; LLVM IR from 6leetcode/6leetcode :: questions/Algorithms/0023. Merge k Sorted Lists (Solution)

; 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.std::__cxx11::basic_string" = type { %"struct.std::__cxx11::basic_string<char>::_Alloc_hider", i64, %union.anon }
%"struct.std::__cxx11::basic_string<char>::_Alloc_hider" = type { ptr }
%union.anon = type { i64, [8 x i8] }
%"class.std::__cxx11::basic_stringstream" = type { %"class.std::basic_iostream.base", %"class.std::__cxx11::basic_stringbuf", %"class.std::basic_ios" }
%"class.std::basic_iostream.base" = type { %"class.std::basic_istream.base", %"class.std::basic_ostream.base" }
%"class.std::basic_istream.base" = type { ptr, i64 }
%"class.std::basic_ostream.base" = type { ptr }
%"class.std::__cxx11::basic_stringbuf" = type { %"class.std::basic_streambuf", i32, %"class.std::__cxx11::basic_string" }
%"class.std::basic_streambuf" = type { ptr, ptr, ptr, ptr, ptr, ptr, ptr, %"class.std::locale" }
%"class.std::locale" = type { ptr }
%"class.std::basic_ios" = type { %"class.std::ios_base", ptr, i8, i8, ptr, ptr, ptr, ptr }
%"class.std::ios_base" = type { ptr, i64, i64, i32, i32, i32, ptr, %"struct.std::ios_base::_Words", [8 x %"struct.std::ios_base::_Words"], i32, ptr, %"class.std::locale" }
%"struct.std::ios_base::_Words" = type { ptr, i64 }
%struct.ListNode = type { i32, ptr }

@.str = external hidden unnamed_addr constant [5 x i8], align 1

; Function Attrs: mustprogress uwtable
define dso_local void @_Z13ListNode_showB5cxx11P8ListNode(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8 %0, ptr noundef %1) #0 personality ptr @__gxx_personality_v0 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca %"class.std::__cxx11::basic_stringstream", align 8
  %6 = alloca i8, align 1
  %7 = alloca ptr, align 8
  %8 = alloca ptr, align 8
  %9 = alloca i32, align 4
  store ptr %0, ptr %3, align 8
  store ptr %1, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 392, ptr %5) #5
  call void @_ZNSt7__cxx1118basic_stringstreamIcSt11char_traitsIcESaIcEEC1Ev(ptr noundef nonnull align 8 dereferenceable(128) %5)
  call void @llvm.lifetime.start.p0(i64 1, ptr %6) #5
  store i8 1, ptr %6, align 1, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #5
  %10 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %10, ptr %7, align 8, !tbaa !5
  br label %11

11:                                               ; preds = %37, %2
  %12 = load ptr, ptr %7, align 8, !tbaa !5
  %13 = icmp ne ptr %12, null
  br i1 %13, label %14, label %41

14:                                               ; preds = %11
  %15 = load i8, ptr %6, align 1, !tbaa !9, !range !11, !noundef !12
  %16 = trunc i8 %15 to i1
  br i1 %16, label %17, label %28

17:                                               ; preds = %14
  %18 = getelementptr inbounds i8, ptr %5, i64 16
  %19 = load ptr, ptr %7, align 8, !tbaa !5
  %20 = getelementptr inbounds %struct.ListNode, ptr %19, i32 0, i32 0
  %21 = load i32, ptr %20, align 8, !tbaa !13
  %22 = invoke noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) %18, i32 noundef %21)
          to label %23 unwind label %24

23:                                               ; preds = %17
  store i8 0, ptr %6, align 1, !tbaa !9
  br label %37

24:                                               ; preds = %41, %31, %28, %17
  %25 = landingpad { ptr, i32 }
          cleanup
  %26 = extractvalue { ptr, i32 } %25, 0
  store ptr %26, ptr %8, align 8
  %27 = extractvalue { ptr, i32 } %25, 1
  store i32 %27, ptr %9, align 4
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #5
  call void @llvm.lifetime.end.p0(i64 1, ptr %6) #5
  call void @_ZNSt7__cxx1118basic_stringstreamIcSt11char_traitsIcESaIcEED1Ev(ptr noundef nonnull align 8 dereferenceable(128) %5) #5
  call void @llvm.lifetime.end.p0(i64 392, ptr %5) #5
  br label %43

28:                                               ; preds = %14
  %29 = getelementptr inbounds i8, ptr %5, i64 16
  %30 = invoke noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) %29, ptr noundef @.str)
          to label %31 unwind label %24

31:                                               ; preds = %28
  %32 = load ptr, ptr %7, align 8, !tbaa !5
  %33 = getelementptr inbounds %struct.ListNode, ptr %32, i32 0, i32 0
  %34 = load i32, ptr %33, align 8, !tbaa !13
  %35 = invoke noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) %30, i32 noundef %34)
          to label %36 unwind label %24

36:                                               ; preds = %31
  br label %37

37:                                               ; preds = %36, %23
  %38 = load ptr, ptr %7, align 8, !tbaa !5
  %39 = getelementptr inbounds %struct.ListNode, ptr %38, i32 0, i32 1
  %40 = load ptr, ptr %39, align 8, !tbaa !16
  store ptr %40, ptr %7, align 8, !tbaa !5
  br label %11, !llvm.loop !17

41:                                               ; preds = %11
  invoke void @_ZNKSt7__cxx1118basic_stringstreamIcSt11char_traitsIcESaIcEE3strEv(ptr dead_on_unwind writable sret(%"class.std::__cxx11::basic_string") align 8 %0, ptr noundef nonnull align 8 dereferenceable(128) %5)
          to label %42 unwind label %24

42:                                               ; preds = %41
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #5
  call void @llvm.lifetime.end.p0(i64 1, ptr %6) #5
  call void @_ZNSt7__cxx1118basic_stringstreamIcSt11char_traitsIcESaIcEED1Ev(ptr noundef nonnull align 8 dereferenceable(128) %5) #5
  call void @llvm.lifetime.end.p0(i64 392, ptr %5) #5
  ret void

43:                                               ; preds = %24
  %44 = load ptr, ptr %8, align 8
  %45 = load i32, ptr %9, align 4
  %46 = insertvalue { ptr, i32 } poison, ptr %44, 0
  %47 = insertvalue { ptr, i32 } %46, i32 %45, 1
  resume { ptr, i32 } %47
}

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

; Function Attrs: mustprogress uwtable
declare void @_ZNSt7__cxx1118basic_stringstreamIcSt11char_traitsIcESaIcEEC1Ev(ptr noundef nonnull align 8 dereferenceable(128)) unnamed_addr #0 align 2

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) #2

declare i32 @__gxx_personality_v0(...)

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) #3

; Function Attrs: mustprogress uwtable
declare void @_ZNKSt7__cxx1118basic_stringstreamIcSt11char_traitsIcESaIcEE3strEv(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8, ptr noundef nonnull align 8 dereferenceable(128)) #0 align 2

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

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1118basic_stringstreamIcSt11char_traitsIcESaIcEED1Ev(ptr noundef nonnull align 8 dereferenceable(128)) unnamed_addr #4 align 2

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" }
attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { "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 = { inlinehint 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 #4 = { 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 #5 = { 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, !10, i64 0}
!10 = !{!"bool", !7, i64 0}
!11 = !{i8 0, i8 2}
!12 = !{}
!13 = !{!14, !15, i64 0}
!14 = !{!"_ZTS8ListNode", !15, i64 0, !6, i64 8}
!15 = !{!"int", !7, i64 0}
!16 = !{!14, !6, i64 8}
!17 = distinct !{!17, !18}
!18 = !{!"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"

%"class.std::__cxx11::basic_string" = type { %"struct.std::__cxx11::basic_string<char>::_Alloc_hider", i64, %union.anon }
%"struct.std::__cxx11::basic_string<char>::_Alloc_hider" = type { ptr }
%union.anon = type { i64, [8 x i8] }
%"class.std::__cxx11::basic_stringstream" = type { %"class.std::basic_iostream.base", %"class.std::__cxx11::basic_stringbuf", %"class.std::basic_ios" }
%"class.std::basic_iostream.base" = type { %"class.std::basic_istream.base", %"class.std::basic_ostream.base" }
%"class.std::basic_istream.base" = type { ptr, i64 }
%"class.std::basic_ostream.base" = type { ptr }
%"class.std::__cxx11::basic_stringbuf" = type { %"class.std::basic_streambuf", i32, %"class.std::__cxx11::basic_string" }
%"class.std::basic_streambuf" = type { ptr, ptr, ptr, ptr, ptr, ptr, ptr, %"class.std::locale" }
%"class.std::locale" = type { ptr }
%"class.std::basic_ios" = type { %"class.std::ios_base", ptr, i8, i8, ptr, ptr, ptr, ptr }
%"class.std::ios_base" = type { ptr, i64, i64, i32, i32, i32, ptr, %"struct.std::ios_base::_Words", [8 x %"struct.std::ios_base::_Words"], i32, ptr, %"class.std::locale" }
%"struct.std::ios_base::_Words" = type { ptr, i64 }

@.str = external hidden unnamed_addr constant [5 x i8], align 1

; Function Attrs: mustprogress uwtable
define dso_local void @_Z13ListNode_showB5cxx11P8ListNode(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8 %0, ptr noundef readonly %1) local_unnamed_addr #0 personality ptr @__gxx_personality_v0 {
  %3 = alloca %"class.std::__cxx11::basic_stringstream", align 8
  call void @llvm.lifetime.start.p0(i64 392, ptr nonnull %3) #5
  call void @_ZNSt7__cxx1118basic_stringstreamIcSt11char_traitsIcESaIcEEC1Ev(ptr noundef nonnull align 8 dereferenceable(128) %3)
  %.not8 = icmp eq ptr %1, null
  br i1 %.not8, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %2
  %4 = getelementptr inbounds i8, ptr %3, i64 16
  %5 = load i32, ptr %1, align 8, !tbaa !5
  %6 = invoke noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) %4, i32 noundef %5)
          to label %7 unwind label %.loopexit.loopexit.split-lp

7:                                                ; preds = %.lr.ph
  %8 = getelementptr inbounds i8, ptr %1, i64 8
  %9 = load ptr, ptr %8, align 8, !tbaa !11
  %.not.peel = icmp eq ptr %9, null
  br i1 %.not.peel, label %._crit_edge, label %.lr.ph.peel.newph

.lr.ph.peel.newph:                                ; preds = %7, %13
  %.079 = phi ptr [ %15, %13 ], [ %9, %7 ]
  %10 = invoke noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) %4, ptr noundef nonnull @.str)
          to label %.invoke unwind label %.loopexit.loopexit

.invoke:                                          ; preds = %.lr.ph.peel.newph
  %11 = load i32, ptr %.079, align 8, !tbaa !5
  %12 = invoke noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) %10, i32 noundef %11)
          to label %13 unwind label %.loopexit.loopexit

.loopexit.loopexit:                               ; preds = %.lr.ph.peel.newph, %.invoke
  %lpad.loopexit12 = landingpad { ptr, i32 }
          cleanup
  br label %.loopexit

.loopexit.loopexit.split-lp:                      ; preds = %.lr.ph
  %lpad.loopexit.split-lp13 = landingpad { ptr, i32 }
          cleanup
  br label %.loopexit

.loopexit.split-lp:                               ; preds = %._crit_edge
  %lpad.loopexit.split-lp = landingpad { ptr, i32 }
          cleanup
  br label %.loopexit

.loopexit:                                        ; preds = %.loopexit.loopexit, %.loopexit.loopexit.split-lp, %.loopexit.split-lp
  %lpad.phi = phi { ptr, i32 } [ %lpad.loopexit.split-lp, %.loopexit.split-lp ], [ %lpad.loopexit12, %.loopexit.loopexit ], [ %lpad.loopexit.split-lp13, %.loopexit.loopexit.split-lp ]
  call void @_ZNSt7__cxx1118basic_stringstreamIcSt11char_traitsIcESaIcEED1Ev(ptr noundef nonnull align 8 dereferenceable(128) %3) #5
  call void @llvm.lifetime.end.p0(i64 392, ptr nonnull %3) #5
  resume { ptr, i32 } %lpad.phi

13:                                               ; preds = %.invoke
  %14 = getelementptr inbounds i8, ptr %.079, i64 8
  %15 = load ptr, ptr %14, align 8, !tbaa !11
  %.not = icmp eq ptr %15, null
  br i1 %.not, label %._crit_edge, label %.lr.ph.peel.newph, !llvm.loop !12

._crit_edge:                                      ; preds = %7, %13, %2
  invoke void @_ZNKSt7__cxx1118basic_stringstreamIcSt11char_traitsIcESaIcEE3strEv(ptr dead_on_unwind writable sret(%"class.std::__cxx11::basic_string") align 8 %0, ptr noundef nonnull align 8 dereferenceable(128) %3)
          to label %16 unwind label %.loopexit.split-lp

16:                                               ; preds = %._crit_edge
  call void @_ZNSt7__cxx1118basic_stringstreamIcSt11char_traitsIcESaIcEED1Ev(ptr noundef nonnull align 8 dereferenceable(128) %3) #5
  call void @llvm.lifetime.end.p0(i64 392, ptr nonnull %3) #5
  ret void
}

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

; Function Attrs: mustprogress uwtable
declare void @_ZNSt7__cxx1118basic_stringstreamIcSt11char_traitsIcESaIcEEC1Ev(ptr noundef nonnull align 8 dereferenceable(128)) unnamed_addr #0 align 2

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) local_unnamed_addr #2

declare i32 @__gxx_personality_v0(...)

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) local_unnamed_addr #3

; Function Attrs: mustprogress uwtable
declare void @_ZNKSt7__cxx1118basic_stringstreamIcSt11char_traitsIcESaIcEE3strEv(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8, ptr noundef nonnull align 8 dereferenceable(128)) local_unnamed_addr #0 align 2

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

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSt7__cxx1118basic_stringstreamIcSt11char_traitsIcESaIcEED1Ev(ptr noundef nonnull align 8 dereferenceable(128)) unnamed_addr #4 align 2

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" }
attributes #1 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { "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 = { inlinehint 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 #4 = { 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 #5 = { 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, !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}
!12 = distinct !{!12, !13, !14}
!13 = !{!"llvm.loop.mustprogress"}
!14 = !{!"llvm.loop.peeled.count", i32 1}


; Effective O3 passes: AggressiveInstCombinePass,EarlyCSEPass,GVNPass,GlobalOptPass,IPSCCPPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LICMPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass