; LLVM IR from smv1999/CompetitiveProgrammingQuestionBank :: Data Structures/Linked Lists/Singly Linked List (merge_k_sorted_linkedlist)

; 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.ListNode = type { i32, ptr }

; Function Attrs: mustprogress uwtable
define dso_local noundef ptr @_Z13mergeTwoListsP8ListNodeS0_(ptr noundef %0, ptr noundef %1) #0 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  store ptr %0, ptr %4, align 8, !tbaa !5
  store ptr %1, ptr %5, align 8, !tbaa !5
  %6 = load ptr, ptr %4, align 8, !tbaa !5
  %7 = icmp ne ptr %6, null
  br i1 %7, label %10, label %8

8:                                                ; preds = %2
  %9 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %9, ptr %3, align 8
  br label %41

10:                                               ; preds = %2
  %11 = load ptr, ptr %5, align 8, !tbaa !5
  %12 = icmp ne ptr %11, null
  br i1 %12, label %15, label %13

13:                                               ; preds = %10
  %14 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %14, ptr %3, align 8
  br label %41

15:                                               ; preds = %10
  %16 = load ptr, ptr %4, align 8, !tbaa !5
  %17 = getelementptr inbounds %struct.ListNode, ptr %16, i32 0, i32 0
  %18 = load i32, ptr %17, align 8, !tbaa !9
  %19 = load ptr, ptr %5, align 8, !tbaa !5
  %20 = getelementptr inbounds %struct.ListNode, ptr %19, i32 0, i32 0
  %21 = load i32, ptr %20, align 8, !tbaa !9
  %22 = icmp slt i32 %18, %21
  br i1 %22, label %23, label %32

23:                                               ; preds = %15
  %24 = load ptr, ptr %4, align 8, !tbaa !5
  %25 = getelementptr inbounds %struct.ListNode, ptr %24, i32 0, i32 1
  %26 = load ptr, ptr %25, align 8, !tbaa !12
  %27 = load ptr, ptr %5, align 8, !tbaa !5
  %28 = call noundef ptr @_Z13mergeTwoListsP8ListNodeS0_(ptr noundef %26, ptr noundef %27)
  %29 = load ptr, ptr %4, align 8, !tbaa !5
  %30 = getelementptr inbounds %struct.ListNode, ptr %29, i32 0, i32 1
  store ptr %28, ptr %30, align 8, !tbaa !12
  %31 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %31, ptr %3, align 8
  br label %41

32:                                               ; preds = %15
  %33 = load ptr, ptr %4, align 8, !tbaa !5
  %34 = load ptr, ptr %5, align 8, !tbaa !5
  %35 = getelementptr inbounds %struct.ListNode, ptr %34, i32 0, i32 1
  %36 = load ptr, ptr %35, align 8, !tbaa !12
  %37 = call noundef ptr @_Z13mergeTwoListsP8ListNodeS0_(ptr noundef %33, ptr noundef %36)
  %38 = load ptr, ptr %5, align 8, !tbaa !5
  %39 = getelementptr inbounds %struct.ListNode, ptr %38, i32 0, i32 1
  store ptr %37, ptr %39, align 8, !tbaa !12
  %40 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %40, ptr %3, align 8
  br label %41

41:                                               ; preds = %32, %23, %13, %8
  %42 = load ptr, ptr %3, align 8
  ret ptr %42
}

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, !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 = !{!"_ZTS8ListNode", !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 @_Z13mergeTwoListsP8ListNodeS0_(ptr noundef %0, ptr noundef %1) local_unnamed_addr #0 {
  %.not = icmp eq ptr %0, null
  br i1 %.not, label %common.ret18, label %3

3:                                                ; preds = %2
  %.not17 = icmp eq ptr %1, null
  br i1 %.not17, label %common.ret18, label %4

4:                                                ; preds = %3
  %5 = load i32, ptr %0, align 8, !tbaa !5
  %6 = load i32, ptr %1, align 8, !tbaa !5
  %7 = icmp slt i32 %5, %6
  br i1 %7, label %8, label %12

common.ret18:                                     ; preds = %3, %2, %12, %8
  %common.ret18.op = phi ptr [ %0, %8 ], [ %1, %12 ], [ %1, %2 ], [ %0, %3 ]
  ret ptr %common.ret18.op

8:                                                ; preds = %4
  %9 = getelementptr inbounds i8, ptr %0, i64 8
  %10 = load ptr, ptr %9, align 8, !tbaa !11
  %11 = tail call noundef ptr @_Z13mergeTwoListsP8ListNodeS0_(ptr noundef %10, ptr noundef nonnull %1)
  store ptr %11, ptr %9, align 8, !tbaa !11
  br label %common.ret18

12:                                               ; preds = %4
  %13 = getelementptr inbounds i8, ptr %1, i64 8
  %14 = load ptr, ptr %13, align 8, !tbaa !11
  %15 = tail call noundef ptr @_Z13mergeTwoListsP8ListNodeS0_(ptr noundef nonnull %0, ptr noundef %14)
  store ptr %15, ptr %13, align 8, !tbaa !11
  br label %common.ret18
}

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 = !{!"_ZTS8ListNode", !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,InstCombinePass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass