; LLVM IR from artagnon/phoenixfs :: btree (enqueue)

; 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.node = type { ptr, ptr, ptr, i8, i16, ptr }

@queue = external dso_local global ptr, align 8

; Function Attrs: nounwind uwtable
define dso_local void @enqueue(ptr noundef %0) #0 {
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  store ptr %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #2
  %4 = load ptr, ptr @queue, align 8, !tbaa !5
  %5 = icmp eq ptr %4, null
  br i1 %5, label %6, label %10

6:                                                ; preds = %1
  %7 = load ptr, ptr %2, align 8, !tbaa !5
  store ptr %7, ptr @queue, align 8, !tbaa !5
  %8 = load ptr, ptr @queue, align 8, !tbaa !5
  %9 = getelementptr inbounds %struct.node, ptr %8, i32 0, i32 5
  store ptr null, ptr %9, align 8, !tbaa !9
  br label %27

10:                                               ; preds = %1
  %11 = load ptr, ptr @queue, align 8, !tbaa !5
  store ptr %11, ptr %3, align 8, !tbaa !5
  br label %12

12:                                               ; preds = %17, %10
  %13 = load ptr, ptr %3, align 8, !tbaa !5
  %14 = getelementptr inbounds %struct.node, ptr %13, i32 0, i32 5
  %15 = load ptr, ptr %14, align 8, !tbaa !9
  %16 = icmp ne ptr %15, null
  br i1 %16, label %17, label %21

17:                                               ; preds = %12
  %18 = load ptr, ptr %3, align 8, !tbaa !5
  %19 = getelementptr inbounds %struct.node, ptr %18, i32 0, i32 5
  %20 = load ptr, ptr %19, align 8, !tbaa !9
  store ptr %20, ptr %3, align 8, !tbaa !5
  br label %12, !llvm.loop !13

21:                                               ; preds = %12
  %22 = load ptr, ptr %2, align 8, !tbaa !5
  %23 = load ptr, ptr %3, align 8, !tbaa !5
  %24 = getelementptr inbounds %struct.node, ptr %23, i32 0, i32 5
  store ptr %22, ptr %24, align 8, !tbaa !9
  %25 = load ptr, ptr %2, align 8, !tbaa !5
  %26 = getelementptr inbounds %struct.node, ptr %25, i32 0, i32 5
  store ptr null, ptr %26, align 8, !tbaa !9
  br label %27

27:                                               ; preds = %21, %6
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #2
  ret void
}

; 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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !6, i64 32}
!10 = !{!"node", !6, i64 0, !6, i64 8, !6, i64 16, !11, i64 24, !12, i64 26, !6, i64 32}
!11 = !{!"_Bool", !7, i64 0}
!12 = !{!"short", !7, i64 0}
!13 = distinct !{!13, !14}
!14 = !{!"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"

@queue = external dso_local local_unnamed_addr global ptr, align 8

; Function Attrs: nofree norecurse nosync nounwind memory(readwrite, inaccessiblemem: none) uwtable
define dso_local void @enqueue(ptr noundef %0) local_unnamed_addr #0 {
  %2 = load ptr, ptr @queue, align 8, !tbaa !5
  %3 = icmp eq ptr %2, null
  br i1 %3, label %8, label %.preheader

.preheader:                                       ; preds = %1, %.preheader
  %.0 = phi ptr [ %5, %.preheader ], [ %2, %1 ]
  %4 = getelementptr inbounds i8, ptr %.0, i64 32
  %5 = load ptr, ptr %4, align 8, !tbaa !9
  %.not = icmp eq ptr %5, null
  br i1 %.not, label %6, label %.preheader, !llvm.loop !13

6:                                                ; preds = %.preheader
  %7 = getelementptr inbounds i8, ptr %.0, i64 32
  br label %8

8:                                                ; preds = %1, %6
  %.sink = phi ptr [ %7, %6 ], [ @queue, %1 ]
  store ptr %0, ptr %.sink, align 8, !tbaa !5
  %9 = getelementptr inbounds i8, ptr %0, i64 32
  store ptr null, ptr %9, align 8, !tbaa !9
  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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !6, i64 32}
!10 = !{!"node", !6, i64 0, !6, i64 8, !6, i64 16, !11, i64 24, !12, i64 26, !6, i64 32}
!11 = !{!"_Bool", !7, i64 0}
!12 = !{!"short", !7, i64 0}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}


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