; LLVM IR from sunkafei/xcpc-algorithm-templates :: 算法/数据结构/TopTree.ll (Z8findrootP4node)

; 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 <{ [4 x ptr], ptr, %struct.info, %struct.info, %struct.info, %struct.info, %struct.mark, %struct.mark, i8, i8, [6 x i8] }>
%struct.info = type { i32, i32, i32, i32 }
%struct.mark = type { i32, i32 }

@null = external dso_local global ptr, align 8

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZN4node4downEv(ptr noundef nonnull align 8 dereferenceable(122)) #0 align 2

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z5splayP4nodei(ptr noundef, i32 noundef) #0

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z5touchP4node(ptr noundef) #0

; Function Attrs: mustprogress uwtable
define dso_local noundef ptr @_Z8findrootP4node(ptr noundef %0) #0 {
  %2 = alloca ptr, align 8
  store ptr %0, ptr %2, align 8, !tbaa !5
  %3 = load ptr, ptr %2, align 8, !tbaa !5
  call void @_Z5touchP4node(ptr noundef %3)
  br label %4

4:                                                ; preds = %11, %1
  %5 = load ptr, ptr %2, align 8, !tbaa !5
  %6 = getelementptr inbounds %struct.node, ptr %5, i32 0, i32 0
  %7 = getelementptr inbounds [4 x ptr], ptr %6, i64 0, i64 0
  %8 = load ptr, ptr %7, align 8, !tbaa !5
  %9 = load ptr, ptr @null, align 8, !tbaa !5
  %10 = icmp ne ptr %8, %9
  br i1 %10, label %11, label %17

11:                                               ; preds = %4
  %12 = load ptr, ptr %2, align 8, !tbaa !5
  call void @_ZN4node4downEv(ptr noundef nonnull align 8 dereferenceable(122) %12)
  %13 = load ptr, ptr %2, align 8, !tbaa !5
  %14 = getelementptr inbounds %struct.node, ptr %13, i32 0, i32 0
  %15 = getelementptr inbounds [4 x ptr], ptr %14, i64 0, i64 0
  %16 = load ptr, ptr %15, align 8, !tbaa !5
  store ptr %16, ptr %2, align 8, !tbaa !5
  br label %4, !llvm.loop !9

17:                                               ; preds = %4
  %18 = load ptr, ptr %2, align 8, !tbaa !5
  call void @_Z5splayP4nodei(ptr noundef %18, i32 noundef 0)
  %19 = load ptr, ptr %2, align 8, !tbaa !5
  ret ptr %19
}

attributes #0 = { 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"

@null = external dso_local local_unnamed_addr global ptr, align 8

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZN4node4downEv(ptr noundef nonnull align 8 dereferenceable(122)) local_unnamed_addr #0 align 2

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z5splayP4nodei(ptr noundef, i32 noundef) local_unnamed_addr #0

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z5touchP4node(ptr noundef) local_unnamed_addr #0

; Function Attrs: mustprogress uwtable
define dso_local noundef ptr @_Z8findrootP4node(ptr noundef %0) local_unnamed_addr #0 {
  tail call void @_Z5touchP4node(ptr noundef %0)
  %2 = load ptr, ptr %0, align 8, !tbaa !5
  %3 = load ptr, ptr @null, align 8, !tbaa !5
  %.not6 = icmp eq ptr %2, %3
  br i1 %.not6, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %1, %.lr.ph
  %.07 = phi ptr [ %4, %.lr.ph ], [ %0, %1 ]
  tail call void @_ZN4node4downEv(ptr noundef nonnull align 8 dereferenceable(122) %.07)
  %4 = load ptr, ptr %.07, align 8, !tbaa !5
  %5 = load ptr, ptr %4, align 8, !tbaa !5
  %6 = load ptr, ptr @null, align 8, !tbaa !5
  %.not = icmp eq ptr %5, %6
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !9

._crit_edge:                                      ; preds = %.lr.ph, %1
  %.0.lcssa = phi ptr [ %0, %1 ], [ %4, %.lr.ph ]
  tail call void @_Z5splayP4nodei(ptr noundef nonnull %.0.lcssa, i32 noundef 0)
  ret ptr %.0.lcssa
}

attributes #0 = { 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: EarlyCSEPass,GVNPass,GlobalOptPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,SROAPass,SimplifyCFGPass,TailCallElimPass