; LLVM IR from ritikbanger/Hacktoberfest2022-DSA :: 10. Linked List/MergeSortLinkedList.ll (Z9mergeSortP4Node)

; 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 nounwind uwtable
declare dso_local noundef ptr @_Z8midPointP4Node(ptr noundef) #1

; Function Attrs: mustprogress uwtable
declare dso_local noundef ptr @_Z11sortedMergeP4NodeS0_(ptr noundef, ptr noundef) #2

; Function Attrs: mustprogress uwtable
define dso_local noundef ptr @_Z9mergeSortP4Node(ptr noundef %0) #2 {
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  %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
  %9 = alloca ptr, align 8
  store ptr %0, ptr %3, align 8, !tbaa !5
  %10 = load ptr, ptr %3, align 8, !tbaa !5
  %11 = icmp eq ptr %10, null
  br i1 %11, label %17, label %12

12:                                               ; preds = %1
  %13 = load ptr, ptr %3, align 8, !tbaa !5
  %14 = getelementptr inbounds %class.Node, ptr %13, i32 0, i32 1
  %15 = load ptr, ptr %14, align 8, !tbaa !9
  %16 = icmp eq ptr %15, null
  br i1 %16, label %17, label %19

17:                                               ; preds = %12, %1
  %18 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %18, ptr %2, align 8
  br label %36

19:                                               ; preds = %12
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #3
  %20 = load ptr, ptr %3, align 8, !tbaa !5
  %21 = call noundef ptr @_Z8midPointP4Node(ptr noundef %20)
  store ptr %21, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #3
  %22 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %22, ptr %5, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #3
  %23 = load ptr, ptr %4, align 8, !tbaa !5
  %24 = getelementptr inbounds %class.Node, ptr %23, i32 0, i32 1
  %25 = load ptr, ptr %24, align 8, !tbaa !9
  store ptr %25, ptr %6, align 8, !tbaa !5
  %26 = load ptr, ptr %5, align 8, !tbaa !5
  %27 = getelementptr inbounds %class.Node, ptr %26, i32 0, i32 1
  store ptr null, ptr %27, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #3
  %28 = load ptr, ptr %3, align 8, !tbaa !5
  %29 = call noundef ptr @_Z9mergeSortP4Node(ptr noundef %28)
  store ptr %29, ptr %7, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %8) #3
  %30 = load ptr, ptr %6, align 8, !tbaa !5
  %31 = call noundef ptr @_Z9mergeSortP4Node(ptr noundef %30)
  store ptr %31, ptr %8, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %9) #3
  %32 = load ptr, ptr %7, align 8, !tbaa !5
  %33 = load ptr, ptr %8, align 8, !tbaa !5
  %34 = call noundef ptr @_Z11sortedMergeP4NodeS0_(ptr noundef %32, ptr noundef %33)
  store ptr %34, ptr %9, align 8, !tbaa !5
  %35 = load ptr, ptr %9, align 8, !tbaa !5
  store ptr %35, ptr %2, align 8
  call void @llvm.lifetime.end.p0(i64 8, ptr %9) #3
  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 8, ptr %5) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #3
  br label %36

36:                                               ; preds = %19, %17
  %37 = load ptr, ptr %2, align 8
  ret ptr %37
}

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 = { 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 #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, !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}


; 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 nounwind uwtable
declare dso_local noundef ptr @_Z8midPointP4Node(ptr noundef) local_unnamed_addr #0

; Function Attrs: mustprogress uwtable
declare dso_local noundef ptr @_Z11sortedMergeP4NodeS0_(ptr noundef, ptr noundef) local_unnamed_addr #1

; Function Attrs: mustprogress uwtable
define dso_local noundef ptr @_Z9mergeSortP4Node(ptr noundef %0) local_unnamed_addr #1 {
  %2 = icmp eq ptr %0, null
  br i1 %2, label %common.ret14, label %3

3:                                                ; preds = %1
  %4 = getelementptr inbounds i8, ptr %0, i64 8
  %5 = load ptr, ptr %4, align 8, !tbaa !5
  %6 = icmp eq ptr %5, null
  br i1 %6, label %common.ret14, label %7

common.ret14:                                     ; preds = %1, %3, %7
  %common.ret14.op = phi ptr [ %13, %7 ], [ %0, %3 ], [ null, %1 ]
  ret ptr %common.ret14.op

7:                                                ; preds = %3
  %8 = tail call noundef ptr @_Z8midPointP4Node(ptr noundef nonnull %0)
  %9 = getelementptr inbounds i8, ptr %8, i64 8
  %10 = load ptr, ptr %9, align 8, !tbaa !5
  store ptr null, ptr %9, align 8, !tbaa !5
  %11 = tail call noundef ptr @_Z9mergeSortP4Node(ptr noundef nonnull %0)
  %12 = tail call noundef ptr @_Z9mergeSortP4Node(ptr noundef %10)
  %13 = tail call noundef ptr @_Z11sortedMergeP4NodeS0_(ptr noundef %11, ptr noundef %12)
  br label %common.ret14
}

attributes #0 = { 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 #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" }

!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}


; Effective O3 passes: CorrelatedValuePropagationPass,EarlyCSEPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,SROAPass,SimplifyCFGPass,TailCallElimPass