; LLVM IR from lzyrapx/Competitive-Programming :: HDUOJ/1988.ll (Z6changei)

; 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"

@a = external dso_local global [35 x i32], 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 void @_Z6changei(i32 noundef %0) #1 {
  %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) #3
  store i32 1, ptr %3, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #3
  %6 = load i32, ptr %2, align 4, !tbaa !5
  store i32 %6, ptr %4, align 4, !tbaa !5
  br label %7

7:                                                ; preds = %19, %1
  %8 = load i32, ptr %3, align 4, !tbaa !5
  %9 = load i32, ptr %4, align 4, !tbaa !5
  %10 = icmp slt i32 %8, %9
  br i1 %10, label %12, label %11

11:                                               ; preds = %7
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #3
  br label %24

12:                                               ; preds = %7
  %13 = load i32, ptr %3, align 4, !tbaa !5
  %14 = sext i32 %13 to i64
  %15 = getelementptr inbounds [35 x i32], ptr @a, i64 0, i64 %14
  %16 = load i32, ptr %4, align 4, !tbaa !5
  %17 = sext i32 %16 to i64
  %18 = getelementptr inbounds [35 x i32], ptr @a, i64 0, i64 %17
  call void @_ZSt4swapIiENSt9enable_ifIXsr6__and_ISt6__not_ISt15__is_tuple_likeIT_EESt21is_move_constructibleIS3_ESt18is_move_assignableIS3_EEE5valueEvE4typeERS3_SC_(ptr noundef nonnull align 4 dereferenceable(4) %15, ptr noundef nonnull align 4 dereferenceable(4) %18) #3
  br label %19

19:                                               ; preds = %12
  %20 = load i32, ptr %3, align 4, !tbaa !5
  %21 = add nsw i32 %20, 1
  store i32 %21, ptr %3, align 4, !tbaa !5
  %22 = load i32, ptr %4, align 4, !tbaa !5
  %23 = add nsw i32 %22, -1
  store i32 %23, ptr %4, align 4, !tbaa !5
  br label %7, !llvm.loop !9

24:                                               ; preds = %11
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #3
  store i32 1, ptr %5, align 4, !tbaa !5
  br label %25

25:                                               ; preds = %39, %24
  %26 = load i32, ptr %5, align 4, !tbaa !5
  %27 = load i32, ptr %2, align 4, !tbaa !5
  %28 = icmp sle i32 %26, %27
  br i1 %28, label %30, label %29

29:                                               ; preds = %25
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #3
  br label %42

30:                                               ; preds = %25
  %31 = load i32, ptr %5, align 4, !tbaa !5
  %32 = sext i32 %31 to i64
  %33 = getelementptr inbounds [35 x i32], ptr @a, i64 0, i64 %32
  %34 = load i32, ptr %33, align 4, !tbaa !5
  %35 = sub nsw i32 0, %34
  %36 = load i32, ptr %5, align 4, !tbaa !5
  %37 = sext i32 %36 to i64
  %38 = getelementptr inbounds [35 x i32], ptr @a, i64 0, i64 %37
  store i32 %35, ptr %38, align 4, !tbaa !5
  br label %39

39:                                               ; preds = %30
  %40 = load i32, ptr %5, align 4, !tbaa !5
  %41 = add nsw i32 %40, 1
  store i32 %41, ptr %5, align 4, !tbaa !5
  br label %25, !llvm.loop !11

42:                                               ; preds = %29
  ret void
}

; Function Attrs: inlinehint mustprogress nounwind uwtable
declare dso_local void @_ZSt4swapIiENSt9enable_ifIXsr6__and_ISt6__not_ISt15__is_tuple_likeIT_EESt21is_move_constructibleIS3_ESt18is_move_assignableIS3_EEE5valueEvE4typeERS3_SC_(ptr noundef nonnull align 4 dereferenceable(4), ptr noundef nonnull align 4 dereferenceable(4)) #2

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 = { inlinehint 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 #3 = { 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"

@a = external dso_local global [35 x i32], align 16

; Function Attrs: mustprogress nounwind uwtable
define dso_local void @_Z6changei(i32 noundef %0) local_unnamed_addr #0 {
  %2 = icmp sgt i32 %0, 1
  br i1 %2, label %.lr.ph.preheader, label %.preheader

.lr.ph.preheader:                                 ; preds = %1
  %3 = zext nneg i32 %0 to i64
  br label %.lr.ph

.preheader:                                       ; preds = %.lr.ph, %1
  %.not16 = icmp slt i32 %0, 1
  br i1 %.not16, label %._crit_edge, label %.lr.ph18.preheader

.lr.ph18.preheader:                               ; preds = %.preheader
  %4 = add nuw i32 %0, 1
  %wide.trip.count = zext i32 %4 to i64
  %5 = zext nneg i32 %0 to i64
  %min.iters.check = icmp ult i32 %0, 8
  br i1 %min.iters.check, label %.lr.ph18.preheader28, label %vector.ph

.lr.ph18.preheader28:                             ; preds = %middle.block, %.lr.ph18.preheader
  %indvars.iv24.ph = phi i64 [ 1, %.lr.ph18.preheader ], [ %ind.end, %middle.block ]
  br label %.lr.ph18

vector.ph:                                        ; preds = %.lr.ph18.preheader
  %n.vec = and i64 %5, 2147483640
  %ind.end = or disjoint i64 %n.vec, 1
  br label %vector.body

vector.body:                                      ; preds = %vector.body, %vector.ph
  %index = phi i64 [ 0, %vector.ph ], [ %index.next, %vector.body ]
  %offset.idx = or disjoint i64 %index, 1
  %6 = getelementptr inbounds [35 x i32], ptr @a, i64 0, i64 %offset.idx
  %7 = getelementptr inbounds i8, ptr %6, i64 16
  %wide.load = load <4 x i32>, ptr %6, align 4, !tbaa !5
  %wide.load27 = load <4 x i32>, ptr %7, align 4, !tbaa !5
  %8 = sub nsw <4 x i32> zeroinitializer, %wide.load
  %9 = sub nsw <4 x i32> zeroinitializer, %wide.load27
  store <4 x i32> %8, ptr %6, align 4, !tbaa !5
  store <4 x i32> %9, ptr %7, align 4, !tbaa !5
  %index.next = add nuw i64 %index, 8
  %10 = icmp eq i64 %index.next, %n.vec
  br i1 %10, label %middle.block, label %vector.body, !llvm.loop !9

middle.block:                                     ; preds = %vector.body
  %cmp.n = icmp eq i64 %n.vec, %5
  br i1 %cmp.n, label %._crit_edge, label %.lr.ph18.preheader28

.lr.ph:                                           ; preds = %.lr.ph.preheader, %.lr.ph
  %indvars.iv19 = phi i64 [ 1, %.lr.ph.preheader ], [ %indvars.iv.next20, %.lr.ph ]
  %indvars.iv = phi i64 [ %3, %.lr.ph.preheader ], [ %indvars.iv.next, %.lr.ph ]
  %11 = getelementptr inbounds [35 x i32], ptr @a, i64 0, i64 %indvars.iv19
  %12 = getelementptr inbounds [35 x i32], ptr @a, i64 0, i64 %indvars.iv
  tail call void @_ZSt4swapIiENSt9enable_ifIXsr6__and_ISt6__not_ISt15__is_tuple_likeIT_EESt21is_move_constructibleIS3_ESt18is_move_assignableIS3_EEE5valueEvE4typeERS3_SC_(ptr noundef nonnull align 4 dereferenceable(4) %11, ptr noundef nonnull align 4 dereferenceable(4) %12) #2
  %indvars.iv.next20 = add nuw nsw i64 %indvars.iv19, 1
  %indvars.iv.next = add nsw i64 %indvars.iv, -1
  %13 = icmp slt i64 %indvars.iv.next20, %indvars.iv.next
  br i1 %13, label %.lr.ph, label %.preheader, !llvm.loop !13

._crit_edge:                                      ; preds = %.lr.ph18, %middle.block, %.preheader
  ret void

.lr.ph18:                                         ; preds = %.lr.ph18.preheader28, %.lr.ph18
  %indvars.iv24 = phi i64 [ %indvars.iv.next25, %.lr.ph18 ], [ %indvars.iv24.ph, %.lr.ph18.preheader28 ]
  %14 = getelementptr inbounds [35 x i32], ptr @a, i64 0, i64 %indvars.iv24
  %15 = load i32, ptr %14, align 4, !tbaa !5
  %16 = sub nsw i32 0, %15
  store i32 %16, ptr %14, align 4, !tbaa !5
  %indvars.iv.next25 = add nuw nsw i64 %indvars.iv24, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next25, %wide.trip.count
  br i1 %exitcond.not, label %._crit_edge, label %.lr.ph18, !llvm.loop !14
}

; Function Attrs: inlinehint mustprogress nounwind uwtable
declare dso_local void @_ZSt4swapIiENSt9enable_ifIXsr6__and_ISt6__not_ISt15__is_tuple_likeIT_EESt21is_move_constructibleIS3_ESt18is_move_assignableIS3_EEE5valueEvE4typeERS3_SC_(ptr noundef nonnull align 4 dereferenceable(4), ptr noundef nonnull align 4 dereferenceable(4)) local_unnamed_addr #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 = { inlinehint 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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = distinct !{!9, !10, !11, !12}
!10 = !{!"llvm.loop.mustprogress"}
!11 = !{!"llvm.loop.isvectorized", i32 1}
!12 = !{!"llvm.loop.unroll.runtime.disable"}
!13 = distinct !{!13, !10}
!14 = distinct !{!14, !10, !12, !11}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopLoadEliminationPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,LoopVectorizePass,SROAPass,SimplifyCFGPass,TailCallElimPass