; LLVM IR from upupming/algorithm :: CCCC-GPLT/L1-015. 跟奥巴马一起画方块 (main)

; 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::basic_istream" = type { ptr, i64, %"class.std::basic_ios" }
%"class.std::basic_ios" = type { %"class.std::ios_base", ptr, i8, i8, ptr, ptr, ptr, ptr }
%"class.std::ios_base" = type { ptr, i64, i64, i32, i32, i32, ptr, %"struct.std::ios_base::_Words", [8 x %"struct.std::ios_base::_Words"], i32, ptr, %"class.std::locale" }
%"struct.std::ios_base::_Words" = type { ptr, i64 }
%"class.std::locale" = type { ptr }
%"class.std::basic_ostream" = type { ptr, %"class.std::basic_ios" }

@_ZSt3cin = external global %"class.std::basic_istream", align 8
@_ZSt4cout = external global %"class.std::basic_ostream", align 8

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() #0 {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  %3 = alloca i8, align 1
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  %8 = alloca i32, align 4
  store i32 0, ptr %1, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #5
  %9 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %2)
  call void @llvm.lifetime.start.p0(i64 1, ptr %3) #5
  %10 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZStrsIcSt11char_traitsIcEERSt13basic_istreamIT_T0_ES6_RS3_(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 1 dereferenceable(1) %3)
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #5
  %11 = load i32, ptr %2, align 4, !tbaa !5
  %12 = sdiv i32 %11, 2
  %13 = load i32, ptr %2, align 4, !tbaa !5
  %14 = srem i32 %13, 2
  %15 = add nsw i32 %12, %14
  store i32 %15, ptr %4, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #5
  store i32 0, ptr %5, align 4, !tbaa !5
  br label %16

16:                                               ; preds = %36, %0
  %17 = load i32, ptr %5, align 4, !tbaa !5
  %18 = load i32, ptr %4, align 4, !tbaa !5
  %19 = sub nsw i32 %18, 1
  %20 = icmp slt i32 %17, %19
  br i1 %20, label %22, label %21

21:                                               ; preds = %16
  store i32 2, ptr %6, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #5
  br label %39

22:                                               ; preds = %16
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #5
  store i32 0, ptr %7, align 4, !tbaa !5
  br label %23

23:                                               ; preds = %31, %22
  %24 = load i32, ptr %7, align 4, !tbaa !5
  %25 = load i32, ptr %2, align 4, !tbaa !5
  %26 = icmp slt i32 %24, %25
  br i1 %26, label %28, label %27

27:                                               ; preds = %23
  store i32 5, ptr %6, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #5
  br label %34

28:                                               ; preds = %23
  %29 = load i8, ptr %3, align 1, !tbaa !9
  %30 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i8 noundef signext %29)
  br label %31

31:                                               ; preds = %28
  %32 = load i32, ptr %7, align 4, !tbaa !5
  %33 = add nsw i32 %32, 1
  store i32 %33, ptr %7, align 4, !tbaa !5
  br label %23, !llvm.loop !10

34:                                               ; preds = %27
  %35 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
  br label %36

36:                                               ; preds = %34
  %37 = load i32, ptr %5, align 4, !tbaa !5
  %38 = add nsw i32 %37, 1
  store i32 %38, ptr %5, align 4, !tbaa !5
  br label %16, !llvm.loop !12

39:                                               ; preds = %21
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #5
  store i32 0, ptr %8, align 4, !tbaa !5
  br label %40

40:                                               ; preds = %48, %39
  %41 = load i32, ptr %8, align 4, !tbaa !5
  %42 = load i32, ptr %2, align 4, !tbaa !5
  %43 = icmp slt i32 %41, %42
  br i1 %43, label %45, label %44

44:                                               ; preds = %40
  store i32 8, ptr %6, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #5
  br label %51

45:                                               ; preds = %40
  %46 = load i8, ptr %3, align 1, !tbaa !9
  %47 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i8 noundef signext %46)
  br label %48

48:                                               ; preds = %45
  %49 = load i32, ptr %8, align 4, !tbaa !5
  %50 = add nsw i32 %49, 1
  store i32 %50, ptr %8, align 4, !tbaa !5
  br label %40, !llvm.loop !13

51:                                               ; preds = %44
  store i32 0, ptr %1, align 4
  store i32 1, ptr %6, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #5
  call void @llvm.lifetime.end.p0(i64 1, ptr %3) #5
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #5
  %52 = load i32, ptr %1, align 4
  ret i32 %52
}

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

declare noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 4 dereferenceable(4)) #2

declare noundef nonnull align 8 dereferenceable(16) ptr @_ZStrsIcSt11char_traitsIcEERSt13basic_istreamIT_T0_ES6_RS3_(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 1 dereferenceable(1)) #2

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8), i8 noundef signext) #3

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

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

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_(ptr noundef nonnull align 8 dereferenceable(8)) #3

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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { "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 #3 = { inlinehint 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 #4 = { 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 #5 = { 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 = !{!7, !7, i64 0}
!10 = distinct !{!10, !11}
!11 = !{!"llvm.loop.mustprogress"}
!12 = distinct !{!12, !11}
!13 = distinct !{!13, !11}


; 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::basic_istream" = type { ptr, i64, %"class.std::basic_ios" }
%"class.std::basic_ios" = type { %"class.std::ios_base", ptr, i8, i8, ptr, ptr, ptr, ptr }
%"class.std::ios_base" = type { ptr, i64, i64, i32, i32, i32, ptr, %"struct.std::ios_base::_Words", [8 x %"struct.std::ios_base::_Words"], i32, ptr, %"class.std::locale" }
%"struct.std::ios_base::_Words" = type { ptr, i64 }
%"class.std::locale" = type { ptr }
%"class.std::basic_ostream" = type { ptr, %"class.std::basic_ios" }

@_ZSt3cin = external global %"class.std::basic_istream", align 8
@_ZSt4cout = external global %"class.std::basic_ostream", align 8

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() local_unnamed_addr #0 {
  %1 = alloca i32, align 4
  %2 = alloca i8, align 1
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %1) #5
  %3 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %1)
  call void @llvm.lifetime.start.p0(i64 1, ptr nonnull %2) #5
  %4 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZStrsIcSt11char_traitsIcEERSt13basic_istreamIT_T0_ES6_RS3_(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 1 dereferenceable(1) %2)
  %5 = load i32, ptr %1, align 4, !tbaa !5
  %6 = sdiv i32 %5, 2
  %7 = srem i32 %5, 2
  %8 = add nsw i32 %7, -1
  %9 = add nsw i32 %8, %6
  %10 = icmp sgt i32 %9, 0
  br i1 %10, label %.preheader10, label %.preheader

.preheader10:                                     ; preds = %0, %._crit_edge
  %.0912 = phi i32 [ %16, %._crit_edge ], [ 0, %0 ]
  %11 = load i32, ptr %1, align 4, !tbaa !5
  %12 = icmp sgt i32 %11, 0
  br i1 %12, label %.lr.ph, label %._crit_edge

.preheader.loopexit:                              ; preds = %._crit_edge
  %.pre = load i32, ptr %1, align 4, !tbaa !5
  br label %.preheader

.preheader:                                       ; preds = %.preheader.loopexit, %0
  %13 = phi i32 [ %.pre, %.preheader.loopexit ], [ %5, %0 ]
  %14 = icmp sgt i32 %13, 0
  br i1 %14, label %.lr.ph14, label %._crit_edge15

._crit_edge:                                      ; preds = %.lr.ph, %.preheader10
  %15 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEPFRSoS_E(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, ptr noundef nonnull @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_)
  %16 = add nuw nsw i32 %.0912, 1
  %exitcond.not = icmp eq i32 %16, %9
  br i1 %exitcond.not, label %.preheader.loopexit, label %.preheader10, !llvm.loop !9

.lr.ph:                                           ; preds = %.preheader10, %.lr.ph
  %.0811 = phi i32 [ %19, %.lr.ph ], [ 0, %.preheader10 ]
  %17 = load i8, ptr %2, align 1, !tbaa !11
  %18 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i8 noundef signext %17)
  %19 = add nuw nsw i32 %.0811, 1
  %20 = load i32, ptr %1, align 4, !tbaa !5
  %21 = icmp slt i32 %19, %20
  br i1 %21, label %.lr.ph, label %._crit_edge, !llvm.loop !12

._crit_edge15:                                    ; preds = %.lr.ph14, %.preheader
  call void @llvm.lifetime.end.p0(i64 1, ptr nonnull %2) #5
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %1) #5
  ret i32 0

.lr.ph14:                                         ; preds = %.preheader, %.lr.ph14
  %.013 = phi i32 [ %24, %.lr.ph14 ], [ 0, %.preheader ]
  %22 = load i8, ptr %2, align 1, !tbaa !11
  %23 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i8 noundef signext %22)
  %24 = add nuw nsw i32 %.013, 1
  %25 = load i32, ptr %1, align 4, !tbaa !5
  %26 = icmp slt i32 %24, %25
  br i1 %26, label %.lr.ph14, label %._crit_edge15, !llvm.loop !13
}

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

declare noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 4 dereferenceable(4)) local_unnamed_addr #2

declare noundef nonnull align 8 dereferenceable(16) ptr @_ZStrsIcSt11char_traitsIcEERSt13basic_istreamIT_T0_ES6_RS3_(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 1 dereferenceable(1)) local_unnamed_addr #2

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_c(ptr noundef nonnull align 8 dereferenceable(8), i8 noundef signext) local_unnamed_addr #3

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

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

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_(ptr noundef nonnull align 8 dereferenceable(8)) #3

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 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { "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 #3 = { inlinehint 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 #4 = { 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 #5 = { 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 = !{!7, !7, i64 0}
!12 = distinct !{!12, !10}
!13 = distinct !{!13, !10}


; Effective O3 passes: EarlyCSEPass,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LICMPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,ReassociatePass,SROAPass,SimplifyCFGPass