; LLVM IR from KishanBGajera/2024-366-Days-Of-DSA :: Data Structures/Linear/Linked List/Doubly Linked List/C (main)

; 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.DoublyLinkedList = type { ptr, i32 }
%struct.Node = type { i32, ptr, 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 void @nodeAdded(ptr noundef, ptr noundef) #1

; Function Attrs: nounwind uwtable
declare dso_local zeroext i1 @isEmpty(ptr noundef) #1

; Function Attrs: nounwind uwtable
define dso_local void @appendToList(ptr noundef %0, ptr noundef %1) #1 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  store ptr %0, ptr %3, align 8, !tbaa !5
  store ptr %1, ptr %4, align 8, !tbaa !5
  %6 = load ptr, ptr %3, align 8, !tbaa !5
  %7 = call zeroext i1 @isEmpty(ptr noundef %6)
  br i1 %7, label %8, label %12

8:                                                ; preds = %2
  %9 = load ptr, ptr %4, align 8, !tbaa !5
  %10 = load ptr, ptr %3, align 8, !tbaa !5
  %11 = getelementptr inbounds %struct.DoublyLinkedList, ptr %10, i32 0, i32 0
  store ptr %9, ptr %11, align 8, !tbaa !9
  br label %32

12:                                               ; preds = %2
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #2
  %13 = load ptr, ptr %3, align 8, !tbaa !5
  %14 = getelementptr inbounds %struct.DoublyLinkedList, ptr %13, i32 0, i32 0
  %15 = load ptr, ptr %14, align 8, !tbaa !9
  store ptr %15, ptr %5, align 8, !tbaa !5
  br label %16

16:                                               ; preds = %21, %12
  %17 = load ptr, ptr %5, align 8, !tbaa !5
  %18 = getelementptr inbounds %struct.Node, ptr %17, i32 0, i32 2
  %19 = load ptr, ptr %18, align 8, !tbaa !12
  %20 = icmp ne ptr %19, null
  br i1 %20, label %21, label %25

21:                                               ; preds = %16
  %22 = load ptr, ptr %5, align 8, !tbaa !5
  %23 = getelementptr inbounds %struct.Node, ptr %22, i32 0, i32 2
  %24 = load ptr, ptr %23, align 8, !tbaa !12
  store ptr %24, ptr %5, align 8, !tbaa !5
  br label %16, !llvm.loop !14

25:                                               ; preds = %16
  %26 = load ptr, ptr %5, align 8, !tbaa !5
  %27 = load ptr, ptr %4, align 8, !tbaa !5
  %28 = getelementptr inbounds %struct.Node, ptr %27, i32 0, i32 1
  store ptr %26, ptr %28, align 8, !tbaa !16
  %29 = load ptr, ptr %4, align 8, !tbaa !5
  %30 = load ptr, ptr %5, align 8, !tbaa !5
  %31 = getelementptr inbounds %struct.Node, ptr %30, i32 0, i32 2
  store ptr %29, ptr %31, align 8, !tbaa !12
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #2
  br label %32

32:                                               ; preds = %25, %8
  %33 = load ptr, ptr %3, align 8, !tbaa !5
  %34 = load ptr, ptr %4, align 8, !tbaa !5
  call void @nodeAdded(ptr noundef %33, ptr noundef %34)
  ret void
}

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 }

!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 0}
!10 = !{!"DoublyLinkedList", !6, i64 0, !11, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = !{!13, !6, i64 16}
!13 = !{!"Node", !11, i64 0, !6, i64 8, !6, i64 16}
!14 = distinct !{!14, !15}
!15 = !{!"llvm.loop.mustprogress"}
!16 = !{!13, !6, 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"

; Function Attrs: nounwind uwtable
declare dso_local void @nodeAdded(ptr noundef, ptr noundef) local_unnamed_addr #0

; Function Attrs: nounwind uwtable
declare dso_local zeroext i1 @isEmpty(ptr noundef) local_unnamed_addr #0

; Function Attrs: nounwind uwtable
define dso_local void @appendToList(ptr noundef %0, ptr noundef %1) local_unnamed_addr #0 {
  %3 = tail call zeroext i1 @isEmpty(ptr noundef %0)
  br i1 %3, label %12, label %4

4:                                                ; preds = %2
  %5 = load ptr, ptr %0, align 8, !tbaa !5
  br label %6

6:                                                ; preds = %6, %4
  %.0 = phi ptr [ %5, %4 ], [ %8, %6 ]
  %7 = getelementptr inbounds i8, ptr %.0, i64 16
  %8 = load ptr, ptr %7, align 8, !tbaa !11
  %.not = icmp eq ptr %8, null
  br i1 %.not, label %9, label %6, !llvm.loop !13

9:                                                ; preds = %6
  %10 = getelementptr inbounds i8, ptr %.0, i64 16
  %11 = getelementptr inbounds i8, ptr %1, i64 8
  store ptr %.0, ptr %11, align 8, !tbaa !15
  br label %12

12:                                               ; preds = %2, %9
  %.sink = phi ptr [ %10, %9 ], [ %0, %2 ]
  store ptr %1, ptr %.sink, align 8, !tbaa !16
  tail call void @nodeAdded(ptr noundef %0, ptr noundef %1)
  ret void
}

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" }

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


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