; LLVM IR from ritikbanger/Hacktoberfest2022-DSA :: 10. Linked List/deleteatend.ll (Z11deleteatendP4Node)

; 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 }

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef ptr @_Z11deleteatendP4Node(ptr noundef %0) #0 {
  %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) #3
  %5 = load ptr, ptr %2, align 8, !tbaa !5
  store ptr %5, ptr %3, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %4) #3
  %6 = load ptr, ptr %2, align 8, !tbaa !5
  %7 = getelementptr inbounds %struct.Node, ptr %6, i32 0, i32 1
  %8 = load ptr, ptr %7, align 8, !tbaa !9
  store ptr %8, ptr %4, align 8, !tbaa !5
  br label %9

9:                                                ; preds = %14, %1
  %10 = load ptr, ptr %4, align 8, !tbaa !5
  %11 = getelementptr inbounds %struct.Node, ptr %10, i32 0, i32 1
  %12 = load ptr, ptr %11, align 8, !tbaa !9
  %13 = icmp ne ptr %12, null
  br i1 %13, label %14, label %21

14:                                               ; preds = %9
  %15 = load ptr, ptr %3, align 8, !tbaa !5
  %16 = getelementptr inbounds %struct.Node, ptr %15, i32 0, i32 1
  %17 = load ptr, ptr %16, align 8, !tbaa !9
  store ptr %17, ptr %3, align 8, !tbaa !5
  %18 = load ptr, ptr %4, 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
  br label %9, !llvm.loop !12

21:                                               ; preds = %9
  %22 = load ptr, ptr %4, 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 %3, align 8, !tbaa !5
  %26 = getelementptr inbounds %struct.Node, ptr %25, i32 0, i32 1
  store ptr %24, ptr %26, align 8, !tbaa !9
  %27 = load ptr, ptr %4, align 8, !tbaa !5
  call void @free(ptr noundef %27) #3
  %28 = load ptr, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 8, ptr %4) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %3) #3
  ret ptr %28
}

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: nounwind
declare void @free(ptr noundef) #2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

attributes #0 = { 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 #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { 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 #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++ TBAA"}
!9 = !{!10, !6, i64 8}
!10 = !{!"_ZTS4Node", !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"

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef ptr @_Z11deleteatendP4Node(ptr noundef returned %0) local_unnamed_addr #0 {
  %2 = getelementptr inbounds i8, ptr %0, i64 8
  %3 = load ptr, ptr %2, align 8, !tbaa !5
  %4 = getelementptr inbounds i8, ptr %3, i64 8
  %5 = load ptr, ptr %4, align 8, !tbaa !5
  %.not11 = icmp eq ptr %5, null
  br i1 %.not11, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %1, %.lr.ph
  %6 = phi ptr [ %10, %.lr.ph ], [ %5, %1 ]
  %.0912 = phi ptr [ %8, %.lr.ph ], [ %0, %1 ]
  %7 = getelementptr inbounds i8, ptr %.0912, i64 8
  %8 = load ptr, ptr %7, align 8, !tbaa !5
  %9 = getelementptr inbounds i8, ptr %6, i64 8
  %10 = load ptr, ptr %9, align 8, !tbaa !5
  %.not = icmp eq ptr %10, null
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !11

._crit_edge:                                      ; preds = %.lr.ph, %1
  %.09.lcssa = phi ptr [ %0, %1 ], [ %8, %.lr.ph ]
  %.0.lcssa = phi ptr [ %3, %1 ], [ %6, %.lr.ph ]
  %11 = getelementptr inbounds i8, ptr %.09.lcssa, i64 8
  store ptr null, ptr %11, align 8, !tbaa !5
  tail call void @free(ptr noundef nonnull %.0.lcssa) #2
  ret ptr %0
}

; Function Attrs: mustprogress nounwind willreturn allockind("free") memory(argmem: readwrite, inaccessiblemem: readwrite)
declare void @free(ptr allocptr nocapture noundef) local_unnamed_addr #1

attributes #0 = { 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 #1 = { 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 #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, !10, i64 8}
!6 = !{!"_ZTS4Node", !7, i64 0, !10, i64 8}
!7 = !{!"int", !8, i64 0}
!8 = !{!"omnipotent char", !9, i64 0}
!9 = !{!"Simple C++ TBAA"}
!10 = !{!"any pointer", !8, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}


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