; LLVM IR from thalium/icebox :: third_party/virtualbox/src/VBox/Devices/EFI/Firmware/MdeModulePkg/Library (NetAddChecksum)

; 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"

; 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 zeroext i16 @NetAddChecksum(i16 noundef zeroext %0, i16 noundef zeroext %1) #1 {
  %3 = alloca i16, align 2
  %4 = alloca i16, align 2
  %5 = alloca i32, align 4
  store i16 %0, ptr %3, align 2, !tbaa !5
  store i16 %1, ptr %4, align 2, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #2
  %6 = load i16, ptr %3, align 2, !tbaa !5
  %7 = zext i16 %6 to i32
  %8 = load i16, ptr %4, align 2, !tbaa !5
  %9 = zext i16 %8 to i32
  %10 = add nsw i32 %7, %9
  store i32 %10, ptr %5, align 4, !tbaa !9
  %11 = load i32, ptr %5, align 4, !tbaa !9
  %12 = lshr i32 %11, 16
  %13 = icmp ne i32 %12, 0
  br i1 %13, label %14, label %18

14:                                               ; preds = %2
  %15 = load i32, ptr %5, align 4, !tbaa !9
  %16 = and i32 %15, 65535
  %17 = add i32 %16, 1
  store i32 %17, ptr %5, align 4, !tbaa !9
  br label %18

18:                                               ; preds = %14, %2
  %19 = load i32, ptr %5, align 4, !tbaa !9
  %20 = trunc i32 %19 to i16
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  ret i16 %20
}

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 = !{!"short", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !7, 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 nosync nounwind willreturn memory(none) uwtable
define dso_local zeroext i16 @NetAddChecksum(i16 noundef zeroext %0, i16 noundef zeroext %1) local_unnamed_addr #0 {
  %3 = zext i16 %0 to i32
  %4 = zext i16 %1 to i32
  %5 = add nuw nsw i32 %4, %3
  %.not = icmp ugt i32 %5, 65535
  %6 = zext i1 %.not to i32
  %.0 = add nuw nsw i32 %5, %6
  %7 = trunc i32 %.0 to i16
  ret i16 %7
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(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)"}


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