; LLVM IR from afrozchakure/Competitive-Programming-Solutions :: HackerRank/30DaysOfCode (Day15linkedlist)

; 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 }
%class.Solution = type { i8 }

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

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

7:                                                ; preds = %11, %0
  %8 = load i32, ptr %4, align 4, !tbaa !9
  %9 = add nsw i32 %8, -1
  store i32 %9, ptr %4, align 4, !tbaa !9
  %10 = icmp sgt i32 %8, 0
  br i1 %10, label %11, label %16

11:                                               ; preds = %7
  %12 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %5)
  %13 = load ptr, ptr %2, align 8, !tbaa !5
  %14 = load i32, ptr %5, align 4, !tbaa !9
  %15 = call noundef ptr @_ZN8Solution6insertEP4Nodei(ptr noundef nonnull align 1 dereferenceable(1) %3, ptr noundef %13, i32 noundef %14)
  store ptr %15, ptr %2, align 8, !tbaa !5
  br label %7, !llvm.loop !11

16:                                               ; preds = %7
  %17 = load ptr, ptr %2, align 8, !tbaa !5
  call void @_ZN8Solution7displayEP4Node(ptr noundef nonnull align 1 dereferenceable(1) %3, ptr noundef %17)
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #4
  call void @llvm.lifetime.end.p0(i64 1, ptr %3) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %2) #4
  %18 = load i32, ptr %1, align 4
  ret i32 %18
}

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

declare noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 4 dereferenceable(4)) #2

; Function Attrs: mustprogress uwtable
declare dso_local noundef ptr @_ZN8Solution6insertEP4Nodei(ptr noundef nonnull align 1 dereferenceable(1), ptr noundef, i32 noundef) #3 align 2

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZN8Solution7displayEP4Node(ptr noundef nonnull align 1 dereferenceable(1), ptr noundef) #3 align 2

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

attributes #0 = { 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 #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 = { 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 = { 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 = !{!"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"

%"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 }
%class.Solution = type { i8 }

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

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

.lr.ph:                                           ; preds = %0, %.lr.ph
  %.02 = phi ptr [ %10, %.lr.ph ], [ null, %0 ]
  %8 = call noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16) @_ZSt3cin, ptr noundef nonnull align 4 dereferenceable(4) %3)
  %9 = load i32, ptr %3, align 4, !tbaa !5
  %10 = call noundef ptr @_ZN8Solution6insertEP4Nodei(ptr noundef nonnull align 1 dereferenceable(1) %1, ptr noundef %.02, i32 noundef %9)
  %11 = load i32, ptr %2, align 4, !tbaa !5
  %12 = add nsw i32 %11, -1
  store i32 %12, ptr %2, align 4, !tbaa !5
  %13 = icmp sgt i32 %11, 0
  br i1 %13, label %.lr.ph, label %._crit_edge, !llvm.loop !9

._crit_edge:                                      ; preds = %.lr.ph, %0
  %.0.lcssa = phi ptr [ null, %0 ], [ %10, %.lr.ph ]
  call void @_ZN8Solution7displayEP4Node(ptr noundef nonnull align 1 dereferenceable(1) %1, ptr noundef %.0.lcssa)
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %3) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %2) #4
  call void @llvm.lifetime.end.p0(i64 1, ptr nonnull %1) #4
  ret i32 0
}

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

declare noundef nonnull align 8 dereferenceable(16) ptr @_ZNSirsERi(ptr noundef nonnull align 8 dereferenceable(16), ptr noundef nonnull align 4 dereferenceable(4)) local_unnamed_addr #2

; Function Attrs: mustprogress uwtable
declare dso_local noundef ptr @_ZN8Solution6insertEP4Nodei(ptr noundef nonnull align 1 dereferenceable(1), ptr noundef, i32 noundef) local_unnamed_addr #3 align 2

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZN8Solution7displayEP4Node(ptr noundef nonnull align 1 dereferenceable(1), ptr noundef) local_unnamed_addr #3 align 2

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

attributes #0 = { 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 #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 = { 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 = { 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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"llvm.loop.mustprogress"}


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