; LLVM IR from tangjz/acm-icpc :: buaa/oj3rd/952.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"

@f = external dso_local global [31 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
  store i32 %0, ptr %3, align 4, !tbaa !5
  %4 = load i32, ptr %3, align 4, !tbaa !5
  %5 = sext i32 %4 to i64
  %6 = getelementptr inbounds [31 x i32], ptr @f, i64 0, i64 %5
  %7 = load i32, ptr %6, align 4, !tbaa !5
  %8 = icmp ne i32 %7, 0
  br i1 %8, label %9, label %14

9:                                                ; preds = %1
  %10 = load i32, ptr %3, align 4, !tbaa !5
  %11 = sext i32 %10 to i64
  %12 = getelementptr inbounds [31 x i32], ptr @f, i64 0, i64 %11
  %13 = load i32, ptr %12, align 4, !tbaa !5
  store i32 %13, ptr %2, align 4
  br label %30

14:                                               ; preds = %1
  %15 = load i32, ptr %3, align 4, !tbaa !5
  %16 = icmp sle i32 %15, 1
  br i1 %16, label %17, label %18

17:                                               ; preds = %14
  store i32 0, ptr %2, align 4
  br label %30

18:                                               ; preds = %14
  %19 = load i32, ptr %3, align 4, !tbaa !5
  %20 = sub nsw i32 %19, 1
  %21 = call noundef i32 @_Z3cnti(i32 noundef %20)
  %22 = load i32, ptr %3, align 4, !tbaa !5
  %23 = sub nsw i32 %22, 2
  %24 = call noundef i32 @_Z3cnti(i32 noundef %23)
  %25 = add nsw i32 %21, %24
  %26 = add nsw i32 %25, 1
  %27 = load i32, ptr %3, align 4, !tbaa !5
  %28 = sext i32 %27 to i64
  %29 = getelementptr inbounds [31 x i32], ptr @f, i64 0, i64 %28
  store i32 %26, ptr %29, align 4, !tbaa !5
  store i32 %26, ptr %2, align 4
  br label %30

30:                                               ; preds = %18, %17, %9
  %31 = load i32, ptr %2, align 4
  ret i32 %31
}

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" }

!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"}


; 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"

@f = external dso_local local_unnamed_addr global [31 x i32], align 16

; Function Attrs: mustprogress nofree nosync nounwind memory(readwrite, argmem: none, inaccessiblemem: none) uwtable
define dso_local noundef i32 @_Z3cnti(i32 noundef %0) local_unnamed_addr #0 {
  %2 = sext i32 %0 to i64
  %3 = getelementptr inbounds [31 x i32], ptr @f, i64 0, i64 %2
  %4 = load i32, ptr %3, align 4, !tbaa !5
  %.not = icmp eq i32 %4, 0
  br i1 %.not, label %5, label %common.ret9

5:                                                ; preds = %1
  %6 = icmp slt i32 %0, 2
  br i1 %6, label %common.ret9, label %7

common.ret9:                                      ; preds = %5, %1, %7
  %common.ret9.op = phi i32 [ %13, %7 ], [ %4, %1 ], [ 0, %5 ]
  ret i32 %common.ret9.op

7:                                                ; preds = %5
  %8 = add nsw i32 %0, -1
  %9 = tail call noundef i32 @_Z3cnti(i32 noundef %8)
  %10 = add nsw i32 %0, -2
  %11 = tail call noundef i32 @_Z3cnti(i32 noundef %10)
  %12 = add i32 %9, 1
  %13 = add i32 %12, %11
  store i32 %13, ptr %3, align 4, !tbaa !5
  br label %common.ret9
}

attributes #0 = { mustprogress nofree nosync nounwind memory(readwrite, argmem: none, inaccessiblemem: 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 = !{!6, !6, i64 0}
!6 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,IPSCCPPass,InstCombinePass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass,TailCallElimPass