; LLVM IR from ritikbanger/Hacktoberfest2022-DSA :: 10. Linked List/cpp/Circular_Double_List.ll (Z11ReverseListPP4Node)

; 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"

%class.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: mustprogress nounwind uwtable
define dso_local void @_Z11ReverseListPP4Node(ptr noundef %0) #1 {
  %2 = alloca ptr, align 8
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  store ptr %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %3) #2
  store ptr null, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #2
  %5 = load ptr, ptr %2, align 8, !tbaa !5
  %6 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %6, ptr %4, align 8, !tbaa !5
  br label %7

7:                                                ; preds = %22, %1
  %8 = load ptr, ptr %4, align 8, !tbaa !5
  %9 = getelementptr inbounds %class.Node, ptr %8, i32 0, i32 1
  %10 = load ptr, ptr %9, align 8, !tbaa !9
  store ptr %10, ptr %3, align 8, !tbaa !5
  %11 = load ptr, ptr %4, align 8, !tbaa !5
  %12 = getelementptr inbounds %class.Node, ptr %11, i32 0, i32 2
  %13 = load ptr, ptr %12, align 8, !tbaa !12
  %14 = load ptr, ptr %4, align 8, !tbaa !5
  %15 = getelementptr inbounds %class.Node, ptr %14, i32 0, i32 1
  store ptr %13, ptr %15, align 8, !tbaa !9
  %16 = load ptr, ptr %3, align 8, !tbaa !5
  %17 = load ptr, ptr %4, align 8, !tbaa !5
  %18 = getelementptr inbounds %class.Node, ptr %17, i32 0, i32 2
  store ptr %16, ptr %18, align 8, !tbaa !12
  %19 = load ptr, ptr %4, align 8, !tbaa !5
  %20 = getelementptr inbounds %class.Node, ptr %19, i32 0, i32 1
  %21 = load ptr, ptr %20, align 8, !tbaa !9
  store ptr %21, ptr %4, align 8, !tbaa !5
  br label %22

22:                                               ; preds = %7
  %23 = load ptr, ptr %4, align 8, !tbaa !5
  %24 = load ptr, ptr %2, align 8, !tbaa !5
  %25 = load ptr, ptr %24, align 8, !tbaa !5
  %26 = icmp ne ptr %23, %25
  br i1 %26, label %7, label %27, !llvm.loop !13

27:                                               ; preds = %22
  %28 = load ptr, ptr %3, align 8, !tbaa !5
  %29 = icmp ne ptr %28, null
  br i1 %29, label %30, label %35

30:                                               ; preds = %27
  %31 = load ptr, ptr %3, align 8, !tbaa !5
  %32 = getelementptr inbounds %class.Node, ptr %31, i32 0, i32 1
  %33 = load ptr, ptr %32, align 8, !tbaa !9
  %34 = load ptr, ptr %2, align 8, !tbaa !5
  store ptr %33, ptr %34, align 8, !tbaa !5
  br label %35

35:                                               ; preds = %30, %27
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #2
  ret void
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { mustprogress 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++ TBAA"}
!9 = !{!10, !6, i64 8}
!10 = !{!"_ZTS4Node", !11, i64 0, !6, i64 8, !6, i64 16}
!11 = !{!"int", !7, i64 0}
!12 = !{!10, !6, i64 16}
!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"

; Function Attrs: mustprogress nofree norecurse nosync nounwind memory(readwrite, inaccessiblemem: none) uwtable
define dso_local void @_Z11ReverseListPP4Node(ptr nocapture noundef %0) local_unnamed_addr #0 {
  %2 = load ptr, ptr %0, align 8, !tbaa !5
  br label %3

3:                                                ; preds = %3, %1
  %.0 = phi ptr [ %2, %1 ], [ %7, %3 ]
  %4 = getelementptr inbounds i8, ptr %.0, i64 8
  %5 = load ptr, ptr %4, align 8, !tbaa !9
  %6 = getelementptr inbounds i8, ptr %.0, i64 16
  %7 = load ptr, ptr %6, align 8, !tbaa !12
  store ptr %7, ptr %4, align 8, !tbaa !9
  store ptr %5, ptr %6, align 8, !tbaa !12
  %8 = load ptr, ptr %0, align 8, !tbaa !5
  %.not = icmp eq ptr %7, %8
  br i1 %.not, label %9, label %3, !llvm.loop !13

9:                                                ; preds = %3
  %.not13 = icmp eq ptr %5, null
  br i1 %.not13, label %13, label %10

10:                                               ; preds = %9
  %11 = getelementptr inbounds i8, ptr %5, i64 8
  %12 = load ptr, ptr %11, align 8, !tbaa !9
  store ptr %12, ptr %0, align 8, !tbaa !5
  br label %13

13:                                               ; preds = %10, %9
  ret void
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind memory(readwrite, inaccessiblemem: none) 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++ TBAA"}
!9 = !{!10, !6, i64 8}
!10 = !{!"_ZTS4Node", !11, i64 0, !6, i64 8, !6, i64 16}
!11 = !{!"int", !7, i64 0}
!12 = !{!10, !6, i64 16}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}


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