; LLVM IR from Ayon-SSP/The-SDE-Prep :: 1]_Data Structures/2]_Linked List/Linked List Problems (Circular_LinkedList)

; 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 }

@.str = external hidden unnamed_addr constant [25 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [3 x i8], align 1
@head = external dso_local global ptr, align 8
@.str.2 = external hidden unnamed_addr constant [38 x i8], align 1

; Function Attrs: nounwind uwtable
define dso_local void @circularlist(ptr noundef %0, i32 noundef %1) #0 {
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = alloca ptr, align 8
  %6 = alloca ptr, align 8
  %7 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #4
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #4
  %8 = call noalias ptr @malloc(i64 noundef 16) #5
  store ptr %8, ptr %3, align 8, !tbaa !5
  %9 = call i32 (ptr, ...) @printf(ptr noundef @.str)
  %10 = load ptr, ptr %3, align 8, !tbaa !5
  %11 = getelementptr inbounds %struct.node, ptr %10, i32 0, i32 0
  %12 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str.1, ptr noundef %11)
  %13 = load ptr, ptr %3, align 8, !tbaa !5
  %14 = getelementptr inbounds %struct.node, ptr %13, i32 0, i32 1
  store ptr null, ptr %14, align 8, !tbaa !11
  %15 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %15, ptr %6, align 8, !tbaa !5
  %16 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %16, ptr @head, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #4
  store i32 1, ptr %7, align 4, !tbaa !9
  br label %17

17:                                               ; preds = %35, %2
  %18 = load i32, ptr %7, align 4, !tbaa !9
  %19 = load i32, ptr %4, align 4, !tbaa !9
  %20 = icmp slt i32 %18, %19
  br i1 %20, label %22, label %21

21:                                               ; preds = %17
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #4
  br label %38

22:                                               ; preds = %17
  %23 = call noalias ptr @malloc(i64 noundef 16) #5
  store ptr %23, ptr %5, align 8, !tbaa !5
  %24 = load i32, ptr %7, align 4, !tbaa !9
  %25 = call i32 (ptr, ...) @printf(ptr noundef @.str.2, i32 noundef %24)
  %26 = load ptr, ptr %5, align 8, !tbaa !5
  %27 = getelementptr inbounds %struct.node, ptr %26, i32 0, i32 0
  %28 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str.1, ptr noundef %27)
  %29 = load ptr, ptr %5, align 8, !tbaa !5
  %30 = getelementptr inbounds %struct.node, ptr %29, i32 0, i32 1
  store ptr null, ptr %30, align 8, !tbaa !11
  %31 = load ptr, ptr %5, align 8, !tbaa !5
  %32 = load ptr, ptr %6, align 8, !tbaa !5
  %33 = getelementptr inbounds %struct.node, ptr %32, i32 0, i32 1
  store ptr %31, ptr %33, align 8, !tbaa !11
  %34 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %34, ptr %6, align 8, !tbaa !5
  br label %35

35:                                               ; preds = %22
  %36 = load i32, ptr %7, align 4, !tbaa !9
  %37 = add nsw i32 %36, 1
  store i32 %37, ptr %7, align 4, !tbaa !9
  br label %17, !llvm.loop !13

38:                                               ; preds = %21
  %39 = load ptr, ptr %3, align 8, !tbaa !5
  %40 = load ptr, ptr %6, align 8, !tbaa !5
  %41 = getelementptr inbounds %struct.node, ptr %40, i32 0, i32 1
  store ptr %39, ptr %41, align 8, !tbaa !11
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #4
  ret void
}

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

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

declare i32 @printf(ptr noundef, ...) #3

declare i32 @__isoc99_scanf(ptr noundef, ...) #3

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = { "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, !6, i64 8}
!12 = !{!"node", !10, i64 0, !6, i64 8}
!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"

@.str = external hidden unnamed_addr constant [25 x i8], align 1
@.str.1 = external hidden unnamed_addr constant [3 x i8], align 1
@head = external dso_local local_unnamed_addr global ptr, align 8
@.str.2 = external hidden unnamed_addr constant [38 x i8], align 1

; Function Attrs: nofree nounwind uwtable
define dso_local void @circularlist(ptr nocapture noundef readnone %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = tail call noalias dereferenceable_or_null(16) ptr @malloc(i64 noundef 16) #3
  %4 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str)
  %5 = tail call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str.1, ptr noundef %3)
  %6 = getelementptr inbounds i8, ptr %3, i64 8
  store ptr null, ptr %6, align 8, !tbaa !5
  store ptr %3, ptr @head, align 8, !tbaa !11
  %7 = icmp sgt i32 %1, 1
  br i1 %7, label %.lr.ph, label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph, %2
  %.014.lcssa = phi ptr [ %3, %2 ], [ %9, %.lr.ph ]
  %8 = getelementptr inbounds i8, ptr %.014.lcssa, i64 8
  store ptr %3, ptr %8, align 8, !tbaa !5
  ret void

.lr.ph:                                           ; preds = %2, %.lr.ph
  %.016 = phi i32 [ %14, %.lr.ph ], [ 1, %2 ]
  %.01415 = phi ptr [ %9, %.lr.ph ], [ %3, %2 ]
  %9 = tail call noalias dereferenceable_or_null(16) ptr @malloc(i64 noundef 16) #3
  %10 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.2, i32 noundef %.016)
  %11 = tail call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str.1, ptr noundef %9)
  %12 = getelementptr inbounds i8, ptr %9, i64 8
  store ptr null, ptr %12, align 8, !tbaa !5
  %13 = getelementptr inbounds i8, ptr %.01415, i64 8
  store ptr %9, ptr %13, align 8, !tbaa !5
  %14 = add nuw nsw i32 %.016, 1
  %exitcond.not = icmp eq i32 %14, %1
  br i1 %exitcond.not, label %._crit_edge, label %.lr.ph, !llvm.loop !12
}

; Function Attrs: mustprogress nofree nounwind willreturn allockind("alloc,uninitialized") allocsize(0) memory(inaccessiblemem: readwrite)
declare noalias noundef ptr @malloc(i64 noundef) local_unnamed_addr #1

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #2

; Function Attrs: nofree nounwind
declare noundef i32 @__isoc99_scanf(ptr nocapture noundef readonly, ...) local_unnamed_addr #2

attributes #0 = { 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 #1 = { 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 #2 = { 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 #3 = { 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, !10, i64 8}
!6 = !{!"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 = !{!10, !10, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}


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