; LLVM IR from bartobri/data-structures-c :: pushdown-stack/array-no-dup-ignore-new (stack)

; 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"

@s = external hidden global ptr, align 8
@N = external hidden global i32, align 4

; Function Attrs: nounwind uwtable
define dso_local void @STACKpush(i32 noundef %0) #0 {
  %2 = alloca i32, align 4
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  store i32 %0, ptr %2, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #2
  store i32 0, ptr %3, align 4, !tbaa !5
  br label %5

5:                                                ; preds = %19, %1
  %6 = load i32, ptr %3, align 4, !tbaa !5
  %7 = load i32, ptr @N, align 4, !tbaa !5
  %8 = icmp slt i32 %6, %7
  br i1 %8, label %9, label %22

9:                                                ; preds = %5
  %10 = load ptr, ptr @s, align 8, !tbaa !9
  %11 = load i32, ptr %3, align 4, !tbaa !5
  %12 = sext i32 %11 to i64
  %13 = getelementptr inbounds i32, ptr %10, i64 %12
  %14 = load i32, ptr %13, align 4, !tbaa !5
  %15 = load i32, ptr %2, align 4, !tbaa !5
  %16 = icmp eq i32 %14, %15
  br i1 %16, label %17, label %18

17:                                               ; preds = %9
  store i32 1, ptr %4, align 4
  br label %29

18:                                               ; preds = %9
  br label %19

19:                                               ; preds = %18
  %20 = load i32, ptr %3, align 4, !tbaa !5
  %21 = add nsw i32 %20, 1
  store i32 %21, ptr %3, align 4, !tbaa !5
  br label %5, !llvm.loop !11

22:                                               ; preds = %5
  %23 = load i32, ptr %2, align 4, !tbaa !5
  %24 = load ptr, ptr @s, align 8, !tbaa !9
  %25 = load i32, ptr @N, align 4, !tbaa !5
  %26 = add nsw i32 %25, 1
  store i32 %26, ptr @N, align 4, !tbaa !5
  %27 = sext i32 %25 to i64
  %28 = getelementptr inbounds i32, ptr %24, i64 %27
  store i32 %23, ptr %28, align 4, !tbaa !5
  store i32 0, ptr %4, align 4
  br label %29

29:                                               ; preds = %22, %17
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #2
  %30 = load i32, ptr %4, align 4
  switch i32 %30, label %32 [
    i32 0, label %31
    i32 1, label %31
  ]

31:                                               ; preds = %29, %29
  ret void

32:                                               ; preds = %29
  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 willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

attributes #0 = { 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 = { 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/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"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"

@s = external hidden local_unnamed_addr global ptr, align 8
@N = external hidden local_unnamed_addr global i32, align 4

; Function Attrs: nofree norecurse nosync nounwind memory(readwrite, inaccessiblemem: none) uwtable
define dso_local void @STACKpush(i32 noundef %0) local_unnamed_addr #0 {
  %2 = load i32, ptr @N, align 4, !tbaa !5
  %3 = icmp sgt i32 %2, 0
  %.pre = load ptr, ptr @s, align 8, !tbaa !9
  br i1 %3, label %.lr.ph, label %._crit_edge

.lr.ph:                                           ; preds = %1
  %wide.trip.count = zext nneg i32 %2 to i64
  br label %5

4:                                                ; preds = %5
  %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 %5, !llvm.loop !11

5:                                                ; preds = %.lr.ph, %4
  %indvars.iv = phi i64 [ 0, %.lr.ph ], [ %indvars.iv.next, %4 ]
  %6 = getelementptr inbounds i32, ptr %.pre, i64 %indvars.iv
  %7 = load i32, ptr %6, align 4, !tbaa !5
  %8 = icmp eq i32 %7, %0
  br i1 %8, label %.loopexit, label %4

._crit_edge:                                      ; preds = %4, %1
  %9 = add nsw i32 %2, 1
  store i32 %9, ptr @N, align 4, !tbaa !5
  %10 = sext i32 %2 to i64
  %11 = getelementptr inbounds i32, ptr %.pre, i64 %10
  store i32 %0, ptr %11, align 4, !tbaa !5
  br label %.loopexit

.loopexit:                                        ; preds = %5, %._crit_edge
  ret void
}

attributes #0 = { nofree norecurse nosync nounwind memory(readwrite, 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/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: EarlyCSEPass,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LCSSAPass,LICMPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass