; LLVM IR from af-jk/rtos :: src (sync)

; 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.stos_mutex = type { i32 }

; Function Attrs: naked noinline nounwind uwtable
declare dso_local i32 @__stos_check_lock(ptr noundef) #0

; Function Attrs: naked noinline nounwind uwtable
declare dso_local i32 @__stos_write_to_lock(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 @STOS_SemWait(ptr noundef %0) #2 {
  %2 = alloca ptr, align 8
  %3 = alloca i32, align 4
  store ptr %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #3
  br label %4

4:                                                ; preds = %8, %1
  %5 = load ptr, ptr %2, align 8, !tbaa !5
  %6 = call i32 @__stos_check_lock(ptr noundef %5)
  store i32 %6, ptr %3, align 4, !tbaa !9
  %7 = icmp eq i32 %6, 0
  br i1 %7, label %8, label %9

8:                                                ; preds = %4
  br label %4, !llvm.loop !11

9:                                                ; preds = %4
  %10 = load i32, ptr %3, align 4, !tbaa !9
  %11 = sub i32 %10, 1
  %12 = load ptr, ptr %2, align 8, !tbaa !5
  %13 = getelementptr inbounds %struct.stos_mutex, ptr %12, i32 0, i32 0
  %14 = call i32 @__stos_write_to_lock(i32 noundef %11, ptr noundef %13)
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #3
  ret void
}

attributes #0 = { naked noinline 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 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 #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/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !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"

; Function Attrs: naked noinline nounwind uwtable
declare dso_local i32 @__stos_check_lock(ptr noundef) #0

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

; Function Attrs: nounwind uwtable
define dso_local void @STOS_SemWait(ptr noundef %0) local_unnamed_addr #1 {
  br label %2

2:                                                ; preds = %2, %1
  %3 = tail call i32 @__stos_check_lock(ptr noundef %0)
  %4 = icmp eq i32 %3, 0
  br i1 %4, label %2, label %5, !llvm.loop !5

5:                                                ; preds = %2
  %6 = add i32 %3, -1
  %7 = tail call i32 @__stos_write_to_lock(i32 noundef %6, ptr noundef %0)
  ret void
}

attributes #0 = { naked noinline 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 = { 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 = distinct !{!5, !6}
!6 = !{!"llvm.loop.mustprogress"}


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