; LLVM IR from JessonYue/LeetCodeLearning :: BaseDataStructure/list/DoublyCircularList.ll (Z10CreateLinkP7tagNodei)

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

@.str = external hidden unnamed_addr constant [3 x i8], align 1

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

; Function Attrs: mustprogress uwtable
define dso_local void @_Z10CreateLinkP7tagNodei(ptr noundef %0, i32 noundef %1) #1 {
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = alloca ptr, align 8
  %6 = alloca ptr, align 8
  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
  %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) #4
  br label %8

8:                                                ; preds = %12, %2
  %9 = load i32, ptr %4, align 4, !tbaa !9
  %10 = add nsw i32 %9, -1
  store i32 %10, ptr %4, align 4, !tbaa !9
  %11 = icmp ne i32 %9, 0
  br i1 %11, label %12, label %30

12:                                               ; preds = %8
  %13 = call noalias ptr @malloc(i64 noundef 24) #5
  store ptr %13, ptr %6, align 8, !tbaa !5
  %14 = load ptr, ptr %6, align 8, !tbaa !5
  %15 = getelementptr inbounds %struct.tagNode, ptr %14, i32 0, i32 0
  %16 = call i32 (ptr, ...) @__isoc99_scanf(ptr noundef @.str, ptr noundef %15)
  %17 = load ptr, ptr %6, align 8, !tbaa !5
  %18 = load ptr, ptr %5, align 8, !tbaa !5
  %19 = getelementptr inbounds %struct.tagNode, ptr %18, i32 0, i32 2
  store ptr %17, ptr %19, align 8, !tbaa !11
  %20 = load ptr, ptr %5, align 8, !tbaa !5
  %21 = load ptr, ptr %6, align 8, !tbaa !5
  %22 = getelementptr inbounds %struct.tagNode, ptr %21, i32 0, i32 1
  store ptr %20, ptr %22, align 8, !tbaa !13
  %23 = load ptr, ptr %3, align 8, !tbaa !5
  %24 = load ptr, ptr %6, align 8, !tbaa !5
  %25 = getelementptr inbounds %struct.tagNode, ptr %24, i32 0, i32 2
  store ptr %23, ptr %25, align 8, !tbaa !11
  %26 = load ptr, ptr %6, align 8, !tbaa !5
  %27 = load ptr, ptr %3, align 8, !tbaa !5
  %28 = getelementptr inbounds %struct.tagNode, ptr %27, i32 0, i32 1
  store ptr %26, ptr %28, align 8, !tbaa !13
  %29 = load ptr, ptr %6, align 8, !tbaa !5
  store ptr %29, ptr %5, align 8, !tbaa !5
  br label %8, !llvm.loop !14

30:                                               ; preds = %8
  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) #2

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) #2

attributes #0 = { 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 #1 = { 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 #2 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = !{!12, !6, i64 16}
!12 = !{!"_ZTS7tagNode", !10, i64 0, !6, i64 8, !6, i64 16}
!13 = !{!12, !6, i64 8}
!14 = distinct !{!14, !15}
!15 = !{!"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 [3 x i8], align 1

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

; Function Attrs: mustprogress nofree nounwind uwtable
define dso_local void @_Z10CreateLinkP7tagNodei(ptr noundef %0, i32 noundef %1) local_unnamed_addr #1 {
  %.not12 = icmp eq i32 %1, 0
  br i1 %.not12, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %2
  %3 = getelementptr inbounds i8, ptr %0, i64 8
  br label %4

4:                                                ; preds = %.lr.ph, %4
  %.014 = phi i32 [ %1, %.lr.ph ], [ %5, %4 ]
  %.01113 = phi ptr [ %0, %.lr.ph ], [ %6, %4 ]
  %5 = add nsw i32 %.014, -1
  %6 = tail call noalias dereferenceable_or_null(24) ptr @malloc(i64 noundef 24) #3
  %7 = tail call i32 (ptr, ...) @__isoc99_scanf(ptr noundef nonnull @.str, ptr noundef %6)
  %8 = getelementptr inbounds i8, ptr %.01113, i64 16
  store ptr %6, ptr %8, align 8, !tbaa !5
  %9 = getelementptr inbounds i8, ptr %6, i64 8
  store ptr %.01113, ptr %9, align 8, !tbaa !11
  %10 = getelementptr inbounds i8, ptr %6, i64 16
  store ptr %0, ptr %10, align 8, !tbaa !5
  store ptr %6, ptr %3, align 8, !tbaa !11
  %.not = icmp eq i32 %5, 0
  br i1 %.not, label %._crit_edge, label %4, !llvm.loop !12

._crit_edge:                                      ; preds = %4, %2
  ret void
}

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

attributes #0 = { 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 #1 = { mustprogress 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 #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 16}
!6 = !{!"_ZTS7tagNode", !7, i64 0, !10, i64 8, !10, i64 16}
!7 = !{!"int", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C++ TBAA"}
!10 = !{!"any pointer", !8, i64 0}
!11 = !{!6, !10, i64 8}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}


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