, align 8, !tbaa !9
  %10 = icmp sgt i64 %9, %8
  br i1 %10, label %11, label %12

11:                                               ; preds = %.lr.ph
  store i64 %8, ptr @ans, align 8, !tbaa !9
  br label %12

12:                                               ; preds = %11, %.lr.ph
  %13 = phi i64 [ %8, %11 ], [ %9, %.lr.ph ]
  %14 = load i32, ptr @n, align 4, !tbaa !5
  %15 = add nsw i32 %14, -1
  store i32 %15, ptr @n, align 4, !tbaa !5
  %.not = icmp eq i32 %14, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !11

._crit_edge:                                      ; preds = %12, %.._crit_edge_crit_edge
  %16 = phi i64 [ %.pre, %.._crit_edge_crit_edge ], [ %13, %12 ]
  %17 = sub nsw i64 0, %16
  %18 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.1, i64 noundef %17)
  ret i32 0
}

; Function Attrs: nofree nounwind
declare noundef i32 @__isoc99_scanf(ptr nocapture noundef readonly, ...) local_unnamed_addr #1

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #1

attributes #0 = { mustprogress nofree norecurse 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 = { 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" }

!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"}


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