; LLVM IR from HarshCasper/NeoAlgo :: C/ds (doubly_linked_list)

; 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.node = type { i32, ptr, ptr }

@start = external dso_local global ptr, align 8
@.str.13 = external hidden unnamed_addr constant [3 x i8], align 1
@.str.18 = external hidden unnamed_addr constant [22 x i8], align 1

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

declare i32 @printf(ptr noundef, ...) #1

declare i32 @__isoc99_scanf(ptr noundef, ...) #1

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

; Function Attrs: nounwind allocsize(0)
declare noalias ptr @malloc(i64 noundef) #2

; Function Attrs: nounwind uwtable
define dso_local void @insertlast() #3 {
  %1 = alloca i32, align 4
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  call void @llvm.lifetime.start.p0(i64 4, ptr %1) #4
  call void @llvm.lifetime.start.p0(i64 8, ptr %2) #4
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #4
  %4 = call noalias ptr @malloc(i64 noundef 24) #5
  store ptr %4, ptr %2, align 8, !tbaa !5
  %5 = call i32 (ptr, ...) @printf(ptr noundef @.str.18)
  %6 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str.13, ptr noundef %1)
  %7 = load i32, ptr %1, align 4, !tbaa !9
  %8 = load ptr, ptr %2, align 8, !tbaa !5
  %9 = getelementptr inbounds %struct.node, ptr %8, i32 0, i32 0
  store i32 %7, ptr %9, align 8, !tbaa !11
  %10 = load ptr, ptr %2, align 8, !tbaa !5
  %11 = getelementptr inbounds %struct.node, ptr %10, i32 0, i32 2
  store ptr null, ptr %11, align 8, !tbaa !13
  %12 = load ptr, ptr @start, align 8, !tbaa !5
  store ptr %12, ptr %3, align 8, !tbaa !5
  %13 = load ptr, ptr @start, align 8, !tbaa !5
  %14 = icmp eq ptr %13, null
  br i1 %14, label %15, label %19

15:                                               ; preds = %0
  %16 = load ptr, ptr %2, align 8, !tbaa !5
  %17 = getelementptr inbounds %struct.node, ptr %16, i32 0, i32 1
  store ptr null, ptr %17, align 8, !tbaa !14
  %18 = load ptr, ptr %2, align 8, !tbaa !5
  store ptr %18, ptr @start, align 8, !tbaa !5
  br label %36

19:                                               ; preds = %0
  br label %20

20:                                               ; preds = %25, %19
  %21 = load ptr, ptr %3, align 8, !tbaa !5
  %22 = getelementptr inbounds %struct.node, ptr %21, i32 0, i32 2
  %23 = load ptr, ptr %22, align 8, !tbaa !13
  %24 = icmp ne ptr %23, null
  br i1 %24, label %25, label %29

25:                                               ; preds = %20
  %26 = load ptr, ptr %3, align 8, !tbaa !5
  %27 = getelementptr inbounds %struct.node, ptr %26, i32 0, i32 2
  %28 = load ptr, ptr %27, align 8, !tbaa !13
  store ptr %28, ptr %3, align 8, !tbaa !5
  br label %20, !llvm.loop !15

29:                                               ; preds = %20
  %30 = load ptr, ptr %3, align 8, !tbaa !5
  %31 = load ptr, ptr %2, align 8, !tbaa !5
  %32 = getelementptr inbounds %struct.node, ptr %31, i32 0, i32 1
  store ptr %30, ptr %32, align 8, !tbaa !14
  %33 = load ptr, ptr %2, align 8, !tbaa !5
  %34 = load ptr, ptr %3, align 8, !tbaa !5
  %35 = getelementptr inbounds %struct.node, ptr %34, i32 0, i32 2
  store ptr %33, ptr %35, align 8, !tbaa !13
  br label %36

36:                                               ; preds = %29, %15
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %2) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr %1) #4
  ret void
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { "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 allocsize(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 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 }
attributes #5 = { nounwind allocsize(0) }

!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 = !{!12, !10, i64 0}
!12 = !{!"node", !10, i64 0, !6, i64 8, !6, i64 16}
!13 = !{!12, !6, i64 16}
!14 = !{!12, !6, i64 8}
!15 = distinct !{!15, !16}
!16 = !{!"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"

@start = external dso_local local_unnamed_addr global ptr, align 8
@.str.13 = external hidden unnamed_addr constant [3 x i8], align 1
@.str.18 = external hidden unnamed_addr constant [22 x i8], align 1

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

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #1

; Function Attrs: nofree nounwind
declare noundef i32 @__isoc99_scanf(ptr nocapture noundef readonly, ...) local_unnamed_addr #1

; 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 nofree nounwind willreturn allockind("alloc,uninitialized") allocsize(0) memory(inaccessiblemem: readwrite)
declare noalias noundef ptr @malloc(i64 noundef) local_unnamed_addr #2

; Function Attrs: nofree nounwind uwtable
define dso_local void @insertlast() local_unnamed_addr #3 {
  %1 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %1) #4
  %2 = tail call noalias dereferenceable_or_null(24) ptr @malloc(i64 noundef 24) #5
  %3 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.18)
  %4 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str.13, ptr noundef nonnull %1)
  %5 = load i32, ptr %1, align 4, !tbaa !5
  store i32 %5, ptr %2, align 8, !tbaa !9
  %6 = getelementptr inbounds i8, ptr %2, i64 16
  store ptr null, ptr %6, align 8, !tbaa !12
  %7 = load ptr, ptr @start, align 8, !tbaa !13
  %8 = icmp eq ptr %7, null
  br i1 %8, label %13, label %.preheader

.preheader:                                       ; preds = %0, %.preheader
  %.0 = phi ptr [ %10, %.preheader ], [ %7, %0 ]
  %9 = getelementptr inbounds i8, ptr %.0, i64 16
  %10 = load ptr, ptr %9, align 8, !tbaa !12
  %.not = icmp eq ptr %10, null
  br i1 %.not, label %11, label %.preheader, !llvm.loop !14

11:                                               ; preds = %.preheader
  %12 = getelementptr inbounds i8, ptr %.0, i64 16
  br label %13

13:                                               ; preds = %0, %11
  %.0.lcssa13.sink = phi ptr [ %.0, %11 ], [ null, %0 ]
  %.sink = phi ptr [ %12, %11 ], [ @start, %0 ]
  %14 = getelementptr inbounds i8, ptr %2, i64 8
  store ptr %.0.lcssa13.sink, ptr %14, align 8, !tbaa !16
  store ptr %2, ptr %.sink, align 8, !tbaa !13
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %1) #4
  ret void
}

attributes #0 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { nofree 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 #2 = { mustprogress nofree nounwind willreturn allockind("alloc,uninitialized") allocsize(0) memory(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 #3 = { nofree 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 #4 = { nounwind }
attributes #5 = { nounwind allocsize(0) }

!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/C++ TBAA"}
!9 = !{!10, !6, i64 0}
!10 = !{!"node", !6, i64 0, !11, i64 8, !11, i64 16}
!11 = !{!"any pointer", !7, i64 0}
!12 = !{!10, !11, i64 16}
!13 = !{!11, !11, i64 0}
!14 = distinct !{!14, !15}
!15 = !{!"llvm.loop.mustprogress"}
!16 = !{!10, !11, i64 8}


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