; LLVM IR from sfu-dis/mosaicdb :: dbcore/mcs_lock.ll (ZN8mcs_lock12spin_on_nextEPNS_5qnodeE)

; 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.mcs_lock::qnode" = type { ptr, i32, i32 }

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef ptr @_ZN8mcs_lock5qnode5vthisEv(ptr noundef nonnull align 8 dereferenceable(16)) #0 align 2

; Function Attrs: mustprogress uwtable
define dso_local noundef ptr @_ZN8mcs_lock12spin_on_nextEPNS_5qnodeE(ptr noundef nonnull align 8 dereferenceable(8) %0, ptr noundef %1) #1 align 2 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  store ptr %0, ptr %3, align 8, !tbaa !5
  store ptr %1, ptr %4, align 8, !tbaa !5
  %6 = load ptr, ptr %3, align 8
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #3
  br label %7

7:                                                ; preds = %14, %2
  %8 = load ptr, ptr %4, align 8, !tbaa !5
  %9 = call noundef ptr @_ZN8mcs_lock5qnode5vthisEv(ptr noundef nonnull align 8 dereferenceable(16) %8)
  %10 = getelementptr inbounds %"struct.mcs_lock::qnode", ptr %9, i32 0, i32 0
  %11 = load volatile ptr, ptr %10, align 8, !tbaa !9
  store ptr %11, ptr %5, align 8, !tbaa !5
  %12 = icmp ne ptr %11, null
  %13 = xor i1 %12, true
  br i1 %13, label %14, label %15

14:                                               ; preds = %7
  br label %7, !llvm.loop !12

15:                                               ; preds = %7
  %16 = load ptr, ptr %5, align 8, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #3
  ret ptr %16
}

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #2

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 = { 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" }
attributes #2 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!10, !6, i64 0}
!10 = !{!"_ZTSN8mcs_lock5qnodeE", !6, i64 0, !11, i64 8, !11, i64 12}
!11 = !{!"int", !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"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"

; Function Attrs: mustprogress nounwind uwtable
declare dso_local noundef ptr @_ZN8mcs_lock5qnode5vthisEv(ptr noundef nonnull align 8 dereferenceable(16)) local_unnamed_addr #0 align 2

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef ptr @_ZN8mcs_lock12spin_on_nextEPNS_5qnodeE(ptr nocapture noundef nonnull readnone align 8 dereferenceable(8) %0, ptr noundef %1) local_unnamed_addr #0 align 2 {
  br label %3

3:                                                ; preds = %3, %2
  %4 = tail call noundef ptr @_ZN8mcs_lock5qnode5vthisEv(ptr noundef nonnull align 8 dereferenceable(16) %1)
  %5 = load volatile ptr, ptr %4, align 8, !tbaa !5
  %.not = icmp eq ptr %5, null
  br i1 %.not, label %3, label %6, !llvm.loop !11

6:                                                ; preds = %3
  ret ptr %5
}

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" }

!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, !7, i64 0}
!6 = !{!"_ZTSN8mcs_lock5qnodeE", !7, i64 0, !10, i64 8, !10, i64 12}
!7 = !{!"any pointer", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C++ TBAA"}
!10 = !{!"int", !8, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}


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