; LLVM IR from freddiev4/dailyprogrammerchallenges :: Easy Challenges/Challenge 0026 Easy/solutions (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"

%struct.l_node = type { i32, ptr }

; 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: nounwind uwtable
declare dso_local ptr @add_node(ptr noundef, i32 noundef) #1

; Function Attrs: nounwind uwtable
define dso_local void @remove_duplicates(ptr noundef %0, ptr noundef %1) #1 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca ptr, align 8
  store ptr %0, ptr %3, align 8, !tbaa !5
  store ptr %1, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #3
  %7 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %7, ptr %5, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #3
  br label %8

8:                                                ; preds = %44, %2
  %9 = load ptr, ptr %5, align 8, !tbaa !5
  %10 = getelementptr inbounds %struct.l_node, ptr %9, i32 0, i32 1
  %11 = load ptr, ptr %10, align 8, !tbaa !9
  %12 = icmp ne ptr %11, null
  br i1 %12, label %13, label %45

13:                                               ; preds = %8
  %14 = load ptr, ptr %5, align 8, !tbaa !5
  %15 = getelementptr inbounds %struct.l_node, ptr %14, i32 0, i32 0
  %16 = load i32, ptr %15, align 8, !tbaa !12
  %17 = load ptr, ptr %5, align 8, !tbaa !5
  %18 = getelementptr inbounds %struct.l_node, ptr %17, i32 0, i32 1
  %19 = load ptr, ptr %18, align 8, !tbaa !9
  %20 = getelementptr inbounds %struct.l_node, ptr %19, i32 0, i32 0
  %21 = load i32, ptr %20, align 8, !tbaa !12
  %22 = icmp eq i32 %16, %21
  br i1 %22, label %23, label %40

23:                                               ; preds = %13
  %24 = load ptr, ptr %5, align 8, !tbaa !5
  %25 = getelementptr inbounds %struct.l_node, ptr %24, i32 0, i32 1
  %26 = load ptr, ptr %25, align 8, !tbaa !9
  store ptr %26, ptr %6, align 8, !tbaa !5
  %27 = load ptr, ptr %6, align 8, !tbaa !5
  %28 = getelementptr inbounds %struct.l_node, ptr %27, i32 0, i32 1
  %29 = load ptr, ptr %28, align 8, !tbaa !9
  %30 = load ptr, ptr %5, align 8, !tbaa !5
  %31 = getelementptr inbounds %struct.l_node, ptr %30, i32 0, i32 1
  store ptr %29, ptr %31, align 8, !tbaa !9
  %32 = load ptr, ptr %4, align 8, !tbaa !5
  %33 = load ptr, ptr %32, align 8, !tbaa !5
  %34 = load ptr, ptr %6, align 8, !tbaa !5
  %35 = getelementptr inbounds %struct.l_node, ptr %34, i32 0, i32 0
  %36 = load i32, ptr %35, align 8, !tbaa !12
  %37 = call ptr @add_node(ptr noundef %33, i32 noundef %36)
  %38 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %37, ptr %38, align 8, !tbaa !5
  %39 = load ptr, ptr %6, align 8, !tbaa !5
  call void @free(ptr noundef %39) #3
  br label %44

40:                                               ; preds = %13
  %41 = load ptr, ptr %5, align 8, !tbaa !5
  %42 = getelementptr inbounds %struct.l_node, ptr %41, i32 0, i32 1
  %43 = load ptr, ptr %42, align 8, !tbaa !9
  store ptr %43, ptr %5, align 8, !tbaa !5
  br label %44

44:                                               ; preds = %40, %23
  br label %8, !llvm.loop !13

45:                                               ; preds = %8
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #3
  ret void
}

; Function Attrs: nounwind
declare void @free(ptr noundef) #2

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 #2 = { nounwind "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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !6, i64 8}
!10 = !{!"l_node", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = !{!10, !11, i64 0}
!13 = distinct !{!13, !14}
!14 = !{!"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 @add_node(ptr noundef, i32 noundef) local_unnamed_addr #0

; Function Attrs: nounwind uwtable
define dso_local void @remove_duplicates(ptr nocapture noundef %0, ptr nocapture noundef %1) local_unnamed_addr #0 {
  %3 = getelementptr inbounds i8, ptr %0, i64 8
  %4 = load ptr, ptr %3, align 8, !tbaa !5
  %.not13 = icmp eq ptr %4, null
  br i1 %.not13, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %2, %15
  %5 = phi ptr [ %17, %15 ], [ %4, %2 ]
  %6 = phi ptr [ %16, %15 ], [ %3, %2 ]
  %.014 = phi ptr [ %.1, %15 ], [ %0, %2 ]
  %7 = load i32, ptr %.014, align 8, !tbaa !11
  %8 = load i32, ptr %5, align 8, !tbaa !11
  %9 = icmp eq i32 %7, %8
  br i1 %9, label %10, label %15

10:                                               ; preds = %.lr.ph
  %11 = getelementptr inbounds i8, ptr %5, i64 8
  %12 = load ptr, ptr %11, align 8, !tbaa !5
  store ptr %12, ptr %6, align 8, !tbaa !5
  %13 = load ptr, ptr %1, align 8, !tbaa !12
  %14 = tail call ptr @add_node(ptr noundef %13, i32 noundef %7)
  store ptr %14, ptr %1, align 8, !tbaa !12
  tail call void @free(ptr noundef nonnull %5) #2
  br label %15

15:                                               ; preds = %.lr.ph, %10
  %.1 = phi ptr [ %.014, %10 ], [ %5, %.lr.ph ]
  %16 = getelementptr inbounds i8, ptr %.1, i64 8
  %17 = load ptr, ptr %16, align 8, !tbaa !5
  %.not = icmp eq ptr %17, null
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !13

._crit_edge:                                      ; preds = %15, %2
  ret void
}

; Function Attrs: mustprogress nounwind willreturn allockind("free") memory(argmem: readwrite, inaccessiblemem: readwrite)
declare void @free(ptr allocptr nocapture noundef) local_unnamed_addr #1

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 = { mustprogress nounwind willreturn allockind("free") memory(argmem: readwrite, inaccessiblemem: readwrite) "alloc-family"="malloc" "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 = { 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, !10, i64 8}
!6 = !{!"l_node", !7, i64 0, !10, i64 8}
!7 = !{!"int", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C/C++ TBAA"}
!10 = !{!"any pointer", !8, i64 0}
!11 = !{!6, !7, i64 0}
!12 = !{!10, !10, i64 0}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}


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