; LLVM IR from ksw2000/Data-Structure-in-C :: Linked-List (05-invert)

; 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.ll = type { ptr, ptr, ptr }
%struct.node = type { 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: nounwind uwtable
declare dso_local ptr @__LinkedList__() #1

; Function Attrs: nounwind uwtable
define dso_local ptr @invert(ptr noundef %0) #1 {
  %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) #2
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #2
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #2
  %7 = load ptr, ptr %2, align 8, !tbaa !5
  %8 = getelementptr inbounds %struct.ll, ptr %7, i32 0, i32 0
  %9 = load ptr, ptr %8, align 8, !tbaa !9
  store ptr %9, ptr %5, align 8, !tbaa !5
  store ptr null, ptr %4, align 8, !tbaa !5
  br label %10

10:                                               ; preds = %13, %1
  %11 = load ptr, ptr %5, align 8, !tbaa !5
  %12 = icmp ne ptr %11, null
  br i1 %12, label %13, label %22

13:                                               ; preds = %10
  %14 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %14, ptr %3, align 8, !tbaa !5
  %15 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %15, ptr %4, align 8, !tbaa !5
  %16 = load ptr, ptr %5, align 8, !tbaa !5
  %17 = getelementptr inbounds %struct.node, ptr %16, i32 0, i32 1
  %18 = load ptr, ptr %17, align 8, !tbaa !11
  store ptr %18, ptr %5, align 8, !tbaa !5
  %19 = load ptr, ptr %3, align 8, !tbaa !5
  %20 = load ptr, ptr %4, align 8, !tbaa !5
  %21 = getelementptr inbounds %struct.node, ptr %20, i32 0, i32 1
  store ptr %19, ptr %21, align 8, !tbaa !11
  br label %10, !llvm.loop !13

22:                                               ; preds = %10
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #2
  %23 = call ptr @__LinkedList__()
  store ptr %23, ptr %6, align 8, !tbaa !5
  %24 = load ptr, ptr %4, align 8, !tbaa !5
  %25 = load ptr, ptr %6, align 8, !tbaa !5
  %26 = getelementptr inbounds %struct.ll, ptr %25, i32 0, i32 0
  store ptr %24, ptr %26, align 8, !tbaa !9
  %27 = load ptr, ptr %2, align 8, !tbaa !5
  %28 = getelementptr inbounds %struct.ll, ptr %27, i32 0, i32 0
  %29 = load ptr, ptr %28, align 8, !tbaa !9
  %30 = load ptr, ptr %6, align 8, !tbaa !5
  %31 = getelementptr inbounds %struct.ll, ptr %30, i32 0, i32 1
  store ptr %29, ptr %31, align 8, !tbaa !15
  %32 = load ptr, ptr %6, align 8, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #2
  ret ptr %32
}

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 = { 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 0}
!10 = !{!"ll", !6, i64 0, !6, i64 8, !6, i64 16}
!11 = !{!12, !6, i64 8}
!12 = !{!"node", !6, i64 0, !6, i64 8}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}
!15 = !{!10, !6, i64 8}


; 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: nounwind uwtable
declare dso_local ptr @__LinkedList__() local_unnamed_addr #0

; Function Attrs: nounwind uwtable
define dso_local noundef ptr @invert(ptr nocapture noundef readonly %0) local_unnamed_addr #0 {
  %2 = load ptr, ptr %0, align 8, !tbaa !5
  %.not13 = icmp eq ptr %2, null
  br i1 %.not13, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %1, %.lr.ph
  %.015 = phi ptr [ %.01214, %.lr.ph ], [ null, %1 ]
  %.01214 = phi ptr [ %4, %.lr.ph ], [ %2, %1 ]
  %3 = getelementptr inbounds i8, ptr %.01214, i64 8
  %4 = load ptr, ptr %3, align 8, !tbaa !10
  store ptr %.015, ptr %3, align 8, !tbaa !10
  %.not = icmp eq ptr %4, null
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !12

._crit_edge:                                      ; preds = %.lr.ph, %1
  %.0.lcssa = phi ptr [ null, %1 ], [ %.01214, %.lr.ph ]
  %5 = tail call ptr @__LinkedList__()
  store ptr %.0.lcssa, ptr %5, align 8, !tbaa !5
  %6 = load ptr, ptr %0, align 8, !tbaa !5
  %7 = getelementptr inbounds i8, ptr %5, i64 8
  store ptr %6, ptr %7, align 8, !tbaa !14
  ret ptr %5
}

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" }

!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, !7, i64 0}
!6 = !{!"ll", !7, i64 0, !7, i64 8, !7, i64 16}
!7 = !{!"any pointer", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C/C++ TBAA"}
!10 = !{!11, !7, i64 8}
!11 = !{!"node", !7, i64 0, !7, i64 8}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}
!14 = !{!6, !7, i64 8}


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