Don't deepcopy accs

Author: penelopeysm

src/logdensityfunction.jl

@@ -305,6 +305,7 @@ closure approach will be used. By default, this function returns `false`, i.e.
 the constant approach will be used.
 """
 use_closure(::ADTypes.AbstractADType) = true
+use_closure(::ADTypes.AutoEnzyme) = false
 
 """
     getmodel(f)

src/varinfo.jl

@@ -287,7 +287,7 @@ function typed_varinfo(vi::UntypedVarInfo)
         )
     end
     nt = NamedTuple{syms_tuple}(Tuple(new_metas))
-    return VarInfo(nt, deepcopy(vi.accs))
+    return VarInfo(nt, vi.accs)
 end
 function typed_varinfo(vi::NTVarInfo)
     # This function preserves the behaviour of typed_varinfo(vi) where vi is
@@ -348,7 +348,7 @@ single `VarNamedVector` as its metadata field.
 """
 function untyped_vector_varinfo(vi::UntypedVarInfo)
     md = metadata_to_varnamedvector(vi.metadata)
-    return VarInfo(md, deepcopy(vi.accs))
+    return VarInfo(md, vi.accs)
 end
 function untyped_vector_varinfo(
     rng::Random.AbstractRNG,
@@ -391,12 +391,12 @@ NamedTuple of `VarNamedVector`s as its metadata field.
 """
 function typed_vector_varinfo(vi::NTVarInfo)
     md = map(metadata_to_varnamedvector, vi.metadata)
-    return VarInfo(md, deepcopy(vi.accs))
+    return VarInfo(md, vi.accs)
 end
 function typed_vector_varinfo(vi::UntypedVectorVarInfo)
     new_metas = group_by_symbol(vi.metadata)
     nt = NamedTuple(new_metas)
-    return VarInfo(nt, deepcopy(vi.accs))
+    return VarInfo(nt, vi.accs)
 end
 function typed_vector_varinfo(
     rng::Random.AbstractRNG,
@@ -447,10 +447,7 @@ function unflatten(vi::VarInfo, x::AbstractVector)
     # The below line is finicky for type stability. For instance, assigning the eltype to
     # convert to into an intermediate variable makes this unstable (constant propagation)
     # fails. Take care when editing.
-    accs = map(
-        acc -> convert_eltype(float_type_with_fallback(eltype(x)), acc),
-        deepcopy(getaccs(vi)),
-    )
+    accs = map(acc -> convert_eltype(float_type_with_fallback(eltype(x)), acc), vi.accs)
     return VarInfo(md, accs)
 end
 
@@ -533,7 +530,7 @@ end
 
 function subset(varinfo::VarInfo, vns::AbstractVector{<:VarName})
     metadata = subset(varinfo.metadata, vns)
-    return VarInfo(metadata, deepcopy(varinfo.accs))
+    return VarInfo(metadata, varinfo.accs)
 end
 
 function subset(metadata::NamedTuple, vns::AbstractVector{<:VarName})
@@ -622,7 +619,7 @@ end
 
 function _merge(varinfo_left::VarInfo, varinfo_right::VarInfo)
     metadata = merge_metadata(varinfo_left.metadata, varinfo_right.metadata)
-    return VarInfo(metadata, deepcopy(varinfo_right.accs))
+    return VarInfo(metadata, varinfo_right.accs)
 end
 
 function merge_metadata(vnv_left::VarNamedVector, vnv_right::VarNamedVector)
@@ -1014,7 +1011,7 @@ istrans(vi::VarInfo, vn::VarName) = istrans(getmetadata(vi, vn), vn)
 istrans(md::Metadata, vn::VarName) = is_flagged(md, vn, "trans")
 
 getaccs(vi::VarInfo) = vi.accs
-setaccs!!(vi::VarInfo, accs::AccumulatorTuple) = Accessors.@set vi.accs = accs
+setaccs!!(vi::VarInfo, accs::AccumulatorTuple) = VarInfo(vi.metadata, accs)
 
 # Need to introduce the _isempty to avoid type piracy of isempty(::NamedTuple).
 isempty(vi::VarInfo) = _isempty(vi.metadata)