; LLVM IR from sunkafei/xcpc-algorithm-templates :: 算法/数据结构/link-cut-tree（指针）.ll (Z7getrootP4node)

; 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.node = type { ptr, [2 x ptr], i32, i32, i32, i32 }

@nil = external dso_local global ptr, align 8

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_Z8pushdownP4node(ptr noundef) #0

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z5splayP4node(ptr noundef) #1

; Function Attrs: mustprogress uwtable
declare dso_local noundef ptr @_Z6accessP4node(ptr noundef) #1

; Function Attrs: mustprogress uwtable
define dso_local noundef ptr @_Z7getrootP4node(ptr noundef %0) #1 {
  %2 = alloca ptr, align 8
  store ptr %0, ptr %2, align 8, !tbaa !5
  %3 = load ptr, ptr %2, align 8, !tbaa !5
  %4 = call noundef ptr @_Z6accessP4node(ptr noundef %3)
  %5 = load ptr, ptr %2, align 8, !tbaa !5
  call void @_Z5splayP4node(ptr noundef %5)
  br label %6

6:                                                ; preds = %14, %1
  %7 = load ptr, ptr %2, align 8, !tbaa !5
  call void @_Z8pushdownP4node(ptr noundef %7)
  %8 = load ptr, ptr %2, align 8, !tbaa !5
  %9 = getelementptr inbounds %struct.node, ptr %8, i32 0, i32 1
  %10 = getelementptr inbounds [2 x ptr], ptr %9, i64 0, i64 0
  %11 = load ptr, ptr %10, align 8, !tbaa !5
  %12 = load ptr, ptr @nil, align 8, !tbaa !5
  %13 = icmp ne ptr %11, %12
  br i1 %13, label %14, label %19

14:                                               ; preds = %6
  %15 = load ptr, ptr %2, align 8, !tbaa !5
  %16 = getelementptr inbounds %struct.node, ptr %15, i32 0, i32 1
  %17 = getelementptr inbounds [2 x ptr], ptr %16, i64 0, i64 0
  %18 = load ptr, ptr %17, align 8, !tbaa !5
  store ptr %18, ptr %2, align 8, !tbaa !5
  br label %6, !llvm.loop !9

19:                                               ; preds = %6
  %20 = load ptr, ptr %2, align 8, !tbaa !5
  call void @_Z5splayP4node(ptr noundef %20)
  %21 = load ptr, ptr %2, align 8, !tbaa !5
  ret ptr %21
}

attributes #0 = { mustprogress 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 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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"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"

@nil = external dso_local local_unnamed_addr global ptr, align 8

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_Z8pushdownP4node(ptr noundef) local_unnamed_addr #0

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z5splayP4node(ptr noundef) local_unnamed_addr #1

; Function Attrs: mustprogress uwtable
declare dso_local noundef ptr @_Z6accessP4node(ptr noundef) local_unnamed_addr #1

; Function Attrs: mustprogress uwtable
define dso_local noundef ptr @_Z7getrootP4node(ptr noundef %0) local_unnamed_addr #1 {
  %2 = tail call noundef ptr @_Z6accessP4node(ptr noundef %0)
  tail call void @_Z5splayP4node(ptr noundef %0)
  br label %3

3:                                                ; preds = %3, %1
  %.0 = phi ptr [ %0, %1 ], [ %5, %3 ]
  tail call void @_Z8pushdownP4node(ptr noundef %.0)
  %4 = getelementptr inbounds i8, ptr %.0, i64 8
  %5 = load ptr, ptr %4, align 8, !tbaa !5
  %6 = load ptr, ptr @nil, align 8, !tbaa !5
  %.not = icmp eq ptr %5, %6
  br i1 %.not, label %7, label %3, !llvm.loop !9

7:                                                ; preds = %3
  tail call void @_Z5splayP4node(ptr noundef nonnull %.0)
  ret ptr %.0
}

attributes #0 = { mustprogress 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 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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: CorrelatedValuePropagationPass,EarlyCSEPass,GVNPass,GlobalOptPass,InstCombinePass,InstSimplifyPass,LCSSAPass,LoopUnrollPass,SROAPass,SimplifyCFGPass,TailCallElimPass