; LLVM IR from bartobri/data-structures-c :: pushdown-stack/linked-list-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"

%struct.STACKnode = type { i32, ptr }

@head = external hidden global ptr, align 8

; Function Attrs: nounwind uwtable
declare dso_local ptr @NEW(i32 noundef, ptr noundef) #0

; 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

; Function Attrs: nounwind uwtable
define dso_local void @STACKpush(i32 noundef %0) #0 {
  %2 = alloca i32, align 4
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  store i32 %0, ptr %2, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #2
  %5 = load ptr, ptr @head, align 8, !tbaa !9
  store ptr %5, ptr %3, align 8, !tbaa !9
  br label %6

6:                                                ; preds = %17, %1
  %7 = load ptr, ptr %3, align 8, !tbaa !9
  %8 = icmp ne ptr %7, null
  br i1 %8, label %9, label %21

9:                                                ; preds = %6
  %10 = load ptr, ptr %3, align 8, !tbaa !9
  %11 = getelementptr inbounds %struct.STACKnode, ptr %10, i32 0, i32 0
  %12 = load i32, ptr %11, align 8, !tbaa !11
  %13 = load i32, ptr %2, align 4, !tbaa !5
  %14 = icmp eq i32 %12, %13
  br i1 %14, label %15, label %16

15:                                               ; preds = %9
  store i32 1, ptr %4, align 4
  br label %25

16:                                               ; preds = %9
  br label %17

17:                                               ; preds = %16
  %18 = load ptr, ptr %3, align 8, !tbaa !9
  %19 = getelementptr inbounds %struct.STACKnode, ptr %18, i32 0, i32 1
  %20 = load ptr, ptr %19, align 8, !tbaa !13
  store ptr %20, ptr %3, align 8, !tbaa !9
  br label %6, !llvm.loop !14

21:                                               ; preds = %6
  %22 = load i32, ptr %2, align 4, !tbaa !5
  %23 = load ptr, ptr @head, align 8, !tbaa !9
  %24 = call ptr @NEW(i32 noundef %22, ptr noundef %23)
  store ptr %24, ptr @head, align 8, !tbaa !9
  store i32 0, ptr %4, align 4
  br label %25

25:                                               ; preds = %21, %15
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #2
  %26 = load i32, ptr %4, align 4
  switch i32 %26, label %28 [
    i32 0, label %27
    i32 1, label %27
  ]

27:                                               ; preds = %25, %25
  ret void

28:                                               ; preds = %25
  unreachable
}

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 = !{!12, !6, i64 0}
!12 = !{!"STACKnode", !6, i64 0, !10, i64 8}
!13 = !{!12, !10, i64 8}
!14 = distinct !{!14, !15}
!15 = !{!"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"

@head = external hidden local_unnamed_addr global ptr, align 8

; Function Attrs: nounwind uwtable
declare dso_local ptr @NEW(i32 noundef, ptr noundef) local_unnamed_addr #0

; Function Attrs: nounwind uwtable
define dso_local void @STACKpush(i32 noundef %0) local_unnamed_addr #0 {
  %.04 = load ptr, ptr @head, align 8, !tbaa !5
  %.not5 = icmp eq ptr %.04, null
  br i1 %.not5, label %._crit_edge, label %.lr.ph

2:                                                ; preds = %.lr.ph
  %3 = getelementptr inbounds i8, ptr %.06, i64 8
  %.0 = load ptr, ptr %3, align 8, !tbaa !5
  %.not = icmp eq ptr %.0, null
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !9

.lr.ph:                                           ; preds = %1, %2
  %.06 = phi ptr [ %.0, %2 ], [ %.04, %1 ]
  %4 = load i32, ptr %.06, align 8, !tbaa !11
  %5 = icmp eq i32 %4, %0
  br i1 %5, label %.loopexit, label %2

._crit_edge:                                      ; preds = %2, %1
  %6 = tail call ptr @NEW(i32 noundef %0, ptr noundef %.04)
  store ptr %6, ptr @head, align 8, !tbaa !5
  br label %.loopexit

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

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" }

!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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}
!11 = !{!12, !13, i64 0}
!12 = !{!"STACKnode", !13, i64 0, !6, i64 8}
!13 = !{!"int", !7, i64 0}


; Effective O3 passes: EarlyCSEPass,GVNPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,SROAPass,SimplifyCFGPass,TailCallElimPass