; LLVM IR from lolosssss/leetcode :: c (19_remove_nth_node_from_end_of_list)

; 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: 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: nounwind uwtable
define dso_local ptr @createList(ptr noundef %0, i32 noundef %1) #1 {
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  %6 = alloca ptr, align 8
  %7 = alloca ptr, align 8
  %8 = alloca ptr, align 8
  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 4, ptr %5) #3
  store i32 0, ptr %5, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #3
  store ptr null, ptr %6, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #3
  store ptr null, ptr %7, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %8) #3
  store ptr null, ptr %8, align 8, !tbaa !5
  %9 = call noalias ptr @malloc(i64 noundef 16) #4
  store ptr %9, ptr %8, align 8, !tbaa !5
  %10 = load ptr, ptr %3, align 8, !tbaa !5
  %11 = load i32, ptr %5, align 4, !tbaa !9
  %12 = add nsw i32 %11, 1
  store i32 %12, ptr %5, align 4, !tbaa !9
  %13 = sext i32 %11 to i64
  %14 = getelementptr inbounds i32, ptr %10, i64 %13
  %15 = load i32, ptr %14, align 4, !tbaa !9
  %16 = load ptr, ptr %8, align 8, !tbaa !5
  %17 = getelementptr inbounds %struct.ListNode, ptr %16, i32 0, i32 0
  store i32 %15, ptr %17, align 8, !tbaa !11
  %18 = load ptr, ptr %8, align 8, !tbaa !5
  store ptr %18, ptr %6, align 8, !tbaa !5
  %19 = load ptr, ptr %8, align 8, !tbaa !5
  store ptr %19, ptr %7, align 8, !tbaa !5
  %20 = load i32, ptr %4, align 4, !tbaa !9
  %21 = add nsw i32 %20, -1
  store i32 %21, ptr %4, align 4, !tbaa !9
  br label %22

22:                                               ; preds = %26, %2
  %23 = load i32, ptr %4, align 4, !tbaa !9
  %24 = add nsw i32 %23, -1
  store i32 %24, ptr %4, align 4, !tbaa !9
  %25 = icmp ne i32 %23, 0
  br i1 %25, label %26, label %40

26:                                               ; preds = %22
  %27 = call noalias ptr @malloc(i64 noundef 16) #4
  store ptr %27, ptr %8, align 8, !tbaa !5
  %28 = load ptr, ptr %3, align 8, !tbaa !5
  %29 = load i32, ptr %5, align 4, !tbaa !9
  %30 = add nsw i32 %29, 1
  store i32 %30, ptr %5, align 4, !tbaa !9
  %31 = sext i32 %29 to i64
  %32 = getelementptr inbounds i32, ptr %28, i64 %31
  %33 = load i32, ptr %32, align 4, !tbaa !9
  %34 = load ptr, ptr %8, align 8, !tbaa !5
  %35 = getelementptr inbounds %struct.ListNode, ptr %34, i32 0, i32 0
  store i32 %33, ptr %35, align 8, !tbaa !11
  %36 = load ptr, ptr %8, align 8, !tbaa !5
  %37 = load ptr, ptr %7, align 8, !tbaa !5
  %38 = getelementptr inbounds %struct.ListNode, ptr %37, i32 0, i32 1
  store ptr %36, ptr %38, align 8, !tbaa !13
  %39 = load ptr, ptr %8, align 8, !tbaa !5
  store ptr %39, ptr %7, align 8, !tbaa !5
  br label %22, !llvm.loop !14

40:                                               ; preds = %22
  %41 = load ptr, ptr %7, align 8, !tbaa !5
  %42 = getelementptr inbounds %struct.ListNode, ptr %41, i32 0, i32 1
  store ptr null, ptr %42, align 8, !tbaa !13
  %43 = load ptr, ptr %6, align 8, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 8, 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 4, ptr %5) #3
  ret ptr %43
}

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

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 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, !10, i64 0}
!12 = !{!"ListNode", !10, i64 0, !6, i64 8}
!13 = !{!12, !6, i64 8}
!14 = distinct !{!14, !15}
!15 = !{!"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"

; Function Attrs: nofree nounwind memory(write, argmem: readwrite, inaccessiblemem: readwrite) uwtable
define dso_local noalias noundef ptr @createList(ptr nocapture noundef readonly %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = tail call noalias dereferenceable_or_null(16) ptr @malloc(i64 noundef 16) #2
  %4 = load i32, ptr %0, align 4, !tbaa !5
  store i32 %4, ptr %3, align 8, !tbaa !9
  %.01516 = add nsw i32 %1, -1
  %.not17 = icmp eq i32 %.01516, 0
  br i1 %.not17, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %2, %.lr.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ 1, %2 ]
  %.01520 = phi i32 [ %.015, %.lr.ph ], [ %.01516, %2 ]
  %.019 = phi ptr [ %5, %.lr.ph ], [ %3, %2 ]
  %5 = tail call noalias dereferenceable_or_null(16) ptr @malloc(i64 noundef 16) #2
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %6 = getelementptr inbounds i32, ptr %0, i64 %indvars.iv
  %7 = load i32, ptr %6, align 4, !tbaa !5
  store i32 %7, ptr %5, align 8, !tbaa !9
  %8 = getelementptr inbounds i8, ptr %.019, i64 8
  store ptr %5, ptr %8, align 8, !tbaa !12
  %.015 = add nsw i32 %.01520, -1
  %.not = icmp eq i32 %.015, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !13

._crit_edge:                                      ; preds = %.lr.ph, %2
  %.0.lcssa = phi ptr [ %3, %2 ], [ %5, %.lr.ph ]
  %9 = getelementptr inbounds i8, ptr %.0.lcssa, i64 8
  store ptr null, ptr %9, align 8, !tbaa !12
  ret ptr %3
}

; 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 memory(write, argmem: readwrite, inaccessiblemem: readwrite) 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, !6, i64 0}
!6 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !6, i64 0}
!10 = !{!"ListNode", !6, i64 0, !11, i64 8}
!11 = !{!"any pointer", !7, i64 0}
!12 = !{!10, !11, i64 8}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}


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