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

; 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.EFI_IPv4_ADDRESS = type { [4 x i8] }

; 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 i8 @IScsiGetSubnetMaskPrefixLength(ptr noundef %0) #1 {
  %2 = alloca i8, align 1
  %3 = alloca ptr, align 8
  %4 = alloca i8, align 1
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 1, ptr %4) #2
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #2
  %7 = load ptr, ptr %3, align 8, !tbaa !5
  %8 = getelementptr inbounds %struct.EFI_IPv4_ADDRESS, ptr %7, i32 0, i32 0
  %9 = getelementptr inbounds [4 x i8], ptr %8, i64 0, i64 0
  %10 = load i8, ptr %9, align 1, !tbaa !9
  %11 = zext i8 %10 to i32
  %12 = shl i32 %11, 24
  %13 = load ptr, ptr %3, align 8, !tbaa !5
  %14 = getelementptr inbounds %struct.EFI_IPv4_ADDRESS, ptr %13, i32 0, i32 0
  %15 = getelementptr inbounds [4 x i8], ptr %14, i64 0, i64 1
  %16 = load i8, ptr %15, align 1, !tbaa !9
  %17 = zext i8 %16 to i32
  %18 = shl i32 %17, 16
  %19 = or i32 %12, %18
  %20 = load ptr, ptr %3, align 8, !tbaa !5
  %21 = getelementptr inbounds %struct.EFI_IPv4_ADDRESS, ptr %20, i32 0, i32 0
  %22 = getelementptr inbounds [4 x i8], ptr %21, i64 0, i64 2
  %23 = load i8, ptr %22, align 1, !tbaa !9
  %24 = zext i8 %23 to i32
  %25 = shl i32 %24, 8
  %26 = or i32 %19, %25
  %27 = load ptr, ptr %3, align 8, !tbaa !5
  %28 = getelementptr inbounds %struct.EFI_IPv4_ADDRESS, ptr %27, i32 0, i32 0
  %29 = getelementptr inbounds [4 x i8], ptr %28, i64 0, i64 3
  %30 = load i8, ptr %29, align 1, !tbaa !9
  %31 = zext i8 %30 to i32
  %32 = or i32 %26, %31
  store i32 %32, ptr %5, align 4, !tbaa !10
  %33 = load i32, ptr %5, align 4, !tbaa !10
  %34 = xor i32 %33, -1
  store i32 %34, ptr %5, align 4, !tbaa !10
  %35 = load i32, ptr %5, align 4, !tbaa !10
  %36 = load i32, ptr %5, align 4, !tbaa !10
  %37 = add i32 %36, 1
  %38 = and i32 %35, %37
  %39 = icmp ne i32 %38, 0
  br i1 %39, label %40, label %41

40:                                               ; preds = %1
  store i8 0, ptr %2, align 1
  store i32 1, ptr %6, align 4
  br label %55

41:                                               ; preds = %1
  store i8 0, ptr %4, align 1, !tbaa !9
  br label %42

42:                                               ; preds = %45, %41
  %43 = load i32, ptr %5, align 4, !tbaa !10
  %44 = icmp ne i32 %43, 0
  br i1 %44, label %45, label %50

45:                                               ; preds = %42
  %46 = load i32, ptr %5, align 4, !tbaa !10
  %47 = lshr i32 %46, 1
  store i32 %47, ptr %5, align 4, !tbaa !10
  %48 = load i8, ptr %4, align 1, !tbaa !9
  %49 = add i8 %48, 1
  store i8 %49, ptr %4, align 1, !tbaa !9
  br label %42, !llvm.loop !12

50:                                               ; preds = %42
  %51 = load i8, ptr %4, align 1, !tbaa !9
  %52 = zext i8 %51 to i32
  %53 = sub nsw i32 32, %52
  %54 = trunc i32 %53 to i8
  store i8 %54, ptr %2, align 1
  store i32 1, ptr %6, align 4
  br label %55

55:                                               ; preds = %50, %40
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  call void @llvm.lifetime.end.p0(i64 1, ptr %4) #2
  %56 = load i8, ptr %2, align 1
  ret i8 %56
}

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 = !{!7, !7, i64 0}
!10 = !{!11, !11, i64 0}
!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: nofree norecurse nosync nounwind memory(argmem: read) uwtable
define dso_local zeroext i8 @IScsiGetSubnetMaskPrefixLength(ptr nocapture noundef readonly %0) local_unnamed_addr #0 {
  %2 = load i8, ptr %0, align 1, !tbaa !5
  %3 = zext i8 %2 to i32
  %4 = shl nuw i32 %3, 24
  %5 = getelementptr inbounds i8, ptr %0, i64 1
  %6 = load i8, ptr %5, align 1, !tbaa !5
  %7 = zext i8 %6 to i32
  %8 = shl nuw nsw i32 %7, 16
  %9 = or disjoint i32 %8, %4
  %10 = getelementptr inbounds i8, ptr %0, i64 2
  %11 = load i8, ptr %10, align 1, !tbaa !5
  %12 = zext i8 %11 to i32
  %13 = shl nuw nsw i32 %12, 8
  %14 = or disjoint i32 %9, %13
  %15 = getelementptr inbounds i8, ptr %0, i64 3
  %16 = load i8, ptr %15, align 1, !tbaa !5
  %17 = zext i8 %16 to i32
  %18 = or disjoint i32 %14, %17
  %19 = add i32 %18, -1
  %20 = or i32 %19, %18
  %.not = icmp eq i32 %20, -1
  br i1 %.not, label %21, label %._crit_edge

21:                                               ; preds = %1
  %.not1314 = icmp eq i32 %18, -1
  br i1 %.not1314, label %._crit_edge, label %.lr.ph.preheader

.lr.ph.preheader:                                 ; preds = %21
  %22 = xor i32 %18, -1
  br label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph.preheader, %.lr.ph
  %.016 = phi i32 [ %23, %.lr.ph ], [ %22, %.lr.ph.preheader ]
  %.01115 = phi i8 [ %24, %.lr.ph ], [ 0, %.lr.ph.preheader ]
  %23 = lshr i32 %.016, 1
  %24 = add nuw nsw i8 %.01115, 1
  %.not13 = icmp ult i32 %.016, 2
  br i1 %.not13, label %._crit_edge.loopexit, label %.lr.ph, !llvm.loop !8

._crit_edge.loopexit:                             ; preds = %.lr.ph
  %25 = sub nsw i8 31, %.01115
  br label %._crit_edge

._crit_edge:                                      ; preds = %21, %._crit_edge.loopexit, %1
  %.012 = phi i8 [ 0, %1 ], [ 32, %21 ], [ %25, %._crit_edge.loopexit ]
  ret i8 %.012
}

attributes #0 = { nofree norecurse nosync nounwind memory(argmem: read) 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 = !{!"omnipotent char", !7, i64 0}
!7 = !{!"Simple C/C++ TBAA"}
!8 = distinct !{!8, !9}
!9 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: EarlyCSEPass,GVNPass,GlobalOptPass,IPSCCPPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass