; LLVM IR from HarshCasper/NeoAlgo :: C/ds (singly_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 }

@first = external dso_local global ptr, align 8
@last = external dso_local global ptr, align 8
@.str.13 = external hidden unnamed_addr constant [3 x i8], align 1
@newnode = external dso_local global ptr, align 8
@.str.26 = external hidden unnamed_addr constant [18 x i8], align 1
@.str.27 = external hidden unnamed_addr constant [31 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 uwtable
declare dso_local ptr @create_node(i32 noundef) #2

; Function Attrs: nounwind uwtable
define dso_local void @insert_node_last() #2 {
  %1 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr %1) #3
  %2 = call i32 (ptr, ...) @printf(ptr noundef @.str.27)
  %3 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str.13, ptr noundef %1)
  %4 = load i32, ptr %1, align 4, !tbaa !5
  %5 = call ptr @create_node(i32 noundef %4)
  store ptr %5, ptr @newnode, align 8, !tbaa !9
  %6 = load ptr, ptr @first, align 8, !tbaa !9
  %7 = load ptr, ptr @last, align 8, !tbaa !9
  %8 = icmp eq ptr %6, %7
  br i1 %8, label %9, label %18

9:                                                ; preds = %0
  %10 = load ptr, ptr @last, align 8, !tbaa !9
  %11 = icmp eq ptr %10, null
  br i1 %11, label %12, label %18

12:                                               ; preds = %9
  %13 = load ptr, ptr @newnode, align 8, !tbaa !9
  store ptr %13, ptr @last, align 8, !tbaa !9
  store ptr %13, ptr @first, align 8, !tbaa !9
  %14 = load ptr, ptr @first, align 8, !tbaa !9
  %15 = getelementptr inbounds %struct.node, ptr %14, i32 0, i32 1
  store ptr null, ptr %15, align 8, !tbaa !11
  %16 = load ptr, ptr @last, align 8, !tbaa !9
  %17 = getelementptr inbounds %struct.node, ptr %16, i32 0, i32 1
  store ptr null, ptr %17, align 8, !tbaa !11
  br label %25

18:                                               ; preds = %9, %0
  %19 = load ptr, ptr @newnode, align 8, !tbaa !9
  %20 = load ptr, ptr @last, align 8, !tbaa !9
  %21 = getelementptr inbounds %struct.node, ptr %20, i32 0, i32 1
  store ptr %19, ptr %21, align 8, !tbaa !11
  %22 = load ptr, ptr @newnode, align 8, !tbaa !9
  store ptr %22, ptr @last, align 8, !tbaa !9
  %23 = load ptr, ptr @last, align 8, !tbaa !9
  %24 = getelementptr inbounds %struct.node, ptr %23, i32 0, i32 1
  store ptr null, ptr %24, align 8, !tbaa !11
  br label %25

25:                                               ; preds = %18, %12
  %26 = call i32 (ptr, ...) @printf(ptr noundef @.str.26)
  call void @llvm.lifetime.end.p0(i64 4, ptr %1) #3
  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 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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !7, i64 0}
!11 = !{!12, !10, i64 8}
!12 = !{!"node", !6, i64 0, !10, i64 8}


; 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"

@first = external dso_local local_unnamed_addr global ptr, align 8
@last = external dso_local local_unnamed_addr global ptr, align 8
@.str.13 = external hidden unnamed_addr constant [3 x i8], align 1
@newnode = external dso_local local_unnamed_addr global ptr, align 8
@.str.26 = external hidden unnamed_addr constant [18 x i8], align 1
@.str.27 = external hidden unnamed_addr constant [31 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: nounwind uwtable
declare dso_local ptr @create_node(i32 noundef) local_unnamed_addr #2

; Function Attrs: nounwind uwtable
define dso_local void @insert_node_last() local_unnamed_addr #2 {
  %1 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %1) #3
  %2 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.27)
  %3 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str.13, ptr noundef nonnull %1)
  %4 = load i32, ptr %1, align 4, !tbaa !5
  %5 = call ptr @create_node(i32 noundef %4)
  store ptr %5, ptr @newnode, align 8, !tbaa !9
  %6 = load ptr, ptr @first, align 8, !tbaa !9
  %7 = load ptr, ptr @last, align 8
  %8 = icmp eq ptr %7, null
  %9 = icmp eq ptr %6, null
  %or.cond = and i1 %9, %8
  %10 = getelementptr inbounds i8, ptr %7, i64 8
  %.sink = select i1 %or.cond, ptr @first, ptr %10
  store ptr %5, ptr %.sink, align 8, !tbaa !9
  store ptr %5, ptr @last, align 8
  %11 = getelementptr inbounds i8, ptr %5, i64 8
  store ptr null, ptr %11, align 8
  %12 = call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.26)
  call void @llvm.lifetime.end.p0(i64 4, ptr nonnull %1) #3
  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 = { 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 #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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !7, i64 0}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,MergedLoadStoreMotionPass,ReassociatePass,SimplifyCFGPass,TailCallElimPass