; LLVM IR from JessonYue/LeetCodeLearning :: Array/luobiao/BaseDataStructure/LinkedList.ll (Z7reverseP11LinkedList_)

; 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.LinkedList_ = type { i32, ptr, ptr }
%struct.Node_ = type { i32, 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: mustprogress nounwind uwtable
define dso_local void @_Z7reverseP11LinkedList_(ptr noundef %0) #1 {
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca ptr, align 8
  store ptr %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #2
  store ptr null, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #2
  %7 = load ptr, ptr %2, align 8, !tbaa !5
  %8 = getelementptr inbounds %struct.LinkedList_, ptr %7, i32 0, i32 1
  %9 = load ptr, ptr %8, align 8, !tbaa !9
  store ptr %9, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #2
  %10 = load ptr, ptr %4, align 8, !tbaa !5
  %11 = getelementptr inbounds %struct.Node_, ptr %10, i32 0, i32 1
  %12 = load ptr, ptr %11, align 8, !tbaa !12
  store ptr %12, ptr %5, align 8, !tbaa !5
  br label %13

13:                                               ; preds = %29, %1
  %14 = load ptr, ptr %4, align 8, !tbaa !5
  %15 = icmp ne ptr %14, null
  br i1 %15, label %16, label %31

16:                                               ; preds = %13
  %17 = load ptr, ptr %3, align 8, !tbaa !5
  %18 = load ptr, ptr %4, align 8, !tbaa !5
  %19 = getelementptr inbounds %struct.Node_, ptr %18, i32 0, i32 1
  store ptr %17, ptr %19, align 8, !tbaa !12
  %20 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %20, ptr %3, align 8, !tbaa !5
  %21 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %21, ptr %4, align 8, !tbaa !5
  %22 = load ptr, ptr %5, align 8, !tbaa !5
  %23 = icmp eq ptr %22, null
  br i1 %23, label %24, label %25

24:                                               ; preds = %16
  br label %29

25:                                               ; preds = %16
  %26 = load ptr, ptr %5, align 8, !tbaa !5
  %27 = getelementptr inbounds %struct.Node_, ptr %26, i32 0, i32 1
  %28 = load ptr, ptr %27, align 8, !tbaa !12
  br label %29

29:                                               ; preds = %25, %24
  %30 = phi ptr [ null, %24 ], [ %28, %25 ]
  store ptr %30, ptr %5, align 8, !tbaa !5
  br label %13, !llvm.loop !14

31:                                               ; preds = %13
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #2
  %32 = load ptr, ptr %2, align 8, !tbaa !5
  %33 = getelementptr inbounds %struct.LinkedList_, ptr %32, i32 0, i32 1
  %34 = load ptr, ptr %33, align 8, !tbaa !9
  store ptr %34, ptr %6, align 8, !tbaa !5
  %35 = load ptr, ptr %2, align 8, !tbaa !5
  %36 = getelementptr inbounds %struct.LinkedList_, ptr %35, i32 0, i32 2
  %37 = load ptr, ptr %36, align 8, !tbaa !16
  %38 = load ptr, ptr %2, align 8, !tbaa !5
  %39 = getelementptr inbounds %struct.LinkedList_, ptr %38, i32 0, i32 1
  store ptr %37, ptr %39, align 8, !tbaa !9
  %40 = load ptr, ptr %6, align 8, !tbaa !5
  %41 = load ptr, ptr %2, align 8, !tbaa !5
  %42 = getelementptr inbounds %struct.LinkedList_, ptr %41, i32 0, i32 2
  store ptr %40, ptr %42, align 8, !tbaa !16
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #2
  ret void
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 #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++ TBAA"}
!9 = !{!10, !6, i64 8}
!10 = !{!"_ZTS11LinkedList_", !11, i64 0, !6, i64 8, !6, i64 16}
!11 = !{!"int", !7, i64 0}
!12 = !{!13, !6, i64 8}
!13 = !{!"_ZTS5Node_", !11, i64 0, !6, i64 8}
!14 = distinct !{!14, !15}
!15 = !{!"llvm.loop.mustprogress"}
!16 = !{!10, !6, i64 16}


; 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 memory(readwrite, inaccessiblemem: none) uwtable
define dso_local void @_Z7reverseP11LinkedList_(ptr nocapture noundef %0) local_unnamed_addr #0 {
  %2 = getelementptr inbounds i8, ptr %0, i64 8
  %3 = load ptr, ptr %2, align 8, !tbaa !5
  %.not16 = icmp eq ptr %3, null
  br i1 %.not16, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %1, %.lr.ph
  %.sink20 = phi ptr [ %5, %.lr.ph ], [ %3, %1 ]
  %.019 = phi ptr [ %.sink20, %.lr.ph ], [ null, %1 ]
  %4 = getelementptr inbounds i8, ptr %.sink20, i64 8
  %5 = load ptr, ptr %4, align 8, !tbaa !11
  %6 = getelementptr inbounds i8, ptr %.sink20, i64 8
  store ptr %.019, ptr %6, align 8, !tbaa !11
  %7 = icmp eq ptr %5, null
  br i1 %7, label %._crit_edge, label %.lr.ph, !llvm.loop !13

._crit_edge:                                      ; preds = %.lr.ph, %1
  %8 = getelementptr inbounds i8, ptr %0, i64 16
  %9 = load ptr, ptr %8, align 8, !tbaa !15
  store ptr %9, ptr %2, align 8, !tbaa !5
  store ptr %3, ptr %8, align 8, !tbaa !15
  ret void
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind memory(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, !10, i64 8}
!6 = !{!"_ZTS11LinkedList_", !7, i64 0, !10, i64 8, !10, i64 16}
!7 = !{!"int", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C++ TBAA"}
!10 = !{!"any pointer", !8, i64 0}
!11 = !{!12, !10, i64 8}
!12 = !{!"_ZTS5Node_", !7, i64 0, !10, i64 8}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}
!15 = !{!6, !10, i64 16}


; Effective O3 passes: EarlyCSEPass,GVNPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass