; LLVM IR from nonstriater/Learn-Algorithms :: 4 Tree/1-二叉树 /btree (bintree)

; 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.Queue = type { ptr, ptr, i32 }
%struct.QNode = type { ptr, 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 @getHead(ptr noundef %0, ptr noundef %1) #1 {
  %3 = alloca i32, align 4
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca ptr, align 8
  %7 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store ptr %1, ptr %5, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #2
  %8 = load ptr, ptr %4, align 8, !tbaa !5
  %9 = getelementptr inbounds %struct.Queue, ptr %8, i32 0, i32 0
  %10 = load ptr, ptr %9, align 8, !tbaa !9
  %11 = getelementptr inbounds %struct.QNode, ptr %10, i32 0, i32 0
  %12 = load ptr, ptr %11, align 8, !tbaa !12
  store ptr %12, ptr %6, align 8, !tbaa !5
  %13 = load ptr, ptr %6, align 8, !tbaa !5
  %14 = icmp ne ptr %13, null
  br i1 %14, label %17, label %15

15:                                               ; preds = %2
  %16 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr null, ptr %16, align 8, !tbaa !5
  store i32 0, ptr %3, align 4
  store i32 1, ptr %7, align 4
  br label %22

17:                                               ; preds = %2
  %18 = load ptr, ptr %6, align 8, !tbaa !5
  %19 = getelementptr inbounds %struct.QNode, ptr %18, i32 0, i32 1
  %20 = load ptr, ptr %19, align 8, !tbaa !14
  %21 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %20, ptr %21, align 8, !tbaa !5
  store i32 1, ptr %3, align 4
  store i32 1, ptr %7, align 4
  br label %22

22:                                               ; preds = %17, %15
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #2
  %23 = load i32, ptr %3, align 4
  ret i32 %23
}

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, !6, i64 0}
!10 = !{!"", !6, i64 0, !6, i64 8, !11, i64 16}
!11 = !{!"int", !7, i64 0}
!12 = !{!13, !6, i64 0}
!13 = !{!"QNode", !6, i64 0, !6, i64 8}
!14 = !{!13, !6, i64 8}


; 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(read, argmem: readwrite, inaccessiblemem: none) uwtable
define dso_local range(i32 0, 2) i32 @getHead(ptr nocapture noundef readonly %0, ptr nocapture noundef writeonly %1) local_unnamed_addr #0 {
  %3 = load ptr, ptr %0, align 8, !tbaa !5
  %4 = load ptr, ptr %3, align 8, !tbaa !11
  %.not = icmp eq ptr %4, null
  br i1 %.not, label %8, label %5

5:                                                ; preds = %2
  %6 = getelementptr inbounds i8, ptr %4, i64 8
  %7 = load ptr, ptr %6, align 8, !tbaa !13
  br label %8

8:                                                ; preds = %2, %5
  %storemerge = phi ptr [ %7, %5 ], [ null, %2 ]
  %.0 = phi i32 [ 1, %5 ], [ 0, %2 ]
  store ptr %storemerge, ptr %1, align 8, !tbaa !14
  ret i32 %.0
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(read, argmem: readwrite, inaccessiblemem: 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)"}
!5 = !{!6, !7, i64 0}
!6 = !{!"", !7, i64 0, !7, i64 8, !10, i64 16}
!7 = !{!"any pointer", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C/C++ TBAA"}
!10 = !{!"int", !8, i64 0}
!11 = !{!12, !7, i64 0}
!12 = !{!"QNode", !7, i64 0, !7, i64 8}
!13 = !{!12, !7, i64 8}
!14 = !{!7, !7, i64 0}


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