; LLVM IR from tangjz/acm-icpc :: codeforces/complete/512D.ll (Z4combPiS_)

; 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

; 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 void @_Z4combPiS_(ptr noundef %0, ptr noundef %1) #1 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  store ptr %1, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #2
  store i32 0, ptr %5, align 4, !tbaa !9
  br label %6

6:                                                ; preds = %37, %2
  %7 = load i32, ptr %5, align 4, !tbaa !9
  %8 = load i32, ptr @n, align 4, !tbaa !9
  %9 = icmp sle i32 %7, %8
  br i1 %9, label %11, label %10

10:                                               ; preds = %6
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  br label %40

11:                                               ; preds = %6
  %12 = load ptr, ptr %4, align 8, !tbaa !5
  %13 = load i32, ptr %5, align 4, !tbaa !9
  %14 = sext i32 %13 to i64
  %15 = getelementptr inbounds i32, ptr %12, i64 %14
  %16 = load i32, ptr %15, align 4, !tbaa !9
  %17 = load ptr, ptr %3, align 8, !tbaa !5
  %18 = load i32, ptr %5, align 4, !tbaa !9
  %19 = sext i32 %18 to i64
  %20 = getelementptr inbounds i32, ptr %17, i64 %19
  %21 = load i32, ptr %20, align 4, !tbaa !9
  %22 = add nsw i32 %21, %16
  store i32 %22, ptr %20, align 4, !tbaa !9
  %23 = load ptr, ptr %3, align 8, !tbaa !5
  %24 = load i32, ptr %5, align 4, !tbaa !9
  %25 = sext i32 %24 to i64
  %26 = getelementptr inbounds i32, ptr %23, i64 %25
  %27 = load i32, ptr %26, align 4, !tbaa !9
  %28 = icmp sge i32 %27, 1000000009
  br i1 %28, label %29, label %36

29:                                               ; preds = %11
  %30 = load ptr, ptr %3, align 8, !tbaa !5
  %31 = load i32, ptr %5, align 4, !tbaa !9
  %32 = sext i32 %31 to i64
  %33 = getelementptr inbounds i32, ptr %30, i64 %32
  %34 = load i32, ptr %33, align 4, !tbaa !9
  %35 = sub nsw i32 %34, 1000000009
  store i32 %35, ptr %33, align 4, !tbaa !9
  br label %36

36:                                               ; preds = %29, %11
  br label %37

37:                                               ; preds = %36
  %38 = load i32, ptr %5, align 4, !tbaa !9
  %39 = add nsw i32 %38, 1
  store i32 %39, ptr %5, align 4, !tbaa !9
  br label %6, !llvm.loop !11

40:                                               ; preds = %10
  ret void
}

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 = !{!"any pointer", !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

; Function Attrs: mustprogress nofree norecurse nosync nounwind memory(read, argmem: readwrite, inaccessiblemem: none) uwtable
define dso_local void @_Z4combPiS_(ptr nocapture noundef %0, ptr nocapture noundef readonly %1) local_unnamed_addr #0 {
  %3 = load i32, ptr @n, align 4, !tbaa !5
  %.not10 = icmp slt i32 %3, 0
  br i1 %.not10, label %._crit_edge, label %.lr.ph

._crit_edge:                                      ; preds = %.lr.ph, %2
  ret void

.lr.ph:                                           ; preds = %2, %.lr.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ 0, %2 ]
  %4 = getelementptr inbounds i32, ptr %1, i64 %indvars.iv
  %5 = load i32, ptr %4, align 4, !tbaa !5
  %6 = getelementptr inbounds i32, ptr %0, i64 %indvars.iv
  %7 = load i32, ptr %6, align 4, !tbaa !5
  %8 = add nsw i32 %7, %5
  %9 = icmp sgt i32 %8, 1000000008
  %10 = add nsw i32 %8, -1000000009
  %spec.select = select i1 %9, i32 %10, i32 %8
  store i32 %spec.select, ptr %6, align 4, !tbaa !5
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %11 = load i32, ptr @n, align 4, !tbaa !5
  %12 = sext i32 %11 to i64
  %.not.not = icmp slt i64 %indvars.iv, %12
  br i1 %.not.not, label %.lr.ph, label %._crit_edge, !llvm.loop !9
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind memory(read, argmem: readwrite, 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 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,IPSCCPPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass