; LLVM IR from afrozchakure/Competitive-Programming-Solutions :: TopicWise/Linked List (MergeSortLinkedList)

; 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::basic_istream" = type { ptr, i64, %"class.std::basic_ios" }
%"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 }
%"class.std::locale" = type { ptr }

@_ZSt3cin = external global %"class.std::basic_istream", align 8

; 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
declare dso_local noundef ptr @_Z9mergeSortP4Node(ptr noundef) #1

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z9printListP4Node(ptr noundef) #1

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z4pushPP4Nodei(ptr noundef, i32 noundef) #1

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() #2 {
  %1 = alloca i32, align 4
  %2 = alloca i64, align 8
  %3 = alloca ptr, align 8
  %4 = alloca i64, align 8
  %5 = alloca i64, align 8
  %6 = alloca i32, align 4
  store i32 0, ptr %1, align 4
  call void @llvm.lifetime.start.p0(i64 8, ptr %2) #3
  %7 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERl(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 8 dereferenceable(8) %2)
  br label %8

8:                                                ; preds = %27, %0
  %9 = load i64, ptr %2, align 8, !tbaa !5
  %10 = add nsw i64 %9, -1
  store i64 %10, ptr %2, align 8, !tbaa !5
  %11 = icmp ne i64 %9, 0
  br i1 %11, label %12, label %31

12:                                               ; preds = %8
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #3
  store ptr null, ptr %3, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #3
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #3
  %13 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERl(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 8 dereferenceable(8) %4)
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #3
  store i32 0, ptr %6, align 4, !tbaa !11
  br label %14

14:                                               ; preds = %24, %12
  %15 = load i32, ptr %6, align 4, !tbaa !11
  %16 = sext i32 %15 to i64
  %17 = load i64, ptr %4, align 8, !tbaa !5
  %18 = icmp slt i64 %16, %17
  br i1 %18, label %20, label %19

19:                                               ; preds = %14
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #3
  br label %27

20:                                               ; preds = %14
  %21 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERl(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 8 dereferenceable(8) %5)
  %22 = load i64, ptr %5, align 8, !tbaa !5
  %23 = trunc i64 %22 to i32
  call void @_Z4pushPP4Nodei(ptr noundef %3, i32 noundef %23)
  br label %24

24:                                               ; preds = %20
  %25 = load i32, ptr %6, align 4, !tbaa !11
  %26 = add nsw i32 %25, 1
  store i32 %26, ptr %6, align 4, !tbaa !11
  br label %14, !llvm.loop !13

27:                                               ; preds = %19
  %28 = load ptr, ptr %3, align 8, !tbaa !9
  %29 = call noundef ptr @_Z9mergeSortP4Node(ptr noundef %28)
  store ptr %29, ptr %3, align 8, !tbaa !9
  %30 = load ptr, ptr %3, align 8, !tbaa !9
  call void @_Z9printListP4Node(ptr noundef %30)
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #3
  br label %8, !llvm.loop !15

31:                                               ; preds = %8
  call void @llvm.lifetime.end.p0(i64 8, ptr %2) #3
  ret i32 0
}

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERl(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 8 dereferenceable(8)) #1 align 2

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 = { mustprogress norecurse 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 #3 = { 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 = !{!"long", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !7, i64 0}
!11 = !{!12, !12, i64 0}
!12 = !{!"int", !7, i64 0}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}
!15 = distinct !{!15, !14}


; 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::basic_istream" = type { ptr, i64, %"class.std::basic_ios" }
%"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 }
%"class.std::locale" = type { ptr }

@_ZSt3cin = external global %"class.std::basic_istream", align 8

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: mustprogress uwtable
declare dso_local noundef ptr @_Z9mergeSortP4Node(ptr noundef) local_unnamed_addr #1

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z9printListP4Node(ptr noundef) local_unnamed_addr #1

; Function Attrs: mustprogress uwtable
declare dso_local void @_Z4pushPP4Nodei(ptr noundef, i32 noundef) local_unnamed_addr #1

; Function Attrs: mustprogress norecurse uwtable
define dso_local noundef i32 @main() local_unnamed_addr #2 {
  %1 = alloca i64, align 8
  %2 = alloca ptr, align 8
  %3 = alloca i64, align 8
  %4 = alloca i64, align 8
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %1) #3
  %5 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERl(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 8 dereferenceable(8) %1)
  %6 = load i64, ptr %1, align 8, !tbaa !5
  %7 = add nsw i64 %6, -1
  store i64 %7, ptr %1, align 8, !tbaa !5
  %.not3 = icmp eq i64 %6, 0
  br i1 %.not3, label %._crit_edge6, label %.lr.ph5

.lr.ph5:                                          ; preds = %0, %._crit_edge
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %2) #3
  store ptr null, ptr %2, align 8, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %3) #3
  call void @llvm.lifetime.start.p0(i64 8, ptr nonnull %4) #3
  %8 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERl(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 8 dereferenceable(8) %3)
  %9 = load i64, ptr %3, align 8, !tbaa !5
  %10 = icmp sgt i64 %9, 0
  br i1 %10, label %.lr.ph, label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph, %.lr.ph5
  %11 = load ptr, ptr %2, align 8, !tbaa !9
  %12 = call noundef ptr @_Z9mergeSortP4Node(ptr noundef %11)
  store ptr %12, ptr %2, align 8, !tbaa !9
  call void @_Z9printListP4Node(ptr noundef %12)
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %4) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %3) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %2) #3
  %13 = load i64, ptr %1, align 8, !tbaa !5
  %14 = add nsw i64 %13, -1
  store i64 %14, ptr %1, align 8, !tbaa !5
  %.not = icmp eq i64 %13, 0
  br i1 %.not, label %._crit_edge6, label %.lr.ph5, !llvm.loop !11

.lr.ph:                                           ; preds = %.lr.ph5, %.lr.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ 0, %.lr.ph5 ]
  %15 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERl(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 8 dereferenceable(8) %4)
  %16 = load i64, ptr %4, align 8, !tbaa !5
  %17 = trunc i64 %16 to i32
  call void @_Z4pushPP4Nodei(ptr noundef nonnull %2, i32 noundef %17)
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %18 = load i64, ptr %3, align 8, !tbaa !5
  %19 = icmp sgt i64 %18, %indvars.iv.next
  br i1 %19, label %.lr.ph, label %._crit_edge, !llvm.loop !13

._crit_edge6:                                     ; preds = %._crit_edge, %0
  call void @llvm.lifetime.end.p0(i64 8, ptr nonnull %1) #3
  ret i32 0
}

; Function Attrs: mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERl(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 8 dereferenceable(8)) local_unnamed_addr #1 align 2

attributes #0 = { mustprogress 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 = { mustprogress norecurse 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 #3 = { 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 = !{!"long", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}
!13 = distinct !{!13, !12}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,SROAPass,SimplifyCFGPass