; LLVM IR from Lakhankumawat/LearnCPP :: L-LinkedList/Merge K Sorted LinkedList/merge_k_ll.ll (Z5mergeP4NodeS0_)

; 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
define dso_local noundef ptr @_Z5mergeP4NodeS0_(ptr noundef %0, ptr noundef %1) #1 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca ptr, align 8
  store ptr %0, ptr %4, align 8, !tbaa !5
  store ptr %1, ptr %5, align 8, !tbaa !5
  %7 = load ptr, ptr %4, align 8, !tbaa !5
  %8 = icmp eq ptr %7, null
  br i1 %8, label %9, label %11

9:                                                ; preds = %2
  %10 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %10, ptr %3, align 8
  br label %54

11:                                               ; preds = %2
  %12 = load ptr, ptr %5, align 8, !tbaa !5
  %13 = icmp eq ptr %12, null
  br i1 %13, label %14, label %16

14:                                               ; preds = %11
  %15 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %15, ptr %3, align 8
  br label %54

16:                                               ; preds = %11
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #2
  %17 = load ptr, ptr %4, align 8, !tbaa !5
  %18 = getelementptr inbounds %class.Node, ptr %17, i32 0, i32 0
  %19 = load i32, ptr %18, align 8, !tbaa !9
  %20 = load ptr, ptr %5, align 8, !tbaa !5
  %21 = getelementptr inbounds %class.Node, ptr %20, i32 0, i32 0
  %22 = load i32, ptr %21, align 8, !tbaa !9
  %23 = icmp sle i32 %19, %22
  br i1 %23, label %24, label %26

24:                                               ; preds = %16
  %25 = load ptr, ptr %4, align 8, !tbaa !5
  br label %28

26:                                               ; preds = %16
  %27 = load ptr, ptr %5, align 8, !tbaa !5
  br label %28

28:                                               ; preds = %26, %24
  %29 = phi ptr [ %25, %24 ], [ %27, %26 ]
  store ptr %29, ptr %6, align 8, !tbaa !5
  %30 = load ptr, ptr %4, align 8, !tbaa !5
  %31 = getelementptr inbounds %class.Node, ptr %30, i32 0, i32 0
  %32 = load i32, ptr %31, align 8, !tbaa !9
  %33 = load ptr, ptr %5, align 8, !tbaa !5
  %34 = getelementptr inbounds %class.Node, ptr %33, i32 0, i32 0
  %35 = load i32, ptr %34, align 8, !tbaa !9
  %36 = icmp sle i32 %32, %35
  br i1 %36, label %37, label %43

37:                                               ; preds = %28
  %38 = load ptr, ptr %4, align 8, !tbaa !5
  %39 = getelementptr inbounds %class.Node, ptr %38, i32 0, i32 1
  %40 = load ptr, ptr %39, align 8, !tbaa !12
  %41 = load ptr, ptr %5, align 8, !tbaa !5
  %42 = call noundef ptr @_Z5mergeP4NodeS0_(ptr noundef %40, ptr noundef %41)
  br label %49

43:                                               ; preds = %28
  %44 = load ptr, ptr %4, align 8, !tbaa !5
  %45 = load ptr, ptr %5, align 8, !tbaa !5
  %46 = getelementptr inbounds %class.Node, ptr %45, i32 0, i32 1
  %47 = load ptr, ptr %46, align 8, !tbaa !12
  %48 = call noundef ptr @_Z5mergeP4NodeS0_(ptr noundef %44, ptr noundef %47)
  br label %49

49:                                               ; preds = %43, %37
  %50 = phi ptr [ %42, %37 ], [ %48, %43 ]
  %51 = load ptr, ptr %6, align 8, !tbaa !5
  %52 = getelementptr inbounds %class.Node, ptr %51, i32 0, i32 1
  store ptr %50, ptr %52, align 8, !tbaa !12
  %53 = load ptr, ptr %6, align 8, !tbaa !5
  store ptr %53, ptr %3, align 8
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #2
  br label %54

54:                                               ; preds = %49, %14, %9
  %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, !11, i64 0}
!10 = !{!"_ZTS4Node", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = !{!10, !6, i64 8}


; 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 nosync nounwind memory(readwrite, inaccessiblemem: none) uwtable
define dso_local noundef ptr @_Z5mergeP4NodeS0_(ptr noundef %0, ptr noundef %1) local_unnamed_addr #0 {
  %3 = icmp eq ptr %0, null
  br i1 %3, label %21, label %4

4:                                                ; preds = %2
  %5 = icmp eq ptr %1, null
  br i1 %5, label %21, label %6

6:                                                ; preds = %4
  %7 = load i32, ptr %0, align 8, !tbaa !5
  %8 = load i32, ptr %1, align 8, !tbaa !5
  %.not = icmp sgt i32 %7, %8
  %9 = select i1 %.not, ptr %1, ptr %0
  br i1 %.not, label %14, label %10

10:                                               ; preds = %6
  %11 = getelementptr inbounds i8, ptr %0, i64 8
  %12 = load ptr, ptr %11, align 8, !tbaa !11
  %13 = tail call noundef ptr @_Z5mergeP4NodeS0_(ptr noundef %12, ptr noundef nonnull %1)
  br label %18

14:                                               ; preds = %6
  %15 = getelementptr inbounds i8, ptr %1, i64 8
  %16 = load ptr, ptr %15, align 8, !tbaa !11
  %17 = tail call noundef ptr @_Z5mergeP4NodeS0_(ptr noundef nonnull %0, ptr noundef %16)
  br label %18

18:                                               ; preds = %14, %10
  %19 = phi ptr [ %13, %10 ], [ %17, %14 ]
  %20 = getelementptr inbounds i8, ptr %9, i64 8
  store ptr %19, ptr %20, align 8, !tbaa !11
  br label %21

21:                                               ; preds = %4, %2, %18
  %.0 = phi ptr [ %9, %18 ], [ %1, %2 ], [ %0, %4 ]
  ret ptr %.0
}

attributes #0 = { mustprogress nofree 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, !7, i64 0}
!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 = !{!6, !10, i64 8}


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