; LLVM IR from tangjz/acm-icpc :: lydsy/4017.ll (Z3idxx)

; 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
@p = external dso_local global [100010 x i64], 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 nounwind uwtable
define dso_local noundef i32 @_Z3idxx(i64 noundef %0) #1 {
  %2 = alloca i64, align 8
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  store i64 %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #2
  store i32 -1, ptr %3, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #2
  %6 = load i32, ptr @n, align 4, !tbaa !9
  store i32 %6, ptr %4, align 4, !tbaa !9
  br label %7

7:                                                ; preds = %28, %1
  %8 = load i32, ptr %3, align 4, !tbaa !9
  %9 = load i32, ptr %4, align 4, !tbaa !9
  %10 = icmp slt i32 %8, %9
  br i1 %10, label %11, label %29

11:                                               ; preds = %7
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #2
  %12 = load i32, ptr %3, align 4, !tbaa !9
  %13 = load i32, ptr %4, align 4, !tbaa !9
  %14 = add nsw i32 %12, %13
  %15 = add nsw i32 %14, 1
  %16 = ashr i32 %15, 1
  store i32 %16, ptr %5, align 4, !tbaa !9
  %17 = load i32, ptr %5, align 4, !tbaa !9
  %18 = sext i32 %17 to i64
  %19 = getelementptr inbounds [100010 x i64], ptr @p, i64 0, i64 %18
  %20 = load i64, ptr %19, align 8, !tbaa !5
  %21 = load i64, ptr %2, align 8, !tbaa !5
  %22 = icmp sle i64 %20, %21
  br i1 %22, label %23, label %25

23:                                               ; preds = %11
  %24 = load i32, ptr %5, align 4, !tbaa !9
  store i32 %24, ptr %3, align 4, !tbaa !9
  br label %28

25:                                               ; preds = %11
  %26 = load i32, ptr %5, align 4, !tbaa !9
  %27 = sub nsw i32 %26, 1
  store i32 %27, ptr %4, align 4, !tbaa !9
  br label %28

28:                                               ; preds = %25, %23
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  br label %7, !llvm.loop !11

29:                                               ; preds = %7
  %30 = load i32, ptr %3, align 4, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #2
  ret i32 %30
}

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 = !{!"long long", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !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 local_unnamed_addr global i32, align 4
@p = external dso_local local_unnamed_addr global [100010 x i64], align 16

; Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(read, argmem: none, inaccessiblemem: none) uwtable
define dso_local noundef range(i32 -1, 1073741824) i32 @_Z3idxx(i64 noundef %0) local_unnamed_addr #0 {
  %2 = load i32, ptr @n, align 4, !tbaa !5
  %3 = icmp sgt i32 %2, -1
  br i1 %3, label %.lr.ph, label %._crit_edge

.lr.ph:                                           ; preds = %1, %.lr.ph
  %.012 = phi i32 [ %.1, %.lr.ph ], [ -1, %1 ]
  %.0911 = phi i32 [ %.110, %.lr.ph ], [ %2, %1 ]
  %4 = add i32 %.0911, 1
  %5 = add i32 %4, %.012
  %6 = lshr i32 %5, 1
  %7 = zext nneg i32 %6 to i64
  %8 = getelementptr inbounds [100010 x i64], ptr @p, i64 0, i64 %7
  %9 = load i64, ptr %8, align 8, !tbaa !9
  %.not = icmp sgt i64 %9, %0
  %10 = add nsw i32 %6, -1
  %.110 = select i1 %.not, i32 %10, i32 %.0911
  %.1 = select i1 %.not, i32 %.012, i32 %6
  %11 = icmp slt i32 %.1, %.110
  br i1 %11, label %.lr.ph, label %._crit_edge, !llvm.loop !11

._crit_edge:                                      ; preds = %.lr.ph, %1
  %.0.lcssa = phi i32 [ -1, %1 ], [ %.1, %.lr.ph ]
  ret i32 %.0.lcssa
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(read, argmem: none, inaccessiblemem: none) 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 = !{!"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: GVNPass,GlobalOptPass,IPSCCPPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass