; LLVM IR from upupming/algorithm :: acwing/算法基础课/第四讲 数学知识/约数/870. 约数个数.ll (Z6dividei)

; 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::unordered_map" = type { %"class.std::_Hashtable" }
%"class.std::_Hashtable" = type { ptr, i64, %"struct.std::__detail::_Hash_node_base", i64, %"struct.std::__detail::_Prime_rehash_policy", ptr }
%"struct.std::__detail::_Hash_node_base" = type { ptr }
%"struct.std::__detail::_Prime_rehash_policy" = type { float, i64 }

@mp = external dso_local global %"class.std::unordered_map", align 8

; Function Attrs: mustprogress uwtable
define dso_local void @_Z6dividei(i32 noundef %0) #0 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  store i32 %0, ptr %2, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #2
  store i32 2, ptr %3, align 4, !tbaa !5
  br label %5

5:                                                ; preds = %35, %1
  %6 = load i32, ptr %3, align 4, !tbaa !5
  %7 = load i32, ptr %2, align 4, !tbaa !5
  %8 = load i32, ptr %3, align 4, !tbaa !5
  %9 = sdiv i32 %7, %8
  %10 = icmp sle i32 %6, %9
  br i1 %10, label %12, label %11

11:                                               ; preds = %5
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #2
  br label %38

12:                                               ; preds = %5
  %13 = load i32, ptr %2, align 4, !tbaa !5
  %14 = load i32, ptr %3, align 4, !tbaa !5
  %15 = srem i32 %13, %14
  %16 = icmp eq i32 %15, 0
  br i1 %16, label %17, label %34

17:                                               ; preds = %12
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #2
  store i32 0, ptr %4, align 4, !tbaa !5
  br label %18

18:                                               ; preds = %23, %17
  %19 = load i32, ptr %2, align 4, !tbaa !5
  %20 = load i32, ptr %3, align 4, !tbaa !5
  %21 = srem i32 %19, %20
  %22 = icmp eq i32 %21, 0
  br i1 %22, label %23, label %29

23:                                               ; preds = %18
  %24 = load i32, ptr %3, align 4, !tbaa !5
  %25 = load i32, ptr %2, align 4, !tbaa !5
  %26 = sdiv i32 %25, %24
  store i32 %26, ptr %2, align 4, !tbaa !5
  %27 = load i32, ptr %4, align 4, !tbaa !5
  %28 = add nsw i32 %27, 1
  store i32 %28, ptr %4, align 4, !tbaa !5
  br label %18, !llvm.loop !9

29:                                               ; preds = %18
  %30 = load i32, ptr %4, align 4, !tbaa !5
  %31 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt13unordered_mapIiiSt4hashIiESt8equal_toIiESaISt4pairIKiiEEEixERS5_(ptr noundef nonnull align 8 dereferenceable(56) @mp, ptr noundef nonnull align 4 dereferenceable(4) %3)
  %32 = load i32, ptr %31, align 4, !tbaa !5
  %33 = add nsw i32 %32, %30
  store i32 %33, ptr %31, align 4, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  br label %34

34:                                               ; preds = %29, %12
  br label %35

35:                                               ; preds = %34
  %36 = load i32, ptr %3, align 4, !tbaa !5
  %37 = add nsw i32 %36, 1
  store i32 %37, ptr %3, align 4, !tbaa !5
  br label %5, !llvm.loop !11

38:                                               ; preds = %11
  %39 = load i32, ptr %2, align 4, !tbaa !5
  %40 = icmp sgt i32 %39, 1
  br i1 %40, label %41, label %45

41:                                               ; preds = %38
  %42 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt13unordered_mapIiiSt4hashIiESt8equal_toIiESaISt4pairIKiiEEEixERS5_(ptr noundef nonnull align 8 dereferenceable(56) @mp, ptr noundef nonnull align 4 dereferenceable(4) %2)
  %43 = load i32, ptr %42, align 4, !tbaa !5
  %44 = add nsw i32 %43, 1
  store i32 %44, ptr %42, align 4, !tbaa !5
  br label %45

45:                                               ; preds = %41, %38
  ret void
}

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: mustprogress uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt13unordered_mapIiiSt4hashIiESt8equal_toIiESaISt4pairIKiiEEEixERS5_(ptr noundef nonnull align 8 dereferenceable(56), ptr noundef nonnull align 4 dereferenceable(4)) #0 align 2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}
!11 = distinct !{!11, !10}


; 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::unordered_map" = type { %"class.std::_Hashtable" }
%"class.std::_Hashtable" = type { ptr, i64, %"struct.std::__detail::_Hash_node_base", i64, %"struct.std::__detail::_Prime_rehash_policy", ptr }
%"struct.std::__detail::_Hash_node_base" = type { ptr }
%"struct.std::__detail::_Prime_rehash_policy" = type { float, i64 }

@mp = external dso_local global %"class.std::unordered_map", align 8

; Function Attrs: mustprogress uwtable
define dso_local void @_Z6dividei(i32 noundef %0) local_unnamed_addr #0 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  store i32 %0, ptr %2, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %3) #2
  store i32 2, ptr %3, align 4, !tbaa !5
  %.not6 = icmp slt i32 %0, 4
  br i1 %.not6, label %._crit_edge10, label %.lr.ph9

._crit_edge10:                                    ; preds = %15, %1
  %.lcssa = phi i32 [ %0, %1 ], [ %.pr, %15 ]
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %3) #2
  %4 = icmp sgt i32 %.lcssa, 1
  br i1 %4, label %19, label %23

.lr.ph9:                                          ; preds = %1, %15
  %.pr14 = phi i32 [ %.pr, %15 ], [ %0, %1 ]
  %storemerge7 = phi i32 [ %17, %15 ], [ 2, %1 ]
  %5 = srem i32 %.pr14, %storemerge7
  %6 = icmp eq i32 %5, 0
  br i1 %6, label %.lr.ph, label %15

.lr.ph:                                           ; preds = %.lr.ph9, %.lr.ph
  %.04 = phi i32 [ %9, %.lr.ph ], [ 0, %.lr.ph9 ]
  %7 = phi i32 [ %8, %.lr.ph ], [ %.pr14, %.lr.ph9 ]
  %8 = sdiv i32 %7, %storemerge7
  %9 = add nuw nsw i32 %.04, 1
  %10 = srem i32 %8, %storemerge7
  %11 = icmp eq i32 %10, 0
  br i1 %11, label %.lr.ph, label %._crit_edge, !llvm.loop !9

._crit_edge:                                      ; preds = %.lr.ph
  store i32 %8, ptr %2, align 4, !tbaa !5
  %12 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt13unordered_mapIiiSt4hashIiESt8equal_toIiESaISt4pairIKiiEEEixERS5_(ptr noundef nonnull align 8 dereferenceable(56) @mp, ptr noundef nonnull align 4 dereferenceable(4) %3)
  %13 = load i32, ptr %12, align 4, !tbaa !5
  %14 = add nsw i32 %13, %9
  store i32 %14, ptr %12, align 4, !tbaa !5
  %.pre = load i32, ptr %3, align 4, !tbaa !5
  br label %15

15:                                               ; preds = %.lr.ph9, %._crit_edge
  %.pr = phi i32 [ %.pr14, %.lr.ph9 ], [ %8, %._crit_edge ]
  %16 = phi i32 [ %storemerge7, %.lr.ph9 ], [ %.pre, %._crit_edge ]
  %17 = add nsw i32 %16, 1
  store i32 %17, ptr %3, align 4, !tbaa !5
  %18 = sdiv i32 %.pr, %17
  %.not.not = icmp slt i32 %16, %18
  br i1 %.not.not, label %.lr.ph9, label %._crit_edge10, !llvm.loop !11

19:                                               ; preds = %._crit_edge10
  %20 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt13unordered_mapIiiSt4hashIiESt8equal_toIiESaISt4pairIKiiEEEixERS5_(ptr noundef nonnull align 8 dereferenceable(56) @mp, ptr noundef nonnull align 4 dereferenceable(4) %2)
  %21 = load i32, ptr %20, align 4, !tbaa !5
  %22 = add nsw i32 %21, 1
  store i32 %22, ptr %20, align 4, !tbaa !5
  br label %23

23:                                               ; preds = %19, %._crit_edge10
  ret void
}

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: mustprogress uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZNSt13unordered_mapIiiSt4hashIiESt8equal_toIiESaISt4pairIKiiEEEixERS5_(ptr noundef nonnull align 8 dereferenceable(56), ptr noundef nonnull align 4 dereferenceable(4)) local_unnamed_addr #0 align 2

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

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 nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}
!11 = distinct !{!11, !10}


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