; LLVM IR from sbshah97/DS-Algo-Handbook :: Data-Structures/Linked_List/Circular_Linked_List (circular)

; 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 [26 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

; 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
define dso_local void @delete_from_list(ptr noundef %0, i32 noundef %1) #1 {
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = alloca ptr, align 8
  %6 = alloca i32, align 4
  %7 = 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
  %8 = load ptr, ptr %3, align 8, !tbaa !5
  store ptr %8, ptr %5, align 8, !tbaa !5
  br label %9

9:                                                ; preds = %25, %2
  %10 = load ptr, ptr %3, align 8, !tbaa !5
  %11 = getelementptr inbounds %struct.Node, ptr %10, i32 0, i32 1
  %12 = load ptr, ptr %11, align 8, !tbaa !11
  %13 = load ptr, ptr %5, align 8, !tbaa !5
  %14 = icmp ne ptr %12, %13
  br i1 %14, label %15, label %23

15:                                               ; preds = %9
  %16 = load ptr, ptr %3, align 8, !tbaa !5
  %17 = getelementptr inbounds %struct.Node, ptr %16, i32 0, i32 1
  %18 = load ptr, ptr %17, align 8, !tbaa !11
  %19 = getelementptr inbounds %struct.Node, ptr %18, i32 0, i32 0
  %20 = load i32, ptr %19, align 8, !tbaa !13
  %21 = load i32, ptr %4, align 4, !tbaa !9
  %22 = icmp ne i32 %20, %21
  br label %23

23:                                               ; preds = %15, %9
  %24 = phi i1 [ false, %9 ], [ %22, %15 ]
  br i1 %24, label %25, label %29

25:                                               ; preds = %23
  %26 = load ptr, ptr %3, align 8, !tbaa !5
  %27 = getelementptr inbounds %struct.Node, ptr %26, i32 0, i32 1
  %28 = load ptr, ptr %27, align 8, !tbaa !11
  store ptr %28, ptr %3, align 8, !tbaa !5
  br label %9, !llvm.loop !14

29:                                               ; preds = %23
  %30 = load ptr, ptr %3, align 8, !tbaa !5
  %31 = getelementptr inbounds %struct.Node, ptr %30, i32 0, i32 1
  %32 = load ptr, ptr %31, align 8, !tbaa !11
  %33 = load ptr, ptr %5, align 8, !tbaa !5
  %34 = icmp eq ptr %32, %33
  br i1 %34, label %35, label %38

35:                                               ; preds = %29
  %36 = load i32, ptr %4, align 4, !tbaa !9
  %37 = call i32 (ptr, ...) @printf(ptr noundef @.str, i32 noundef %36)
  store i32 1, ptr %6, align 4
  br label %48

38:                                               ; preds = %29
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #4
  %39 = load ptr, ptr %3, align 8, !tbaa !5
  %40 = getelementptr inbounds %struct.Node, ptr %39, i32 0, i32 1
  %41 = load ptr, ptr %40, align 8, !tbaa !11
  store ptr %41, ptr %7, align 8, !tbaa !5
  %42 = load ptr, ptr %7, align 8, !tbaa !5
  %43 = getelementptr inbounds %struct.Node, ptr %42, i32 0, i32 1
  %44 = load ptr, ptr %43, align 8, !tbaa !11
  %45 = load ptr, ptr %3, align 8, !tbaa !5
  %46 = getelementptr inbounds %struct.Node, ptr %45, i32 0, i32 1
  store ptr %44, ptr %46, align 8, !tbaa !11
  %47 = load ptr, ptr %7, align 8, !tbaa !5
  call void @free(ptr noundef %47) #4
  store i32 1, ptr %6, align 4
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #4
  br label %48

48:                                               ; preds = %38, %35
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #4
  ret void
}

declare i32 @printf(ptr noundef, ...) #2

; Function Attrs: nounwind
declare void @free(ptr noundef) #3

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 = { "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 "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 }

!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 = !{!12, !10, i64 0}
!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 [26 x i8], align 1

; Function Attrs: nounwind uwtable
define dso_local void @delete_from_list(ptr noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  br label %3

3:                                                ; preds = %6, %2
  %.0 = phi ptr [ %0, %2 ], [ %5, %6 ]
  %4 = getelementptr inbounds i8, ptr %.0, i64 8
  %5 = load ptr, ptr %4, align 8, !tbaa !5
  %.not = icmp eq ptr %5, %0
  br i1 %.not, label %8, label %6

6:                                                ; preds = %3
  %7 = load i32, ptr %5, align 8, !tbaa !11
  %.not14 = icmp eq i32 %7, %1
  br i1 %.not14, label %.critedge, label %3, !llvm.loop !12

8:                                                ; preds = %3
  %9 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str, i32 noundef %1)
  br label %13

.critedge:                                        ; preds = %6
  %10 = getelementptr inbounds i8, ptr %.0, i64 8
  %11 = getelementptr inbounds i8, ptr %5, i64 8
  %12 = load ptr, ptr %11, align 8, !tbaa !5
  store ptr %12, ptr %10, align 8, !tbaa !5
  tail call void @free(ptr noundef nonnull %5) #3
  br label %13

13:                                               ; preds = %.critedge, %8
  ret void
}

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #1

; Function Attrs: mustprogress nounwind willreturn allockind("free") memory(argmem: readwrite, inaccessiblemem: readwrite)
declare void @free(ptr allocptr nocapture noundef) local_unnamed_addr #2

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 = { 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 = { 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 #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, !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 = !{!6, !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}


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