; LLVM IR from tangjz/acm-icpc :: hdu/2815.ll (Z3phii)

; 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"

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z3phii(i32 noundef %0) #0 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  store i32 %0, ptr %2, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #2
  %6 = load i32, ptr %2, align 4, !tbaa !5
  store i32 %6, ptr %3, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #2
  %7 = load i32, ptr %2, align 4, !tbaa !5
  store i32 %7, ptr %4, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #2
  store i32 2, ptr %5, align 4, !tbaa !5
  br label %8

8:                                                ; preds = %37, %1
  %9 = load i32, ptr %5, align 4, !tbaa !5
  %10 = load i32, ptr %5, align 4, !tbaa !5
  %11 = mul nsw i32 %9, %10
  %12 = load i32, ptr %4, align 4, !tbaa !5
  %13 = icmp sle i32 %11, %12
  br i1 %13, label %15, label %14

14:                                               ; preds = %8
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  br label %40

15:                                               ; preds = %8
  %16 = load i32, ptr %4, align 4, !tbaa !5
  %17 = load i32, ptr %5, align 4, !tbaa !5
  %18 = srem i32 %16, %17
  %19 = icmp eq i32 %18, 0
  br i1 %19, label %20, label %36

20:                                               ; preds = %15
  %21 = load i32, ptr %3, align 4, !tbaa !5
  %22 = load i32, ptr %5, align 4, !tbaa !5
  %23 = sdiv i32 %21, %22
  %24 = load i32, ptr %3, align 4, !tbaa !5
  %25 = sub nsw i32 %24, %23
  store i32 %25, ptr %3, align 4, !tbaa !5
  br label %26

26:                                               ; preds = %31, %20
  %27 = load i32, ptr %4, align 4, !tbaa !5
  %28 = load i32, ptr %5, align 4, !tbaa !5
  %29 = srem i32 %27, %28
  %30 = icmp eq i32 %29, 0
  br i1 %30, label %31, label %35

31:                                               ; preds = %26
  %32 = load i32, ptr %5, align 4, !tbaa !5
  %33 = load i32, ptr %4, align 4, !tbaa !5
  %34 = sdiv i32 %33, %32
  store i32 %34, ptr %4, align 4, !tbaa !5
  br label %26, !llvm.loop !9

35:                                               ; preds = %26
  br label %36

36:                                               ; preds = %35, %15
  br label %37

37:                                               ; preds = %36
  %38 = load i32, ptr %5, align 4, !tbaa !5
  %39 = add nsw i32 %38, 1
  store i32 %39, ptr %5, align 4, !tbaa !5
  br label %8, !llvm.loop !11

40:                                               ; preds = %14
  %41 = load i32, ptr %4, align 4, !tbaa !5
  %42 = icmp sgt i32 %41, 1
  br i1 %42, label %43, label %49

43:                                               ; preds = %40
  %44 = load i32, ptr %3, align 4, !tbaa !5
  %45 = load i32, ptr %4, align 4, !tbaa !5
  %46 = sdiv i32 %44, %45
  %47 = load i32, ptr %3, align 4, !tbaa !5
  %48 = sub nsw i32 %47, %46
  store i32 %48, ptr %3, align 4, !tbaa !5
  br label %49

49:                                               ; preds = %43, %40
  %50 = load i32, ptr %3, align 4, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #2
  ret i32 %50
}

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

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

attributes #0 = { 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 #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"

; Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none) uwtable
define dso_local noundef i32 @_Z3phii(i32 noundef %0) local_unnamed_addr #0 {
  %.not25 = icmp slt i32 %0, 4
  br i1 %.not25, label %._crit_edge, label %.lr.ph29

._crit_edge:                                      ; preds = %.loopexit, %1
  %.021.lcssa = phi i32 [ %0, %1 ], [ %.122, %.loopexit ]
  %.020.lcssa = phi i32 [ %0, %1 ], [ %.2, %.loopexit ]
  %2 = icmp sgt i32 %.020.lcssa, 1
  br i1 %2, label %12, label %15

.lr.ph29:                                         ; preds = %1, %.loopexit
  %.028 = phi i32 [ %10, %.loopexit ], [ 2, %1 ]
  %.02027 = phi i32 [ %.2, %.loopexit ], [ %0, %1 ]
  %.02126 = phi i32 [ %.122, %.loopexit ], [ %0, %1 ]
  %3 = srem i32 %.02027, %.028
  %4 = icmp eq i32 %3, 0
  br i1 %4, label %.lr.ph.preheader, label %.loopexit

.lr.ph.preheader:                                 ; preds = %.lr.ph29
  %5 = sdiv i32 %.02126, %.028
  %6 = sub nsw i32 %.02126, %5
  br label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph.preheader, %.lr.ph
  %.124 = phi i32 [ %7, %.lr.ph ], [ %.02027, %.lr.ph.preheader ]
  %7 = sdiv i32 %.124, %.028
  %8 = srem i32 %7, %.028
  %9 = icmp eq i32 %8, 0
  br i1 %9, label %.lr.ph, label %.loopexit, !llvm.loop !5

.loopexit:                                        ; preds = %.lr.ph, %.lr.ph29
  %.122 = phi i32 [ %.02126, %.lr.ph29 ], [ %6, %.lr.ph ]
  %.2 = phi i32 [ %.02027, %.lr.ph29 ], [ %7, %.lr.ph ]
  %10 = add nuw nsw i32 %.028, 1
  %11 = mul nuw nsw i32 %10, %10
  %.not = icmp sgt i32 %11, %.2
  br i1 %.not, label %._crit_edge, label %.lr.ph29, !llvm.loop !7

12:                                               ; preds = %._crit_edge
  %13 = sdiv i32 %.021.lcssa, %.020.lcssa
  %14 = sub nsw i32 %.021.lcssa, %13
  br label %15

15:                                               ; preds = %12, %._crit_edge
  %.223 = phi i32 [ %14, %12 ], [ %.021.lcssa, %._crit_edge ]
  ret i32 %.223
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(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 = distinct !{!5, !6}
!6 = !{!"llvm.loop.mustprogress"}
!7 = distinct !{!7, !6}


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