; LLVM IR from HarshCasper/NeoAlgo :: C/ds (singly_linked_list)

; 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 }

@first = external dso_local global ptr, align 8
@ptr = external dso_local global ptr, align 8
@.str.31 = external hidden unnamed_addr constant [13 x i8], align 1
@.str.32 = external hidden unnamed_addr constant [28 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

declare i32 @printf(ptr noundef, ...) #1

; 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 @count() #2 {
  %1 = alloca ptr, align 8
  %2 = alloca i32, align 4
  call void @llvm.lifetime.start.p0(i64 8, ptr %1) #3
  call void @llvm.lifetime.start.p0(i64 4, ptr %2) #3
  store i32 0, ptr %2, align 4, !tbaa !5
  %3 = load ptr, ptr @first, align 8, !tbaa !9
  %4 = icmp eq ptr %3, null
  br i1 %4, label %5, label %7

5:                                                ; preds = %0
  %6 = call i32 (ptr, ...) @printf(ptr noundef @.str.31)
  br label %22

7:                                                ; preds = %0
  %8 = load ptr, ptr @first, align 8, !tbaa !9
  store ptr %8, ptr @ptr, align 8, !tbaa !9
  br label %9

9:                                                ; preds = %15, %7
  %10 = load ptr, ptr @ptr, align 8, !tbaa !9
  %11 = icmp ne ptr %10, null
  br i1 %11, label %12, label %19

12:                                               ; preds = %9
  %13 = load i32, ptr %2, align 4, !tbaa !5
  %14 = add nsw i32 %13, 1
  store i32 %14, ptr %2, align 4, !tbaa !5
  br label %15

15:                                               ; preds = %12
  %16 = load ptr, ptr @ptr, align 8, !tbaa !9
  %17 = getelementptr inbounds %struct.node, ptr %16, i32 0, i32 1
  %18 = load ptr, ptr %17, align 8, !tbaa !11
  store ptr %18, ptr @ptr, align 8, !tbaa !9
  br label %9, !llvm.loop !13

19:                                               ; preds = %9
  %20 = load i32, ptr %2, align 4, !tbaa !5
  %21 = call i32 (ptr, ...) @printf(ptr noundef @.str.32, i32 noundef %20)
  br label %22

22:                                               ; preds = %19, %5
  call void @llvm.lifetime.end.p0(i64 4, ptr %2) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %1) #3
  ret void
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { "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 = { 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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"any pointer", !7, i64 0}
!11 = !{!12, !10, i64 8}
!12 = !{!"node", !6, i64 0, !10, 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"

@first = external dso_local local_unnamed_addr global ptr, align 8
@ptr = external dso_local local_unnamed_addr global ptr, align 8
@.str.31 = external hidden unnamed_addr constant [13 x i8], align 1
@.str.32 = external hidden unnamed_addr constant [28 x i8], align 1

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

; Function Attrs: nofree nounwind uwtable
define dso_local void @count() local_unnamed_addr #1 {
  %1 = load ptr, ptr @first, align 8, !tbaa !5
  %2 = icmp eq ptr %1, null
  br i1 %2, label %3, label %.preheader

3:                                                ; preds = %0
  %4 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.31)
  br label %10

.preheader:                                       ; preds = %0, %.preheader
  %.05 = phi i32 [ %5, %.preheader ], [ 0, %0 ]
  %storemerge4 = phi ptr [ %7, %.preheader ], [ %1, %0 ]
  %5 = add nuw nsw i32 %.05, 1
  %6 = getelementptr inbounds i8, ptr %storemerge4, i64 8
  %7 = load ptr, ptr %6, align 8, !tbaa !9
  %.not = icmp eq ptr %7, null
  br i1 %.not, label %8, label %.preheader, !llvm.loop !12

8:                                                ; preds = %.preheader
  store ptr null, ptr @ptr, align 8, !tbaa !5
  %9 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.32, i32 noundef %5)
  br label %10

10:                                               ; preds = %8, %3
  ret void
}

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 = { 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" }

!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 = !{!"node", !11, i64 0, !6, i64 8}
!11 = !{!"int", !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}


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