; LLVM IR from JessonYue/LeetCodeLearning :: Array/zhangjunwei/linked_list (removeNthFromEnd_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 ptr, align 8
  %6 = alloca ptr, align 8
  %7 = alloca ptr, align 8
  %8 = 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 8, ptr %5) #3
  %9 = call noalias ptr @malloc(i64 noundef 16) #4
  store ptr %9, ptr %5, align 8, !tbaa !5
  %10 = load ptr, ptr %3, align 8, !tbaa !5
  %11 = load ptr, ptr %5, 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 %6) #3
  %13 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %13, ptr %6, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #3
  %14 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %14, ptr %7, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #3
  store i32 1, ptr %8, align 4, !tbaa !9
  %15 = load i32, ptr %4, align 4, !tbaa !9
  %16 = add nsw i32 %15, 1
  store i32 %16, ptr %4, align 4, !tbaa !9
  br label %17

17:                                               ; preds = %21, %2
  %18 = load i32, ptr %8, align 4, !tbaa !9
  %19 = load i32, ptr %4, align 4, !tbaa !9
  %20 = icmp sle i32 %18, %19
  br i1 %20, label %21, label %27

21:                                               ; preds = %17
  %22 = load ptr, ptr %6, align 8, !tbaa !5
  %23 = getelementptr inbounds %struct.ListNode_, ptr %22, i32 0, i32 1
  %24 = load ptr, ptr %23, align 8, !tbaa !11
  store ptr %24, ptr %6, align 8, !tbaa !5
  %25 = load i32, ptr %8, align 4, !tbaa !9
  %26 = add nsw i32 %25, 1
  store i32 %26, ptr %8, align 4, !tbaa !9
  br label %17, !llvm.loop !13

27:                                               ; preds = %17
  br label %28

28:                                               ; preds = %31, %27
  %29 = load ptr, ptr %6, align 8, !tbaa !5
  %30 = icmp ne ptr %29, null
  br i1 %30, label %31, label %38

31:                                               ; preds = %28
  %32 = load ptr, ptr %6, 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 %6, align 8, !tbaa !5
  %35 = load ptr, ptr %7, align 8, !tbaa !5
  %36 = getelementptr inbounds %struct.ListNode_, ptr %35, i32 0, i32 1
  %37 = load ptr, ptr %36, align 8, !tbaa !11
  store ptr %37, ptr %7, align 8, !tbaa !5
  br label %28, !llvm.loop !15

38:                                               ; preds = %28
  %39 = load ptr, ptr %7, align 8, !tbaa !5
  %40 = getelementptr inbounds %struct.ListNode_, ptr %39, i32 0, i32 1
  %41 = load ptr, ptr %40, align 8, !tbaa !11
  %42 = getelementptr inbounds %struct.ListNode_, ptr %41, i32 0, i32 1
  %43 = load ptr, ptr %42, align 8, !tbaa !11
  %44 = load ptr, ptr %7, align 8, !tbaa !5
  %45 = getelementptr inbounds %struct.ListNode_, ptr %44, i32 0, i32 1
  store ptr %43, ptr %45, align 8, !tbaa !11
  %46 = load ptr, ptr %5, align 8, !tbaa !5
  %47 = getelementptr inbounds %struct.ListNode_, ptr %46, i32 0, i32 1
  %48 = load ptr, ptr %47, align 8, !tbaa !11
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #3
  ret ptr %48
}

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

; Function Attrs: nounwind allocsize(0)
declare noalias ptr @malloc(i64 noundef) #2

; 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 allocsize(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 #3 = { nounwind }
attributes #4 = { nounwind allocsize(0) }

!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"}
!15 = distinct !{!15, !14}


; 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 nounwind uwtable
define dso_local ptr @removeNthFromEnd(ptr noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = tail call noalias dereferenceable_or_null(16) ptr @malloc(i64 noundef 16) #2
  %4 = getelementptr inbounds i8, ptr %3, i64 8
  store ptr %0, ptr %4, align 8, !tbaa !5
  %.not17 = icmp slt i32 %1, 0
  br i1 %.not17, label %.lr.ph23.preheader, label %.lr.ph.preheader

.lr.ph.preheader:                                 ; preds = %2
  %5 = add nuw i32 %1, 1
  %xtraiter = and i32 %5, 7
  %6 = icmp ult i32 %1, 7
  br i1 %6, label %.preheader.unr-lcssa, label %.lr.ph.preheader.new

.lr.ph.preheader.new:                             ; preds = %.lr.ph.preheader
  %unroll_iter = and i32 %5, -8
  br label %.lr.ph

.preheader.unr-lcssa:                             ; preds = %.lr.ph, %.lr.ph.preheader
  %.lcssa31.ph = phi ptr [ poison, %.lr.ph.preheader ], [ %24, %.lr.ph ]
  %.01518.unr = phi ptr [ %3, %.lr.ph.preheader ], [ %24, %.lr.ph ]
  %lcmp.mod.not = icmp eq i32 %xtraiter, 0
  br i1 %lcmp.mod.not, label %.preheader, label %.lr.ph.epil

.lr.ph.epil:                                      ; preds = %.preheader.unr-lcssa, %.lr.ph.epil
  %.01518.epil = phi ptr [ %8, %.lr.ph.epil ], [ %.01518.unr, %.preheader.unr-lcssa ]
  %epil.iter = phi i32 [ %epil.iter.next, %.lr.ph.epil ], [ 0, %.preheader.unr-lcssa ]
  %7 = getelementptr inbounds i8, ptr %.01518.epil, i64 8
  %8 = load ptr, ptr %7, align 8, !tbaa !5
  %epil.iter.next = add i32 %epil.iter, 1
  %epil.iter.cmp.not = icmp eq i32 %epil.iter.next, %xtraiter
  br i1 %epil.iter.cmp.not, label %.preheader, label %.lr.ph.epil, !llvm.loop !11

.preheader:                                       ; preds = %.lr.ph.epil, %.preheader.unr-lcssa
  %.lcssa31 = phi ptr [ %.lcssa31.ph, %.preheader.unr-lcssa ], [ %8, %.lr.ph.epil ]
  %.not1620 = icmp eq ptr %.lcssa31, null
  br i1 %.not1620, label %._crit_edge, label %.lr.ph23.preheader

.lr.ph23.preheader:                               ; preds = %2, %.preheader
  %.121.ph = phi ptr [ %.lcssa31, %.preheader ], [ %3, %2 ]
  br label %.lr.ph23

.lr.ph:                                           ; preds = %.lr.ph, %.lr.ph.preheader.new
  %.01518 = phi ptr [ %3, %.lr.ph.preheader.new ], [ %24, %.lr.ph ]
  %niter = phi i32 [ 0, %.lr.ph.preheader.new ], [ %niter.next.7, %.lr.ph ]
  %9 = getelementptr inbounds i8, ptr %.01518, i64 8
  %10 = load ptr, ptr %9, align 8, !tbaa !5
  %11 = getelementptr inbounds i8, ptr %10, i64 8
  %12 = load ptr, ptr %11, align 8, !tbaa !5
  %13 = getelementptr inbounds i8, ptr %12, i64 8
  %14 = load ptr, ptr %13, align 8, !tbaa !5
  %15 = getelementptr inbounds i8, ptr %14, i64 8
  %16 = load ptr, ptr %15, align 8, !tbaa !5
  %17 = getelementptr inbounds i8, ptr %16, i64 8
  %18 = load ptr, ptr %17, align 8, !tbaa !5
  %19 = getelementptr inbounds i8, ptr %18, i64 8
  %20 = load ptr, ptr %19, align 8, !tbaa !5
  %21 = getelementptr inbounds i8, ptr %20, i64 8
  %22 = load ptr, ptr %21, align 8, !tbaa !5
  %23 = getelementptr inbounds i8, ptr %22, i64 8
  %24 = load ptr, ptr %23, align 8, !tbaa !5
  %niter.next.7 = add i32 %niter, 8
  %niter.ncmp.7 = icmp eq i32 %niter.next.7, %unroll_iter
  br i1 %niter.ncmp.7, label %.preheader.unr-lcssa, label %.lr.ph, !llvm.loop !13

.lr.ph23:                                         ; preds = %.lr.ph23.preheader, %.lr.ph23
  %.01422 = phi ptr [ %28, %.lr.ph23 ], [ %3, %.lr.ph23.preheader ]
  %.121 = phi ptr [ %26, %.lr.ph23 ], [ %.121.ph, %.lr.ph23.preheader ]
  %25 = getelementptr inbounds i8, ptr %.121, i64 8
  %26 = load ptr, ptr %25, align 8, !tbaa !5
  %27 = getelementptr inbounds i8, ptr %.01422, i64 8
  %28 = load ptr, ptr %27, align 8, !tbaa !5
  %.not16 = icmp eq ptr %26, null
  br i1 %.not16, label %._crit_edge.loopexit, label %.lr.ph23, !llvm.loop !15

._crit_edge.loopexit:                             ; preds = %.lr.ph23
  %.phi.trans.insert = getelementptr inbounds i8, ptr %28, i64 8
  %.pre = load ptr, ptr %.phi.trans.insert, align 8, !tbaa !5
  br label %._crit_edge

._crit_edge:                                      ; preds = %._crit_edge.loopexit, %.preheader
  %29 = phi ptr [ %0, %.preheader ], [ %.pre, %._crit_edge.loopexit ]
  %.014.lcssa = phi ptr [ %3, %.preheader ], [ %28, %._crit_edge.loopexit ]
  %30 = getelementptr inbounds i8, ptr %.014.lcssa, i64 8
  %31 = getelementptr inbounds i8, ptr %29, i64 8
  %32 = load ptr, ptr %31, align 8, !tbaa !5
  store ptr %32, ptr %30, align 8, !tbaa !5
  %33 = load ptr, ptr %4, align 8, !tbaa !5
  ret ptr %33
}

; Function Attrs: mustprogress nofree nounwind willreturn allockind("alloc,uninitialized") allocsize(0) memory(inaccessiblemem: readwrite)
declare noalias noundef ptr @malloc(i64 noundef) local_unnamed_addr #1

attributes #0 = { nofree 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 nofree nounwind willreturn allockind("alloc,uninitialized") allocsize(0) memory(inaccessiblemem: readwrite) "alloc-family"="malloc" "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 allocsize(0) }

!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.unroll.disable"}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}
!15 = distinct !{!15, !14}


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