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

; 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.13 = 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

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #0

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

; Function Attrs: nounwind uwtable
define dso_local void @reverseList(ptr noundef %0) #2 {
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca ptr, align 8
  store ptr %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #3
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #3
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #3
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #3
  %7 = load ptr, ptr %2, align 8, !tbaa !5
  %8 = load ptr, ptr %7, align 8, !tbaa !5
  %9 = icmp eq ptr %8, null
  br i1 %9, label %10, label %12

10:                                               ; preds = %1
  %11 = call i32 (ptr, ...) @printf(ptr noundef @.str.13)
  br label %49

12:                                               ; preds = %1
  %13 = load ptr, ptr %2, align 8, !tbaa !5
  %14 = load ptr, ptr %13, align 8, !tbaa !5
  store ptr %14, ptr %6, align 8, !tbaa !5
  %15 = load ptr, ptr %2, align 8, !tbaa !5
  %16 = load ptr, ptr %15, align 8, !tbaa !5
  store ptr %16, ptr %3, align 8, !tbaa !5
  %17 = load ptr, ptr %2, align 8, !tbaa !5
  %18 = load ptr, ptr %17, align 8, !tbaa !5
  %19 = getelementptr inbounds %struct.node, ptr %18, i32 0, i32 1
  %20 = load ptr, ptr %19, align 8, !tbaa !9
  store ptr %20, ptr %4, align 8, !tbaa !5
  %21 = load ptr, ptr %2, align 8, !tbaa !5
  %22 = load ptr, ptr %21, align 8, !tbaa !5
  %23 = getelementptr inbounds %struct.node, ptr %22, i32 0, i32 1
  %24 = load ptr, ptr %23, align 8, !tbaa !9
  %25 = load ptr, ptr %2, align 8, !tbaa !5
  store ptr %24, ptr %25, align 8, !tbaa !5
  br label %26

26:                                               ; preds = %31, %12
  %27 = load ptr, ptr %2, align 8, !tbaa !5
  %28 = load ptr, ptr %27, align 8, !tbaa !5
  %29 = load ptr, ptr %6, align 8, !tbaa !5
  %30 = icmp ne ptr %28, %29
  br i1 %30, label %31, label %43

31:                                               ; preds = %26
  %32 = load ptr, ptr %2, align 8, !tbaa !5
  %33 = load ptr, ptr %32, align 8, !tbaa !5
  %34 = getelementptr inbounds %struct.node, ptr %33, i32 0, i32 1
  %35 = load ptr, ptr %34, align 8, !tbaa !9
  %36 = load ptr, ptr %2, align 8, !tbaa !5
  store ptr %35, ptr %36, align 8, !tbaa !5
  %37 = load ptr, ptr %3, align 8, !tbaa !5
  %38 = load ptr, ptr %4, align 8, !tbaa !5
  %39 = getelementptr inbounds %struct.node, ptr %38, i32 0, i32 1
  store ptr %37, ptr %39, align 8, !tbaa !9
  %40 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %40, ptr %3, align 8, !tbaa !5
  %41 = load ptr, ptr %2, align 8, !tbaa !5
  %42 = load ptr, ptr %41, align 8, !tbaa !5
  store ptr %42, ptr %4, align 8, !tbaa !5
  br label %26, !llvm.loop !12

43:                                               ; preds = %26
  %44 = load ptr, ptr %3, align 8, !tbaa !5
  %45 = load ptr, ptr %4, align 8, !tbaa !5
  %46 = getelementptr inbounds %struct.node, ptr %45, i32 0, i32 1
  store ptr %44, ptr %46, align 8, !tbaa !9
  %47 = load ptr, ptr %3, align 8, !tbaa !5
  %48 = load ptr, ptr %2, align 8, !tbaa !5
  store ptr %47, ptr %48, align 8, !tbaa !5
  br label %49

49:                                               ; preds = %43, %10
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #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 = !{!"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"}


; 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.13 = 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 @reverseList(ptr nocapture noundef %0) local_unnamed_addr #1 {
  %2 = load ptr, ptr %0, align 8, !tbaa !5
  %3 = icmp eq ptr %2, null
  br i1 %3, label %4, label %6

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

6:                                                ; preds = %1
  %7 = getelementptr inbounds i8, ptr %2, i64 8
  %8 = load ptr, ptr %7, align 8, !tbaa !9
  store ptr %8, ptr %0, align 8, !tbaa !5
  %.not21 = icmp eq ptr %8, %2
  br i1 %.not21, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %6, %.lr.ph
  %.023 = phi ptr [ %.01822, %.lr.ph ], [ %2, %6 ]
  %.01822 = phi ptr [ %11, %.lr.ph ], [ %8, %6 ]
  %9 = getelementptr inbounds i8, ptr %.01822, i64 8
  %10 = load ptr, ptr %9, align 8, !tbaa !9
  store ptr %10, ptr %0, align 8, !tbaa !5
  store ptr %.023, ptr %9, align 8, !tbaa !9
  %11 = load ptr, ptr %0, align 8, !tbaa !5
  %.not = icmp eq ptr %11, %2
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !12

._crit_edge:                                      ; preds = %.lr.ph, %6
  %.018.lcssa = phi ptr [ %8, %6 ], [ %11, %.lr.ph ]
  %.0.lcssa = phi ptr [ %2, %6 ], [ %.01822, %.lr.ph ]
  %12 = getelementptr inbounds i8, ptr %.018.lcssa, i64 8
  store ptr %.0.lcssa, ptr %12, align 8, !tbaa !9
  store ptr %.0.lcssa, ptr %0, align 8, !tbaa !5
  br label %13

13:                                               ; preds = %._crit_edge, %4
  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,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass