; LLVM IR from MostafaTwfiq/C-DataStructures-And-Algorithms :: DataStructure/LinkedLists/Sources (DoublyLinkedList)

; 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, ptr, i32, ptr, ptr }
%struct.Node = type { ptr, ptr, ptr }

@stderr = external global ptr, align 8
@.str.2 = external hidden unnamed_addr constant [34 x i8], align 1
@.str.5 = external hidden unnamed_addr constant [31 x i8], align 1
@.str.6 = external hidden unnamed_addr constant [20 x i8], align 1
@.str.11 = external hidden unnamed_addr constant [33 x i8], align 1

; Function Attrs: nounwind
declare i32 @fprintf(ptr noundef, ptr noundef, ...) #0

; Function Attrs: noreturn nounwind
declare void @exit(i32 noundef) #1

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #2

; Function Attrs: nounwind uwtable
declare dso_local i32 @doublyLinkedListIsEmpty(ptr noundef) #3

; Function Attrs: nounwind
declare void @free(ptr noundef) #0

; Function Attrs: nounwind uwtable
define dso_local ptr @doublyLinkedListDeleteLastWtoFr(ptr noundef %0) #3 {
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  store ptr %0, ptr %2, align 8, !tbaa !5
  %5 = load ptr, ptr %2, align 8, !tbaa !5
  %6 = icmp eq ptr %5, null
  br i1 %6, label %7, label %10

7:                                                ; preds = %1
  %8 = load ptr, ptr @stderr, align 8, !tbaa !5
  %9 = call i32 (ptr, ptr, ...) @fprintf(ptr noundef %8, ptr noundef @.str.5, ptr noundef @.str.6, ptr noundef @.str.2) #4
  call void @exit(i32 noundef -83386157) #5
  unreachable

10:                                               ; preds = %1
  %11 = load ptr, ptr %2, align 8, !tbaa !5
  %12 = call i32 @doublyLinkedListIsEmpty(ptr noundef %11)
  %13 = icmp ne i32 %12, 0
  br i1 %13, label %14, label %17

14:                                               ; preds = %10
  %15 = load ptr, ptr @stderr, align 8, !tbaa !5
  %16 = call i32 (ptr, ptr, ...) @fprintf(ptr noundef %15, ptr noundef @.str.11, ptr noundef @.str.2) #4
  call void @exit(i32 noundef -833816740) #5
  unreachable

17:                                               ; preds = %10
  br label %18

18:                                               ; preds = %17
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #4
  %19 = load ptr, ptr %2, align 8, !tbaa !5
  %20 = getelementptr inbounds %struct.DoublyLinkedList, ptr %19, i32 0, i32 1
  %21 = load ptr, ptr %20, align 8, !tbaa !9
  store ptr %21, ptr %3, align 8, !tbaa !5
  %22 = load ptr, ptr %2, align 8, !tbaa !5
  %23 = getelementptr inbounds %struct.DoublyLinkedList, ptr %22, i32 0, i32 0
  %24 = load ptr, ptr %23, align 8, !tbaa !12
  %25 = load ptr, ptr %2, align 8, !tbaa !5
  %26 = getelementptr inbounds %struct.DoublyLinkedList, ptr %25, i32 0, i32 1
  %27 = load ptr, ptr %26, align 8, !tbaa !9
  %28 = icmp eq ptr %24, %27
  br i1 %28, label %29, label %34

29:                                               ; preds = %18
  %30 = load ptr, ptr %2, align 8, !tbaa !5
  %31 = getelementptr inbounds %struct.DoublyLinkedList, ptr %30, i32 0, i32 1
  store ptr null, ptr %31, align 8, !tbaa !9
  %32 = load ptr, ptr %2, align 8, !tbaa !5
  %33 = getelementptr inbounds %struct.DoublyLinkedList, ptr %32, i32 0, i32 0
  store ptr null, ptr %33, align 8, !tbaa !12
  br label %44

34:                                               ; preds = %18
  %35 = load ptr, ptr %3, align 8, !tbaa !5
  %36 = getelementptr inbounds %struct.Node, ptr %35, i32 0, i32 2
  %37 = load ptr, ptr %36, align 8, !tbaa !13
  %38 = load ptr, ptr %2, align 8, !tbaa !5
  %39 = getelementptr inbounds %struct.DoublyLinkedList, ptr %38, i32 0, i32 1
  store ptr %37, ptr %39, align 8, !tbaa !9
  %40 = load ptr, ptr %2, align 8, !tbaa !5
  %41 = getelementptr inbounds %struct.DoublyLinkedList, ptr %40, i32 0, i32 1
  %42 = load ptr, ptr %41, align 8, !tbaa !9
  %43 = getelementptr inbounds %struct.Node, ptr %42, i32 0, i32 1
  store ptr null, ptr %43, align 8, !tbaa !15
  br label %44

44:                                               ; preds = %34, %29
  %45 = load ptr, ptr %2, align 8, !tbaa !5
  %46 = getelementptr inbounds %struct.DoublyLinkedList, ptr %45, i32 0, i32 2
  %47 = load i32, ptr %46, align 8, !tbaa !16
  %48 = add nsw i32 %47, -1
  store i32 %48, ptr %46, align 8, !tbaa !16
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #4
  %49 = load ptr, ptr %3, align 8, !tbaa !5
  %50 = getelementptr inbounds %struct.Node, ptr %49, i32 0, i32 0
  %51 = load ptr, ptr %50, align 8, !tbaa !17
  store ptr %51, ptr %4, align 8, !tbaa !5
  %52 = load ptr, ptr %3, align 8, !tbaa !5
  call void @free(ptr noundef %52) #4
  %53 = load ptr, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #4
  ret ptr %53
}

attributes #0 = { 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 #1 = { noreturn 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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = { noreturn 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 8}
!10 = !{!"DoublyLinkedList", !6, i64 0, !6, i64 8, !11, i64 16, !6, i64 24, !6, i64 32}
!11 = !{!"int", !7, i64 0}
!12 = !{!10, !6, i64 0}
!13 = !{!14, !6, i64 16}
!14 = !{!"Node", !6, i64 0, !6, i64 8, !6, i64 16}
!15 = !{!14, !6, i64 8}
!16 = !{!10, !11, i64 16}
!17 = !{!14, !6, i64 0}


; 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"

@stderr = external local_unnamed_addr global ptr, align 8
@.str.2 = external hidden unnamed_addr constant [34 x i8], align 1
@.str.5 = external hidden unnamed_addr constant [31 x i8], align 1
@.str.6 = external hidden unnamed_addr constant [20 x i8], align 1
@.str.11 = external hidden unnamed_addr constant [33 x i8], align 1

; Function Attrs: nofree nounwind
declare noundef i32 @fprintf(ptr nocapture noundef, ptr nocapture noundef readonly, ...) local_unnamed_addr #0

; Function Attrs: noreturn nounwind
declare void @exit(i32 noundef) local_unnamed_addr #1

; Function Attrs: nounwind uwtable
declare dso_local i32 @doublyLinkedListIsEmpty(ptr noundef) local_unnamed_addr #2

; Function Attrs: mustprogress nounwind willreturn allockind("free") memory(argmem: readwrite, inaccessiblemem: readwrite)
declare void @free(ptr allocptr nocapture noundef) local_unnamed_addr #3

; Function Attrs: nounwind uwtable
define dso_local ptr @doublyLinkedListDeleteLastWtoFr(ptr noundef %0) local_unnamed_addr #2 {
  %2 = icmp eq ptr %0, null
  br i1 %2, label %3, label %6

3:                                                ; preds = %1
  %4 = load ptr, ptr @stderr, align 8, !tbaa !5
  %5 = tail call i32 (ptr, ptr, ...) @fprintf(ptr noundef %4, ptr noundef nonnull @.str.5, ptr noundef nonnull @.str.6, ptr noundef nonnull @.str.2) #4
  tail call void @exit(i32 noundef -83386157) #5
  unreachable

6:                                                ; preds = %1
  %7 = tail call i32 @doublyLinkedListIsEmpty(ptr noundef nonnull %0)
  %.not = icmp eq i32 %7, 0
  br i1 %.not, label %11, label %8

8:                                                ; preds = %6
  %9 = load ptr, ptr @stderr, align 8, !tbaa !5
  %10 = tail call i32 (ptr, ptr, ...) @fprintf(ptr noundef %9, ptr noundef nonnull @.str.11, ptr noundef nonnull @.str.2) #4
  tail call void @exit(i32 noundef -833816740) #5
  unreachable

11:                                               ; preds = %6
  %12 = getelementptr inbounds i8, ptr %0, i64 8
  %13 = load ptr, ptr %12, align 8, !tbaa !9
  %14 = load ptr, ptr %0, align 8, !tbaa !12
  %15 = icmp eq ptr %14, %13
  br i1 %15, label %20, label %16

16:                                               ; preds = %11
  %17 = getelementptr inbounds i8, ptr %13, i64 16
  %18 = load ptr, ptr %17, align 8, !tbaa !13
  %19 = getelementptr inbounds i8, ptr %18, i64 8
  br label %20

20:                                               ; preds = %11, %16
  %.sink15 = phi ptr [ %19, %16 ], [ %0, %11 ]
  %.sink = phi ptr [ %18, %16 ], [ null, %11 ]
  store ptr null, ptr %.sink15, align 8, !tbaa !5
  store ptr %.sink, ptr %12, align 8
  %21 = getelementptr inbounds i8, ptr %0, i64 16
  %22 = load i32, ptr %21, align 8, !tbaa !15
  %23 = add nsw i32 %22, -1
  store i32 %23, ptr %21, align 8, !tbaa !15
  %24 = load ptr, ptr %13, align 8, !tbaa !16
  tail call void @free(ptr noundef %13) #6
  ret ptr %24
}

attributes #0 = { 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 #1 = { noreturn 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 = { mustprogress nounwind willreturn allockind("free") memory(argmem: readwrite, 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 #4 = { cold nounwind }
attributes #5 = { noreturn nounwind }
attributes #6 = { 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 8}
!10 = !{!"DoublyLinkedList", !6, i64 0, !6, i64 8, !11, i64 16, !6, i64 24, !6, i64 32}
!11 = !{!"int", !7, i64 0}
!12 = !{!10, !6, i64 0}
!13 = !{!14, !6, i64 16}
!14 = !{!"Node", !6, i64 0, !6, i64 8, !6, i64 16}
!15 = !{!10, !11, i64 16}
!16 = !{!14, !6, i64 0}


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