; LLVM IR from afrozchakure/Competitive-Programming-Solutions :: TopicWise/Linked List/MergeSortLinkedList.ll (Z5splitP4NodePS0_S1_)

; 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.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 nounwind uwtable
define dso_local void @_Z5splitP4NodePS0_S1_(ptr noundef %0, ptr noundef %1, ptr noundef %2) #1 {
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca ptr, align 8
  %7 = alloca ptr, align 8
  %8 = alloca ptr, align 8
  store ptr %0, ptr %4, align 8, !tbaa !5
  store ptr %1, ptr %5, align 8, !tbaa !5
  store ptr %2, ptr %6, align 8, !tbaa !5
  %9 = load ptr, ptr %4, align 8, !tbaa !5
  %10 = icmp eq ptr %9, null
  br i1 %10, label %11, label %12

11:                                               ; preds = %3
  br label %45

12:                                               ; preds = %3
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #2
  call void @llvm.lifetime.start.p0(i64 8, ptr %8) #2
  %13 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %13, ptr %7, align 8, !tbaa !5
  %14 = load ptr, ptr %4, align 8, !tbaa !5
  %15 = getelementptr inbounds %struct.Node, ptr %14, i32 0, i32 1
  %16 = load ptr, ptr %15, align 8, !tbaa !9
  store ptr %16, ptr %8, align 8, !tbaa !5
  br label %17

17:                                               ; preds = %27, %12
  %18 = load ptr, ptr %8, align 8, !tbaa !5
  %19 = icmp ne ptr %18, null
  br i1 %19, label %20, label %25

20:                                               ; preds = %17
  %21 = load ptr, ptr %8, align 8, !tbaa !5
  %22 = getelementptr inbounds %struct.Node, ptr %21, i32 0, i32 1
  %23 = load ptr, ptr %22, align 8, !tbaa !9
  %24 = icmp ne ptr %23, null
  br label %25

25:                                               ; preds = %20, %17
  %26 = phi i1 [ false, %17 ], [ %24, %20 ]
  br i1 %26, label %27, label %36

27:                                               ; preds = %25
  %28 = load ptr, ptr %7, align 8, !tbaa !5
  %29 = getelementptr inbounds %struct.Node, ptr %28, i32 0, i32 1
  %30 = load ptr, ptr %29, align 8, !tbaa !9
  store ptr %30, ptr %7, align 8, !tbaa !5
  %31 = load ptr, ptr %8, align 8, !tbaa !5
  %32 = getelementptr inbounds %struct.Node, ptr %31, i32 0, i32 1
  %33 = load ptr, ptr %32, align 8, !tbaa !9
  %34 = getelementptr inbounds %struct.Node, ptr %33, i32 0, i32 1
  %35 = load ptr, ptr %34, align 8, !tbaa !9
  store ptr %35, ptr %8, align 8, !tbaa !5
  br label %17, !llvm.loop !12

36:                                               ; preds = %25
  %37 = load ptr, ptr %4, align 8, !tbaa !5
  %38 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %37, ptr %38, align 8, !tbaa !5
  %39 = load ptr, ptr %7, align 8, !tbaa !5
  %40 = getelementptr inbounds %struct.Node, ptr %39, i32 0, i32 1
  %41 = load ptr, ptr %40, align 8, !tbaa !9
  %42 = load ptr, ptr %6, align 8, !tbaa !5
  store ptr %41, ptr %42, align 8, !tbaa !5
  %43 = load ptr, ptr %7, align 8, !tbaa !5
  %44 = getelementptr inbounds %struct.Node, ptr %43, i32 0, i32 1
  store ptr null, ptr %44, align 8, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 8, ptr %8) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #2
  br label %45

45:                                               ; preds = %36, %11
  ret void
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { mustprogress 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 }

!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, !6, i64 8}
!10 = !{!"_ZTS4Node", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"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: mustprogress nofree norecurse nosync nounwind memory(readwrite, inaccessiblemem: none) uwtable
define dso_local void @_Z5splitP4NodePS0_S1_(ptr noundef %0, ptr nocapture noundef writeonly %1, ptr nocapture noundef writeonly %2) local_unnamed_addr #0 {
  %4 = icmp eq ptr %0, null
  br i1 %4, label %12, label %.preheader

.preheader:                                       ; preds = %3
  %.0.in16 = getelementptr inbounds i8, ptr %0, i64 8
  %.017 = load ptr, ptr %.0.in16, align 8, !tbaa !5
  %.not18 = icmp eq ptr %.017, null
  br i1 %.not18, label %.critedge, label %.lr.ph

.lr.ph:                                           ; preds = %.preheader, %7
  %.020 = phi ptr [ %.0, %7 ], [ %.017, %.preheader ]
  %.01219 = phi ptr [ %9, %7 ], [ %0, %.preheader ]
  %5 = getelementptr inbounds i8, ptr %.020, i64 8
  %6 = load ptr, ptr %5, align 8, !tbaa !5
  %.not15 = icmp eq ptr %6, null
  br i1 %.not15, label %.critedge, label %7

7:                                                ; preds = %.lr.ph
  %8 = getelementptr inbounds i8, ptr %.01219, i64 8
  %9 = load ptr, ptr %8, align 8, !tbaa !5
  %.0.in = getelementptr inbounds i8, ptr %6, i64 8
  %.0 = load ptr, ptr %.0.in, align 8, !tbaa !5
  %.not = icmp eq ptr %.0, null
  br i1 %.not, label %.critedge, label %.lr.ph, !llvm.loop !11

.critedge:                                        ; preds = %.lr.ph, %7, %.preheader
  %.012.lcssa = phi ptr [ %0, %.preheader ], [ %9, %7 ], [ %.01219, %.lr.ph ]
  store ptr %0, ptr %1, align 8, !tbaa !13
  %10 = getelementptr inbounds i8, ptr %.012.lcssa, i64 8
  %11 = load ptr, ptr %10, align 8, !tbaa !5
  store ptr %11, ptr %2, align 8, !tbaa !13
  store ptr null, ptr %10, align 8, !tbaa !5
  br label %12

12:                                               ; preds = %3, %.critedge
  ret void
}

attributes #0 = { mustprogress 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 = !{!"_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 = !{!10, !10, i64 0}


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