; LLVM IR from IOsonata/IOsonata :: src (cfifo)

; 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.__CFIFO_Header = type <{ i32, i32, i32, i8, [3 x i8], i32, i32, i32, ptr }>

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: nounwind uwtable
define dso_local i32 @CFifoAvail(ptr noundef %0) #1 {
  %2 = alloca i32, align 4
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #2
  store i32 0, ptr %4, align 4, !tbaa !9
  %6 = load ptr, ptr %3, align 8, !tbaa !5
  %7 = getelementptr inbounds %struct.__CFIFO_Header, ptr %6, i32 0, i32 1
  %8 = load volatile i32, ptr %7, align 4, !tbaa !11
  %9 = icmp slt i32 %8, 0
  br i1 %9, label %10, label %14

10:                                               ; preds = %1
  %11 = load ptr, ptr %3, align 8, !tbaa !5
  %12 = getelementptr inbounds %struct.__CFIFO_Header, ptr %11, i32 0, i32 2
  %13 = load i32, ptr %12, align 4, !tbaa !14
  store i32 %13, ptr %2, align 4
  store i32 1, ptr %5, align 4
  br label %53

14:                                               ; preds = %1
  %15 = load ptr, ptr %3, align 8, !tbaa !5
  %16 = getelementptr inbounds %struct.__CFIFO_Header, ptr %15, i32 0, i32 0
  %17 = load volatile i32, ptr %16, align 4, !tbaa !15
  %18 = load ptr, ptr %3, align 8, !tbaa !5
  %19 = getelementptr inbounds %struct.__CFIFO_Header, ptr %18, i32 0, i32 1
  %20 = load volatile i32, ptr %19, align 4, !tbaa !11
  %21 = icmp sgt i32 %17, %20
  br i1 %21, label %22, label %34

22:                                               ; preds = %14
  %23 = load ptr, ptr %3, align 8, !tbaa !5
  %24 = getelementptr inbounds %struct.__CFIFO_Header, ptr %23, i32 0, i32 2
  %25 = load i32, ptr %24, align 4, !tbaa !14
  %26 = load ptr, ptr %3, align 8, !tbaa !5
  %27 = getelementptr inbounds %struct.__CFIFO_Header, ptr %26, i32 0, i32 0
  %28 = load volatile i32, ptr %27, align 4, !tbaa !15
  %29 = sub nsw i32 %25, %28
  %30 = load ptr, ptr %3, align 8, !tbaa !5
  %31 = getelementptr inbounds %struct.__CFIFO_Header, ptr %30, i32 0, i32 1
  %32 = load volatile i32, ptr %31, align 4, !tbaa !11
  %33 = add nsw i32 %29, %32
  store i32 %33, ptr %4, align 4, !tbaa !9
  br label %51

34:                                               ; preds = %14
  %35 = load ptr, ptr %3, align 8, !tbaa !5
  %36 = getelementptr inbounds %struct.__CFIFO_Header, ptr %35, i32 0, i32 0
  %37 = load volatile i32, ptr %36, align 4, !tbaa !15
  %38 = load ptr, ptr %3, align 8, !tbaa !5
  %39 = getelementptr inbounds %struct.__CFIFO_Header, ptr %38, i32 0, i32 1
  %40 = load volatile i32, ptr %39, align 4, !tbaa !11
  %41 = icmp slt i32 %37, %40
  br i1 %41, label %42, label %50

42:                                               ; preds = %34
  %43 = load ptr, ptr %3, align 8, !tbaa !5
  %44 = getelementptr inbounds %struct.__CFIFO_Header, ptr %43, i32 0, i32 1
  %45 = load volatile i32, ptr %44, align 4, !tbaa !11
  %46 = load ptr, ptr %3, align 8, !tbaa !5
  %47 = getelementptr inbounds %struct.__CFIFO_Header, ptr %46, i32 0, i32 0
  %48 = load volatile i32, ptr %47, align 4, !tbaa !15
  %49 = sub nsw i32 %45, %48
  store i32 %49, ptr %4, align 4, !tbaa !9
  br label %50

50:                                               ; preds = %42, %34
  br label %51

51:                                               ; preds = %50, %22
  %52 = load i32, ptr %4, align 4, !tbaa !9
  store i32 %52, ptr %2, align 4
  store i32 1, ptr %5, align 4
  br label %53

53:                                               ; preds = %51, %10
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  %54 = load i32, ptr %2, align 4
  ret i32 %54
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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" }
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, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = !{!12, !10, i64 4}
!12 = !{!"__CFIFO_Header", !10, i64 0, !10, i64 4, !10, i64 8, !13, i64 12, !10, i64 16, !10, i64 20, !10, i64 24, !6, i64 28}
!13 = !{!"_Bool", !7, i64 0}
!14 = !{!12, !10, i64 8}
!15 = !{!12, !10, i64 0}


; 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 nofree norecurse nounwind willreturn memory(argmem: readwrite, inaccessiblemem: readwrite) uwtable
define dso_local i32 @CFifoAvail(ptr noundef %0) local_unnamed_addr #0 {
  %2 = getelementptr inbounds i8, ptr %0, i64 4
  %3 = load volatile i32, ptr %2, align 4, !tbaa !5
  %4 = icmp slt i32 %3, 0
  br i1 %4, label %5, label %8

5:                                                ; preds = %1
  %6 = getelementptr inbounds i8, ptr %0, i64 8
  %7 = load i32, ptr %6, align 4, !tbaa !12
  br label %27

8:                                                ; preds = %1
  %9 = load volatile i32, ptr %0, align 4, !tbaa !13
  %10 = load volatile i32, ptr %2, align 4, !tbaa !5
  %11 = icmp sgt i32 %9, %10
  br i1 %11, label %12, label %19

12:                                               ; preds = %8
  %13 = getelementptr inbounds i8, ptr %0, i64 8
  %14 = load i32, ptr %13, align 4, !tbaa !12
  %15 = load volatile i32, ptr %0, align 4, !tbaa !13
  %16 = sub i32 %14, %15
  %17 = load volatile i32, ptr %2, align 4, !tbaa !5
  %18 = add nsw i32 %16, %17
  br label %27

19:                                               ; preds = %8
  %20 = load volatile i32, ptr %0, align 4, !tbaa !13
  %21 = load volatile i32, ptr %2, align 4, !tbaa !5
  %22 = icmp slt i32 %20, %21
  br i1 %22, label %23, label %27

23:                                               ; preds = %19
  %24 = load volatile i32, ptr %2, align 4, !tbaa !5
  %25 = load volatile i32, ptr %0, align 4, !tbaa !13
  %26 = sub nsw i32 %24, %25
  br label %27

27:                                               ; preds = %12, %23, %19, %5
  %.012 = phi i32 [ %7, %5 ], [ %18, %12 ], [ %26, %23 ], [ 0, %19 ]
  ret i32 %.012
}

attributes #0 = { mustprogress nofree norecurse nounwind willreturn memory(argmem: readwrite, inaccessiblemem: readwrite) 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 4}
!6 = !{!"__CFIFO_Header", !7, i64 0, !7, i64 4, !7, i64 8, !10, i64 12, !7, i64 16, !7, i64 20, !7, i64 24, !11, i64 28}
!7 = !{!"int", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C/C++ TBAA"}
!10 = !{!"_Bool", !8, i64 0}
!11 = !{!"any pointer", !8, i64 0}
!12 = !{!6, !7, i64 8}
!13 = !{!6, !7, i64 0}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass