; LLVM IR from HarshCasper/NeoAlgo :: C-Plus-Plus/ds/Append_Last_N_To_First.ll (Z18appendLastNToFirstP4Nodei)

; 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"

%class.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 uwtable
declare dso_local noundef i32 @_Z7length1P4Node(ptr noundef) #1

; Function Attrs: mustprogress uwtable
define dso_local noundef ptr @_Z18appendLastNToFirstP4Nodei(ptr noundef %0, i32 noundef %1) #1 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca ptr, align 8
  %7 = alloca i32, align 4
  %8 = alloca i32, align 4
  %9 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #2
  %10 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %10, ptr %6, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #2
  %11 = load ptr, ptr %6, align 8, !tbaa !5
  %12 = call noundef i32 @_Z7length1P4Node(ptr noundef %11)
  store i32 %12, ptr %7, align 4, !tbaa !9
  %13 = load ptr, ptr %6, align 8, !tbaa !5
  %14 = icmp eq ptr %13, null
  br i1 %14, label %15, label %17

15:                                               ; preds = %2
  %16 = load ptr, ptr %6, align 8, !tbaa !5
  store ptr %16, ptr %3, align 8
  store i32 1, ptr %8, align 4
  br label %54

17:                                               ; preds = %2
  br label %18

18:                                               ; preds = %23, %17
  %19 = load ptr, ptr %6, align 8, !tbaa !5
  %20 = getelementptr inbounds %class.Node, ptr %19, i32 0, i32 1
  %21 = load ptr, ptr %20, align 8, !tbaa !11
  %22 = icmp ne ptr %21, null
  br i1 %22, label %23, label %27

23:                                               ; preds = %18
  %24 = load ptr, ptr %6, align 8, !tbaa !5
  %25 = getelementptr inbounds %class.Node, ptr %24, i32 0, i32 1
  %26 = load ptr, ptr %25, align 8, !tbaa !11
  store ptr %26, ptr %6, align 8, !tbaa !5
  br label %18, !llvm.loop !13

27:                                               ; preds = %18
  %28 = load ptr, ptr %4, align 8, !tbaa !5
  %29 = load ptr, ptr %6, align 8, !tbaa !5
  %30 = getelementptr inbounds %class.Node, ptr %29, i32 0, i32 1
  store ptr %28, ptr %30, align 8, !tbaa !11
  %31 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %31, ptr %6, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %9) #2
  store i32 1, ptr %9, align 4, !tbaa !9
  br label %32

32:                                               ; preds = %44, %27
  %33 = load i32, ptr %9, align 4, !tbaa !9
  %34 = load i32, ptr %7, align 4, !tbaa !9
  %35 = load i32, ptr %5, align 4, !tbaa !9
  %36 = sub nsw i32 %34, %35
  %37 = sub nsw i32 %36, 1
  %38 = icmp sle i32 %33, %37
  br i1 %38, label %40, label %39

39:                                               ; preds = %32
  store i32 4, ptr %8, align 4
  call void @llvm.lifetime.end.p0(i64 4, ptr %9) #2
  br label %47

40:                                               ; preds = %32
  %41 = load ptr, ptr %6, align 8, !tbaa !5
  %42 = getelementptr inbounds %class.Node, ptr %41, i32 0, i32 1
  %43 = load ptr, ptr %42, align 8, !tbaa !11
  store ptr %43, ptr %6, align 8, !tbaa !5
  br label %44

44:                                               ; preds = %40
  %45 = load i32, ptr %9, align 4, !tbaa !9
  %46 = add nsw i32 %45, 1
  store i32 %46, ptr %9, align 4, !tbaa !9
  br label %32, !llvm.loop !15

47:                                               ; preds = %39
  %48 = load ptr, ptr %6, align 8, !tbaa !5
  %49 = getelementptr inbounds %class.Node, ptr %48, i32 0, i32 1
  %50 = load ptr, ptr %49, align 8, !tbaa !11
  store ptr %50, ptr %4, align 8, !tbaa !5
  %51 = load ptr, ptr %6, align 8, !tbaa !5
  %52 = getelementptr inbounds %class.Node, ptr %51, i32 0, i32 1
  store ptr null, ptr %52, align 8, !tbaa !11
  %53 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %53, ptr %3, align 8
  store i32 1, ptr %8, align 4
  br label %54

54:                                               ; preds = %47, %15
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #2
  %55 = load ptr, ptr %3, align 8
  ret ptr %55
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { mustprogress 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, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = !{!12, !6, i64 8}
!12 = !{!"_ZTS4Node", !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: mustprogress uwtable
declare dso_local noundef i32 @_Z7length1P4Node(ptr noundef) local_unnamed_addr #0

; Function Attrs: mustprogress uwtable
define dso_local noundef ptr @_Z18appendLastNToFirstP4Nodei(ptr noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = tail call noundef i32 @_Z7length1P4Node(ptr noundef %0)
  %4 = icmp eq ptr %0, null
  br i1 %4, label %35, label %.preheader

.preheader:                                       ; preds = %2, %.preheader
  %.018 = phi ptr [ %6, %.preheader ], [ %0, %2 ]
  %5 = getelementptr inbounds i8, ptr %.018, i64 8
  %6 = load ptr, ptr %5, align 8, !tbaa !5
  %.not = icmp eq ptr %6, null
  br i1 %.not, label %7, label %.preheader, !llvm.loop !11

7:                                                ; preds = %.preheader
  %8 = getelementptr inbounds i8, ptr %.018, i64 8
  store ptr %0, ptr %8, align 8, !tbaa !5
  %9 = sub i32 %1, %3
  %.not2223 = icmp sgt i32 %9, -2
  br i1 %.not2223, label %._crit_edge, label %.lr.ph.preheader

.lr.ph.preheader:                                 ; preds = %7
  %10 = xor i32 %1, -1
  %11 = add i32 %3, %10
  %12 = add i32 %3, -2
  %13 = sub i32 %12, %1
  %xtraiter = and i32 %11, 7
  %14 = icmp ult i32 %13, 7
  br i1 %14, label %._crit_edge.loopexit.unr-lcssa, label %.lr.ph.preheader.new

.lr.ph.preheader.new:                             ; preds = %.lr.ph.preheader
  %unroll_iter = and i32 %11, -8
  br label %.lr.ph

._crit_edge.loopexit.unr-lcssa:                   ; preds = %.lr.ph, %.lr.ph.preheader
  %.lcssa.ph = phi ptr [ poison, %.lr.ph.preheader ], [ %34, %.lr.ph ]
  %.124.unr = phi ptr [ %0, %.lr.ph.preheader ], [ %34, %.lr.ph ]
  %lcmp.mod.not = icmp eq i32 %xtraiter, 0
  br i1 %lcmp.mod.not, label %._crit_edge, label %.lr.ph.epil

.lr.ph.epil:                                      ; preds = %._crit_edge.loopexit.unr-lcssa, %.lr.ph.epil
  %.124.epil = phi ptr [ %16, %.lr.ph.epil ], [ %.124.unr, %._crit_edge.loopexit.unr-lcssa ]
  %epil.iter = phi i32 [ %epil.iter.next, %.lr.ph.epil ], [ 0, %._crit_edge.loopexit.unr-lcssa ]
  %15 = getelementptr inbounds i8, ptr %.124.epil, i64 8
  %16 = load ptr, ptr %15, 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 %._crit_edge, label %.lr.ph.epil, !llvm.loop !13

._crit_edge:                                      ; preds = %._crit_edge.loopexit.unr-lcssa, %.lr.ph.epil, %7
  %.1.lcssa = phi ptr [ %0, %7 ], [ %.lcssa.ph, %._crit_edge.loopexit.unr-lcssa ], [ %16, %.lr.ph.epil ]
  %17 = getelementptr inbounds i8, ptr %.1.lcssa, i64 8
  %18 = load ptr, ptr %17, align 8, !tbaa !5
  store ptr null, ptr %17, align 8, !tbaa !5
  br label %35

.lr.ph:                                           ; preds = %.lr.ph, %.lr.ph.preheader.new
  %.124 = phi ptr [ %0, %.lr.ph.preheader.new ], [ %34, %.lr.ph ]
  %niter = phi i32 [ 0, %.lr.ph.preheader.new ], [ %niter.next.7, %.lr.ph ]
  %19 = getelementptr inbounds i8, ptr %.124, 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
  %25 = getelementptr inbounds i8, ptr %24, i64 8
  %26 = load ptr, ptr %25, align 8, !tbaa !5
  %27 = getelementptr inbounds i8, ptr %26, i64 8
  %28 = load ptr, ptr %27, align 8, !tbaa !5
  %29 = getelementptr inbounds i8, ptr %28, i64 8
  %30 = load ptr, ptr %29, align 8, !tbaa !5
  %31 = getelementptr inbounds i8, ptr %30, i64 8
  %32 = load ptr, ptr %31, align 8, !tbaa !5
  %33 = getelementptr inbounds i8, ptr %32, i64 8
  %34 = load ptr, ptr %33, 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 %._crit_edge.loopexit.unr-lcssa, label %.lr.ph, !llvm.loop !15

35:                                               ; preds = %2, %._crit_edge
  %.017 = phi ptr [ %18, %._crit_edge ], [ null, %2 ]
  ret ptr %.017
}

attributes #0 = { mustprogress 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 = !{!"_ZTS4Node", !7, i64 0, !10, i64 8}
!7 = !{!"int", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C++ TBAA"}
!10 = !{!"any pointer", !8, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.unroll.disable"}
!15 = distinct !{!15, !12}


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