; LLVM IR from lzyrapx/Competitive-Programming :: HDUOJ/1988.ll (Z4findi)

; 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 [35 x i32], align 16

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z4findi(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 %3, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #3
  store i32 1, ptr %4, align 4, !tbaa !5
  br label %6

6:                                                ; preds = %22, %1
  %7 = load i32, ptr %4, align 4, !tbaa !5
  %8 = load i32, ptr @n, align 4, !tbaa !5
  %9 = icmp sle i32 %7, %8
  br i1 %9, label %11, label %10

10:                                               ; preds = %6
  store i32 2, ptr %5, align 4
  br label %25

11:                                               ; preds = %6
  %12 = load i32, ptr %4, align 4, !tbaa !5
  %13 = sext i32 %12 to i64
  %14 = getelementptr inbounds [35 x i32], ptr @a, i64 0, i64 %13
  %15 = load i32, ptr %14, align 4, !tbaa !5
  %16 = call i32 @llvm.abs.i32(i32 %15, i1 true)
  %17 = load i32, ptr %3, align 4, !tbaa !5
  %18 = icmp eq i32 %16, %17
  br i1 %18, label %19, label %21

19:                                               ; preds = %11
  %20 = load i32, ptr %4, align 4, !tbaa !5
  store i32 %20, ptr %2, align 4
  store i32 1, ptr %5, align 4
  br label %25

21:                                               ; preds = %11
  br label %22

22:                                               ; preds = %21
  %23 = load i32, ptr %4, align 4, !tbaa !5
  %24 = add nsw i32 %23, 1
  store i32 %24, ptr %4, align 4, !tbaa !5
  br label %6, !llvm.loop !9

25:                                               ; preds = %19, %10
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #3
  %26 = load i32, ptr %5, align 4
  switch i32 %26, label %30 [
    i32 2, label %27
    i32 1, label %28
  ]

27:                                               ; preds = %25
  store i32 0, ptr %2, align 4
  br label %28

28:                                               ; preds = %27, %25
  %29 = load i32, ptr %2, align 4
  ret i32 %29

30:                                               ; preds = %25
  unreachable
}

; 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 speculatable willreturn memory(none)
declare i32 @llvm.abs.i32(i32, i1 immarg) #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 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 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
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
@a = external dso_local local_unnamed_addr global [35 x i32], align 16

; Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(read, argmem: none, inaccessiblemem: none) uwtable
define dso_local noundef i32 @_Z4findi(i32 noundef %0) local_unnamed_addr #0 {
  %2 = load i32, ptr @n, align 4, !tbaa !5
  %.not9 = icmp slt i32 %2, 1
  br i1 %.not9, label %._crit_edge, label %.lr.ph.preheader

.lr.ph.preheader:                                 ; preds = %1
  %3 = add nuw i32 %2, 1
  %wide.trip.count = zext i32 %3 to i64
  br label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph.preheader, %8
  %indvars.iv = phi i64 [ 1, %.lr.ph.preheader ], [ %indvars.iv.next, %8 ]
  %4 = getelementptr inbounds [35 x i32], ptr @a, i64 0, i64 %indvars.iv
  %5 = load i32, ptr %4, align 4, !tbaa !5
  %6 = tail call i32 @llvm.abs.i32(i32 %5, i1 true)
  %7 = icmp eq i32 %6, %0
  br i1 %7, label %._crit_edge.loopexit.split.loop.exit, label %8

8:                                                ; preds = %.lr.ph
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next, %wide.trip.count
  br i1 %exitcond.not, label %._crit_edge, label %.lr.ph, !llvm.loop !9

._crit_edge.loopexit.split.loop.exit:             ; preds = %.lr.ph
  %9 = trunc nuw nsw i64 %indvars.iv to i32
  br label %._crit_edge

._crit_edge:                                      ; preds = %8, %._crit_edge.loopexit.split.loop.exit, %1
  %spec.select = phi i32 [ 0, %1 ], [ %9, %._crit_edge.loopexit.split.loop.exit ], [ 0, %8 ]
  ret i32 %spec.select
}

; Function Attrs: mustprogress nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i32 @llvm.abs.i32(i32, i1 immarg) #1

attributes #0 = { mustprogress nofree norecurse 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" }
attributes #1 = { mustprogress nocallback nofree nosync nounwind speculatable willreturn memory(none) }

!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: CorrelatedValuePropagationPass,GlobalOptPass,IPSCCPPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LICMPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass