; LLVM IR from tangjz/acm-icpc :: lydsy/1299.ll (Z3dfsii)

; 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
@a = external dso_local global [15 x i32], align 16

; Function Attrs: mustprogress uwtable
define dso_local noundef zeroext i1 @_Z3dfsii(i32 noundef %0, i32 noundef %1) #0 {
  %3 = alloca i1, align 1
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  store i32 %0, ptr %4, align 4, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !5
  %6 = load i32, ptr %5, align 4, !tbaa !5
  %7 = icmp ne i32 %6, 0
  br i1 %7, label %9, label %8

8:                                                ; preds = %2
  store i1 true, ptr %3, align 1
  br label %37

9:                                                ; preds = %2
  %10 = load i32, ptr %4, align 4, !tbaa !5
  %11 = load i32, ptr @n, align 4, !tbaa !5
  %12 = icmp eq i32 %10, %11
  br i1 %12, label %13, label %14

13:                                               ; preds = %9
  store i1 false, ptr %3, align 1
  br label %37

14:                                               ; preds = %9
  %15 = load i32, ptr %4, align 4, !tbaa !5
  %16 = add nsw i32 %15, 1
  %17 = load i32, ptr %5, align 4, !tbaa !5
  %18 = call noundef zeroext i1 @_Z3dfsii(i32 noundef %16, i32 noundef %17)
  br i1 %18, label %35, label %19

19:                                               ; preds = %14
  %20 = load i32, ptr %4, align 4, !tbaa !5
  %21 = add nsw i32 %20, 1
  %22 = load i32, ptr %5, align 4, !tbaa !5
  %23 = icmp eq i32 %22, -1
  br i1 %23, label %24, label %25

24:                                               ; preds = %19
  br label %27

25:                                               ; preds = %19
  %26 = load i32, ptr %5, align 4, !tbaa !5
  br label %27

27:                                               ; preds = %25, %24
  %28 = phi i32 [ 0, %24 ], [ %26, %25 ]
  %29 = load i32, ptr %4, align 4, !tbaa !5
  %30 = sext i32 %29 to i64
  %31 = getelementptr inbounds [15 x i32], ptr @a, i64 0, i64 %30
  %32 = load i32, ptr %31, align 4, !tbaa !5
  %33 = xor i32 %28, %32
  %34 = call noundef zeroext i1 @_Z3dfsii(i32 noundef %21, i32 noundef %33)
  br label %35

35:                                               ; preds = %27, %14
  %36 = phi i1 [ true, %14 ], [ %34, %27 ]
  store i1 %36, ptr %3, align 1
  br label %37

37:                                               ; preds = %35, %13, %8
  %38 = load i1, ptr %3, align 1
  ret i1 %38
}

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"

@n = external dso_local local_unnamed_addr global i32, align 4
@a = external dso_local local_unnamed_addr global [15 x i32], align 16

; Function Attrs: mustprogress nofree nosync nounwind willreturn memory(read, argmem: none, inaccessiblemem: none) uwtable
define dso_local noundef zeroext i1 @_Z3dfsii(i32 noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %.not11 = icmp eq i32 %1, 0
  br i1 %.not11, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %2
  %3 = load i32, ptr @n, align 4, !tbaa !5
  %4 = sext i32 %0 to i64
  %sext = sext i32 %3 to i64
  br label %5

5:                                                ; preds = %.lr.ph, %tailrecurse
  %indvars.iv = phi i64 [ %4, %.lr.ph ], [ %indvars.iv.next, %tailrecurse ]
  %.tr1013 = phi i32 [ %1, %.lr.ph ], [ %13, %tailrecurse ]
  %.not18 = icmp ne i64 %indvars.iv, %sext
  br i1 %.not18, label %6, label %._crit_edge

6:                                                ; preds = %5
  %indvars.iv.next = add nsw i64 %indvars.iv, 1
  %7 = trunc nsw i64 %indvars.iv.next to i32
  %8 = tail call noundef zeroext i1 @_Z3dfsii(i32 noundef %7, i32 noundef %.tr1013)
  br i1 %8, label %._crit_edge, label %tailrecurse

tailrecurse:                                      ; preds = %6
  %9 = icmp eq i32 %.tr1013, -1
  %10 = select i1 %9, i32 0, i32 %.tr1013
  %11 = getelementptr inbounds [15 x i32], ptr @a, i64 0, i64 %indvars.iv
  %12 = load i32, ptr %11, align 4, !tbaa !5
  %13 = xor i32 %12, %10
  %.not = icmp eq i32 %12, %10
  br i1 %.not, label %._crit_edge, label %5

._crit_edge:                                      ; preds = %tailrecurse, %5, %6, %2
  %.0 = phi i1 [ true, %2 ], [ %.not18, %6 ], [ %.not18, %5 ], [ %.not18, %tailrecurse ]
  ret i1 %.0
}

attributes #0 = { mustprogress nofree nosync nounwind willreturn memory(read, 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: CorrelatedValuePropagationPass,EarlyCSEPass,GlobalOptPass,IndVarSimplifyPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LICMPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass,TailCallElimPass