; LLVM IR from ImChong/Practice_LeetCode_C :: F02_Programming_Topics/F01_Data_Structure/02_Linked_List/11_MergeKLists (main)

; 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 @mergeKLists(ptr noundef %0, i32 noundef %1) #0 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca ptr, align 8
  %7 = alloca ptr, align 8
  %8 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !9
  %9 = load i32, ptr %5, align 4, !tbaa !9
  %10 = icmp eq i32 %9, 0
  br i1 %10, label %11, label %12

11:                                               ; preds = %2
  store ptr null, ptr %3, align 8
  br label %35

12:                                               ; preds = %2
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #2
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #2
  %13 = load ptr, ptr %4, align 8, !tbaa !5
  %14 = getelementptr inbounds ptr, ptr %13, i64 0
  %15 = load ptr, ptr %14, align 8, !tbaa !5
  store ptr %15, ptr %6, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #2
  store i32 1, ptr %8, align 4, !tbaa !9
  br label %16

16:                                               ; preds = %30, %12
  %17 = load i32, ptr %8, align 4, !tbaa !9
  %18 = load i32, ptr %5, align 4, !tbaa !9
  %19 = icmp slt i32 %17, %18
  br i1 %19, label %21, label %20

20:                                               ; preds = %16
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #2
  br label %33

21:                                               ; preds = %16
  %22 = load ptr, ptr %4, align 8, !tbaa !5
  %23 = load i32, ptr %8, align 4, !tbaa !9
  %24 = sext i32 %23 to i64
  %25 = getelementptr inbounds ptr, ptr %22, i64 %24
  %26 = load ptr, ptr %25, align 8, !tbaa !5
  store ptr %26, ptr %7, align 8, !tbaa !5
  %27 = load ptr, ptr %6, align 8, !tbaa !5
  %28 = load ptr, ptr %7, align 8, !tbaa !5
  %29 = call ptr @MergeTwoLists(ptr noundef %27, ptr noundef %28)
  store ptr %29, ptr %6, align 8, !tbaa !5
  br label %30

30:                                               ; preds = %21
  %31 = load i32, ptr %8, align 4, !tbaa !9
  %32 = add nsw i32 %31, 1
  store i32 %32, ptr %8, align 4, !tbaa !9
  br label %16, !llvm.loop !11

33:                                               ; preds = %20
  %34 = load ptr, ptr %6, align 8, !tbaa !5
  store ptr %34, ptr %3, align 8
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #2
  br label %35

35:                                               ; preds = %33, %11
  %36 = load ptr, ptr %3, align 8
  ret ptr %36
}

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}
!11 = distinct !{!11, !12}
!12 = !{!"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: nounwind uwtable
declare dso_local ptr @MergeTwoLists(ptr noundef, ptr noundef) local_unnamed_addr #0

; Function Attrs: nounwind uwtable
define dso_local ptr @mergeKLists(ptr nocapture noundef readonly %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = icmp eq i32 %1, 0
  br i1 %3, label %.loopexit, label %4

4:                                                ; preds = %2
  %5 = load ptr, ptr %0, align 8, !tbaa !5
  %6 = icmp sgt i32 %1, 1
  br i1 %6, label %.lr.ph.preheader, label %.loopexit

.lr.ph.preheader:                                 ; preds = %4
  %wide.trip.count = zext nneg i32 %1 to i64
  br label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph.preheader, %.lr.ph
  %indvars.iv = phi i64 [ 1, %.lr.ph.preheader ], [ %indvars.iv.next, %.lr.ph ]
  %.01113 = phi ptr [ %5, %.lr.ph.preheader ], [ %9, %.lr.ph ]
  %7 = getelementptr inbounds ptr, ptr %0, i64 %indvars.iv
  %8 = load ptr, ptr %7, align 8, !tbaa !5
  %9 = tail call ptr @MergeTwoLists(ptr noundef %.01113, ptr noundef %8)
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next, %wide.trip.count
  br i1 %exitcond.not, label %.loopexit, label %.lr.ph, !llvm.loop !9

.loopexit:                                        ; preds = %.lr.ph, %4, %2
  %.010 = phi ptr [ null, %2 ], [ %5, %4 ], [ %9, %.lr.ph ]
  ret ptr %.010
}

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"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


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