; LLVM IR from JessonYue/LeetCodeLearning :: Array/wuchao/linkedlist (RemoveNEndOfLinkedList(6-10))

; 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 @removeNthFromEnd(ptr noundef %0, i32 noundef %1) #0 {
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = alloca %struct.ListNode, align 8
  %6 = alloca ptr, align 8
  %7 = alloca ptr, align 8
  %8 = alloca ptr, align 8
  %9 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 16, ptr %5) #2
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #2
  store ptr %5, ptr %6, align 8, !tbaa !5
  %10 = load ptr, ptr %3, align 8, !tbaa !5
  %11 = load ptr, ptr %6, align 8, !tbaa !5
  %12 = getelementptr inbounds %struct.ListNode, ptr %11, i32 0, i32 1
  store ptr %10, ptr %12, align 8, !tbaa !11
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #2
  %13 = load ptr, ptr %6, align 8, !tbaa !5
  store ptr %13, ptr %7, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %8) #2
  %14 = load ptr, ptr %6, align 8, !tbaa !5
  store ptr %14, ptr %8, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %9) #2
  store i32 0, ptr %9, align 4, !tbaa !9
  br label %15

15:                                               ; preds = %31, %2
  %16 = load ptr, ptr %8, align 8, !tbaa !5
  %17 = getelementptr inbounds %struct.ListNode, ptr %16, i32 0, i32 1
  %18 = load ptr, ptr %17, align 8, !tbaa !11
  %19 = icmp ne ptr %18, null
  br i1 %19, label %20, label %35

20:                                               ; preds = %15
  %21 = load i32, ptr %9, align 4, !tbaa !9
  %22 = load i32, ptr %4, align 4, !tbaa !9
  %23 = icmp slt i32 %21, %22
  br i1 %23, label %24, label %27

24:                                               ; preds = %20
  %25 = load i32, ptr %9, align 4, !tbaa !9
  %26 = add nsw i32 %25, 1
  store i32 %26, ptr %9, align 4, !tbaa !9
  br label %31

27:                                               ; preds = %20
  %28 = load ptr, ptr %7, align 8, !tbaa !5
  %29 = getelementptr inbounds %struct.ListNode, ptr %28, i32 0, i32 1
  %30 = load ptr, ptr %29, align 8, !tbaa !11
  store ptr %30, ptr %7, align 8, !tbaa !5
  br label %31

31:                                               ; preds = %27, %24
  %32 = load ptr, ptr %8, align 8, !tbaa !5
  %33 = getelementptr inbounds %struct.ListNode, ptr %32, i32 0, i32 1
  %34 = load ptr, ptr %33, align 8, !tbaa !11
  store ptr %34, ptr %8, align 8, !tbaa !5
  br label %15, !llvm.loop !13

35:                                               ; preds = %15
  %36 = load ptr, ptr %7, align 8, !tbaa !5
  %37 = getelementptr inbounds %struct.ListNode, ptr %36, i32 0, i32 1
  %38 = load ptr, ptr %37, align 8, !tbaa !11
  %39 = getelementptr inbounds %struct.ListNode, ptr %38, i32 0, i32 1
  %40 = load ptr, ptr %39, align 8, !tbaa !11
  %41 = load ptr, ptr %7, align 8, !tbaa !5
  %42 = getelementptr inbounds %struct.ListNode, ptr %41, i32 0, i32 1
  store ptr %40, ptr %42, align 8, !tbaa !11
  %43 = load ptr, ptr %6, align 8, !tbaa !5
  %44 = getelementptr inbounds %struct.ListNode, ptr %43, i32 0, i32 1
  %45 = load ptr, ptr %44, align 8, !tbaa !11
  call void @llvm.lifetime.end.p0(i64 4, ptr %9) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %8) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #2
  call void @llvm.lifetime.end.p0(i64 16, ptr %5) #2
  ret ptr %45
}

; 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, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = !{!12, !6, i64 8}
!12 = !{!"ListNode", !10, i64 0, !6, i64 8}
!13 = distinct !{!13, !14}
!14 = !{!"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"

%struct.ListNode = type { i32, ptr }

; Function Attrs: nofree norecurse nosync nounwind memory(readwrite, inaccessiblemem: write) uwtable
define dso_local ptr @removeNthFromEnd(ptr noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = alloca %struct.ListNode, align 8
  call void @llvm.lifetime.start.p0(i64 16, ptr nonnull %3) #3
  %4 = getelementptr inbounds i8, ptr %3, i64 8
  store ptr %0, ptr %4, align 8, !tbaa !5
  %.not15 = icmp ne ptr %0, null
  tail call void @llvm.assume(i1 %.not15)
  br label %.lr.ph

.lr.ph:                                           ; preds = %2, %12
  %5 = phi ptr [ %14, %12 ], [ %0, %2 ]
  %.017 = phi i32 [ %.1, %12 ], [ 0, %2 ]
  %.01316 = phi ptr [ %.114, %12 ], [ %3, %2 ]
  %6 = icmp slt i32 %.017, %1
  br i1 %6, label %7, label %9

7:                                                ; preds = %.lr.ph
  %8 = add nsw i32 %.017, 1
  br label %12

9:                                                ; preds = %.lr.ph
  %10 = getelementptr inbounds i8, ptr %.01316, i64 8
  %11 = load ptr, ptr %10, align 8, !tbaa !5
  br label %12

12:                                               ; preds = %9, %7
  %.114 = phi ptr [ %.01316, %7 ], [ %11, %9 ]
  %.1 = phi i32 [ %8, %7 ], [ %.017, %9 ]
  %13 = getelementptr inbounds i8, ptr %5, i64 8
  %14 = load ptr, ptr %13, align 8, !tbaa !5
  %.not = icmp eq ptr %14, null
  br i1 %.not, label %._crit_edge.loopexit, label %.lr.ph, !llvm.loop !11

._crit_edge.loopexit:                             ; preds = %12
  %.phi.trans.insert = getelementptr inbounds i8, ptr %.114, i64 8
  %.pre = load ptr, ptr %.phi.trans.insert, align 8, !tbaa !5
  %15 = getelementptr inbounds i8, ptr %.114, i64 8
  %16 = getelementptr inbounds i8, ptr %.pre, i64 8
  %17 = load ptr, ptr %16, align 8, !tbaa !5
  store ptr %17, ptr %15, align 8, !tbaa !5
  %18 = load ptr, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 16, ptr nonnull %3) #3
  ret ptr %18
}

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(inaccessiblemem: write)
declare void @llvm.assume(i1 noundef) #2

attributes #0 = { nofree norecurse nosync nounwind memory(readwrite, inaccessiblemem: write) 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 nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { nocallback nofree nosync nounwind willreturn memory(inaccessiblemem: write) }
attributes #3 = { 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, !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}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}


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