; LLVM IR from upupming/algorithm :: acwing/算法竞赛进阶指南/0x08-总结与练习/120. 防线.ll (Z3cnti)

; 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
@s = external dso_local global [200010 x i32], align 16
@e = external dso_local global [200010 x i32], align 16
@d = external dso_local global [200010 x i32], align 16

; Function Attrs: mustprogress uwtable
define dso_local noundef i32 @_Z3cnti(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) #3
  store i32 0, ptr %3, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #3
  store i32 0, ptr %4, align 4, !tbaa !5
  br label %6

6:                                                ; preds = %35, %1
  %7 = load i32, ptr %4, align 4, !tbaa !5
  %8 = load i32, ptr @n, align 4, !tbaa !5
  %9 = icmp slt i32 %7, %8
  br i1 %9, label %11, label %10

10:                                               ; preds = %6
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #3
  br label %38

11:                                               ; preds = %6
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #3
  %12 = load i32, ptr %4, align 4, !tbaa !5
  %13 = sext i32 %12 to i64
  %14 = getelementptr inbounds [200010 x i32], ptr @e, i64 0, i64 %13
  %15 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZSt3minIiERKT_S2_S2_(ptr noundef nonnull align 4 dereferenceable(4) %2, ptr noundef nonnull align 4 dereferenceable(4) %14)
  %16 = load i32, ptr %15, align 4, !tbaa !5
  %17 = load i32, ptr %4, align 4, !tbaa !5
  %18 = sext i32 %17 to i64
  %19 = getelementptr inbounds [200010 x i32], ptr @s, i64 0, i64 %18
  %20 = load i32, ptr %19, align 4, !tbaa !5
  %21 = sub nsw i32 %16, %20
  store i32 %21, ptr %5, align 4, !tbaa !5
  %22 = load i32, ptr %5, align 4, !tbaa !5
  %23 = icmp sge i32 %22, 0
  br i1 %23, label %24, label %34

24:                                               ; preds = %11
  %25 = load i32, ptr %5, align 4, !tbaa !5
  %26 = load i32, ptr %4, align 4, !tbaa !5
  %27 = sext i32 %26 to i64
  %28 = getelementptr inbounds [200010 x i32], ptr @d, i64 0, i64 %27
  %29 = load i32, ptr %28, align 4, !tbaa !5
  %30 = sdiv i32 %25, %29
  %31 = add nsw i32 %30, 1
  %32 = load i32, ptr %3, align 4, !tbaa !5
  %33 = add nsw i32 %32, %31
  store i32 %33, ptr %3, align 4, !tbaa !5
  br label %34

34:                                               ; preds = %24, %11
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #3
  br label %35

35:                                               ; preds = %34
  %36 = load i32, ptr %4, align 4, !tbaa !5
  %37 = add nsw i32 %36, 1
  store i32 %37, ptr %4, align 4, !tbaa !5
  br label %6, !llvm.loop !9

38:                                               ; preds = %10
  %39 = load i32, ptr %3, align 4, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #3
  ret i32 %39
}

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

; Function Attrs: inlinehint mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZSt3minIiERKT_S2_S2_(ptr noundef nonnull align 4 dereferenceable(4), ptr noundef nonnull align 4 dereferenceable(4)) #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 = { 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"}


; 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
@s = external dso_local local_unnamed_addr global [200010 x i32], align 16
@e = external dso_local global [200010 x i32], align 16
@d = external dso_local local_unnamed_addr global [200010 x i32], align 16

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z3cnti(i32 noundef %0) local_unnamed_addr #0 {
  %2 = alloca i32, align 4
  store i32 %0, ptr %2, align 4, !tbaa !5
  %3 = load i32, ptr @n, align 4, !tbaa !5
  %4 = icmp sgt i32 %3, 0
  br i1 %4, label %.lr.ph, label %._crit_edge

._crit_edge:                                      ; preds = %18, %1
  %.0.lcssa = phi i32 [ 0, %1 ], [ %.1, %18 ]
  ret i32 %.0.lcssa

.lr.ph:                                           ; preds = %1, %18
  %indvars.iv = phi i64 [ %indvars.iv.next, %18 ], [ 0, %1 ]
  %.012 = phi i32 [ %.1, %18 ], [ 0, %1 ]
  %5 = getelementptr inbounds [200010 x i32], ptr @e, i64 0, i64 %indvars.iv
  %6 = call noundef nonnull align 4 dereferenceable(4) ptr @_ZSt3minIiERKT_S2_S2_(ptr noundef nonnull align 4 dereferenceable(4) %2, ptr noundef nonnull align 4 dereferenceable(4) %5)
  %7 = load i32, ptr %6, align 4, !tbaa !5
  %8 = getelementptr inbounds [200010 x i32], ptr @s, i64 0, i64 %indvars.iv
  %9 = load i32, ptr %8, align 4, !tbaa !5
  %10 = sub nsw i32 %7, %9
  %11 = icmp sgt i32 %10, -1
  br i1 %11, label %12, label %18

12:                                               ; preds = %.lr.ph
  %13 = getelementptr inbounds [200010 x i32], ptr @d, i64 0, i64 %indvars.iv
  %14 = load i32, ptr %13, align 4, !tbaa !5
  %15 = sdiv i32 %10, %14
  %16 = add i32 %.012, 1
  %17 = add i32 %16, %15
  br label %18

18:                                               ; preds = %12, %.lr.ph
  %.1 = phi i32 [ %17, %12 ], [ %.012, %.lr.ph ]
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %19 = load i32, ptr @n, align 4, !tbaa !5
  %20 = sext i32 %19 to i64
  %21 = icmp slt i64 %indvars.iv.next, %20
  br i1 %21, label %.lr.ph, label %._crit_edge, !llvm.loop !9
}

; Function Attrs: inlinehint mustprogress nounwind uwtable
declare dso_local noundef nonnull align 4 dereferenceable(4) ptr @_ZSt3minIiERKT_S2_S2_(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" }

!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,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass