; LLVM IR from JessonYue/LeetCodeLearning :: Array/wuchao/linkedlist/7-2 反转链表 递归实现 (ReverseLinkedList)

; 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.ListNode = type { i32, ptr }

; Function Attrs: nounwind uwtable
define dso_local ptr @reverse(ptr noundef %0, ptr noundef %1) #0 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca ptr, align 8
  store ptr %0, ptr %4, align 8, !tbaa !5
  store ptr %1, ptr %5, align 8, !tbaa !5
  %7 = load ptr, ptr %5, align 8, !tbaa !5
  %8 = icmp eq ptr %7, null
  br i1 %8, label %9, label %11

9:                                                ; preds = %2
  %10 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %10, ptr %3, align 8
  br label %21

11:                                               ; preds = %2
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #2
  %12 = load ptr, ptr %5, align 8, !tbaa !5
  %13 = getelementptr inbounds %struct.ListNode, ptr %12, i32 0, i32 1
  %14 = load ptr, ptr %13, align 8, !tbaa !9
  store ptr %14, ptr %6, align 8, !tbaa !5
  %15 = load ptr, ptr %4, align 8, !tbaa !5
  %16 = load ptr, ptr %5, align 8, !tbaa !5
  %17 = getelementptr inbounds %struct.ListNode, ptr %16, i32 0, i32 1
  store ptr %15, ptr %17, align 8, !tbaa !9
  %18 = load ptr, ptr %5, align 8, !tbaa !5
  %19 = load ptr, ptr %6, align 8, !tbaa !5
  %20 = call ptr @reverse(ptr noundef %18, ptr noundef %19)
  store ptr %20, ptr %3, align 8
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #2
  br label %21

21:                                               ; preds = %11, %9
  %22 = load ptr, ptr %3, align 8
  ret ptr %22
}

; 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 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 = { 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 8}
!10 = !{!"ListNode", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}


; 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: nofree norecurse nosync nounwind memory(readwrite, inaccessiblemem: none) uwtable
define dso_local ptr @reverse(ptr noundef %0, ptr noundef %1) local_unnamed_addr #0 {
  %3 = icmp eq ptr %1, null
  br i1 %3, label %tailrecurse._crit_edge, label %tailrecurse

tailrecurse:                                      ; preds = %2, %tailrecurse
  %.tr911 = phi ptr [ %5, %tailrecurse ], [ %1, %2 ]
  %.tr10 = phi ptr [ %.tr911, %tailrecurse ], [ %0, %2 ]
  %4 = getelementptr inbounds i8, ptr %.tr911, i64 8
  %5 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %.tr10, ptr %4, align 8, !tbaa !5
  %6 = icmp eq ptr %5, null
  br i1 %6, label %tailrecurse._crit_edge, label %tailrecurse

tailrecurse._crit_edge:                           ; preds = %tailrecurse, %2
  %.tr.lcssa = phi ptr [ %0, %2 ], [ %.tr911, %tailrecurse ]
  ret ptr %.tr.lcssa
}

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


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