; LLVM IR from tangjz/acm-icpc :: 51nod (1381)

; 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"

@t = external dso_local global i64, align 8
@n = external dso_local global i64, align 8

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z4scanRx(ptr noundef nonnull align 8 dereferenceable(8)) #0

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z5printx(i64 noundef) #0

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() #1 {
  %1 = alloca i32, align 4
  store i32 0, ptr %1, align 4
  call void @_Z4scanRx(ptr noundef nonnull align 8 dereferenceable(8) @t)
  br label %2

2:                                                ; preds = %6, %0
  %3 = load i64, ptr @t, align 8, !tbaa !5
  %4 = add nsw i64 %3, -1
  store i64 %4, ptr @t, align 8, !tbaa !5
  %5 = icmp ne i64 %3, 0
  br i1 %5, label %6, label %9

6:                                                ; preds = %2
  call void @_Z4scanRx(ptr noundef nonnull align 8 dereferenceable(8) @n)
  %7 = load i64, ptr @n, align 8, !tbaa !5
  %8 = mul nsw i64 %7, 2
  call void @_Z5printx(i64 noundef %8)
  br label %2, !llvm.loop !9

9:                                                ; preds = %2
  ret i32 0
}

attributes #0 = { 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 #1 = { 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" }

!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"}


; 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"

@t = external dso_local global i64, align 8
@n = external dso_local global i64, align 8

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z4scanRx(ptr noundef nonnull align 8 dereferenceable(8)) local_unnamed_addr #0

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z5printx(i64 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() local_unnamed_addr #1 {
  tail call void @_Z4scanRx(ptr noundef nonnull align 8 dereferenceable(8) @t)
  %1 = load i64, ptr @t, align 8, !tbaa !5
  %2 = add nsw i64 %1, -1
  store i64 %2, ptr @t, align 8, !tbaa !5
  %.not1 = icmp eq i64 %1, 0
  br i1 %.not1, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %0, %.lr.ph
  tail call void @_Z4scanRx(ptr noundef nonnull align 8 dereferenceable(8) @n)
  %3 = load i64, ptr @n, align 8, !tbaa !5
  %4 = shl nsw i64 %3, 1
  tail call void @_Z5printx(i64 noundef %4)
  %5 = load i64, ptr @t, align 8, !tbaa !5
  %6 = add nsw i64 %5, -1
  store i64 %6, ptr @t, align 8, !tbaa !5
  %.not = icmp eq i64 %5, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !9

._crit_edge:                                      ; preds = %.lr.ph, %0
  ret i32 0
}

attributes #0 = { 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 #1 = { 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" }

!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,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,SROAPass,SimplifyCFGPass,TailCallElimPass