; LLVM IR from JessonYue/LeetCodeLearning :: Array/wuchao/other/9-5 dns解析 (DnsParser)

; 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.Header = type { i16, i16, i16, i16, i16, i16 }

; Function Attrs: nounwind uwtable
define dso_local void @buildHeader(ptr noundef %0) #0 {
  %2 = alloca ptr, align 8
  %3 = alloca %struct.Header, align 2
  %4 = alloca ptr, align 8
  store ptr %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 12, ptr %3) #6
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #6
  store ptr %3, ptr %4, align 8, !tbaa !5
  %5 = load ptr, ptr %4, align 8, !tbaa !5
  call void @llvm.memset.p0.i64(ptr align 2 %5, i8 0, i64 12, i1 false)
  %6 = call i32 @getpid() #6
  %7 = trunc i32 %6 to i16
  %8 = call zeroext i16 @__bswap_16(i16 noundef zeroext %7)
  %9 = load ptr, ptr %4, align 8, !tbaa !5
  %10 = getelementptr inbounds %struct.Header, ptr %9, i32 0, i32 0
  store i16 %8, ptr %10, align 2, !tbaa !9
  %11 = load ptr, ptr %4, align 8, !tbaa !5
  %12 = getelementptr inbounds %struct.Header, ptr %11, i32 0, i32 1
  %13 = load i16, ptr %12, align 2
  %14 = and i16 %13, -2
  %15 = or i16 %14, 0
  store i16 %15, ptr %12, align 2
  %16 = call zeroext i16 @__bswap_16(i16 noundef zeroext 1)
  %17 = load ptr, ptr %4, align 8, !tbaa !5
  %18 = getelementptr inbounds %struct.Header, ptr %17, i32 0, i32 2
  store i16 %16, ptr %18, align 2, !tbaa !12
  %19 = load ptr, ptr %2, align 8, !tbaa !5
  %20 = load ptr, ptr %4, align 8, !tbaa !5
  call void @llvm.memcpy.p0.p0.i64(ptr align 1 %19, ptr align 2 %20, i64 12, i1 false)
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #6
  call void @llvm.lifetime.end.p0(i64 12, ptr %3) #6
  ret void
}

; 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 nounwind willreturn memory(argmem: write)
declare void @llvm.memset.p0.i64(ptr nocapture writeonly, i8, i64, i1 immarg) #2

; Function Attrs: inlinehint nounwind uwtable
declare hidden zeroext i16 @__bswap_16(i16 noundef zeroext) #3

; Function Attrs: nounwind
declare i32 @getpid() #4

; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
declare void @llvm.memcpy.p0.p0.i64(ptr noalias nocapture writeonly, ptr noalias nocapture readonly, i64, i1 immarg) #5

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

attributes #0 = { 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 = { nocallback nofree nounwind willreturn memory(argmem: write) }
attributes #3 = { inlinehint 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 #4 = { nounwind "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 #5 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
attributes #6 = { 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, !11, i64 0}
!10 = !{!"Header", !11, i64 0, !11, i64 2, !11, i64 2, !11, i64 2, !11, i64 2, !11, i64 2, !11, i64 3, !11, i64 3, !11, i64 3, !11, i64 4, !11, i64 6, !11, i64 8, !11, i64 10}
!11 = !{!"short", !7, i64 0}
!12 = !{!10, !11, i64 4}


; 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: nounwind uwtable
define dso_local void @buildHeader(ptr nocapture noundef writeonly %0) local_unnamed_addr #0 {
  %2 = tail call i32 @getpid() #4
  %3 = trunc i32 %2 to i16
  %4 = tail call zeroext i16 @__bswap_16(i16 noundef zeroext %3)
  %5 = tail call zeroext i16 @__bswap_16(i16 noundef zeroext 1)
  store i16 %4, ptr %0, align 1
  %.sroa.5.0..sroa_idx = getelementptr inbounds i8, ptr %0, i64 2
  store i16 0, ptr %.sroa.5.0..sroa_idx, align 1
  %.sroa.7.0..sroa_idx = getelementptr inbounds i8, ptr %0, i64 4
  store i16 %5, ptr %.sroa.7.0..sroa_idx, align 1
  %.sroa.8.0..sroa_idx = getelementptr inbounds i8, ptr %0, i64 6
  tail call void @llvm.memset.p0.i64(ptr noundef nonnull align 1 dereferenceable(6) %.sroa.8.0..sroa_idx, i8 0, i64 6, i1 false)
  ret void
}

; Function Attrs: mustprogress nocallback nofree nounwind willreturn memory(argmem: write)
declare void @llvm.memset.p0.i64(ptr nocapture writeonly, i8, i64, i1 immarg) #1

; Function Attrs: inlinehint nounwind uwtable
declare hidden zeroext i16 @__bswap_16(i16 noundef zeroext) local_unnamed_addr #2

; Function Attrs: nounwind
declare i32 @getpid() local_unnamed_addr #3

attributes #0 = { 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 nocallback nofree nounwind willreturn memory(argmem: write) }
attributes #2 = { inlinehint 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 "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 #4 = { 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)"}


; Effective O3 passes: CorrelatedValuePropagationPass,DSEPass,EarlyCSEPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,MemCpyOptPass,PostOrderFunctionAttrsPass,SROAPass,TailCallElimPass