; LLVM IR from lolosssss/leetcode :: c (23_merge_k_sorted_lists)

; 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"

; Function Attrs: nounwind uwtable
declare dso_local ptr @mergeTwoLists(ptr noundef, ptr noundef) #0

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: nounwind uwtable
define dso_local ptr @merge(ptr noundef %0, i32 noundef %1, i32 noundef %2) #0 {
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  %8 = alloca i32, align 4
  %9 = alloca ptr, align 8
  %10 = alloca ptr, align 8
  store ptr %0, ptr %5, align 8, !tbaa !5
  store i32 %1, ptr %6, align 4, !tbaa !9
  store i32 %2, ptr %7, align 4, !tbaa !9
  %11 = load i32, ptr %6, align 4, !tbaa !9
  %12 = load i32, ptr %7, align 4, !tbaa !9
  %13 = icmp sgt i32 %11, %12
  br i1 %13, label %14, label %15

14:                                               ; preds = %3
  store ptr null, ptr %4, align 8
  br label %42

15:                                               ; preds = %3
  %16 = load i32, ptr %6, align 4, !tbaa !9
  %17 = load i32, ptr %7, align 4, !tbaa !9
  %18 = icmp eq i32 %16, %17
  br i1 %18, label %19, label %25

19:                                               ; preds = %15
  %20 = load ptr, ptr %5, align 8, !tbaa !5
  %21 = load i32, ptr %6, align 4, !tbaa !9
  %22 = sext i32 %21 to i64
  %23 = getelementptr inbounds ptr, ptr %20, i64 %22
  %24 = load ptr, ptr %23, align 8, !tbaa !5
  store ptr %24, ptr %4, align 8
  br label %42

25:                                               ; preds = %15
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #2
  %26 = load i32, ptr %6, align 4, !tbaa !9
  %27 = load i32, ptr %7, align 4, !tbaa !9
  %28 = add nsw i32 %26, %27
  %29 = sdiv i32 %28, 2
  store i32 %29, ptr %8, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %9) #2
  %30 = load ptr, ptr %5, align 8, !tbaa !5
  %31 = load i32, ptr %6, align 4, !tbaa !9
  %32 = load i32, ptr %8, align 4, !tbaa !9
  %33 = call ptr @merge(ptr noundef %30, i32 noundef %31, i32 noundef %32)
  store ptr %33, ptr %9, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %10) #2
  %34 = load ptr, ptr %5, align 8, !tbaa !5
  %35 = load i32, ptr %8, align 4, !tbaa !9
  %36 = add nsw i32 %35, 1
  %37 = load i32, ptr %7, align 4, !tbaa !9
  %38 = call ptr @merge(ptr noundef %34, i32 noundef %36, i32 noundef %37)
  store ptr %38, ptr %10, align 8, !tbaa !5
  %39 = load ptr, ptr %9, align 8, !tbaa !5
  %40 = load ptr, ptr %10, align 8, !tbaa !5
  %41 = call ptr @mergeTwoLists(ptr noundef %39, ptr noundef %40)
  store ptr %41, ptr %4, align 8
  call void @llvm.lifetime.end.p0(i64 8, ptr %10) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %9) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #2
  br label %42

42:                                               ; preds = %25, %19, %14
  %43 = load ptr, ptr %4, align 8
  ret ptr %43
}

attributes #0 = { 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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"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: nounwind uwtable
declare dso_local ptr @mergeTwoLists(ptr noundef, ptr noundef) local_unnamed_addr #0

; Function Attrs: nounwind uwtable
define dso_local ptr @merge(ptr noundef %0, i32 noundef %1, i32 noundef %2) local_unnamed_addr #0 {
  %4 = icmp sgt i32 %1, %2
  br i1 %4, label %common.ret18, label %5

5:                                                ; preds = %3
  %6 = icmp eq i32 %1, %2
  br i1 %6, label %7, label %11

7:                                                ; preds = %5
  %8 = sext i32 %1 to i64
  %9 = getelementptr inbounds ptr, ptr %0, i64 %8
  %10 = load ptr, ptr %9, align 8, !tbaa !5
  br label %common.ret18

common.ret18:                                     ; preds = %3, %7, %11
  %common.ret18.op = phi ptr [ %17, %11 ], [ %10, %7 ], [ null, %3 ]
  ret ptr %common.ret18.op

11:                                               ; preds = %5
  %12 = add nsw i32 %2, %1
  %13 = sdiv i32 %12, 2
  %14 = tail call ptr @merge(ptr noundef %0, i32 noundef %1, i32 noundef %13)
  %15 = add nsw i32 %13, 1
  %16 = tail call ptr @merge(ptr noundef %0, i32 noundef %15, i32 noundef %2)
  %17 = tail call ptr @mergeTwoLists(ptr noundef %14, ptr noundef %16)
  br label %common.ret18
}

attributes #0 = { 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" }

!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"}


; Effective O3 passes: GlobalOptPass,InferFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass,TailCallElimPass